JP2024003247A - Decorative sheet manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a decorative sheet that is recognizable at broad view angle even if design and the like is monochrome and has small concentration difference.

SOLUTION: A method manufactures a decorative sheet having at least 0.25% of standard deviation in variation of glossiness difference (%) in a measurement chart indicating a relation between a plurality of measuring points and glossiness difference, which is obtained by measuring glossiness of a surface in a prescribed length and linearly at prescribed intervals and n points according to JIS Z 8741:1997 as the plurality of measuring points m to m+n (m and n are natural numbers 1 or more) and by defining that obtained glossiness at the plurality of measuring points are X₁ to X_n and that glossiness difference between adjacent measuring points is Y₂=X₂-X₁ to Y_n=X_n-X_n-1.

SELECTED DRAWING: Figure 12

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present invention relates to a method for manufacturing a decorative sheet. In particular, the present invention relates to a method for manufacturing a decorative sheet that allows a realistic design to be recognized at a wide viewing angle even if the design is monochromatic and has little shading.

Conventionally, in addition to interior and exterior materials for buildings such as walls, ceilings, floors, and entrance doors, fittings and fixtures such as window frames, doors, handrails, baseboards, edges, and moldings, roof surface materials, and kitchens. In general, metal members such as steel plates, resin members, and wood members are used as adherends for decorative surfaces of cabinets such as furniture, light electrical appliances, and OA equipment, and interior and exterior members of vehicles. A decorative sheet pasted onto the adherend is used.

In recent years, with the diversification of consumer preferences, decorative sheets exhibiting dark colors such as black, dark gray, navy blue, deep purple, brownish brown, and dark brown, as well as makeup using these, have become popular. members are starting to be preferred.
Conventionally, decorative sheets and decorative members exhibiting such dark colors have either a uniform design on the entire surface, or a design that allows a clear pattern to be seen from both far and near distances due to a combination of dark and light colors. It is common to have

Therefore, for example, a decorative sheet has been proposed that attempts to reproduce a more realistic wood grain design by expressing a feeling of low gloss (for example, see Patent Document 1).
More specifically, at least a surface protective layer is provided on the base material, the surface protective layer contains a curable resin and an inorganic filler, and the content of the inorganic filler is 100 parts by mass of the curable resin. 12 to 25 parts by mass relative to the base material, the surface protective layer has an uneven pattern on the surface opposite to the surface facing the base material, and the area ratio of the depressions in the uneven pattern is 15% or more, When the width of the frontage of the recess in the short side direction is b ₁ (μm), the width of the bottom of the recess in the short side direction is b ₂ (μm), and the depth of the recess is h (μm), the following This is a decorative sheet that simultaneously satisfies formulas (1) to (3).
Formula (1): b ₂ /h≧4.2
Formula (2): b ₂ /b ₁ >0.22
Formula (3): 130μm≧h≧5μm

In addition, decorative sheets have been proposed that exhibit a delicate dark pattern design, which is visible from a distance as a single dark color, but from close up, a pattern that corresponds to the shade of the dark color is visible (for example, a patented (See Reference 2).
More specifically, a base sheet and a plurality of regions are adjacent to each other in plan view, and one region is measured according to JIS Z8781-4:2013 according to CIE (Commission Internationale de l'Eclairage) L ^*. a decorative layer including a pattern layer that covers at least a part of a plane and has a different L ^* value in the a ^* b ^* color system and an L ^* value in a region adjacent to the one region; , a dark-colored patterned decorative sheet in which the L ^* value of the one region and the region adjacent to the one region is 0 or more and 40 or less.

JP 2014-069507 (Claims, etc.) JP2019-38195A (Claims, etc.)

However, the decorative sheet disclosed in Patent Document 1 focuses on reproducing a more realistic wood grain design, and although it has a low gloss, the design includes bright colors, so demand has increased in recent years. It cannot be said to be a decorative sheet exhibiting an increasingly dark color.
In addition, decorative sheets and decorative parts exhibiting dark colors are limited to those with a uniform design over the entire surface, or those with a clear design created by a combination of dark and light colors, resulting in a lack of variety and demand. The situation is such that it has not been able to adequately respond to the diversification of people's tastes.

On the other hand, the decorative sheet etc. of Patent Document 2 is expressed by printing a design pattern, and in order to recognize a more realistic design, the expression is subordinate to the design pattern, and uneven shapes are combined with the design. Moreover, I was trying to express myself by synchronizing with them.
Therefore, if a single color design with little shading is printed, it cannot be recognized at a wide viewing angle, resulting in a problem that the visibility of a realistic design is inferior.
Further, in the case of the decorative sheet etc. of Patent Document 2, the base sheet, the L ^* value of the CIEL ^* a ^* b ^* color system in one region where a plurality of regions are adjacent to each other in plan view, and the one It was necessary to control the L ^* values to be different from each other in adjacent regions.
Furthermore, in the case of the decorative sheet etc. of Patent Document 2, a decorative layer including a pattern layer including a pattern covering at least a part of a plane is provided, and L of the one area and the area adjacent to the one area is provided. ^* It was necessary to set the value to 0 or more and 40 or less to make a decorative sheet with a dark color pattern.

In view of the above circumstances, the inventors of the present invention have made extensive efforts to effectively recognize realistic designs by controlling the difference in glossiness between adjacent measurement points measured under predetermined conditions. The present invention was completed based on the discovery that it is possible to obtain a decorative sheet that can be used as a decorative sheet.
That is, an object of the present invention is to reduce the variation in glossiness difference between adjacent measurement points when measured under predetermined conditions even when the pattern and the uneven shape are not synchronized in the case of a decorative sheet with small shading such as a single color. An object of the present invention is to provide an efficient method for manufacturing a decorative sheet that allows a realistic design to be recognized over a wide viewing angle by controlling standard deviation and the like.

According to the present invention, there is provided a method for manufacturing a decorative sheet having predetermined surface irregularities, the method comprising the following steps (1) and (2).
(1) A step of preparing a resin composition for forming a decorative sheet.
(2) A step of forming a decorative sheet derived from a resin composition, in which a plurality of measurement points M to M+n (M and n are each a natural number of 1 or more, the same shall apply hereinafter) are formed using an embossing roll. The length is within the range of 40 to 1000 mm, and the glossiness is measured in accordance with JIS Z 8741:1997 at equal intervals of 1 to 12 mm in a straight line and at n locations (for example, 80 locations). , the glossiness of the plurality of measurement points obtained is defined as X ₁ to X _n , and the difference in glossiness of adjacent measurement points is Y ₂ (=X ₂ -X ₁ ) to Y _n (=X _n -X _n-1 ). In the measurement chart showing the relationship between multiple measurement points and glossiness differences obtained when
The maximum value/minimum value of glossiness at multiple measurement points is a value of 1.5 or more, and
A step of forming a decorative sheet that satisfies the following first relationship and second relationship.
(First relationship)
Among the plurality of measurement points M to M+n, measurement points m to m+3 (m is 1 or more ), and the arithmetic mean roughness Ra measured in accordance with JIS B 0601:1982 at the measurement points m to m+3 satisfies Ra _m >Ra _m+1 >Ra _m+2 >Ra _m+3 .
(Second relationship)
Among the plurality of measurement points M to M+n, at least four points are measured points m' to m'+3 (m' is , a natural number of 1 or more), and the arithmetic mean roughness measured in accordance with JIS B 0601:1982 at the measurement points m' to m'+3 is Ram _' <Ra _m '+1<Ra _{m '+2} <Ra _m'+3 .

In other words, by controlling the standard deviation regarding the variation in glossiness difference to a predetermined value or more, even in designs with little shading, even in the case of a free pattern in which the pattern and the unevenness are not synchronized, it can be , it is possible to efficiently produce a decorative sheet that can be recognized as having a realistic design.
In addition, in accordance with JIS Z 8741:1997, the difference in gloss measured at n points, that is, the value of the standard deviation regarding the variation in the difference in gloss, is used as a control factor when determining the quality of manufacturing. As a result, it is possible to obtain a decorative sheet that is further rich in quantitative properties and reproducibility in terms of good design and the like.
Note that the value of the standard deviation regarding the variation in the difference in glossiness depends on the embossing processing conditions (pressure force, embossing temperature, rotation speed, etc.), the type of embossing roll (surface hardness, embossing height, embossing shape), and the composition of the decorative sheet ( It can be adjusted by appropriately changing the material, thickness, hardness, etc.

Further, when carrying out the method for producing a decorative sheet of the present invention, it is preferable that the difference between the maximum value and the minimum value of the difference in glossiness be a value within the range of 40 to 80%.
That is, by controlling the difference between the maximum value and the minimum value of the glossiness difference in this manner, it is possible to obtain a decorative sheet with a realistic design that can be recognized at a wider viewing angle.
In addition, by adopting the difference between the maximum value and the minimum value based on the difference in glossiness as one of the control factors, it is possible to use the difference between the maximum value and the minimum value based on the gloss level difference as one of the control factors. As a result, it is possible to obtain a decorative sheet that has good design properties and is further rich in reproducibility and quantitative properties.

Furthermore, when carrying out the method for manufacturing a decorative sheet of the present invention, the arithmetic mean roughness Ra measured in accordance with JIS B 0601:1982 with respect to the predetermined surface unevenness may be set to a value within the range of 5 to 20 μm. preferable.
In this way, by setting the arithmetic mean roughness Ra within a predetermined range with respect to the predetermined surface unevenness, this Ra can also be used as a control factor when determining the quality of manufacturing. Therefore, as a result, it is possible to provide a decorative sheet having a predetermined surface unevenness that is highly reproducible and quantitative in terms of good design and the like.

Further, when carrying out the method for producing a decorative sheet of the present invention, it is preferable that the total thickness is within the range of 50 to 500 μm.
By setting the overall thickness of the decorative sheet to a value within a predetermined range, the mechanical properties, handling properties, and decorative properties of the decorative sheet can be improved, and furthermore, embossing treatment etc. to achieve the surface condition of the present invention can be performed. It can also be carried out easily and with good reproducibility.

Further, when carrying out the method for manufacturing a decorative sheet of the present invention, it is preferable that the type of decorative sheet having predetermined surface irregularities is at least one of polyvinyl chloride resin, polyester resin, and polyolefin resin.
By using a predetermined type of decorative sheet in this way, the mechanical properties, handling properties, decorative properties, transparency, etc. of the decorative sheet can be improved, and furthermore, the embossing treatment etc. that provide the surface condition of the present invention can be improved. , can be carried out easily and with good reproducibility.

Further, when carrying out the method for manufacturing a decorative sheet of the present invention, it is preferable that the viewing angle is set to a value of 120° or more.
When the viewing angle is set in this way, the design can be clearly recognized from the front of the decorative sheet even when the decorative sheet is tilted from the front toward 60 degrees (the viewing angle is 120 degrees).

Furthermore, in carrying out the method for producing a decorative sheet of the present invention, a decorative sheet of a predetermined size (width: 90 cm or more, length 10 m or more, thickness 70 μm or more) is formed from a monochromatic resin composition. In this case, it is preferable to form a glossy pattern with predetermined surface irregularities on the surface using an embossing roll.

Further, when carrying out the method for producing a decorative sheet of the present invention, it is preferable that the glossy pattern is one of a wood grain pattern, a Japanese paper pattern, or a geometric pattern.

Further, in carrying out the method for producing a decorative sheet of the present invention, it is preferable that the surface of the embossing roll is embossed by any one of laser engraving, mill engraving, and etching.

Further, in carrying out the method for producing a decorative sheet of the present invention, it is preferable to form a printed layer on the surface of a decorative sheet base material that is a monochromatic sheet, and then provide a clear layer on the surface of the printed layer.

FIGS. 1(a) to 1(c) are diagrams provided to explain aspects of the decorative sheet, respectively. FIG. 2(a) is a diagram provided to explain the relationship between surface irregularities (convex shapes) of the decorative sheet and differences in glossiness of adjacent measurement points, and FIG. 2(b) is a diagram showing a predetermined surface of the decorative sheet. FIG. 2 is a diagram (part 1) used to explain the relationship between unevenness (a convex shape having a flat portion) and a difference in glossiness between adjacent measurement points. FIG. 3 is a diagram (part 2) used to explain the relationship between the predetermined surface irregularities (approximately three-stroke shape) of the decorative sheet and the difference in glossiness between adjacent measurement locations. FIG. 4(a) is a diagram for explaining the relationship between the glossiness of the decorative sheet and the arithmetic mean roughness (Ra), and FIG. 4(b) is a diagram showing the difference in glossiness between adjacent measurement points of the decorative sheet. FIG. 12 is a diagram for explaining the relationship between the arithmetic mean (Ra) and the arithmetic square (Ra). FIG. 5(a) is a diagram showing the specular glossiness at each measurement location of the decorative sheet #1 corresponding to Example 1, and FIG. 5(b) is a diagram showing the difference in glossiness between adjacent measurement locations. . FIG. 6(a) is a diagram showing the specular glossiness at each measurement location of the decorative sheet #2 corresponding to Example 2, and FIG. 6(b) is a diagram showing the difference in glossiness between adjacent measurement locations. . FIG. 7(a) is a diagram showing the specular glossiness at each measurement location of the decorative sheet #3 corresponding to Example 3, and FIG. 7(b) is a diagram showing the glossiness difference between adjacent measurement locations. . FIG. 8(a) is a diagram showing the specular glossiness at each measurement location of the decorative sheet #4 corresponding to Comparative Example 1, and FIG. 8(b) is a diagram showing the difference in glossiness between adjacent measurement locations. . FIG. 9(a) is a diagram showing the gloss distribution of the decorative sheet #5 corresponding to Comparative Example 2, and FIG. 9(b) is a diagram showing the gloss difference based on the diagram showing the same gloss distribution. FIG. FIG. 10(a) is a diagram showing the gloss distribution of the decorative sheet #6 corresponding to Comparative Example 3, and FIG. 10(b) is a diagram showing the difference in glossiness based on the diagram showing the same gloss distribution. FIG. FIG. 11 is a diagram for explaining a method for evaluating the visibility of a decorative sheet. FIG. 12 is a diagram for explaining the relationship between the standard deviation of the variation in glossiness difference between adjacent measurement locations and the visibility evaluation of the decorative sheet.

[First reference embodiment]
The first reference embodiment is a decorative sheet having predetermined surface irregularities, as shown in FIG. are each a natural number greater than or equal to 1), and measure at n points (e.g., 80 points) at a predetermined length (e.g., 40 mm to 1000 mm) and at predetermined intervals (e.g., 1 to 12 mm) in a straight line. The glossiness of the plurality of measured points is set as X ₁ to X _n , and the gloss difference between adjacent measurement points is set as Y ₂ =X ₂ -X to Y _n =X _n -X _n-1 . This decorative sheet is characterized in that, in a measurement chart showing the relationship between a plurality of measurement points and gloss differences, the standard deviation of the variation in gloss differences (%) is 0.25% or more.

That is, the decorative sheet has a predetermined surface unevenness, and the glossiness of the surface of the decorative sheet is measured at a plurality of points M to M+n (M and n are each a natural number of 1 or more), and the predetermined length is 40 to 1000 mm. The glossiness is measured in accordance with JIS Z 8741:1997 at equal intervals of 1 to 12 mm in a straight line and at n locations (for example, 80 locations), and the resulting multiple When the glossiness of _the measurement points is set to X ₁ to X _n , and the glossiness difference between adjacent measurement points is set to Y _{2 (} = _{X 2 -} In the measurement chart that shows the relationship between multiple measurement points and the glossiness difference, the standard deviation of the variation in glossiness difference (%) is set to a value within the range of 0.25 to 1%. A decorative sheet is characterized in that the maximum value/minimum value of glossiness is a value of 1.5 or more and satisfies the following first relationship and second relationship.
(First relationship)
Among the plurality of measurement points M to M+n, at least four points are measured points m to m+3 where the value of the glossiness difference between adjacent measurement points is a positive value at three or more consecutive points (m is 1 or more). natural number), and the arithmetic mean roughness Ra measured in accordance with JIS B 0601:1982 at the measurement points m to m+3 satisfies Ra _m >Ra _m+1 >Ra _m+2 >Ra _m+3 .
(Second relationship)
Among the plurality of measurement points M to M+n, at least four points are measured points m' to m'+3 (m' is , a natural number of 1 or more), and the arithmetic mean roughness measured in accordance with JIS B 0601:1982 at the measurement points m' to m'+3 is Ram _' <Ra _m'+1 <Ra _{m '+2} <Ra _m'+3 .
Hereinafter, the decorative sheet of the first reference embodiment will be specifically explained by dividing it into constituent elements.

1. Decorative sheet having a predetermined surface unevenness (1) Aspect The decorative sheet having a predetermined surface unevenness (when combined with other layers, may be referred to as a decorative sheet base material) is not limited to the following embodiments, but Typical embodiments include embodiments 1) to 8) below.
1) A decorative sheet consisting of a single decorative sheet base material.
2) A decorative sheet consisting of a two-layer structure of a decorative sheet base material and an adhesive layer.
3) It is a decorative sheet consisting of a two-layer structure of a primer layer and a decorative sheet base material.
4) A decorative sheet consisting of a three-layer structure including a primer layer, a decorative sheet base material, and an adhesive layer.
5) A decorative sheet consisting of three layers: a clear layer, a printing layer, and a decorative sheet base material.
6) A decorative sheet consisting of a four-layer structure including a clear layer, a printing layer, a decorative sheet base material, and an adhesive layer.
7) A decorative sheet consisting of four layers: a primer layer, a clear layer, a printing layer, and a decorative sheet base material.
8) A decorative sheet consisting of a five-layer structure including a primer layer, a clear layer, a printing layer, a decorative sheet base material, and an adhesive layer.

The above-mentioned adhesive layer is usually a resin layer for attaching a decorative sheet (decorative sheet base material) to a wall base material or the like.
Further, the primer layer is usually an easily adhesive layer for laminating another resin layer on the surface of the decorative sheet (decorative sheet base material).
Further, the clear layer is usually a transparent resin layer provided on the surface of the decorative sheet (decorative sheet base material) for protection without changing visibility.
Furthermore, the printing layer is one of the decorative layers formed by printing characters, figures, symbols, etc. on the surface of the decorative sheet (decorative sheet base material).

Further, it is usually preferable that the decorative sheet is provided with a release sheet on both sides or one side.
That is, the release sheet can be effectively protected from surrounding dirt and dust during storage and transportation until the decorative sheet is actually used.
Furthermore, if the decorative sheet is provided with a release sheet on both or one side, handling, alignment, pasting work, etc. can be improved.

(2) Predetermined surface unevenness The form of the predetermined surface unevenness is not particularly limited, but for example, it may be in the form of a decorative sheet having at least one pattern of a wood grain pattern, a Japanese paper pattern, and a geometric pattern. is preferred.
The reason for this is that by providing such a specific pattern, the decorativeness of the resulting decorative sheet can be enhanced and controlled, and furthermore, surface treatment can be facilitated.

Therefore, regarding the predetermined surface irregularities of the decorative sheet, it is preferable to set the arithmetic mean roughness Ra to a value within the range of 5 to 20 μm.
The reason for this is that by controlling the arithmetic mean roughness Ra to a value, a desired pattern can be clearly recognized, and furthermore, it can be stably formed by embossing or the like.
In addition, this Ra can be used as a control factor when determining the quality of manufacturing, and as a result, a decorative sheet with a predetermined surface unevenness that is highly reproducible and quantitative in terms of good design, etc. It can be done.
Therefore, the arithmetic mean roughness Ra of the predetermined surface irregularities of the decorative sheet is more preferably set to a value within the range of 6 to 18 μm, and even more preferably set to a value within the range of 7 to 16 μm.

(3) Difference in Glossiness (3)-1 Spacing When selecting measurement points using any point as the end, it is usually done at equal intervals within the range of 1 to 12 mm, preferably at equal intervals within the range of 3 to 11 mm. It is preferable to select four or more locations at intervals, more preferably at equal intervals within the range of 5 to 10 mm, as shown in FIGS. 2(a) to 2(b) and FIG. 3.

Here, FIG. 2(a) is a diagram provided to explain the relationship between the surface unevenness (convex shape) of the decorative sheet and the glossiness difference between adjacent measurement points, and FIG. FIG. 3 is a diagram provided to explain the relationship between predetermined surface irregularities (a convex shape having a flat portion) and a difference in glossiness between adjacent measurement points.

Further, FIG. 3 is a diagram provided to explain the relationship between the predetermined surface irregularities (approximately three-stroke shape) of the decorative sheet and the glossiness difference between adjacent measurement points.
That is, by measuring at least four arbitrary measurement points in a straight line, it is possible to observe continuous changes in the glossiness of the design pattern.
Therefore, for example, four or more adjacent locations can be specified by checking whether the first relationship, the second relationship, or either one of the relationships is satisfied.

(3)-2 Measurement length When measuring and controlling the difference in glossiness between adjacent measurement points, it is usually preferable to set the measurement length to a value within the range of 40 mm to 1000 mm.
The reason for this is that when measuring at least four measurement points in a straight line with multiple points as the ends, by determining the minimum length, maximum length, and size of the design, it is possible to visually recognize the design. This is because the size of the pattern etc. can be determined.
Also, with such a measurement length, it is easy to downsize the device used to create decorative sheets. Therefore, it is more preferable to set the measurement length to a value within the range of 100 mm to 800 mm. More preferably, the value is within the range of 200 mm to 640 mm.

(3)-3 Linear In addition, in measuring and controlling the difference in gloss between adjacent measurement locations, it is preferable to measure at least four locations and usually measure the gloss in a straight line.
The reason for this is that in the case of a zigzag shape or a rectangular shape (right angle shape), it is not possible to accurately determine continuous changes in glossiness in a design pattern.
However, even though it is said to be measured in a straight line, it does not necessarily have to be a physically straight line, but as long as the gloss is measured by passing through at least four measurement points in a virtual straight line. good.

(3)-4 Standard deviation of variation in glossiness difference When measuring and controlling the glossiness difference between adjacent measurement points, the standard deviation of variation in glossiness difference should be set to a value of 0.25% or more. Features.
That is, in a measurement chart showing the relationship between a plurality of measurement points and glossiness differences, the standard deviation of the variation in glossiness differences (%) is set to a value equal to or greater than a predetermined value.
The reason for this is that when the standard deviation of the variation in glossiness difference (%) is less than 0.25%, a decorative sheet with a single color and a color design with little shading will not look realistic at a wide viewing angle. This is because it becomes difficult to recognize the design.

Here, referring to FIG. 12, the relationship between the standard deviation (%) of the variation in glossiness difference between adjacent measurement points and the visibility evaluation (relative value) of the decorative sheet will be explained.
The horizontal axis of FIG. 12 shows the standard deviation (%) of the variation in glossiness difference between adjacent measurement points, and the vertical axis shows the relative value of visibility evaluation.
That is, when the visibility evaluation shown in Example 1 etc. described below is ◎, it is 5 points, 〇 is 3 points, △ is 1 point, and × is 0 points, and the glossiness of the adjacent measurement point is This is the result of evaluating visibility in relation to the standard deviation of the variation of the difference.

As can be easily determined from the characteristic curve shown in FIG. 12, when the standard deviation of the variation in glossiness difference between adjacent measurement points is less than 0.25%, the visibility evaluation (relative value) is approximately 0.
On the other hand, when the standard deviation of the variation in glossiness difference between adjacent measurement points exceeds 0.25%, the visibility evaluation (relative value) tends to improve rapidly.

Therefore, if you want to obtain good results as a visibility evaluation (relative value), it is preferable to set the standard deviation of the variation in glossiness difference between adjacent measurement points to a value of 0.25% or more. If you want to obtain a good visibility evaluation, it is preferable to set the value to 0.3% or more, and if you want to obtain a more stable evaluation of good visibility, the value should be 0.4 to 1.0%. It is understood that it is best to set the value within the range of .

(3)-5 Maximum value - minimum value of glossiness difference When measuring the glossiness difference between adjacent measurement points, set the glossiness of multiple measurement points in order from the end to X ₁ to X _n , and calculate the glossiness of the adjacent measurement points. Let the degree difference be Y ₂ =X ₂ -X ₁ to Y _n =X _n-1 -X _n .
Based on this premise, it is preferable to set the glossiness difference (maximum value - minimum value) to a value within the range of 40 to 80%.
The reason for this is that by setting the (maximum value - minimum value) of the glossiness of adjacent measurement points within a predetermined range, the maximum value, minimum value, and dispersion of the glossiness difference can be controlled. This is because it can be done.

(3)-6 Maximum/minimum value of glossiness difference Further, it is preferable that the maximum value/minimum value of the glossiness difference between adjacent measurement points is set to a value of 1.5 or more.
The reason for this is that by setting the maximum value/minimum value of the difference in glossiness between adjacent measurement points to a predetermined value or more in this way, it is possible to ensure a visually recognizable difference in glossiness value.
However, if the maximum value/minimum value of the difference in glossiness between adjacent measurement points becomes excessively large, it may become difficult to control surface irregularities as surface roughness.
Therefore, it is more preferable to set the maximum value/minimum value of the glossiness difference between adjacent measurement points to a value within the range of 1.8 to 10, and more preferably to a value within the range of 1.8 to 8. More preferably, the value is within the range of 2 to 6.

(3)-7 Surface roughness (arithmetic mean roughness Ra)
Regarding the predetermined surface unevenness, it is preferable that the arithmetic mean roughness Ra measured in accordance with JIS B 0601:1982 is a value within the range of 5 to 20 μm.
The reason for this is that by setting the arithmetic mean roughness Ra to a value within a predetermined range, Ra can also be used as a control factor when determining the quality of manufacturing.
As a result, it is possible to obtain a decorative sheet having a predetermined surface irregularity that is highly reproducible and quantitative in terms of good design and the like.
Therefore, regarding the predetermined surface irregularities, it is more preferable to set the arithmetic mean roughness Ra to a value within the range of 10 to 20 μm, and even more preferably to a value within the range of 12 to 18 μm.

(4) Continuity of arithmetic mean roughness (4)-1 When positive In addition, among the plurality of measurement points m to m+n, the glossiness differences between adjacent measurement points Ym to Ym+n are all positive, and It is preferable that the arithmetic mean roughness Ra at a plurality of measurement locations satisfy the relationship Ram>Ram+1>Ram+2>Ram+3 (first relationship).
In other words, if the glossiness difference between adjacent measurement points is positive in at least 4 points among the plurality of measurement points m to m+n, the arithmetic average roughness of the plurality of measurement points is This means that it is preferable that Ra satisfies the relationship Ram>Ram+1>Ram+2>Ram+3 (first relationship).
The reason for this is that as the glossiness at the measurement location increases, the maximum height Rz does not increase proportionally, but the arithmetic mean roughness Ra decreases proportionally.
Therefore, it is thought that the arithmetic mean roughness Ra, which decreases proportionally, affects the ability to recognize a realistic design at a wide viewing angle, even if the design is monochromatic and has little shading. It's for a reason.

(4)-2 In the case of negative In addition, if Ym' to Ym'+n, which are the glossiness differences at multiple measurement points m' to m'+n, are all negative, and each arithmetic It is preferable that the average roughness Ra satisfies the relationship Ram'<Ram'+1<Ram'+2<Ram'+3 (second relationship).
In other words, in the case where the glossiness difference between the adjacent measurement points in at least four adjacent measurement points among the plurality of measurement points m' to m'+n is negative at three or more consecutive points, This means that it is preferable that the arithmetic mean roughness Ra at the measurement location satisfies the relationship Ra'm>R'am+1>R'am+2>R'am+3 (second relation).
The reason for this is that the maximum height Rz does not decrease proportionally, but the arithmetic mean roughness Ra increases proportionally and continuously as the glossiness at the measurement location decreases in order.
Therefore, it is thought that the arithmetic mean roughness Ra, which decreases proportionally and continuously, affects the ability to recognize a realistic design at a wide viewing angle, even in a color design with little shading. be.

In addition, if the difference in glossiness at a plurality of measurement points is partially positive and continuously positive to satisfy the first relationship, or negative to satisfy the second relationship, Such positive and negative cases will appear repeatedly.
Therefore, if either the first relationship or the second relationship is satisfied, even if the decorative sheet is monochromatic and has a color design with little shading, a realistic design can be recognized at a wide viewing angle. However, in order to obtain good visibility, it is more preferable to satisfy each of the first relationship and the second relationship.

Here, referring to FIGS. 4(a) and 4(b), which are data scatter diagrams, we will explain the relationship between the glossiness at the measurement location of the decorative sheet and the arithmetic mean roughness (Ra), and the relationship between the glossiness at the measurement location of the decorative sheet and the adjacent The relationship between the glossiness difference at the measurement location and the arithmetic mean roughness (Ra) will be explained.
The glossiness value of the decorative sheet in FIG. 4(a) and the glossiness difference value of the decorative sheet in FIG. 4(b) are based on Example 1, Comparative Example 1, etc. described later. .
According to the data scatter diagram of FIG. 4(a), it is suggested that there is a considerable correlation between the glossiness of the decorative sheet and the arithmetic mean roughness (Ra).

On the other hand, according to the data scatter diagram of FIG. 4(b), it is a diagram for explaining the relationship between the glossiness difference between adjacent measurement points of the decorative sheet and the arithmetic mean (Ra).
According to the data scatter diagram of FIG. 4(ba), it is suggested that there is no correlation between the glossiness difference of the decorative sheet and the arithmetic mean roughness (Ra).
Therefore, at four points among the plurality of measurement points m to m+n, there are cases where the glossiness difference between these adjacent measurement points is positive at three or more consecutive points, or when the difference in glossiness between the plurality of measurement points m' to m'+n is positive. When the glossiness differences Ym' to Ym'+3 are negative at three or more consecutive points in four of the points, the visibility of the design becomes significantly better.

(5) Type In constituting the decorative sheet of the present invention, the type of decorative sheet having a predetermined surface unevenness is not particularly limited, but it is usually made of polyvinyl chloride resin, polyester resin, or polyolefin resin. Preferably, there is at least one.
The reason for this is that with such a resin, the decorative properties, mechanical properties, stability, adhesion, etc. of the final decorative sheet can be controlled relatively easily within the desired range. It's for a reason.
Moreover, such resins have the advantage of being relatively easily available and inexpensive, even if they have different thicknesses, weight average molecular weights, and even hardnesses.

(6) Thickness The thickness of the decorative sheet can be changed as appropriate depending on the use, etc., but it is usually preferred to have a value within the range of 50 to 500 μm.
The reason for this is that by controlling the thickness of the decorative sheet within this thickness range, it is easier to exhibit the various characteristics of the decorative sheet, and it is also easier to manufacture. It is.
Therefore, the thickness of the decorative sheet is more preferably within the range of 80 to 350 μm, more preferably within the range of 100 to 300 μm, and more preferably within the range of 120 to 250 μm. Most preferred.

(7) Planar shape The shape of the decorative sheet is not particularly limited, and can be changed as appropriate depending on the application.
Therefore, the shape can be, for example, tape-shaped, triangular, square (rectangular), polygonal, circular, elliptical, irregular, or the like.

(8) Form Regarding the form of the decorative sheet, it may be in the form of a roll or a sheet.
In that case, if the decorative sheet is in the form of a roll, it is preferably 90 cm wide and 1 m or more in length, for example.
Moreover, if the decorative sheet is a sheet, it is preferable that the width of the sides is 50 cm and the length is 1 m or more, for example.

[Second embodiment]
A second embodiment of the present invention is a method for manufacturing a decorative sheet having predetermined surface irregularities, the method comprising the following steps (1) and (2).
(1) A step of preparing a resin composition for forming a decorative sheet. (2) A step of forming a decorative sheet derived from a resin composition, in which a plurality of measurement points m to m+n (m and n are each a natural number of 1 or more), the glossiness is measured in accordance with JIS Z 8741:1997 at a predetermined length and at a predetermined interval in a straight line at n locations, and the glossiness of the multiple measurement locations obtained is Multiple measurement points and gloss obtained when the glossiness is set as X ₁ to X _n and the gloss difference between adjacent measurement points is set as Y ₂ =X ₂ -X to Y _n =X _n -X _n-1 . A process for forming a decorative sheet in which the standard deviation of the variation in glossiness difference (%) is 0.25% or more in the measurement chart showing the relationship with the glossiness difference.

That is, there is provided a method for manufacturing a decorative sheet having predetermined surface irregularities, the method comprising the following steps (1) and (2).
(1) A step of preparing a resin composition for forming a decorative sheet.
(2) A step of forming a decorative sheet derived from a resin composition, in which a plurality of measurement points M to M+n (M and n are each a natural number of 1 or more, the same shall apply hereinafter) are formed using an embossing roll. The length is within the range of 40 to 1000 mm, and the glossiness is measured in accordance with JIS Z 8741:1997 at equal intervals of 1 to 12 mm in a straight line and at n locations (e.g., 80 locations). Then, let the glossiness of the plurality of measurement points obtained be X ₁ to X _n , and the difference in glossiness of adjacent measurement points be Y ₂ (=X ₂ - X ₁ ) to Y _n (=X _n - _{X n-1} ) In the measurement chart that shows the relationship between multiple measurement points and glossiness differences, the standard deviation of the variation in glossiness differences (%) is set to a value within the range of 0.25 to 1%. ,
The maximum value/minimum value of glossiness at multiple measurement points is a value of 1.5 or more, and
A step of forming a decorative sheet that satisfies the following first relationship and second relationship.
(First relationship)
Among the plurality of measurement points M to M+n, at least four points are measured points m to m+3 where the value of the glossiness difference between adjacent measurement points is a positive value at three or more consecutive points (m is 1 or more). natural number), and the arithmetic mean roughness Ra measured in accordance with JIS B 0601:1982 at the measurement points m to m+3 satisfies Ra _m >Ra _m+1 >Ra _m+2 >Ra _m+3 .
(Second relationship)
Among the plurality of measurement points M to M+n, at least four points are measured points m' to m'+3 (m' is , a natural number of 1 or more), and the arithmetic mean roughness measured in accordance with JIS B 0601:1982 at the measurement points m' to m'+3 is Ram _' <Ra _m '+1<Ra _{m '+2} <Ra _m'+3 .
Hereinafter, the method for manufacturing a decorative sheet according to the second embodiment will be explained in detail by dividing it into constituent elements and not overlapping with the first reference embodiment.

1. Preparation step of resin composition This is a step of preparing a monochromatic resin composition.
As such a resin composition, a thermoplastic resin is used, and as described in the first reference embodiment, at least one resin material of polyvinyl chloride resin, polyester resin, or polyolefin resin, and further a coloring material is used. Since a coloring agent can be suitably used, a detailed explanation thereof will be omitted here.

Furthermore, when polyvinyl chloride resin or the like is used, it is preferable that the average degree of polymerization is within the range of 100 to 10,000.
The reason for this is that if the average degree of polymerization of polyvinyl chloride resin, etc. is less than 100, it may be difficult to maintain a predetermined shape or the surface tack may become excessively high. .
On the other hand, when the average degree of polymerization of polyvinyl chloride resin exceeds 10,000, it is difficult to mix and disperse the ingredients uniformly or to create a flame-retardant sheet with a predetermined uniform thickness. This is because there are cases where
Therefore, the average degree of polymerization of the polyvinyl chloride resin is more preferably within the range of 500 to 5,000, and even more preferably within the range of 800 to 2,000.
Note that the average degree of polymerization of the polyvinyl chloride resin can be calculated by comparing it with the molecular weight of the monomer using a GPC device or a GC-MS device.

2. Decorative sheet forming process (1) Basic process The decorative sheet forming process is to form a predetermined polyvinyl chloride sheet (e.g. roll shape, width: 90 cm or more, length: 10 m or more, thickness) from a monochrome resin composition. When molding a sheet (with a diameter of 70 μm or more), for example, a wood grain pattern can be embossed as a glossy pattern having a predetermined surface unevenness to form a decorative sheet.

For example, to create a wood grain pattern as a glossy pattern, when molding a polyvinyl chloride sheet, add 20 parts by weight of a plasticizer (DOP) and 0.5 parts by weight of a black pigment to 100 parts by weight of (A) polyvinyl chloride resin. These are mixed together to create a polyvinyl chloride resin composition.
Next, a desired uneven shape can be formed on the surface using a predetermined embossing roll so that the wood grain pattern is visually recognized as a glossy pattern.

(2) Additional manufacturing process Also, when creating the typical basic forms 1) to 8) of the decorative sheet described in the first reference embodiment, for example, as a decorative sheet, basic form 2) When creating a decorative sheet, it is preferable to provide an additional step of forming an adhesive layer made of a predetermined adhesive resin, such as an acrylic adhesive resin, on the back surface of the decorative sheet base material.

Similarly, in order to create basic form 3), it is preferable to provide, as an additional step, a step of forming a thin primer layer made of a predetermined resin on the surface of the decorative sheet base material.
Further, in order to create basic form 4), it is preferable to provide an additional step of forming an adhesive layer made of a predetermined resin on the back side of the decorative sheet base material of basic form 3).

In addition, in order to create basic form 5), as an additional step, a printed layer is formed by printing on the surface of the decorative sheet base material, which is a single color sheet, and then a clear layer is provided on the surface of the printed layer. At the same time, it is preferable to provide a step of forming an uneven shape using an embossing roll.
Furthermore, when creating basic form 6), it is preferable to provide an additional step of forming an adhesive layer made of a predetermined resin on the back side of the decorative sheet base material of basic form 5).

Furthermore, in order to create the decorative sheet of basic form 7), it is preferable to provide a step of forming a primer layer on the surface of the decorative sheet base material of basic form 5) as an additional step.
Moreover, in order to create basic form 8), it is preferable to provide an additional step of forming an adhesive layer made of a predetermined resin on the back side of the decorative sheet base material of basic form 7).

(3) Inspection process It is preferable to include an inspection process to determine whether the obtained decorative sheet has a predetermined specular gloss, surface roughness, etc., and whether visibility is good or not. .
More specifically, the specular gloss and surface roughness of the obtained decorative sheet were measured using a specular gloss meter (for example, manufactured by Nippon Denshoku Kogyo Co., Ltd.) and a surface roughness meter (for example, Kosaka Institute), respectively. Co., Ltd.) to confirm that the value is within a predetermined range.
Note that this inspection process may be a complete inspection of the decorative sheets, or may be a random inspection at a predetermined rate in consideration of production efficiency.

(3)-1 Specular gloss In accordance with JIS Z 8741:1997, the surface of the decorative sheet was measured at approximately 80 locations in a straight line at a measurement interval of 8 mm and a measurement length of 640 mm. Specular gloss (%) was measured by irradiating laser light from a 60° direction.
Note that the glossiness difference (%) between adjacent measurement points can be calculated from the glossiness of a plurality of measurement points and can be evaluated.

(3)-2 Surface roughness In accordance with JIS B 0601:1982, the surface of the decorative sheet is measured, for example, at approximately 80 locations in a straight line with a measurement interval of 8 mm and a measurement length of 640 mm, to determine the arithmetic surface roughness (Ra). ) to measure.
The surface unevenness of the decorative sheet is preferably expressed by an arithmetic mean roughness based on a plurality of measurement points m to m+n (or m' to m'+n).

(3)-3 Visibility It is more preferable that the visibility of the decorative sheet is evaluated in accordance with the evaluation criteria shown in Example 1 to be described later, and that an evaluation result of at least △, and more preferably ○ or ◎ is obtained.
That is, the visibility of the obtained decorative sheet was determined by changing the angle (θ1) between the incident light from the light source 32 and the direction in which the viewer 34 views the decorative sheet 30, as shown in FIG. Evaluation was made according to the criteria shown in Example 1.
Further, θ1×2 is called a viewing angle, and there is a relationship such that θ1+θ2 is 90°.

In addition, even if the decorative sheet is tilted 45 degrees from the front (viewing angle is 90 degrees), if the viewer can see the design from the front of the decorative sheet and clearly recognize the pattern (rating: △ ), there is no problem in practical use.
Further, even when the decorative sheet is tilted toward 60° from the front (viewing angle is 120°), it is more preferable if the design can be clearly recognized from the front of the decorative sheet (rating: 0).
Furthermore, even when the decorative sheet is tilted toward 75° from the front (viewing angle is 150°), it is even more preferable if the design can be clearly recognized from the front of the decorative sheet (rating ◎).

Hereinafter, the present invention will be explained in detail based on Examples. However, the scope of the rights of the present invention is not narrowed by the description of the examples without any particular reason.

[Example 1]
1. Decorative sheet manufacturing process (1) Preparation of polyvinyl chloride resin composition In a mixing container, 40 parts by weight of plasticizer (DOP) and black color are added to 100 parts by weight of vinyl chloride resin having a weight average molecular weight of 1 million. They were each placed in a proportion of 0.5 parts by weight of pigment, and then mixed and stirred until uniform, to prepare a polyvinyl chloride resin composition.

(2) Step of Forming Decorative Sheet Next, using the polyvinyl chloride resin composition taken out from the mixing container, a monochrome (black) polyvinyl chloride sheet (thickness: 150 μm) was obtained using a calendar molding machine.
Next, an embossing roll with a wood grain pattern created by laser engraving was used on the surface (one side) of the obtained polyvinyl chloride sheet to obtain a decorative sheet having predetermined surface irregularities.
That is, a wood grain pattern was applied to the surface as a glossy pattern using a predetermined embossing roll to obtain a decorative sheet having a wood grain pattern (decorative sheet #1).

2. Evaluation process for decorative sheets (1) Specular glossiness In accordance with JIS Z 8741:1997, the 60° specular glossiness (hereinafter simply referred to as glossiness) of the surface of the decorative sheet was measured at a measurement interval of 8 mm. The measurement length was 640 mm, and the measurement was performed in a straight line at approximately 80 locations using a specular gloss measuring device COLUMUN 07 (manufactured by Nippon Denshoku Kogyo Co., Ltd.).

That is, as shown in Table 1, the average value, maximum value, minimum value, maximum value - minimum value, maximum value / minimum value, and standard deviation of the variation in specular gloss in the decorative sheet were calculated.
Note that FIG. 5(a) shows a diagram showing the specular glossiness at each measurement location of the decorative sheet #1, and FIG. 5(b) shows the difference in glossiness at adjacent measurement locations.

(2) Surface roughness In accordance with JIS B 0601:1982, the arithmetic surface roughness (Ra) on the surface of the decorative sheet was measured at approximately 80 locations in a straight line at a measurement interval of 8 mm and a measurement length of 640 mm. The measurement was performed using a surfboard meter (Surfcorder SE-300, manufactured by Kosaka Institute).

(3) Visibility The visibility of the obtained decorative sheet is determined by changing the angle (θ1) between the incident light from the light source 32 and the direction in which the viewer 34 views the decorative sheet 30, as shown in FIG. Evaluation was made according to the following criteria.
As a result, as shown in Table 1, the standard deviation of the variation in glossiness difference (%) in the measurement chart showing the relationship between the measurement point and the glossiness difference between adjacent measurement points for the obtained decorative sheet was found to be It was 0.47%, and the visibility evaluation was ◎.

◎: The design can be recognized from the front of the decorative sheet even if the decorative sheet is tilted toward the front at 75°, that is, the viewing angle is 150°.
Good: The design can be recognized from the front of the decorative sheet even when the decorative sheet is tilted at 60° with respect to the front, that is, the viewing angle is 120°.
Δ: The design can be recognized from the front of the decorative sheet even if the decorative sheet is tilted at 45° with respect to the front, that is, the viewing angle is 90°.
×: When the decorative sheet is tilted at 45° with respect to the front, the design cannot be recognized from the front of the decorative sheet, that is, the viewing angle is less than 90°.

[Example 2]
In Example 2, a decorative sheet (#2 decorative sheet) was created in the same manner as in Example 1, except that a Japanese paper pattern was applied as a glossy pattern to the surface by embossing, and visibility etc. were evaluated. did.
FIG. 6(a) shows the specular glossiness at each measurement location of the decorative sheet #2, and FIG. 6(b) shows the difference in glossiness between adjacent measurement locations.
Furthermore, as shown in Table 1, in the measurement chart showing the relationship between the glossiness difference between a measurement point and an adjacent measurement point for the obtained decorative sheet, the standard deviation of the variation in the glossiness difference (%) is 0. .29%, and the visibility evaluation was 0.

[Example 3]
In Example 3, a decorative sheet (#3 decorative sheet) was prepared and evaluated in the same manner as in Example 1, except that a geometric pattern was applied as a glossy pattern by embossing.

FIG. 6(a) shows the specular glossiness at each measurement location of the obtained decorative sheet, and FIG. 6(b) shows the difference in glossiness between adjacent measurement locations.
As a result, as shown in Table 1, the standard deviation of the variation in glossiness difference (%) in the measurement chart showing the relationship between the measurement point and the glossiness difference between adjacent measurement points for the obtained decorative sheet was found to be It was 0.37%, and the visibility evaluation was ◎.

[Example 4]
In Example 4, a decorative sheet was created by embossing in the same manner as in Example 1, except that a PETG sheet (width: 2 m, length: 3 m) was used, and the visibility and the like were evaluated.
As a result, as shown in Table 1, the standard deviation of the variation in glossiness difference (%) in the measurement chart showing the relationship between the measurement point and the glossiness difference between adjacent measurement points for the obtained decorative sheet was found to be It was 0.45%, and the visibility evaluation was ◎.

[Comparative example 1]
In Comparative Example 1, a decorative sheet (#4 decorative sheet) was created and evaluated in the same manner as in Example 1 using an embossing roll created by milling.
In addition, as shown in Table 1, in the measurement chart showing the relationship between the glossiness difference between a measurement point and an adjacent measurement point for the obtained decorative sheet, the standard deviation of the variation in the glossiness difference (%) is 0. The value was less than .25% (0.21%), and the visibility was evaluated as ×.

[Comparative example 2]
In Comparative Example 2, a decorative sheet (#5 decorative sheet) was created in the same manner as in Example 1 using an embossing roll created by etching (processing time: 30 minutes) and evaluated.
In addition, as shown in Table 1, in the measurement chart showing the relationship between the glossiness difference between a measurement point and an adjacent measurement point for the obtained decorative sheet, the standard deviation of the variation in the glossiness difference (%) is 0. The value was less than .25% (0.09%), and the visibility was evaluated as ×.

[Comparative example 3]
In Comparative Example 3, a decorative sheet (#6 decorative sheet) was created in the same manner as in Example 1 using an embossing roll created by etching treatment (processing time: 60 minutes) as in Comparative Example 2, and evaluated. did.
In addition, as shown in Table 1, in the measurement chart showing the relationship between the glossiness difference between a measurement point and an adjacent measurement point for the obtained decorative sheet, the standard deviation of the variation in the glossiness difference (%) is 0. The value was less than .25% (0.12%), and the visibility was evaluated as ×.

As described in detail above, according to the present invention, in a measurement chart showing the relationship between a plurality of measurement points and glossiness differences between adjacent measurement points, the standard deviation of the variation in glossiness differences (%) is kept below a predetermined value. It is characterized by having a value of .

Therefore, even if the pattern and the unevenness are not synchronized in a decorative sheet having a design with little shading, such as a single color, it is now possible to obtain a decorative sheet with a realistic design that can be recognized from a wide viewing angle. Ta.

Furthermore, the standard deviation of the variation in glossiness can be used as a control factor when determining the quality of manufacturing. It can now be used as a decorative sheet.

Therefore, according to the decorative sheet obtained by the manufacturing method of the present invention, not only a single-layer decorative sheet but also a multi-layer decorative sheet in combination with a colored layer, an optical film (such as a light emitting film for a liquid crystal device or an EL light emitting device) Diffusion films, polarization films for liquid crystal devices, retardation films for liquid crystal devices, color filters for liquid crystal devices and EL light emitting devices, films for televisions using liquid crystal devices and EL light emitting devices, and films for projectors using liquid crystal devices and EL light emitting devices. , films for mobile phones using liquid crystal devices and EL light emitting devices), light-shielding films, protective films, cushion films, etc., and can be used in a wide range of fields.

10, 30: Decorative sheet 10a: Predetermined surface irregularities 12: Adhesive 14: Base material 32: Light source 34: Viewer

Claims (10)

A method for manufacturing a decorative sheet having predetermined surface irregularities, the method comprising the following steps (1) and (2).
(1) A step of preparing a resin composition for forming a decorative sheet.
(2) A process of forming a decorative sheet derived from a resin composition, in which a predetermined length of 40 to The glossiness is measured in accordance with JIS Z 8741:1997 at equal intervals of 1 to 12mm and at n locations in a straight line, with a value within the range of 1000mm, and the glossiness at the multiple measurement locations obtained is X ₁ to X _n and the difference in glossiness between adjacent measurement points to Y ₂ (=X ₂ -X ₁ ) to Y _n (=X _n -X _n-1 ). , in the measurement chart showing the relationship with the glossiness difference, the standard deviation of the variation in the glossiness difference (%) is a value within the range of 0.25 to 1%,
The maximum value/minimum value of glossiness at multiple measurement points is a value of 1.5 or more, and
A step of forming a decorative sheet that satisfies the following first relationship and second relationship.
(First relationship)
Among the plurality of measurement points M to M+n, at least four points are measured points m to m+3 where the value of the glossiness difference between adjacent measurement points is a positive value at three or more consecutive points (m is 1 or more). natural number), and the arithmetic mean roughness Ra measured in accordance with JIS B 0601:1982 at the measurement points m to m+3 satisfies Ra _m >Ra _m+1 >Ra _m+2 >Ra _m+3 .
(Second relationship)
Among the plurality of measurement points M to M+n, at least four points are measured points m' to m'+3 (m' is , a natural number of 1 or more), and the arithmetic mean roughness measured in accordance with JIS B 0601:1982 at the measurement points m' to m'+3 is Ram _' <Ra _m '+1<Ra _{m '+2} <Ra _m'+3 . The method for manufacturing a decorative sheet according to claim 1, wherein the difference between the maximum value and the minimum value of the difference in glossiness is within a range of 40 to 80%. The decorative sheet according to claim 1 or 2, wherein the predetermined surface unevenness has an arithmetic mean roughness Ra measured in accordance with JIS B 0601:1982 within a range of 5 to 20 μm. Production method. The method for producing a decorative sheet according to claim 1 or 2, characterized in that the overall thickness is within the range of 50 to 500 μm. 3. The method for producing a decorative sheet according to claim 1, wherein the type of the decorative sheet having the predetermined surface irregularities is at least one of polyvinyl chloride resin, polyester resin, and polyolefin resin. 3. The method for manufacturing a decorative sheet according to claim 1, wherein the viewing angle is set to a value of 120 degrees or more. When molding a decorative sheet of a predetermined size (width: 90 cm or more, length 10 m or more, thickness 70 μm or more) derived from a monochromatic resin composition, the predetermined surface irregularities are formed on the surface by the embossing roll. 3. The method for producing a decorative sheet according to claim 1, further comprising forming a glossy pattern comprising: 8. The method for manufacturing a decorative sheet according to claim 7, wherein the glossy pattern is one of a wood grain pattern, a Japanese paper pattern, or a geometric pattern. 3. The method for manufacturing a decorative sheet according to claim 1, wherein the surface of the embossing roll is embossed by one of laser engraving, mill engraving, and etching. 3. The method for producing a decorative sheet according to claim 1, further comprising forming a printed layer on the surface of a decorative sheet base material that is a monochromatic sheet, and then providing a clear layer on the surface of the printed layer.

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