JP7707614B2 - Decorative sheet and decorative board using same - Google Patents

Description

The present invention relates to a decorative sheet for use, for example, in entrance doors or exteriors, and a decorative panel using the same, which can be produced in-line in a single process and prevents peeling between sheet layers and whitening of the surface.

Conventionally, a decorative sheet has been known that is made up of a printed base material formed into a sheet shape from a thermoplastic resin, a picture print layer formed on the surface of the printed base material, an uneven pattern formed by processing the surface of the printed base material including the picture print layer into an uneven shape, and a laminate layer that laminates the surface of the uneven pattern with the same resin as the printed base material (see paragraph [0007] and Figure 1 of Patent Document 1).

JP 2012-051218 A

However, conventional decorative sheets require multiple steps, including a printing step and a laminating step, making it difficult to integrate them into a single process, resulting in a first problem of high manufacturing costs.
Further, a second problem with conventional decorative sheets is that the laminate layer may peel off between the sheet layers after long-term use.
In consideration of the first and second problems described above, the present invention is devised to eliminate the need for a laminate layer, thereby enabling in-line production in a single process and preventing peeling between sheet layers and surface whitening.

The decorative sheet according to one aspect of the present invention is characterized in that a printed pattern layer, a colored layer, and a primer layer are formed in this order on the back side of a transparent base layer made of a transparent olefin resin, a surface protective layer is formed on the front side of the transparent base layer, an ultraviolet absorber and a light stabilizer are added to the transparent base layer and the surface protective layer, and neither the front side nor the back side of the transparent base layer has a laminate layer made of another film.

Furthermore, the decorative sheet according to one embodiment of the present invention is characterized in that the transparent base layer contains at least either a benzotriazole-based ultraviolet absorber or a hydroxyphenyltriazine-based ultraviolet absorber, and that the amount of either ultraviolet absorber in the transparent base layer is 0.1 parts by mass or more and 2 parts by mass or less per 100 parts by mass of the olefin resin.
The decorative sheet according to one embodiment of the present invention is characterized in that the surface protective layer contains at least a hydroxyphenyltriazine-based ultraviolet absorber, and the hydroxyphenyltriazine-based ultraviolet absorber is present in an amount of 1 part by mass or more and 30 parts by mass or less per 100 parts by mass of the acrylic resin composition that forms the surface protective layer.

The decorative sheet according to one embodiment of the present invention is characterized in that the printed pattern layer, the colored layer and the primer layer contain at least one urethane resin selected from the group consisting of polyester polyol, polycaprolactone polyol, polyalkylene glycol, acrylic polyol and polyisocyanate as a binder resin.
The decorative sheet according to one aspect of the present invention is characterized in that an embossed portion is formed on the surface side of the surface protective layer.

The decorative sheet according to one aspect of the present invention is characterized in that the printed pattern layer is monochromatic.
The decorative sheet according to one aspect of the present invention is characterized in that the colored layer is transparent or translucent.
A decorative board according to one aspect of the present invention is characterized in that a substrate is adhered to the primer layer side of the decorative sheet.

According to one aspect of the present invention, in-line production in one process is possible, and peeling between sheet layers and surface whitening can be prevented.

1 is a cross-sectional view of a decorative sheet and a base material portion according to a first embodiment.

(Embodiment 1)
An embodiment of the present invention will now be described with reference to FIG.
Here, the drawings are schematic, and the relationship between thickness and planar dimensions, the thickness ratio of each layer, etc. differ from the actual ones. Furthermore, the embodiments shown below are examples of configurations for embodying the technical idea of the present invention, and the technical idea of the present invention does not specify the materials, shapes, structures, etc. of the components as described below. The technical idea of the present invention can be modified in various ways within the technical scope defined by the claims.

(Decorative sheet 10 according to embodiment 1)
In FIG. 1, reference numeral 10 denotes a decorative sheet, and although not shown, the decorative sheet 10 is used for, for example, entrance doors and exteriors.
The decorative sheet 10 is then adhered to a metal substrate 20, such as an entrance door or an exterior, to produce a decorative panel 30.

(Decorative sheet 10)
As shown in FIG. 1, the decorative sheet 10 is composed mainly of a transparent base layer 11, and on the back side thereof, (1) a printed pattern layer 12, (2) a colored layer 13, and (3) a primer layer 14 are formed in this order.
On the front surface side of the transparent raw layer 11, a surface protective layer 15 (4) is formed.
The transparent film layer 11 and the items (1) to (4) will be described later.
The configuration of the decorative sheet 10 is not limited to (1) to (4) in addition to the transparent original layer 11, and an embossed portion 16 located on the surface protective layer 15 side may be formed.

(Base material part 20)
The base material 20 is made of, for example, aluminum.
Although aluminum is used as the base material 20, the base material is not limited to aluminum and may be made of metal such as steel plate or stainless steel.
As shown in FIG. 1, the base material portion 20 is composed of a base material 21 at its core, and an adhesive layer 22 formed by applying an adhesive to the surface side of the base material 21.

(Regarding the point that "it does not have a laminate layer made of other films")
Neither the front side nor the back side of the transparent raw fabric layer 11 has a laminate layer made of another film.
That is, it basically means a single-layer film with the transparent raw fabric layer 11 at the center.
Here, the "surface side" of "on both the front and back sides of the transparent raw fabric layer 11" means the front side of the surface protective layer 15, or between the transparent raw fabric layer 11 and the surface protective layer 15. "Other films" means that there is no film other than the surface protective layer 15.
Moreover, the "reverse side" means the reverse side of the primer layer 14, or between the transparent base layer 11 and the primer layer 14. The "other films" means that there is no film other than the printed pattern layer 12, the colored layer 13, and the primer layer 14.

The "laminate layer made of another film" refers to a "transparent olefin resin layer" (not shown) as described in Comparative Example 1 below, and the "transparent olefin resin layer" is also referred to as the "laminate layer" below. Although the "transparent olefin resin layer" is exemplified as the "laminate layer", this also applies to coloring.
The "transparent olefin resin layer" (laminate layer) is a transparent homopolypropylene resin (Prime Polymer's "Prime PP") to which 0.5 parts by mass of a benzotriazole-based ultraviolet absorber (BASF Japan Ltd.'s "Tinuvin 326") and 0.5 parts by mass of a light stabilizer (BASF Japan Ltd.'s "Kimassorb 2020") have been added, and an adhesive resin (Mitsui Chemicals, Inc.'s "Admer SE800") to which functional groups have been imparted by modification with maleic anhydride. The transparent homopolypropylene resin is 80 μm thick, the adhesive resin is 10 μm thick, and the extrusion temperature is 230 ° C., so that the adhesive resin side is in contact with the adhesive layer.

Here, the term "laminate layer" refers to a "layer" formed by "lamination processing" or "lamination step" using a film.
"Lamination" refers to the process of covering printed material with a thin, transparent film made from materials such as polypropylene or polyethylene.
Here, "lamination" is roughly divided into "hot lamination" and "cold lamination".
"Hot lamination," also known as "pouch processing," is a method of sandwiching printed material between laminate film and bonding it with heat.
"Cold lamination" differs from "hot lamination" in that it does not use heat; that is, it is a method of laminating only one side of a printed material.
In other words, the decorative sheet 10 can be manufactured by a printing process alone, and does not require a lamination process.

(Transparent raw fabric layer 11)
The transparent base layer 11 is the base material of the decorative sheet 10 and is made of a transparent olefin resin.
The transparent raw fabric layer 11 is formed by melt-extruding a resin composition.
The transparent raw film layer 11 contains (1) an ultraviolet absorbing agent and (2) a light stabilizer.

(Ultraviolet absorber)
Here, the "ultraviolet absorbing agent" includes at least either a benzotriazole-based ultraviolet absorbing agent or a hydroxyphenyltriazine-based ultraviolet absorbing agent, and is present in an amount of 0.1 to 2 parts by mass per 100 parts by mass of the olefin resin.
Here, by setting the content of the ultraviolet absorbing agent to "0.1 parts by mass or more" per 100 parts by mass of the olefin resin, weather resistance can be improved.
By setting the content to "2 parts by mass or less", it is possible to prevent the surface from becoming cloudy due to bleeding out of the ultraviolet absorbing agent over time, and to improve the adhesion of the surface protective layer 15.
In Example 1 described later, 0.5 parts by mass of a benzotriazole-based ultraviolet absorber ("Tinuvin 326" manufactured by BASF Japan Ltd.) was added.
In Example 2 described later, the ultraviolet absorbing agent was changed to a hydroxyphenyltriazine ultraviolet absorbing agent ("Cyasorb 1164" manufactured by Sun Chemical Co., Ltd.) The hydroxyphenyltriazine ultraviolet absorbing agent is also called a "triazine-based" ultraviolet absorbing agent.

(Benzotriazole-based UV absorber)
Examples of the "benzotriazole-based" ultraviolet absorbers include 2-(2-hydroxy-5-t-butylphenyl)-2H-benzotriazole, 2-(5-methyl-2-hydroxyphenyl)benzotriazole, 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole, 2-(3,5-di-t-butyl-2-hydroxyphenyl)benzotriazole, 2-(3-t-butyl-5-methyl-2-hydroxyphenyl)-5-chlorobenzotriazole, 2-(3,5-di-t-butyl-2-hydroxyphenyl)-5-chlorobenzotriazole, 2-(3,5-di-t-amyl-2-hydroxyphenyl)benzotriazole, 2-(2'-hydroxy-5'-t-octylphenyl)benzotriazole, and mixtures, modified products, polymers, and derivatives thereof.

(Triazine-based UV absorber)
Examples of the "triazine-based" ultraviolet absorbers include 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-[(hexyl)oxy]-phenol, 2-[4-[(2-hydroxy-3-dodecyloxypropyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2-[4-[(2-hydroxy-3-tridecyloxypropyl)oxy]-2-hydroxyphenyl]-4,6-bis(2,4-dimethylphenyl)-1,3,5-triazine, 2,4-bis(2,4-dimethylphenyl)-6-(2-hydroxy-4-iso-octyloxyphenyl)-s-triazine, and mixtures, modified products, polymers, and derivatives thereof.

(Light stabilizer)
In Example 1 described later, 0.5 parts by mass of a light stabilizer ("Chimasorb 2020" manufactured by BASF Japan Ltd.) was added.
A resin composition containing 100 parts by mass of transparent homopolypropylene resin (Prime PP manufactured by Prime Polymer Co., Ltd.), 0.5 parts by mass of a light stabilizer (Kimasorb 2020), and 0.5 parts by mass of a benzotriazole-based ultraviolet absorber (Tinuvin 326) is melt-extruded to a thickness of 120 μm to obtain a transparent base layer 11.
In Example 2 described later, the light stabilizer was changed to "Tinuvin 850" manufactured by BASF Japan Ltd.
Examples of the light stabilizer that can be used include bis(1,2,2,6,6-pentamethyl-4-piperidyl)[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]butyl malonate, bis(1,2,2,6,6-pentamethyl-4-piperidinyl)sebacate, methyl(1,2,2,6,6-pentamethyl-4-poperidinyl)sebacate, decanedioic acid bis(2,2,6,6-tetramethyl-1(octyloxy)-4-piperidinyl)ester, and mixtures, modified products, polymers, and derivatives thereof.

(Printed pattern layer 12)
The printed pattern layer 12 decorates the decorative sheet 10, is located on the back side of the transparent base layer 11, and is a layer on which a pattern is printed.
The printed pattern layer 12 can be seen from the front surface side of the decorative sheet 10 through the transparent base layer 11 and the transparent or semi-transparent surface protective layer 15 .
Here, the type of pattern is not particularly limited, and for example, wood grain patterns, stone patterns, fabric patterns, abstract patterns, geometric figures, letters, symbols, etc. may be formed alone or in combination of two or more types.

The printed pattern layer 12 contains at least any one of urethane resins selected from polyester polyol, polycaprolactone polyol, polyalkylene glycol, acrylic polyol, and polyisocyanate as a binder resin. This is common to the printed pattern layer 12, the colored layer 13, and the primer layer 14, improving the adhesion of each layer.
In Example 1 described later, a pattern is printed on the back side of the transparent raw fabric layer 11 using a gravure printing method with a urethane resin made of polyester polyol to provide a printed pattern layer 12 .
In Example 3 described later, the resin is changed to a "urethane resin" made of an "acrylic polyol."
Although gravure printing has been exemplified as the printing method, the printing method is not limited to this, and ordinary printing methods such as offset printing, screen printing, flexographic printing, and ink jet printing may also be used.
On the other hand, the printed image layer 12 is, for example, monochromatic.
Although the print design layer 12 is illustrated as being monochromatic, the present invention is not limited to this and may be multicolored.

(Colored layer 13)
The colored layer 13 is intended to impart concealment to the back surface of the decorative sheet 10, and is a colored layer located on the back surface of the printed design layer 12.
The colored layer 13 can be seen from the front surface of the decorative sheet 10 through the transparent base layer 11 and the light-transmitting surface protective layer 15 as a background for the printed pattern layer 12 .
The colored layer 13, like the printed design layer 12, contains at least any one of urethane resins selected from polyester polyol, polycaprolactone polyol, polyalkylene glycol, acrylic polyol, and polyisocyanate as a binder resin.
In Example 1 described later, a colored layer 13 is provided on the back side of the printed design layer 12 by printing with a urethane resin made of polyester polyol by gravure printing in the same manner as the printed design layer 12 .
In Example 3 described later, the resin is changed to a "urethane resin" made of an "acrylic polyol."
The colored layer 13 is, for example, transparent or semi-transparent.
Although the colored layer 13 is exemplified as being transparent or semi-transparent, the present invention is not limited thereto and may be any layer that has light-transmitting properties.

(Primer layer 14)
The primer layer 14 is located on the back surface of the colored layer 13 and is a layer that has been subjected to a base treatment when adhesion is performed.
The primer layer 14, like the printed pattern layer 12 and the colored layer 13, contains at least any one of urethane resins selected from polyester polyol, polycaprolactone polyol, polyalkylene glycol, acrylic polyol, and polyisocyanate as a binder resin.
In Example 1 described later, a urethane resin made of polyester polyol is applied to the back side of the colored layer 13 by gravure printing so that the solid content is 1 g/ ^m2 , in the same manner as the printed pattern layer 12 and the colored layer 13, to form a primer layer 14.
In Example 3 described later, the resin is changed to a "urethane resin" made of an "acrylic polyol."
On the other hand, a substrate 21 is adhered to the back surface side of the primer layer 14 via an adhesive layer 22 of a substrate portion 20 .

(Surface protective layer 15)
The surface protective layer 15 is located on the surface side of the transparent raw fabric layer 11 and is a layer that protects the surface of the transparent raw fabric layer 11 .
The surface protective layer 15 contains an ultraviolet absorbing agent and a light stabilizer, similar to the transparent raw fabric layer 11 .
The surface protective layer 15 also contains at least a hydroxyphenyltriazine-based ultraviolet absorber, and the amount of the hydroxyphenyltriazine-based ultraviolet absorber is 1 part by mass or more and 30 parts by mass or less per 100 parts by mass of the acrylic resin composition that forms the surface protective layer 15 .
By making the content "1 part by mass or more" relative to 100 parts by mass of the acrylic resin composition, weather resistance can be improved. Also, by making the content "30 parts by mass or less", it is possible to prevent surface clouding due to bleeding out of the ultraviolet absorbent over time and surface clouding when wiping off the solvent.

In Example 1 described later, 6 parts by weight of a light stabilizer ("Tinuvin 292" manufactured by BASF Japan Ltd.), 3 parts by weight of a hydroxyphenyl triazine-based ultraviolet absorber ("Tinuvin 400" manufactured by BASF Japan Ltd.), and 3 parts by weight of a similar agent (Tinuvin 479 manufactured by BASF Japan Ltd.) are added to 100 parts by weight of an acrylic polyol resin on the surface side of the transparent raw fabric layer 11, and further, ethyl acetate is added as a solvent component to adjust the solid content to 20 parts by weight. The coating liquid is applied to a thickness of 9 μm after the solvent evaporates to form a surface protective layer 15.

(Gloss/matt coat)
The surface side of the surface protection layer 15 may be provided with a gloss/matte coating or an embossed portion 16 may be formed.
Gloss/matt refers to the visual expression of high and low gloss. Currently, printing and coating are carried out in two processes, but in the future, if an additional printing unit is added to the printing press, it will be possible to carry out the process in one process.
That is, while the "lamination layer" requires an additional lamination process, the "gloss/matt coat" can be integrated into the printing process, i.e., one process can be integrated into the line.
(Embossed portion 16)
The embossed portion 16 is located on the surface side of the surface protection layer 15 and is formed in a concave shape.
The embossed portion 16 may be, for example, made to match the pattern of the printed pattern layer 12. By making the embossed portion 16 match the pattern of the printed pattern layer 12, the design can be improved.

(Method of manufacturing the decorative sheet 10)
The decorative sheet 10 has the above-mentioned configuration, and its manufacturing method includes the following steps.
(1) First Step In the first step, a resin composition obtained by adding a light stabilizer and a benzotriazole-based ultraviolet absorber to a transparent homopolypropylene resin is melt-extruded to form a transparent raw fabric layer 11 .
(2) Second Step In the second step, a pattern is printed on the back side of the transparent raw fabric layer 11 by gravure printing using a urethane resin made of polyester polyol to form a printed pattern layer 12.

(3) Third Step In the third step, a urethane resin made of polyester polyol is printed on the back side of the printed design layer 12 in the same manner as the printed design layer 12, to form a colored layer 13.
(4) Fourth Step In the fourth step, a urethane resin made of polyester polyol is applied to the back side of the colored layer 13 by gravure printing, in the same manner as the printed pattern layer 12 and the colored layer 13, to form a primer layer 14.

(5) Fifth Step In the fifth step, a surface protective layer 15 is formed on the front side of the transparent raw layer 11 by adding a light stabilizer and a hydroxyphenyltriazine-based ultraviolet absorbing agent to an acrylic polyol resin.
A base solution to which ethyl acetate solvent has been added for adjusting the solid content and a hexamethylene diisocyanate type hardener solution to which ethyl acetate solvent has been added for adjusting the solid content are mixed, and a coating liquid to which ethyl acetate has been added as a solvent component is then applied to form a surface protective layer 15, thereby producing the decorative sheet 10.
(Method of manufacturing the decorative board 30)
The decorative board 30 has the above-mentioned configuration, and is produced by adhering the primer layer 14 of the decorative sheet 10 to the front surface side of the substrate 21 via the adhesive layer 22 .

(First characteristic of the embodiment)
A first characteristic feature of the decorative sheet 10 in the embodiment is that a printed pattern layer 12 having a pattern printed thereon, a colored layer 13, and a primer layer 14 are formed in that order on the back side of a transparent raw fabric layer 11 made of a transparent olefin resin, a surface protective layer 15 is formed on the front side of the transparent raw fabric layer 11, a surface protective layer 15 is formed on the front side of the transparent raw fabric layer 11, an ultraviolet absorber and a light stabilizer are added to the transparent raw fabric layer 11 and the surface protective layer 15, and neither the front side nor the back side of the transparent raw fabric layer 11 has a laminate layer made of another film.

(Effect of the first characteristic point)
According to the first characteristic, the production can be carried out in-line in one process, and peeling between sheet layers and whitening of the surface can be prevented.
Furthermore, according to the first characteristic, by providing a gloss/matte coating on the surface protective layer 15 as necessary, there is an advantage that the design is improved and the manufacturing cost can be reduced.

(Second characteristic of the embodiment)
A second feature of the decorative sheet 10 according to the embodiment is that the transparent raw fabric layer 11 contains at least either a benzotriazole-based ultraviolet absorber or a hydroxyphenyltriazine-based ultraviolet absorber, and the amount of either ultraviolet absorber in the transparent raw fabric layer 11 is 0.1 parts by mass or more and 2 parts by mass or less per 100 parts by mass of the olefin resin.

(Effect of the second characteristic point)
According to the second characteristic, by adding a light stabilizer, at least either a benzotriazole-based ultraviolet absorbing agent or a hydroxyphenyltriazine-based ultraviolet absorbing agent, to the transparent raw film layer 11, the weather resistance can be improved.
According to the second characteristic, by adding an ultraviolet absorber to the transparent raw fabric layer 11 in an amount of 0.1 parts by mass or more per 100 parts by mass of olefin resin, weather resistance can be improved, and by adding 2 parts by mass or less, surface clouding due to bleeding out of the ultraviolet absorber over time can be prevented and adhesion of the surface protective layer 15 can be improved.

(Third characteristic of the embodiment)
A third feature of the decorative sheet 10 according to the embodiment is that the surface protective layer 15 contains at least a hydroxyphenyltriazine-based ultraviolet absorber, and the hydroxyphenyltriazine-based ultraviolet absorber is contained in an amount of 1 part by mass or more and 30 parts by mass or less per 100 parts by mass of the acrylic resin composition that forms the surface protective layer 15.
(Effect of the third characteristic point)
According to the third characteristic point, by making the amount of the ultraviolet absorber 1 part by mass or more per 100 parts by mass of the acrylic resin composition, it is possible to improve weather resistance, and by making the amount of the ultraviolet absorber 30 parts by mass or less, it is possible to prevent surface clouding due to bleed-out of the ultraviolet absorber over time and surface clouding when wiping off the solvent.

(Fourth feature of the embodiment)
A fourth characteristic feature of the decorative sheet 10 according to the embodiment is that the printed pattern layer 12, the colored layer 13 and the primer layer 14 contain at least one urethane resin selected from the group consisting of polyester polyol, polycaprolactone polyol, polyalkylene glycol, acrylic polyol and polyisocyanate as a binder resin.
(Effect of the fourth characteristic point)
According to the fourth feature, the printed pattern layer 12, the colored layer 13, and the primer layer 14 contain at least any one of urethane resins selected from polyester polyol, polycaprolactone polyol, polyalkylene glycol, acrylic polyol, and polyisocyanate as a binder resin, thereby improving the adhesion of each layer.

(Fifth feature of the embodiment)
A fifth feature of the decorative sheet 10 according to this embodiment is that an embossed portion 16 is formed on the surface side of the surface protective layer 15 .
(Effect of the fifth characteristic point)
According to the fifth feature, the embossed portion 16 can improve the texture of the decorative sheet 10 and improve the design.

(Sixth feature of the embodiment)
A sixth characteristic feature of the decorative sheet 10 according to this embodiment is that the printed design layer 12 is monochromatic.
(Effect of the sixth characteristic point)
According to the sixth feature, by making the print pattern layer 12 monochromatic, it is possible to give a chic and calm impression.

(Seventh characteristic of the embodiment)
A seventh feature of the decorative sheet 10 according to this embodiment is that the colored layer 13 is transparent or translucent.
(Effect of the seventh characteristic point)
According to the seventh characteristic, by making the colored layer 13 transparent or translucent, the texture and pattern of the surface of the substrate 21 adhered to the decorative sheet 10 can be reflected on the surface side of the decorative sheet 10 through the colored layer 13.

(Eighth characteristic of the embodiment)
An eighth feature of the decorative board 30 according to the embodiment is that a substrate 21 is adhered to the side of the decorative sheet 10 facing the primer layer 14 .
(Effect of the eighth characteristic point)
According to the eighth characteristic, it is possible to provide a decorative board 30 having a decorative sheet 10 that can reduce manufacturing costs and improve weather resistance.

The decorative sheet according to the present invention will be described below with reference to Examples 1 to 3 and Comparative Examples 1 to 6. Note that the present invention is not limited to the following Examples 1 to 3.
Example 1
The main configuration of the first embodiment is as shown in Table 1 below.
In addition, in Table 1 below, in addition to the configuration of Example 1, the evaluation results, and Example 2 and the configuration and evaluation results of Example 2 are also shown.

The decorative board 30 of the first embodiment is produced as follows.
In Example 1, first, a resin composition containing 100 parts by mass of a transparent homopolypropylene resin (Prime PP manufactured by Prime Polymer Co., Ltd.), 0.5 parts by mass of a light stabilizer (Chimasorb 2020 manufactured by BASF Japan Ltd.), and 0.5 parts by mass of a benzotriazole-based ultraviolet absorber (Tinuvin 326 manufactured by BASF Japan Ltd.) was melt-extruded to a thickness of 120 μm to obtain a transparent raw fabric layer 11.
Secondly, a pattern was printed on the back side of the transparent raw fabric layer 11 using a gravure printing method with a urethane resin made of polyester polyol to form a printed pattern layer 12, and then a colored layer 13 was formed using a urethane resin made of polyester polyol in the same manner.
Thirdly, a urethane resin made of polyester polyol was applied by gravure printing so that the solid content was 1 g/m ² to form a primer layer 14 .

Fourth, as the surface protective layer 15, 6 parts by mass of a light stabilizer ("Tinuvin 292" manufactured by BASF Japan Ltd.), 3 parts by mass of a hydroxyphenyltriazine-based ultraviolet absorber ("Tinuvin 400" manufactured by BASF Japan Ltd.), and 3 parts by mass of a hydroxyphenyltriazine-based ultraviolet absorber ("Tinuvin 479" manufactured by BASF Japan Ltd.) are added per 100 parts by mass of the acrylic polyol resin.
A base solution with a solid content of 33 parts by mass, to which ethyl acetate solvent has been added to adjust the solid content, and a hexamethylene diisocyanate-type hardener solution with a solid content of 75 parts by mass, to which ethyl acetate solvent has been added to adjust the solid content, are mixed so that the ratio of the base solution to the hardener solution is 10:1 (the ratio of the number of hydroxyl groups in the base solution to the number of isocyanate groups in the hardener solution is about 1:2).
Furthermore, a coating liquid in which ethyl acetate has been added as a solvent component to adjust the solid content to 20 parts by mass is applied so that the thickness after solvent evaporation is 9 μm, forming a surface protective layer 15 and obtaining the decorative sheet 10.
Fifth, a urethane adhesive was applied to the back surface of the decorative sheet 10 to a thickness of 50 μm, which was then attached to the aluminum substrate 20 and cured for 48 hours to produce the decorative board 30 of Example 1.

Example 2
Example 2 was the same as Example 1, except that the light stabilizer in the transparent raw fabric layer 11 was changed to "Tinuvin 850" manufactured by BASF Japan Ltd., and the UV absorber was changed to "Cyasorb 1164" manufactured by Sun Chemical Co., Ltd., which is a hydroxyphenyltriazine-based UV absorber. A decorative panel 30 of Example 2 was produced in the same manner as Example 1.

Example 3
Example 3 was the same as Example 2, except that the printed pattern layer 12, the colored layer 13, and the primer layer 14 were changed to "urethane resin" made of "acrylic polyol," and a decorative board 30 of Example 3 was produced.

(Comparative Example 1)
The main configuration of Comparative Example 1 is as shown in Table 2 below.
In addition, in Table 2 below, in addition to the configuration of Comparative Example 1, the evaluation results, and the configurations and evaluation results of Comparative Example 2 and Comparative Example 2 are also shown.

In Comparative Example 1, first, although not shown in the figure, a 70 μm thick polypropylene film ("OW" manufactured by RIKEN TECHNOS CORPORATION) containing added titanium oxide and calcium carbonate was subjected to corona treatment as a colored base layer, and a wood grain pattern was gravure printed on the front side of the film using gravure ink ("LAMISTAR" manufactured by TOYO INK Mfg. Co., Ltd.) to provide a printed design layer.
At this time, the average thickness of the ink coating was measured using a thickness meter and found to be 2 μm.
On the printed pattern layer, a two-component curing polyurethane adhesive ("Takelac" or "Takenate" manufactured by Mitsui Chemicals, Inc.) was applied as an adhesive layer to a thickness of 1 μm after drying.

Secondly, although not shown, a transparent homopolypropylene resin (Prime PP manufactured by Prime Polymer Co., Ltd.) to which 0.5 parts by mass of a benzotriazole-based ultraviolet absorber (Tinuvin 326 manufactured by BASF Japan Ltd.) and 0.5 parts by mass of a light stabilizer (Chimasorb 2020 manufactured by BASF Japan Ltd.) have been added, and an adhesive resin (Admer SE800 manufactured by Mitsui Chemicals Inc.) to which functional groups have been imparted by modification with maleic anhydride was laminated by a co-extrusion lamination method with the adhesive resin side in contact with the adhesive layer, with the transparent homopolypropylene resin having a thickness of 80 μm, the adhesive resin having a thickness of 10 μm, and an extrusion temperature of 230° C. to obtain a transparent olefin resin layer.

Thirdly, as a surface protective layer, 6 parts by mass of a light stabilizer ("Tinuvin 292" manufactured by BASF Japan Ltd.), 3 parts by mass of a hydroxyphenyltriazine-based ultraviolet absorber ("Tinuvin 400" manufactured by BASF Japan Ltd.), and 3 parts by mass of a hydroxyphenyltriazine-based ultraviolet absorber ("Tinuvin 479" manufactured by BASF Japan Ltd.) are added per 100 parts by mass of the acrylic polyol resin.
A base solution with 33 parts by mass of solid content with ethyl acetate solvent added for solid content adjustment and a hexamethylene diisocyanate type hardener solution with 75 parts by mass of solid content with ethyl acetate solvent added for solid content adjustment are prepared. They are mixed so that the ratio of the base solution to the hardener solution is 10:1 (the ratio of the number of hydroxyl groups in the base solution to the number of isocyanate groups in the hardener solution is about 1:2).
Furthermore, ethyl acetate is added as a solvent component to adjust the solid content to 20 parts by mass, and the coating liquid is applied to a thickness of 9 μm after evaporation of the solvent to form a surface protective layer, thereby obtaining a decorative sheet.
Fourth, an aluminum substrate was attached to the rear surface of the decorative sheet to prepare a decorative board of Comparative Example 1.

<Comparative Example 2>
Comparative Example 2 was the same as Example 1 except that the amount of hydroxyphenyltriazine-based ultraviolet absorbers ("Tinuvin 400" and "Tinuvin 479") added was changed to 0.4 parts by mass each, and a decorative board for Comparative Example 2 was prepared.
<Comparative Example 3>
Comparative Example 3 was the same as Example 1, except that the amount of ultraviolet absorber ("Tinuvin 400" and "Tinuvin 479") added to the surface protective layer was changed to 16 parts by mass each, and a decorative panel for Comparative Example 3 was prepared.

<Comparative Example 4>
The main configuration of Comparative Example 4 is as shown in Table 3 below.
In addition, in Table 3 below, in addition to the configuration of Comparative Example 4, the evaluation results, and the configurations and evaluation results of Comparative Examples 5 and 6 are also shown.

Comparative Example 4 was the same as Example 1, except that the amount of ultraviolet absorber ("Tinuvin 326" and "Kimasorb 2020") added to the transparent base layer was changed to 0.04 parts by mass each, and a decorative panel for Comparative Example 4 was prepared.
<Comparative Example 5>
Comparative Example 5 was the same as Example 1, except that the amount of ultraviolet absorber ("Tinuvin 326" and "Kimasorb 2020") added to the transparent base layer was changed to 1.5 parts by mass each, and a decorative panel for Comparative Example 5 was produced.
<Comparative Example 6>
Comparative Example 6 was similar to Example 1 except that the printed pattern layer, colored layer, and primer layer were changed to "vinyl chloride-vinyl acetate resin," and a decorative board of Comparative Example 6 was produced.

(Evaluation Method)
The evaluation methods are two types: (1) weather resistance and (2) solvent resistance.
(1) Weather Resistance Weather resistance was performed as follows.
(a) Testing machine: Daipla Metal Weather (Model: KU-R5DCI-A, manufactured by Daipla Wintes Co., Ltd.)
(b) Test conditions: 1 cycle=Light (illuminance 70 mW/cm ² , temperature 63° C., humidity 50% RH) 20 hours + Dew (temperature 30° C., humidity 95% RH) 4 hours (30-second shower before and after) cycle test.
(2) Solvent Resistance Solvent resistance was evaluated by immersing a nonwoven fabric in ethyl acetate and running it back and forth over the surface of the decorative material 20 times, and then observing the surface condition.

(Evaluation Criteria)
Weather resistance was evaluated in terms of (1) change in appearance and (2) peeling.
(1) Change in Appearance When the appearance changed to discoloration or cloudiness, the sample was rated as “failed” and otherwise as “passed.”
(2) Peeling Regarding peeling, when interlayer peeling occurred in the sheet, it was rated as "failed", and otherwise it was rated as "passed".
Solvent resistance was evaluated by immersing a nonwoven fabric in ethyl acetate and running it back and forth over the surface of the decorative material 20 times, and then observing the surface condition. If the surface turned white, it was rated "failed" and otherwise it was rated "passed."

(Evaluation Results)
The evaluation results are shown in Tables 1 to 3 above.

(Examples 1 to 3 and Comparative Examples 1 to 6)
Among Examples 1 to 3 and Comparative Examples 1 to 6, Examples 1 to 3 are "passed" in all evaluation items.
In contrast, Comparative Examples 1 to 6 had a "fail" in one or more of the evaluation items.

(Appearance change due to weather resistance)
Regarding the change in appearance due to weather resistance, among Comparative Examples 1 to 6, Comparative Examples 2, 4 and 5 were "failed."
The reason for the "fail" of Comparative Example 2 (due to peeling) is presumably because the amount of hydroxyphenyltriazine-based ultraviolet absorbers (Tinuvin 400, Tinuvin 479) was too small, at 0.4 parts by mass each (0.8 parts by mass in total).
The reason for the "fail" of Comparative Example 4 (due to peeling) is presumably that the amount of the benzotriazole-based ultraviolet absorber (Tinuvin 326, Kimasove 2020) was too small, at 0.04 parts by mass each (total 0.08 parts by mass). Peeling occurred because the absolute amount of the ultraviolet absorber contained in the transparent raw fabric layer was small.
The reason for the "fail" (surface whitening) of Comparative Example 5 is presumably because the amounts of ultraviolet absorbers ("Tinuvin 326" and "Kimasorb 2020") added were too high, at 1.5 parts by mass each (total 3.0 parts by mass).

(About weather resistance peeling)
Regarding weather resistance peeling, among Comparative Examples 1 to 6, Comparative Examples 1, 2, 4, and 6 were "failed."
The reason for the "fail" of Comparative Example 1 (peel time 552 hours) is presumably due to the "co-extrusion lamination method."
The reason for the "fail" of Comparative Example 2 (peel time 216 hours) is presumably because the amount of hydroxyphenyltriazine-based ultraviolet absorbers (Tinuvin 400, Tinuvin 479) was too small, at 0.4 parts by mass each (total 0.8 parts by mass). In the case of Comparative Example 2, the absolute amount of ultraviolet absorber was small, so the durability of the surface protective layer itself and the pattern ink layer below the surface protective layer were significantly damaged, causing peeling.
The reason for the "fail" of Comparative Example 4 (peel time 216 hours) is presumably that the amount of benzotriazole-based ultraviolet absorbers (Tinuvin 326, Chimassorb 2020) was too small, at 0.04 parts by mass each (total 0.08 parts by mass). Peeling occurred because the absolute amount of ultraviolet absorber contained in the transparent raw fabric layer was small.
The reason for the "fail" of Comparative Example 6 (peel time 120 hours) is presumably due to the change in the design layer, colored layer, and primer layer from "polyester urethane" to "vinyl chloride acetate resin."

(Solvent resistance)
Regarding the solvent resistance, among Comparative Examples 1 to 6, only Comparative Example 3 was "failed."
The reason for the "fail" (whitening of the surface) of Comparative Example 3 is presumably that too much additive was added to the surface protective layer, causing the additive to precipitate when the surface was rubbed with a solvent.

REFERENCE SIGNS LIST 10 Decorative sheet 11 Transparent base layer 12 Printed pattern layer 13 Colored layer 14 Primer layer 15 Surface protective layer 16 Embossed portion 20 Substrate portion 21 Substrate 22 Adhesive layer 30 Decorative plate

Claims (6)

On the back side of the transparent base layer made of transparent olefin resin, a printed pattern layer, a colored layer, and a primer layer are formed in that order.
A surface protective layer is formed on the surface side of the transparent base layer,
The transparent base layer and the surface protective layer contain an ultraviolet absorbing agent and a light stabilizer.
The transparent raw material layer does not have a laminate layer made of another film on either the front side or the back side thereof,
The surface protective layer contains two types of ultraviolet absorbents as hydroxyphenyltriazine-based ultraviolet absorbents,
A decorative sheet characterized in that the printed pattern layer, the colored layer and the primer layer contain a polyester-urethane resin or an acrylic-urethane resin as a binder resin . The transparent base layer contains at least one of a benzotriazole-based ultraviolet absorber and a hydroxyphenyltriazine-based ultraviolet absorber,
2. The decorative sheet according to claim 1, wherein the content of the ultraviolet absorbing agent in any one of said transparent base layers is 0.1 parts by mass or more and 2 parts by mass or less per 100 parts by mass of the olefin resin. The decorative sheet according to claim 1 or 2, characterized in that the hydroxyphenyltriazine-based ultraviolet absorber in the surface protective layer is 1 part by mass or more and 30 parts by mass or less per 100 parts by mass of the acrylic resin composition that forms the surface protective layer. 4. The decorative sheet according to claim 1, wherein the transparent base layer contains at least a hydroxyphenyltriazine-based ultraviolet absorbing agent. An embossed portion is formed on the surface side of the surface protection layer,
The printed image layer is monochrome,
5. The decorative sheet according to claim 1, wherein the colored layer is transparent or translucent. A decorative board using the decorative sheet according to any one of claims 1 to 5 , characterized in that a substrate is adhered to the primer layer side of the decorative sheet.