Decorative sheet and decorative board

Abstract

The present disclosure provides a decorative sheet that conforms to the "Blue Angel" German environmental label, is excellent in terms of flame retardancy and external appearance, and has sufficient scratch resistance and abrasion resistance. Specifically, the present disclosure provides a decorative sheet having at least a transparent resin layer on a substrate sheet, wherein the transparent resin layer has a first transparent resin layer and a second transparent resin layer in this order from the substrate sheet side, and the first transparent resin layer contains ammonium polyphosphate.

Description

Decorative sheets and decorative panels

[0001] This disclosure relates to decorative sheets and decorative panels.

[0002] Traditionally, decorative sheets have been laminated onto the surfaces of various articles to enhance their aesthetic appeal. For example, decorative panels used on the floors of buildings are typically made by laminating decorative sheets onto wood-based or resin-based boards.

[0003] To impart flame retardancy to decorative sheets, it is necessary to add flame retardants. Conventionally, halogen-based flame retardants, antimony-based flame retardants, metal hydroxide-based flame retardants, phosphinate metal salt-based flame retardants, and phosphate ester-based flame retardants have been widely known.

[0004] For example, the examples in Patent Document 1 describe a flame-retardant resin composition for building materials, which is obtained by blending melamine pyrophosphate and piperazine pyrophosphate, which are flame retardant components, with an ethylene-vinyl acetate copolymer resin composition.

[0005] Furthermore, Patent Document 2 describes a decorative sheet having at least one thermoplastic resin layer selected from the group consisting of a transparent resin layer, a base sheet, and a synthetic resin backer layer, wherein (1) at least one of the thermoplastic resin layers contains a phosphinate metal salt-based flame retardant, and (2) the transparent resin layer and the base sheet contain at least one selected from the group consisting of polyolefin resins and polyester resins.

[0006] Regarding flame retardants, due to environmental concerns, the German environmental label "Blue Angel" limits the use of flame retardants to ammonium polyphosphate, metal hydroxides, and expanded graphite (see "3.3.2 Flame Retardants" in Non-Patent Literature 1).

[0007] Japanese Patent Publication No. 2010-222402, International Publication No. 2020 / 196217

[0008] DE-UZ 120 Basic Award Criteria Edition February 2011 Version 12

[0009] When large amounts of metal hydroxide are used to achieve flame retardancy, poor compatibility with the resin during film formation on plastic films, etc., leads to problems such as the generation of foreign matter and uneven thickness during sheeting. Furthermore, the use of large amounts of metal hydroxide reduces the transparency of the plastic film, resulting in poor aesthetic appearance of decorative sheets. On the other hand, reducing the amount of metal hydroxide added to improve film formation results in poor flame retardancy.

[0010] Even when using expanded graphite, because expanded graphite has a black, flaky shape, there is a problem of not being able to obtain transparency in the plastic film, similar to the case with metal hydroxides, and there is also a problem of poor film formation during the deposition of the plastic film.

[0011] Ammonium polyphosphate (APP) forms char (also called residual char) during combustion, which inhibits combustion. However, because many APP particles are large, using APP in printing sheets results in surface foreign matter, leading to problems such as printing defects. Therefore, adding APP to the protective layer of decorative sheets is considered. However, if the layer with added APP is formed as the protective layer, the affinity between the resin and the APP particles can cause delamination at the interface between the resin and the APP particles when external stress such as scratching is applied, resulting in the whitening of the decorative sheet surface.

[0012] Furthermore, reducing the thickness of the resin layer to improve flame retardancy limits the embossed patterns that can be applied to the surface of the decorative sheet, resulting in inferior aesthetic design, as well as reduced abrasion and scratch resistance. Therefore, a balance between flame retardancy and physical properties is required. Moreover, while adding a large amount of flame retardant can provide some effect, there are limitations on the amount of flame retardant that can be added due to processability and aesthetic design considerations.

[0013] This disclosure is made in view of the above and aims to provide a decorative sheet that conforms to the German environmental label "Blue Angel," has excellent flame retardancy and appearance, and possesses sufficient scratch resistance and abrasion resistance.

[0014] The inventors conducted extensive research to achieve the above objective and discovered that it could be achieved using the decorative sheet described below.

[0015] This disclosure encompasses the subject matter set forth in the following sections: Section 1. A decorative sheet having at least a transparent resin layer on a base sheet, wherein the transparent resin layer comprises a first transparent resin layer and a second transparent resin layer from the base sheet side, and the first transparent resin layer contains ammonium polyphosphate.

[0016] The decorative sheet of this disclosure conforms to the German environmental label "Blue Angel," has excellent flame retardancy and aesthetic design, and possesses sufficient scratch and abrasion resistance. Furthermore, the decorative panel of this disclosure, having the decorative sheet of this disclosure on a base material, conforms to the German environmental label "Blue Angel," has excellent flame retardancy and aesthetic design, and possesses sufficient scratch and abrasion resistance.

[0017] This is a schematic diagram showing an example of the layer structure of the decorative sheet of this disclosure. This is a schematic diagram showing the layer structure of the decorative sheet manufactured in Example 1 of this disclosure. This is a schematic diagram showing the layer structure of the decorative panel manufactured in Example 1 of this disclosure.

[0018] Preferred embodiments of the decorative sheets and decorative panels of this disclosure will be described in detail below. The following descriptions of constituent elements may be based on representative embodiments and specific examples, but this disclosure is not limited to such embodiments.

[0019] In this disclosure, the expressions “contains” and “includes” include the concepts of “contains,” “includes,” “substantially consists of,” and “consistes of only.”

[0020] In the numerical ranges described in stages in this disclosure, the upper or lower limit of one stage of the numerical range can be arbitrarily combined with the upper or lower limit of another stage of the numerical range. Furthermore, in the numerical ranges described in this disclosure, the upper or lower limit of that numerical range may be replaced with values ​​shown in the examples or values ​​that can be uniquely derived from the examples.

[0021] In this disclosure, the phrase "any number A to any number B" means number A and a range greater than number A, and number B and a range less than number B.

[0022] In this disclosure, “A and / or B” means “either A or B” or “both A and B,” and more specifically, “A,” “B,” or “A and B.”

[0023] In this disclosure, "(meth)acrylic acid" means acrylic acid or methacrylic acid.

[0024] 1. Decorative Sheet The decorative sheet of this disclosure comprises the following (1) to (3): (1) A base sheet having at least a transparent resin layer. (2) The transparent resin layer having a first transparent resin layer and a second transparent resin layer from the base sheet side. (3) The first transparent resin layer contains ammonium polyphosphate.

[0025] The decorative sheet of this disclosure, having the above-described features (1) to (3), conforms to the German environmental label "Blue Angel," has excellent flame retardancy and appearance, and possesses sufficient scratch resistance and abrasion resistance.

[0026] Figure 1 is a schematic diagram showing an example of the layer structure of the decorative sheet of this disclosure. In Figure 1, a first transparent resin layer 4 and a second transparent resin layer 5 are laminated in order on a base sheet 2.

[0027] The decorative sheet of this disclosure is not limited in its specific composition (layer structure) as long as it satisfies the prescribed requirements shown in (1) to (3) above.

[0028] As one embodiment of the present disclosure, the decorative sheet of the present disclosure may be composed of a laminate having, in order in the thickness direction, for example, a base sheet, a pattern layer, a first transparent resin layer, and a second transparent resin layer.

[0029] As one embodiment of the present disclosure, the decorative sheet of the present disclosure may be composed of a laminate having, in order in the thickness direction, for example, a base sheet, a pattern layer, a first transparent resin layer, a second transparent resin layer, and a surface protective layer.

[0030] As one embodiment of the present disclosure, the decorative sheet of the present disclosure may be composed of a laminate having at least, for example, a base sheet, a pattern layer, a transparent adhesive layer, a first transparent resin layer, a second transparent resin layer, a primer layer, and a surface protective layer in order in the thickness direction, and further having a back primer layer on the surface of the base sheet opposite to the surface protective layer side.

[0031] As a preferred embodiment of the present disclosure, the decorative sheet of the present disclosure has at least a transparent resin layer on a base sheet, the transparent resin layer has a transparent resin layer A, a first transparent resin layer and a second transparent resin layer from the base sheet side, the first transparent resin layer contains ammonium polyphosphate, and the transparent resin layer A has a resin layer containing a polyolefin resin. In the present disclosure, this preferred embodiment is also referred to as "Embodiment A".

[0032] In Embodiment A, the decorative sheet of the present disclosure may be composed of a laminate having at least, for example, a base sheet, a pattern layer, a transparent resin layer A, a first transparent resin layer, and a second transparent resin layer in order in the thickness direction.

[0033] In Embodiment A, the decorative sheet of the present disclosure may be composed of a laminate having at least, for example, a base sheet, a pattern layer, a transparent resin layer A, a first transparent resin layer, a second transparent resin layer, and a surface protective layer in order in the thickness direction.

[0034] In Embodiment A, the decorative sheet of the present disclosure has at least, for example, a base sheet, a pattern layer, a transparent adhesive layer, a transparent resin layer A, a first transparent resin layer, a second transparent resin layer, a primer layer, and a surface protective layer in order in the thickness direction, and may be composed of a laminate having a back primer layer on the surface of the base sheet opposite to the surface protective layer side. Hereinafter, each layer will be specifically described with a decorative sheet having such a layer configuration as a representative example.

[0035] In the present disclosure, the surface that is visible after the decorative sheet of the present disclosure is applied, that is, the direction in which the surface protective layer is laminated when viewed from the base sheet is referred to as "upper" or "front surface", and the direction in which the back primer layer is laminated when viewed from the base sheet is referred to as "lower" or "back surface". This relationship is the same for the decorative board of the present disclosure.

[0036] (Base Sheet) The base sheet generally has a transparent resin layer or the like sequentially laminated on its surface (front surface).

[0037] Various materials such as resin films, paper, and resin-impregnated paper can be exemplified as the base sheet. In the present disclosure, the base sheet preferably contains a thermoplastic resin, and more preferably consists of a thermoplastic resin. Examples of the thermoplastic resin include polyolefin resins, polyester resins, polyacrylic resins, polyamide resins, polyurethane resins, polystyrene resins, and polyvinyl chloride resins. These can be used alone or in combination of two or more kinds thereof.

[0038] In the present disclosure, from the viewpoint of allowing the decorative sheet to exhibit more excellent strength, the base sheet preferably contains at least one resin selected from the group consisting of polyolefin resins, polyester resins, and polyacrylic resins, more preferably contains a polyolefin resin and / or a polyester resin, and even more preferably contains a polyolefin resin.

[0039] As the polyolefin resin, a polyolefin thermoplastic resin can be used. Examples of polyolefin thermoplastic resins include polyethylene resin, ethylene-α-olefin copolymer resin, polypropylene resin, polymethylpentene resin, polybutene resin, ethylene-propylene copolymer resin, propylene-butene copolymer resin, ethylene-vinyl acetate copolymer resin, ethylene-vinyl acetate copolymer saponified resin, ethylene-(meth)acrylic acid copolymer resin, and ethylene-(meth)acrylic acid ester copolymer resin. These can be used individually or in combination of two or more. In this disclosure, from the viewpoint of the decorative sheet exhibiting superior strength, polypropylene resin is preferred as the polyolefin resin.

[0040] The thickness of the base sheet can be set as appropriate depending on the application and method of use of the final product, but is preferably 20 μm to 300 μm, and more preferably 50 μm to 250 μm.

[0041] The base sheet may be colored as needed. For example, the base sheet can be colored by adding a coloring agent (pigment or dye) to the thermoplastic resin. Examples of such coloring agents include inorganic pigments such as titanium dioxide, carbon black, and iron oxide; organic pigments such as phthalocyanine blue; and various dyes. These can be used individually or in combination of two or more. The amount of coloring agent added can also be appropriately set according to the desired color.

[0042] The base sheet may contain various additives such as fillers, matting agents, foaming agents, lubricants, antistatic agents, antioxidants, ultraviolet absorbers, and light stabilizers, to the extent that they do not affect the effects of the decorative sheets and decorative panels of this disclosure.

[0043] The base sheet may, if necessary, have its surface (front side) treated with a surface treatment such as corona discharge treatment, ozone treatment, or plasma treatment to improve the adhesion of the ink forming the pattern layer. A wide range of known methods commonly used in this field can be employed for the surface treatment. Furthermore, if necessary, the back side of the base sheet may be treated with corona discharge treatment, have a pattern layer (so-called back print) formed, or have a backside primer layer, etc., formed on it.

[0044] (Pattern Layer) The decorative sheet of this disclosure preferably has a pattern layer between the base sheet and the transparent resin layer. The pattern layer imparts a desired pattern (design) to the decorative sheet. The pattern layer is usually composed of a pattern ink layer and / or a solid ink layer.

[0045] Patterns in the patterned ink layer include, for example, wood grain, leather, stone, sand, tile, brick, fabric, geometric shapes, letters, symbols, abstract patterns, floral patterns, landscapes, characters, etc. The solid ink layer can be obtained by solid printing of colored inks.

[0046] The method for forming the pattern layer is not particularly limited. For example, it can be formed on the surface of a substrate sheet by a known printing method using an ink obtained by dissolving or dispersing a coloring agent together with a binder resin in a solvent or dispersion medium. As the ink, an aqueous composition can be used from the viewpoint of reducing volatile organic compounds (VOCs) in the decorative sheet.

[0047] Examples of colorants include inorganic pigments such as carbon black, titanium white, zinc oxide, red iron oxide, Prussian blue, and cadmium red; organic pigments such as azo pigments, lake pigments, anthraquinone pigments, quinacridone pigments, phthalocyanine pigments, isoindolinone pigments, and dioxazine pigments; metallic powder pigments such as aluminum powder and bronze powder; pearlescent pigments such as titanium dioxide-coated mica and bismuth oxide; fluorescent pigments; and luminescent pigments. These can be used individually or in combination of two or more. These colorants can be used together with fillers such as silica, extender pigments such as organic beads, neutralizing agents, surfactants, etc.

[0048] Examples of binder resins include polyester-based urethane resins, hydrophilic treated polyester-based urethane resins, polyester, polyacrylate, polyvinyl acetate, polybutadiene, polyvinyl chloride, chlorinated polypropylene, polyethylene, polystyrene, polystyrene-acrylate copolymer, rosin derivatives, alcohol adducts of styrene-maleic anhydride copolymers, and cellulose-based resins. These can be used individually or in combination of two or more.

[0049] More specifically, the binder resin can be water-soluble synthetic resins such as polyacrylamide resins, poly(meth)acrylic acid resins, polyethylene oxide resins, poly-N-vinylpyrrolidone resins, water-soluble polyester resins, water-soluble polyamide resins, water-soluble amino resins, and water-soluble phenolic resins; water-soluble natural polymers such as polynucleotides, polypeptides, and polysaccharides can also be used. In addition, for example, natural rubber, synthetic rubber, polyvinyl acetate resins, (meth)acrylic resins, polyvinyl chloride resins, polyurethane-polyacrylic resins, or modified versions thereof can also be used. The above binder resins can be used individually or in combination of two or more types.

[0050] Examples of solvents and dispersion media include petroleum-based organic solvents such as hexane, heptane, octane, toluene, xylene, ethylbenzene, cyclohexane, and methylcyclohexane; ester-based organic solvents such as ethyl acetate, butyl acetate, 2-methoxyethyl acetate, and 2-ethoxyethyl acetate; alcohol-based organic solvents such as methyl alcohol, ethyl alcohol, n-propyl alcohol, isopropyl alcohol, isobutyl alcohol, ethylene glycol, and propylene glycol; ketone-based organic solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ether-based organic solvents such as diethyl ether, dioxane, and tetrahydrofuran; chlorine-based organic solvents such as dichloromethane, carbon tetrachloride, trichloroethylene, and tetrachloroethylene; and inorganic solvents such as water. These solvents and dispersion media can be used individually or in combination of two or more.

[0051] Printing methods used to form the pattern layer include, for example, gravure printing, offset printing, screen printing, flexographic printing, electrostatic printing, and inkjet printing. Furthermore, when forming a solid pattern layer covering the entire surface, various coating methods can be used, such as roll coating, knife coating, air knife coating, die coating, lip coating, comma coating, kiss coating, flow coating, and dip coating.

[0052] In addition to the above, methods such as hand-drawing, suminagashi (marbling), photography, transfer, laser beam drawing, electron beam drawing, partial deposition of metals, etching, etc. may be used, or used in combination with other formation methods.

[0053] The thickness of the pattern layer can be set appropriately according to the product characteristics, but is preferably 0.1 μm or more and 15 μm or less.

[0054] (Transparent adhesive layer) In this disclosure, a transparent adhesive layer may be formed between the pattern layer and the first transparent resin layer in order to further improve the adhesion between the pattern layer and the first transparent resin layer.

[0055] In this disclosure, if the transparent resin layer has a transparent resin layer A, a first transparent resin layer, and a second transparent resin layer from the substrate sheet side, a transparent adhesive layer may be formed between the pattern layer and the transparent resin layer A from the viewpoint of further improving the adhesion between the pattern layer and the transparent resin layer A.

[0056] The transparent adhesive layer is not particularly limited as long as it is transparent, and may be colorless, colored, or translucent.

[0057] A transparent adhesive layer can be obtained by applying and drying an adhesive. As the adhesive, for example, known adhesives commonly used in this field can be used. Examples of such adhesives include thermoplastic resins such as polyamide resins, acrylic resins, and vinyl acetate resins; and thermosetting resins such as urethane resins. These can be used individually or in combination of two or more. Furthermore, two-component curing polyurethane resins or polyester resins using isocyanate as a curing agent can also be used as the adhesive.

[0058] In this disclosure, a urethane-based resin is preferred as the adhesive used to form the transparent adhesive layer.

[0059] The thickness of the transparent adhesive layer can be set appropriately according to the product characteristics, but is preferably 0.1 μm to 30 μm, and more preferably 1 μm to 20 μm.

[0060] (Transparent Resin Layer) In this disclosure, the transparent resin layer has a first transparent resin layer and a second transparent resin layer from the substrate sheet side. In this disclosure, the transparent resin layer may consist of two or more layers, each having a first transparent resin layer and a second transparent resin layer from the substrate sheet side. Both the first transparent resin layer and the second transparent resin layer are not particularly limited as long as they are transparent, and may be colorless transparent, colored transparent, or translucent.

[0061] In this disclosure, the first transparent resin layer contains ammonium polyphosphate as an essential component. The inclusion of ammonium polyphosphate in the first transparent resin layer allows the decorative sheets and decorative panels of this disclosure to conform to the German environmental label "Blue Angel".

[0062] In this disclosure, the thickness of the second transparent resin layer is preferably 100 μm to 140 μm. By setting it within this range, the decorative sheets and decorative panels of this disclosure have better flame retardancy and good scratch resistance.

[0063] In this disclosure, the ratio of the thickness of the first transparent resin layer to the thickness of the second transparent resin layer (thickness of the first transparent resin layer:thickness of the second transparent resin layer) may be 1:1 to 12:1, 1:1 to 11:1, 1:1 to 8:1, or 1:1 to 7:1, in order to improve the scratch resistance and abrasion resistance of the decorative sheet and decorative panel.

[0064] In this disclosure, the ammonium polyphosphate content is preferably 9.0% by mass or more and 16.0% by mass or less, based on 100% by mass of the total mass of the first transparent resin layer, in order to obtain superior flame retardancy and aesthetic design of the decorative sheet and decorative panel.

[0065] In this disclosure, the ammonium polyphosphate content is preferably 4.5% by mass or more and 9.6% by mass or less, based on 100% by mass of the total mass of the transparent resin layer, in order to obtain superior flame retardancy and aesthetic design of the decorative sheet and decorative panel.

[0066] In this disclosure, the ammonium polyphosphate content is more preferably 5.0% by mass or more and 9.4% by mass or less, based on 100% by mass of the total mass of the transparent resin layer, in order to further improve the flame retardancy and appearance of the decorative sheet and decorative panel.

[0067] In this disclosure, it is preferable that the first transparent resin layer contains ammonium polyphosphate and a thermoplastic resin, and the second transparent resin layer contains a thermoplastic resin. Examples of thermoplastic resins include polyolefin resins, polyester resins, polyacrylic resins, polyamide resins, polyurethane resins, polystyrene resins, and polyvinyl chloride resins, which can be used individually or in combination of two or more.

[0068] In this disclosure, from the viewpoint of the decorative sheet exhibiting superior strength, the first transparent resin layer and the second transparent resin layer preferably contain at least one resin selected from the group consisting of polyolefin resins, polyester resins, and polyacrylic resins, more preferably contain a polyolefin resin and / or a polyester resin, even more preferably contain a polyolefin resin, and particularly preferably contain a polypropylene resin.

[0069] In this disclosure, the ammonium polyphosphate content is preferably less than 1.0% by mass, more preferably 0.5% by mass or less, and even more preferably 0.1% by mass or less, based on 100% by mass of the total mass of the second transparent resin layer. In this disclosure, it is particularly preferable that the second transparent resin layer does not contain ammonium polyphosphate.

[0070] The first transparent resin layer, the second transparent resin layer, and transparent resin layer A may be colored as long as they are transparent. If the first transparent resin layer, the second transparent resin layer, and transparent resin layer A contain a thermoplastic resin, a coloring agent can be added to the thermoplastic resin. As the coloring agent, pigments or dyes used in the pattern layer can be used.

[0071] The first transparent resin layer, the second transparent resin layer, and transparent resin layer A may contain various additives such as fillers, matting agents, foaming agents, lubricants, antistatic agents, antioxidants, ultraviolet absorbers, light stabilizers, radical scavengers, and softening components (e.g., rubber), to the extent that they do not affect the effects of the decorative sheet and decorative panel of this disclosure.

[0072] The surface of the transparent resin layer may be subjected to surface treatments such as corona discharge treatment, ozone treatment, or plasma treatment, as needed. The surface treatment methods and conditions can be broadly based on known methods commonly used in this field.

[0073] A primer layer (a primer layer to facilitate the formation of a surface protective layer) may be formed on the surface of the transparent resin layer.

[0074] In Embodiment A, the transparent resin layer may consist of a transparent resin layer A, a first transparent resin layer, and a second transparent resin layer, from the base sheet side.

[0075] In Embodiment A, the ratio of the thickness of the first transparent resin layer to the thickness of the second transparent resin layer (thickness of the first transparent resin layer:thickness of the second transparent resin layer) may be 1:1 to 12:1, 1:1 to 11:1, 1:1 to 8:1, 1:1 to 7:1, 7:1 to 12:1, or 7:1 to 11:1.

[0076] In Embodiment A, the thickness of the transparent resin layer may be 200 μm or more and 280 μm or less.

[0077] In Embodiment A, the thickness of the transparent resin layer A may be 40 μm or more and 80 μm or more.

[0078] In Embodiment A, the transparent resin layer A is not particularly limited as long as it is transparent, and may be colorless transparent, colored transparent, or translucent.

[0079] In Embodiment A, the transparent resin layer A preferably has a resin layer containing a polypropylene resin, and more preferably has a resin layer containing a maleic acid-modified polypropylene resin.

[0080] In Embodiment A, the transparent resin layer A may be one layer, two layers, two or more layers, three layers, or three or more layers.

[0081] In Embodiment A, in order to provide superior flame retardancy and aesthetic design of the decorative sheet and decorative panel, the ammonium polyphosphate content in the first transparent resin layer may be 9.0% by mass or more and 16.0% by mass or less, 9.0% by mass or more and 14.0% by mass or less, or 9.0% by mass or more and 12.0% by mass or less, based on 100% by mass of the total mass of the first transparent resin layer.

[0082] In Embodiment A, in order to provide superior flame retardancy and aesthetic design of the decorative sheet and decorative panel, the ammonium polyphosphate content in the transparent resin layer may be 4.5% by mass or more and 9.6% by mass or less, 4.6% by mass or more and 9.0% by mass or less, 4.7% by mass or more and 8.0% by mass or less, or 4.8% by mass or more and 7.0% by mass or less, based on 100% by mass of the total mass of the transparent resin layer.

[0083] In Embodiment A, the ammonium polyphosphate content in the second transparent resin layer may be less than 1.0% by mass, 0.5% by mass or less, or 0.1% by mass or less, based on the total mass of the second transparent resin layer as 100% by mass. In Embodiment A, it is preferable that the second transparent resin layer does not contain ammonium polyphosphate.

[0084] In Embodiment A, the ammonium polyphosphate content in the transparent resin layer A may be less than 1.0% by mass, 0.5% by mass or less, or 0.1% by mass or less, based on the total mass of the transparent resin layer A as 100% by mass. In Embodiment A, it is preferable that the transparent resin layer A does not contain ammonium polyphosphate.

[0085] In Embodiment A, the base sheet, the first transparent resin layer, and the second transparent resin layer preferably all contain a thermoplastic resin, more preferably all contain a polyolefin resin, and even more preferably all contain a polypropylene resin.

[0086] (Primer layer) In this disclosure, a primer layer for the surface protection layer may be formed on the second transparent resin layer. In addition to improving the adhesion between the second transparent resin layer and the surface protection layer, the primer layer, in combination with the surface protection layer, can further improve the bendability and scratch resistance of the decorative sheet. The primer layer is not particularly limited as long as it is transparent, and may be colorless transparent, colored transparent, or translucent.

[0087] The primer layer can be formed by applying a known primer commonly used in this field to the surface of the second transparent resin layer. Examples of such primers include urethane resin primers made of acrylic-modified urethane resin (acrylic urethane resin), polycarbonate-based acrylic urethane resin, etc.; urethane-cellulose resin primers (for example, resins made by adding hexamethylene diisocyanate to a mixture of urethane and nitrate); and resin primers made of a block copolymer of acrylic and urethane.

[0088] In this disclosure, a urethane resin primer is preferred as the primer agent used to form the primer layer.

[0089] The primer agent may contain additives to the extent that they do not affect the effects of the decorative sheets and decorative panels of this disclosure. Examples of additives include weathering agents such as UV absorbers and light stabilizers; fillers such as silica, calcium carbonate, and clay; antioxidants; lubricants; and foaming agents. The amount of additives can be appropriately set according to the product characteristics.

[0090] The amount of primer to be applied (dry mass) is typically 0.1 g / m². ２ More than 100g / m ２ Preferably, 0.1 g / m ２ 50g / m or more ２ The following applies:

[0091] The thickness of the primer layer is not limited, but is preferably 0.5 μm to 12 μm, and more preferably 1 μm to 8 μm. Setting the thickness within this range, in combination with the surface protective layer, can further improve the bendability and scratch resistance of the decorative sheet. Furthermore, setting the thickness within this range makes it easier to incorporate additives such as weather-resistant agents, thus making it easier to impart weather resistance to the decorative sheet.

[0092] (Surface Protection Layer) The decorative sheet of this disclosure preferably has a surface protection layer on its outermost surface. Having a surface protection layer on the outermost surface, combined with the fact that the surface protection layer contains a curable resin, delays the generation of combustion gases due to the decomposition of the resin in the layer below the surface protection layer in the event of a fire, thereby suppressing the spread of fire and further improving flame retardancy.

[0093] The resin forming the surface protective layer is preferably a curable resin. More preferably a thermosetting resin and / or an ionizing radiation-curable resin. From the viewpoint of high surface hardness, productivity, etc., an ionizing radiation-curable resin is even more preferable for forming the surface protective layer. Furthermore, as the ionizing radiation-curable resin, an electron beam-curable resin is most preferred from the viewpoint of further improving the abrasion resistance and scratch resistance of the decorative sheet.

[0094] The surface protective layer is not particularly limited as long as it is transparent, and may be colorless, colored, or translucent.

[0095] Examples of thermosetting resins include unsaturated polyester resins, polyurethane resins (including two-component curing polyurethanes), epoxy resins, aminoalkyd resins, phenolic resins, urea resins, diallyl phthalate resins, melamine resins, guanamine resins, melamine-urea cocondensation resins, silicon resins, and polysiloxane resins. These can be used individually or in combination of two or more types.

[0096] In this disclosure, from the viewpoint of further improving the abrasion resistance and scratch resistance of the decorative sheet, the surface protective layer is preferably made of a cured product of an ionizing radiation-curable resin, more preferably made of a cured product of an electron beam-curable resin, and even more preferably made of a cured product of a urethane acrylate-based electron beam-curable resin.

[0097] The resin forming the surface protective layer can be supplemented with crosslinking agents, polymerization initiators, curing agents, polymerization accelerators, etc. For example, isocyanates and organic sulfonates can be added to unsaturated polyester resins and polyurethane resins as curing agents, organic amines can be added to epoxy resins, and peroxides such as methyl ethyl ketone peroxide and radical initiators such as azoisobutylnitrile can be added to unsaturated polyester resins.

[0098] One method for forming a surface protective layer with a thermosetting resin is to apply a solution of the thermosetting resin using a coating method such as roll coating or gravure coating, and then dry it. The amount of thermosetting resin solution applied (thickness after drying) is preferably 3 μm to 50 μm, more preferably 4 μm to 40 μm.

[0099] As ionizing radiation-curable resins, for example, transparent resins mainly composed of prepolymers (including oligomers) and / or monomers having radically polymerizable double bonds in their molecules that can be crosslinked by irradiation with ionizing radiation can be used. These prepolymers or monomers can be used individually or in combination. The curing reaction is usually a crosslinking curing reaction.

[0100] Examples of ionizing radiation-curable resins (preferably electron beam-curable resins) include acrylate resins such as urethane acrylate resin, polyester acrylate resin, and epoxy acrylate resin; silicon resins such as siloxane; polyester resins; epoxy resins, etc. Urethane acrylate resin is preferred as the ionizing radiation-curable resin (preferably electron beam-curable resin).

[0101] Examples of ionizing radiation include ultraviolet rays (near-ultraviolet rays, vacuum ultraviolet rays, etc.), X-rays, electron beams, and ion beams. Of the ionizing radiation, ultraviolet rays or electron beams are preferred, and electron beams are more preferred.

[0102] As ultraviolet light sources, light sources such as ultra-high pressure mercury lamps, high pressure mercury lamps, low pressure mercury lamps, carbon arc lamps, black light fluorescent lamps, and metal halide lamps can be used. The wavelength of the ultraviolet light is preferably between 190 nm and 380 nm.

[0103] As the electron source, for example, electron beam accelerators such as Cockcroftwald type, Van de Graft type, resonant transformer type, insulated core transformer type, linear type, Dynamitron type, and high-frequency type can be used. The acceleration voltage of the electron beam is preferably 100 keV to 1000 keV, and more preferably 100 keV to 300 keV. The irradiation dose of the electron beam is preferably 20 kGy to 150 kGy.

[0104] Ionizing radiation-curable resins can be sufficiently cured by irradiation with electron beams, but when curing by irradiation with ultraviolet light, it is preferable to add a photopolymerization initiator and / or a photosensitizer.

[0105] For resin systems having radically polymerizable unsaturated groups, at least one of the following photopolymerization initiators can be used: acetophenone compounds, benzophenone compounds, thioxanthone compounds, benzoin, benzoin methyl ether, Michler benzoyl benzoate, Michler ketone, diphenyl sulfide, dibenzyl disulfide, diethyl oxide, triphenylbiimidazole, isopropyl-N,N-dimethylaminobenzoate, etc. For resin systems having cationic polymerizable functional groups, at least one of the following can be used: aromatic diazonium salts, aromatic sulfonium salts, metallocene compounds, benzoin sulfonic acid esters, fryloxysulfoxonium diallylodosyl salts, etc.

[0106] The amount of photopolymerization initiator added is preferably 0.1 parts by mass or more and 10 parts by mass or less per 100 parts by mass of ionizing radiation-curable resin.

[0107] When forming a surface protective layer using an ionizing radiation-curable resin, for example, the ionizing radiation-curable resin solution can be applied by coating methods such as gravure coating or roll coating, and then the coated film can be irradiated with ionizing radiation to form the protective layer.

[0108] The thickness of the surface protective layer is preferably 3 μm to 45 μm, more preferably 4 μm to 35 μm, and even more preferably 5 μm to 30 μm. Setting the thickness within this range further improves the abrasion resistance of the decorative sheet and further suppresses warping and whitening of the decorative sheet. In the case of the decorative sheet of this disclosure, if the surface protective layer has an embossed shape, the thickness of the surface protective layer is measured at a location other than the embossed shape.

[0109] Various additives such as solvents, dyes, pigments and other colorants, inorganic fillers and other inorganic fillers, defoamers, leveling agents, and thixotropy-imparting agents may be added to the surface protective layer, to the extent that they do not affect the effects of the decorative sheets and decorative panels of this disclosure.

[0110] (Embossing) The decorative sheet of this disclosure may be embossed on the transparent resin layer and / or on the surface protective layer. The decorative sheet of this disclosure preferably has an embossed shape on the transparent resin layer side due to embossing. The decorative sheet of this disclosure preferably has an embossed shape on the surface protective layer side due to embossing.

[0111] Embossing is performed to impart a desired texture, such as a wood grain pattern, to the decorative sheet of this disclosure. For example, the texture is imparted by heating and softening the surface protective layer, then applying pressure and shaping it with an embossing plate having a desired shape of raised and recessed pattern, and finally cooling and fixing it. Embossing can be performed using a known sheet-fed or rotary embossing machine commonly used in this art. Examples of raised and recessed patterns for embossing include wood grain grooves, raised patterns (raised and recessed patterns of annual rings), hairline patterns, sandy patterns, and pear-skin patterns.

[0112] In this disclosure, the thickness of each layer of the decorative sheet is the value measured in a flat area where the embossed pattern described above is not formed.

[0113] If embossing is applied, ink may be filled into the embossed recesses by wiping, if necessary. For example, ink can be filled into the embossed recesses by scraping the surface with a doctor blade. As the ink to be filled (for example, wiping ink), a two-component curing type ink with a urethane resin binder can usually be used. In particular, by performing a wiping process on the wood grain grooves and irregularities, it is possible to express a design that is closer to the actual wood grain, thereby increasing the value of the product.

[0114] (Backside Primer Layer) In this disclosure, it is preferable to have a backside primer layer beneath (on the back side of) the base sheet. By providing a backside primer layer, adhesion between the base sheet and the decorative panel base material can be easily achieved.

[0115] The back surface primer layer can be formed by applying a known primer commonly used in this field to the back surface of the substrate sheet. Examples of such primers include acrylic-modified urethane resins (acrylic urethane resins), polycarbonate-based acrylic urethane resins, urethane-cellulose resins (for example, urethane resins obtained by adding hexamethylene diisocyanate to a mixture of urethane and nitrate), and urethane resins made from block copolymers of acrylic and urethane.

[0116] In this disclosure, a urethane resin primer is preferred as the primer agent used to form the back surface primer layer.

[0117] The primer may contain additives to the extent that they do not affect the effects of the decorative sheets and decorative panels of this disclosure. Examples of additives include weathering agents such as UV absorbers and light stabilizers; fillers such as silica, calcium carbonate, and clay; antioxidants; lubricants; and foaming agents. The amount of additives can be appropriately set according to the product characteristics.

[0118] The amount of primer to be applied (dry mass) is typically 0.1 g / m². ２ More than 100g / m ２ Preferably, 0.1 g / m ２ 50g / m or more２ The following applies:

[0119] The thickness of the primer layer on the back surface is preferably 0.01 μm or more and 10 μm or less, and more preferably 0.1 μm or more and 1 μm or less.

[0120] 2. Decorative Panel The decorative panel of this disclosure has a decorative sheet of this disclosure on a decorative panel substrate.

[0121] (Decorative Sheet) Details of the decorative sheet constituting the decorative panel of this disclosure are as described in "1. Decorative Sheet" above, unless otherwise specified.

[0122] (Decorative Panel Substrate) In this disclosure, the decorative panel substrate is preferably at least one selected from the group consisting of wood-based substrates, resin-based substrates, and metal-based substrates, with wood-based substrates being more preferred.

[0123] Examples of wood-based substrates include medium-density fiberboard (MDF), high-density fiberboard (HDF), particleboard, softwood plywood, hardwood plywood, fast-growing plywood, laminated timber, and cross-laminated timber (CLT). These can be used individually or in combination of two or more types. From the viewpoint of the decorative panel exhibiting superior strength, MDF is preferred as the wood-based substrate.

[0124] The thickness of the wood-based substrate is preferably 3.0 mm to 15.0 mm, and more preferably 4.0 mm to 10.0 mm.

[0125] Examples of resin-based substrates include thermoplastic resin sheets such as polyvinyl chloride resin sheets, polypropylene resin sheets, polyethylene resin sheets, acrylic resin sheets, and ABS resin polycarbonate sheets; thermosetting resin sheets such as phenolic resin sheets, urea resin sheets, unsaturated polyester resin sheets, polyurethane resin sheets, epoxy resin sheets, and melamine resin sheets; and so-called FRP sheets, which are composites obtained by impregnating and curing glass fiber nonwoven fabrics, cloth, paper, and other various fibrous substrates with resins such as phenolic resin, urea resin, unsaturated polyester resin, polyurethane resin, epoxy resin, melamine resin, and diallyl phthalate resin. These may be used individually or two or more of them may be laminated together.

[0126] Further, the resin-based substrate may contain an inorganic filler such as calcium carbonate, talc, silica, alumina, mica, or barium sulfate.

[0127] Examples of the metal-based substrate include an iron plate, a galvanized steel sheet, a polyvinyl chloride sol-coated steel sheet, an aluminum plate, and a copper plate. These may be used each alone, or two or more of these may be used by being laminated.

[0128] As a method for laminating the decorative sheet of the present disclosure on a decorative board substrate, for example, a lamination method may be mentioned in which an adhesive layer is formed on the front surface of the decorative board substrate, the decorative sheet of the present disclosure is laminated thereon, and pressure is applied with a pressure roller or the like.

[0129] Examples of the adhesive used to form the adhesive layer include a water-soluble emulsion adhesive, a polyester adhesive, an acrylic adhesive, and a urethane adhesive. One kind or a combination of two or more kinds of the adhesive may be used.

[0130] In the present disclosure, the adhesive used for forming the adhesive layer is preferably a water-soluble emulsion adhesive, and more preferably a two-component curable water-soluble emulsion adhesive. The two-component curable water-soluble emulsion adhesive is usually obtained by mixing a water-soluble emulsion adhesive and a curing agent.

[0131] Examples of the curing agent include an isocyanate compound, an epoxy compound, an aziridine compound, and a carbodiimide compound. These may be used each alone, or two or more of these may be used in combination. From the viewpoint of further improving adhesiveness and durability, an isocyanate compound is preferable as the curing agent.

[0132] The mass ratio of the water-soluble emulsion adhesive to the curing agent (mass of water-soluble emulsion adhesive : mass of curing agent) in the two-component curable water-soluble emulsion adhesive is preferably 100:0.5 to 100:8.0, and more preferably 100:1.0 to 100:4.0.

[0133] The coating amount (dry mass) of the adhesive is usually 0.1 g / m ２ or more and 200 g / m ２Preferably, 0.5 g / m ２ 150g / m or more ２ The following applies:

[0134] This disclosure encompasses the subject matter described in the following sections: Section 1. A decorative sheet having at least a transparent resin layer on a base sheet, wherein the transparent resin layer comprises a first transparent resin layer and a second transparent resin layer from the base sheet side, and the first transparent resin layer contains ammonium polyphosphate. Section 2. The decorative sheet according to Section 1, wherein the ratio of the thickness of the first transparent resin layer to the thickness of the second transparent resin layer (thickness of the first transparent resin layer:thickness of the second transparent resin layer) is 1:1 to 12:1. Section 3. The decorative sheet according to Section 1 or 2, wherein the ratio of the thickness of the first transparent resin layer to the thickness of the second transparent resin layer (thickness of the first transparent resin layer:thickness of the second transparent resin layer) is 1:1 to 8:1. Section 4. The decorative sheet according to any one of Sections 1 to 3, wherein the thickness of the transparent resin layer is 200 μm or more and 280 μm or less. Section 5. A decorative sheet according to any one of claims 1 to 3, wherein the transparent resin layer consists of three or more layers, from the base sheet side, having a first transparent resin layer and a second transparent resin layer, and the thickness of the transparent resin layer is 200 μm or more and 280 μm or less. Claim 6. A decorative sheet according to any one of claims 1 to 5, wherein the transparent resin layer has a transparent resin layer A, a first transparent resin layer and a second transparent resin layer, from the base sheet side, and the transparent resin layer A has a resin layer containing a polyolefin resin. Claim 7. A decorative sheet according to claim 6, wherein the polyolefin resin is a maleic acid-modified polypropylene resin. Claim 8. A decorative sheet according to any one of claims 1 to 7, wherein the ammonium polyphosphate content is 9.0% by mass or more and 16.0% by mass or less, with the total mass of the first transparent resin layer being 100% by mass. Claim 9. A decorative sheet according to any one of claims 1 to 8, wherein the ammonium polyphosphate content is 4.5% by mass or more and 9.6% by mass or less, based on 100% by mass of the total mass of the transparent resin layers. Claim 10. A decorative sheet according to any one of claims 1 to 9, wherein the base sheet, the first transparent resin layer, and the second transparent resin layer contain a thermoplastic resin. Claim 11. A decorative sheet according to any one of claims 1 to 10, wherein a pattern layer is provided between the base sheet and the transparent resin layer.Item 12. A decorative sheet according to any one of items 1 to 11, wherein the transparent resin layer side has an embossed shape. Item 13. A decorative sheet according to any one of items 1 to 12, wherein the outermost surface has a surface protective layer. Item 14. A decorative panel having a decorative sheet according to any one of items 1 to 13 on a decorative panel substrate. Item 15. A decorative panel according to item 14, wherein the decorative panel substrate is at least one selected from the group consisting of wood-based substrates, resin-based substrates, and metal-based substrates.

[0135] The present disclosure will be described in more detail below based on examples, but the present disclosure is not limited to the embodiments described herein.

[0136] (Example 1) <Manufacturing of decorative sheet> An opaque colored polypropylene film (60 μm thick) was prepared as a base sheet, and a urethane resin adhesive primer was applied to the back surface of the base sheet to form a back surface primer layer (2 μm thick). A pattern was printed on the other side (front surface) of the base sheet to form a pattern layer (5 μm thick). Furthermore, a urethane resin adhesive was applied to the pattern side (front surface) of the pattern layer to form a transparent adhesive layer (10 μm thick). Subsequently, a first transparent resin layer (140 μm thick) containing ammonium polyphosphate as a flame retardant and having polypropylene resin as the resin component was formed into a film on the transparent adhesive layer using an extrusion molding machine with a T-die, and laminated with a laminator. Next, a second transparent resin layer (100 μm thick), which does not contain a flame retardant and whose resin component is polypropylene resin, was laminated onto the first transparent resin layer by heat-seal lamination simultaneously with film formation using an extrusion molding machine equipped with a T-die.

[0137] The types and content of the flame retardant and resin components in the first transparent resin layer were as follows: • Flame retardant content (ammonium polyphosphate, "EXOLIT AP423" manufactured by Clariant Japan Co., Ltd.) per 100% of the total mass of the first transparent resin layer: 11.0% by mass • Polypropylene resin content per 100% of the total mass of the first transparent resin layer: 89.0% by mass

[0138] Next, corona discharge treatment was applied to the surface of the second transparent resin layer, and then a urethane-based resin primer was applied to the second transparent resin layer to form a primer layer (2 μm thick). Furthermore, a urethane acrylate-based electron beam curable resin was applied to the surface of the primer layer using a gravure coating method and dried. Then, an electron beam was irradiated using an electron irradiation device (manufactured by Energy Sciences Inc. (ESI)) under the conditions of an acceleration voltage of 165 keV and an irradiation dose of 30 kGy to form a surface protective layer (15 μm thick).

[0139] Next, the surface of the protective layer was heated with an infrared non-contact heater to soften the base sheet and the transparent resin layer. Immediately afterward, an embossed pattern was formed on the surface of the protective layer by hot-pressure embossing using an embossing plate with an oak pore pattern. The decorative sheet of Example 1 was manufactured by the above method (see Figure 2).

[0140] Figure 2 is a schematic diagram showing the layer structure of a decorative sheet manufactured in Example 1 of this disclosure. In Figure 2, a decorative sheet 1 is shown in which a pattern layer 7, a transparent adhesive layer 8, a first transparent resin layer 4, a second transparent resin layer 5, a primer layer 9, and a surface protection layer 10 are sequentially laminated on a base sheet 2, and a backside primer layer 6 is formed on the back surface of the base sheet 2.

[0141] In Example 1, the sum of the thicknesses of the first transparent resin layer and the second transparent resin layer was 240 μm, and the flame retardant (ammonium polyphosphate) content was 6.4% by mass, with the total mass of the transparent resin layers (i.e., the sum of the mass of the first transparent resin layer and the mass of the second transparent resin layer) being 100% by mass.

[0142] <Manufacturing of decorative panels> MDF (4.0 mm thick) was prepared as the wood-based substrate.

[0143] A two-component water-soluble emulsion adhesive was applied to the surface of the MDF, and the surface of the MDF with the adhesive applied was bonded to the base sheet side of the decorative sheet manufactured in Example 1. The amount of two-component water-soluble emulsion adhesive applied was 130 g / m². ２ That was the case.

[0144] Next, 25℃, 10 kg / m ２ After applying pressure and curing for three days, a decorative panel was manufactured using the decorative sheet obtained in Example 1 (see Figure 3).

[0145] The following two-component water-soluble emulsion adhesive was used: • Main component: Water-soluble emulsion adhesive ("Licabond BA-10L" manufactured by Japan Coating Resin Co., Ltd.) • Hardener: Isocyanate compound ("Licabond BA-11B" manufactured by Japan Coating Resin Co., Ltd.) • Mass ratio of main component to hardener: Mass of main component : Mass of hardener = 100 : 2.5

[0146] Figure 3 is a schematic diagram showing the layer structure of a decorative panel manufactured in Embodiment 1 of this disclosure. In Figure 3, a decorative panel 12 having a decorative sheet 1 is shown on a decorative panel substrate 11.

[0147] (Example 2) Decorative sheets and decorative panels were manufactured in the same manner as in Example 1, except that the thickness of the first transparent resin layer was 100 μm and the thickness of the second transparent resin layer was 100 μm. In Example 2, the sum of the thicknesses of the first and second transparent resin layers was 200 μm, and the flame retardant (ammonium polyphosphate) content was 5.5% by mass, with the total mass of the transparent resin layers (i.e., the sum of the mass of the first and second transparent resin layers) being 100% by mass. The polypropylene resin content relative to the total mass of the first transparent resin layer was 89.0% by mass.

[0148] (Example 3) Decorative sheets and decorative panels were manufactured in the same manner as in Example 1, except that the thickness of the first transparent resin layer was 140 μm and the thickness of the second transparent resin layer was 140 μm. In Example 3, the sum of the thicknesses of the first transparent resin layer and the second transparent resin layer was 280 μm, and the flame retardant (ammonium polyphosphate) content was 5.5% by mass, with the total mass of the transparent resin layers (i.e., the sum of the mass of the first transparent resin layer and the mass of the second transparent resin layer) being 100% by mass. The polypropylene resin content relative to 100% by mass of the total mass of the first transparent resin layer was 89.0% by mass.

[0149] (Example 4) Decorative sheets and decorative panels were manufactured in the same manner as in Example 1, except that the thickness of the first transparent resin layer was 140 μm, the content of the flame retardant (ammonium polyphosphate) relative to 100% by mass of the total mass of the first transparent resin layer was 9.0% by mass, and the thickness of the second transparent resin layer was 100 μm. In Example 4, the sum of the thicknesses of the first and second transparent resin layers was 240 μm, and the content of the flame retardant (ammonium polyphosphate) was 5.3% by mass, based on 100% by mass of the total mass of the transparent resin layers (i.e., the sum of the mass of the first and second transparent resin layers). The content of polypropylene resin relative to 100% by mass of the total mass of the first transparent resin layer was 91.0% by mass.

[0150] (Example 5) Decorative sheets and decorative panels were manufactured in the same manner as in Example 1, except that the thickness of the first transparent resin layer was 140 μm, the content of the flame retardant (ammonium polyphosphate) relative to 100% by mass of the total mass of the first transparent resin layer was 16.0% by mass, and the thickness of the second transparent resin layer was 100 μm. In Example 5, the sum of the thicknesses of the first and second transparent resin layers was 240 μm, and the content of the flame retardant (ammonium polyphosphate) was 9.3% by mass, based on 100% by mass of the total mass of the transparent resin layers (i.e., the sum of the mass of the first and second transparent resin layers). The content of polypropylene resin relative to 100% by mass of the total mass of the first transparent resin layer was 84.0% by mass.

[0151] (Example 6) A transparent resin layer A (thickness 40 μm) that does not contain a flame retardant (ammonium polyphosphate) and whose resin component is polypropylene resin was formed into a film on a transparent adhesive layer using an extrusion molding machine with a T-die, and laminated in a laminator. Next, a first transparent resin layer (thickness 140 μm) that contains a flame retardant (ammonium polyphosphate) and whose resin component is polypropylene resin was formed into a film using an extrusion molding machine with a T-die, and laminated in a laminator. Next, a second transparent resin layer (thickness 20 μm) that does not contain a flame retardant (ammonium polyphosphate) and whose resin component is polypropylene resin was laminated on the first transparent resin layer by heat-seal lamination simultaneously with film formation using an extrusion molding machine with a T-die. Except for the transparent resin layers being prepared in this procedure, decorative sheets and decorative panels were manufactured in the same manner as in Example 1.

[0152] The types and content of the flame retardant and resin components in the first transparent resin layer were as follows: • Flame retardant content (ammonium polyphosphate, "EXOLIT AP423" manufactured by Clariant Japan Co., Ltd.) per 100% of the total mass of the first transparent resin layer: 9.0% by mass • Polypropylene resin content per 100% of the total mass of the first transparent resin layer: 91.0% by mass

[0153] (Example 7) A transparent resin layer A (thickness 80 μm) was formed on a transparent adhesive layer using an extrusion molding machine with a T-die, and was made of a mixed resin that did not contain a flame retardant (ammonium polyphosphate) and whose resin component was 10 parts by mass of maleic acid-modified polypropylene per 100 parts by mass of random polypropylene resin. This layer was then laminated in a laminator. Next, a first transparent resin layer (thickness 110 μm) containing ammonium polyphosphate as a flame retardant and whose resin component was polypropylene resin was formed on a transparent adhesive layer using an extrusion molding machine with a T-die, and was then laminated in a laminator. Next, a second transparent resin layer (thickness 10 μm) that did not contain a flame retardant (ammonium polyphosphate) and whose resin component was polypropylene resin was laminated on the first transparent resin layer using an extrusion molding machine with a T-die, simultaneously with film formation by heat-seal lamination. Except for the transparent resin layers being prepared using this procedure, decorative sheets and decorative panels were manufactured in the same manner as in Example 1.

[0154] The types and content of the flame retardant and resin components in the first transparent resin layer were as follows: • Flame retardant content (ammonium polyphosphate, "EXOLIT AP423" manufactured by Clariant Japan Co., Ltd.) per 100% of the total mass of the first transparent resin layer: 9.0% by mass • Polypropylene resin content per 100% of the total mass of the first transparent resin layer: 91.0% by mass

[0155] (Comparative Example 1) A decorative sheet and a decorative panel were manufactured in the same manner as in Example 1, except that the first transparent resin layer (thickness 140 μm) did not contain a flame retardant and the resin component was made of polypropylene resin. In Comparative Example 1, the sum of the thickness of the first transparent resin layer and the thickness of the second transparent resin layer was 240 μm, and the flame retardant content was 0% by mass, with the total mass of the transparent resin layers (i.e., the sum of the mass of the first transparent resin layer and the mass of the second transparent resin layer) being 100% by mass.

[0156] (Comparative Example 2) A decorative sheet and a decorative panel were manufactured in the same manner as in Example 1, except that the first transparent resin layer (thickness 140 μm) contained magnesium hydroxide as a flame retardant and the resin component was made of polypropylene resin. In Comparative Example 2, the sum of the thickness of the first transparent resin layer and the thickness of the second transparent resin layer was 240 μm, and the flame retardant (magnesium hydroxide) content was 6.4% by mass, with the total mass of the transparent resin layers (i.e., the sum of the mass of the first transparent resin layer and the mass of the second transparent resin layer) being 100% by mass.

[0157] The types and content of the flame retardant and resin components in the first transparent resin layer were as follows: • Flame retardant content (magnesium hydroxide, "MagSeeds TS-50" manufactured by Kamishima Chemical Industry Co., Ltd.) per 100% of the total mass of the first transparent resin layer: 11.0% by mass • Polypropylene resin content per 100% of the total mass of the first transparent resin layer: 89.0% by mass

[0158] (Comparative Example 3) A decorative sheet and a decorative panel were manufactured in the same manner as in Example 1, except that the first transparent resin layer (thickness 140 μm) contained expanded graphite as a flame retardant and the resin component was made of polypropylene resin. In Comparative Example 3, the sum of the thickness of the first transparent resin layer and the thickness of the second transparent resin layer was 240 μm, and the flame retardant (expanded graphite) content was 6.4% by mass, with the total mass of the transparent resin layers (i.e., the sum of the mass of the first transparent resin layer and the mass of the second transparent resin layer) being 100% by mass.

[0159] The types and content of the flame retardant and resin components in the first transparent resin layer were as follows: • Flame retardant content (expanded graphite, "GREP-EG" manufactured by Suzuhiro Chemical Co., Ltd.) per 100% of the total mass of the first transparent resin layer: 11.0% by mass • Polypropylene resin content per 100% of the total mass of the first transparent resin layer: 89.0% by mass

[0160] (Comparative Example 4) A decorative sheet and a decorative panel were manufactured in the same manner as in Example 1, except that the first transparent resin layer (thickness 100 μm) did not contain a flame retardant and its resin component was made of polypropylene resin, and the second transparent resin layer (thickness 140 μm) contained ammonium polyphosphate as a flame retardant and its resin component was made of polypropylene resin. In Comparative Example 4, the sum of the thickness of the first transparent resin layer and the thickness of the second transparent resin layer was 240 μm, and the content of the flame retardant (ammonium polyphosphate) was 6.4% by mass, with the total mass of the transparent resin layers (i.e., the sum of the mass of the first transparent resin layer and the mass of the second transparent resin layer) being 100% by mass.

[0161] The types and content of the flame retardant and resin components in the second transparent resin layer were as follows: • Flame retardant content (ammonium polyphosphate, "EXOLIT AP423" manufactured by Clariant Japan Co., Ltd.) per 100% of the total mass of the second transparent resin layer: 11.0% by mass • Polypropylene resin content per 100% of the total mass of the second transparent resin layer: 89.0% by mass

[0162] (Comparative Example 5) Decorative sheets and decorative panels were manufactured in the same manner as in Example 1, except that a second transparent resin layer was not prepared.

[0163] The types and content of the flame retardant and resin components in the first transparent resin layer were as follows: • Flame retardant content (ammonium polyphosphate, "EXOLIT AP423" manufactured by Clariant Japan Co., Ltd.) per 100% of the total mass of the first transparent resin layer: 11.0% by mass • Polypropylene resin content per 100% of the total mass of the first transparent resin layer: 89.0% by mass

[0164] (Comparative Example 6) A decorative sheet and a decorative panel were manufactured in the same manner as in Example 1, except that the first transparent resin layer (thickness 140 μm) did not contain a flame retardant and the resin component was made of polypropylene resin, and the second transparent resin layer was not prepared.

[0165] (Comparative Example 7) A decorative sheet and a decorative panel were manufactured in the same manner as in Example 1, except that the first transparent resin layer (thickness 200 μm) was made of polypropylene resin, the flame retardant (ammonium polyphosphate) contained in the first transparent resin layer was 16.7% by mass, and a second transparent resin layer was not prepared.

[0166] The types and content of the flame retardant and resin components in the first transparent resin layer were as follows: • Flame retardant content (ammonium polyphosphate, "EXOLIT AP423" manufactured by Clariant Japan Co., Ltd.) per 100% of the total mass of the first transparent resin layer: 16.7% by mass • Polypropylene resin content per 100% of the total mass of the first transparent resin layer: 83.3% by mass

[0167] (Comparative Example 8) A decorative sheet and decorative panel were manufactured in the same manner as in Example 1, except that the first transparent resin layer (thickness 200 μm) was made of polypropylene resin, the amount of flame retardant (ammonium polyphosphate) contained in the first transparent resin layer was 3.0% by mass, and a second transparent resin layer was not prepared.

[0168] The types and content of the flame retardant and resin components in the first transparent resin layer were as follows: • Flame retardant content (ammonium polyphosphate, "EXOLIT AP423" manufactured by Clariant Japan Co., Ltd.) per 100% of the total mass of the first transparent resin layer: 3.0% by mass • Polypropylene resin content per 100% of the total mass of the first transparent resin layer: 97.0% by mass

[0169] (Evaluation) The decorative panels made using the decorative sheets produced in each example and comparative example were evaluated using the following method.

[0170] (1) Flame retardancy The flame retardancy of the decorative panel was evaluated by evaluating its horizontal flame retardancy performance (resistance to fire spreading). A combustion test was performed on the decorative panel using a measurement method compliant with ISO 9239-1 (Flame propagation test for flooring materials). Specifically, a 250 mm x 1050 mm test piece was placed horizontally in a panel test apparatus (Flooring Radiation Panel EN ISO 9239-1), and the test piece was heated for 2 minutes with a radiant panel tilted at 30 degrees. Next, a pilot burner was used to apply flame to the edge of the test piece, and the flame was applied for 10 minutes, after which the pilot burner was removed from the test piece. The combustion distance was then evaluated after 18 minutes (30 minutes after the start of heating the test piece with the radiant panel). Specifically, the critical heat quantity (kW / m) at the fire extinguishing point was calculated from the combustion distance to the fire extinguishing point. ２ The critical heat load was calculated. The calculated critical heat load was evaluated according to the evaluation criteria below. If the evaluation of the critical heat load is positive or higher, it is evaluated as having flame retardancy suitable for commercial flooring. [Critical Heat Load (Flame Retardancy Class)] ++: 8 kW / m ２ Above (Bfl) +: 4.5 kW / m ２ More than 8KW / m ２ Less than (Cfl) - : 3.0 kW / m ２ More than 4.5KW / m ２ Less than (Dfl) --: 3.0 kW / m ２ Less than (Efl)

[0171] (2) Scratch Resistance Using a scratch resistance tester (Elcometer 3000 Automatic Clemente Hardness Tester manufactured by Elcometer), two test needles [needle needle (φ1 mm tungsten carbide cutting needle) and Clemente needle (φ2 mm tungsten carbide cutting needle)] were used to scratch the surface of the decorative sheet of the decorative panel at a speed of 30 mm / s and a length of 50 mm with a load of 1 to 3 kg, perpendicular to the MD direction of the decorative sheet of the decorative panel. When using the needle needle (φ1 mm tungsten carbide cutting needle), the load at which the decorative panel whitens was evaluated according to the following evaluation criteria. When using the Clemente needle (φ2 mm tungsten carbide cutting needle), the load at which the transparent resin layer of the decorative panel is gouged down to the substrate was evaluated according to the following evaluation criteria. Note that if the evaluation of the needle needle (φ1 mm tungsten carbide cutting needle) is ++ or higher, it is considered that there will be no problems in actual use. If the rating of the Clement needle (φ2 mm tungsten carbide cutting needle) is + or higher, it is considered to be fine for practical use. [Needle needle (φ1 mm tungsten carbide cutting needle)] +++: 3 kg or more ++: 2 kg or more but less than 3 kg +: 1 kg or more but less than 2 kg -: less than 1 kg [Clement needle (φ2 mm tungsten carbide cutting needle)] +++: 3 kg or more ++: 2 kg or more but less than 3 kg +: 1 kg or more but less than 2 kg -: less than 1 kg

[0172] (3) Abrasion Resistance The abrasion resistance of the decorative laminate was evaluated using an abrasion resistance evaluation device (TABER Industries' "Taber type abrasion tester model 1700") in accordance with JAS 1073-3 (2019) 5.2 Abrasion A test. The load on the decorative laminate was set to 1 kg, and the abrasive material used was abrasive paper "product number: S-42, 3M company" in accordance with JIS A1453 (2015). The rotation speed of the rotating disc when it reached the pattern layer of the decorative laminate was evaluated according to the evaluation criteria below. Note that an evaluation of + or higher is considered to indicate that there are no problems in actual use. +++: 4000 rpm or more ++: 3000 rpm or more and less than 4000 rpm +: 2500 rpm or more and less than 3000 rpm -: Less than 2500 rpm

[0173] (4) For decorative laminates, the aesthetic appearance was evaluated visually according to the following evaluation criteria. Specifically, the surface of the decorative laminate was observed visually from the decorative sheet side to check how the pattern of the patterned layer was visible through the transparent resin layer and the sense of depth of the pattern, and the aesthetic appearance was evaluated. [Visibility of the pattern] +: The pattern is clearly visible -: The pattern is blurry --: The pattern is not clearly visible [Sense of depth of the pattern] +: Depth is perceived -: Depth is not perceived

[0174] (5) Whether or not the Blue Angel compliant decorative panels conform to the German environmental label "Blue Angel" was evaluated according to the following evaluation criteria: +: Conforms -: Does not conform

[0175] (6) Adhesion Strength The decorative sheets obtained in Examples 1 to 5 or Comparative Examples 1 to 7 were cut into strips measuring 1 inch (2.54 cm) in width and 4 inches in length to form Sample A, and the decorative sheets obtained in Examples 6 to 7 were cut into strips measuring 1 inch (2.54 cm) in width and 4 inches in length to form Sample B. Using a Tensilon universal tester ("RTC-1210A (model number)", manufactured by Orientec Co., Ltd.), the peel strength from the 1-inch width direction when peeling was performed between the pattern layer and the first transparent resin layer was measured for Sample A, and the peel strength from the 1-inch width direction when peeling was performed between the pattern layer and the transparent resin layer A was measured for Sample B. Specifically, the peel strength (N) from the 1-inch width direction when peeling was performed under conditions of a tensile speed of 50 mm / min and a temperature of 20°C was measured. The measured peel strength was evaluated according to the following evaluation criteria. ++: Material broke, or the peel strength was 25 N or higher. +: Peel strength was 18N or higher and less than 25N. -: Peel strength was less than 18N.

[0176] (7) The decorative sheet obtained in the weather-resistant adhesion example or comparative example is set in an accelerated weathering tester (Daipla Wintes Co., Ltd., "Metal Weather® CW-R8PL-A (model)") and tested under light conditions (illuminance: 60 mW / cm²). ２ (Black panel temperature 63°C, intralayer humidity 50% RH) for 20 hours under condensation conditions (illuminance: 0 mW / cm²) ２A weather resistance test was conducted by leaving the samples for 4 hours under black panel temperature of 30°C and intralayer humidity of 98% RH, followed by 100 hours under water spray conditions (10 seconds before and after condensation conditions). After this test, the samples were kept at 25°C and 50% RH for 48 hours, and then the peel strength (N) was measured according to the adhesion strength test method described in (6) above. The measured peel strength was evaluated according to the following evaluation criteria: ++: Material broke, or peel strength was 15N or higher. +: Peel strength was 10N or higher and less than 15N. -: Peel strength was less than 10N.

[0177] The results for each example and each comparative example are shown in Tables 1 and 2.

[0178]

[0179]

[0180] 1. Decorative sheet 2. Base sheet 3. Transparent resin layer 4. First transparent resin layer 5. Second transparent resin layer 6. Backside primer layer 7. Pattern layer 8. Transparent adhesive layer 9. Primer layer 10. Surface protection layer 11. Decorative panel base material 12. Decorative panel

Claims

1. A decorative sheet having at least a transparent resin layer on a base sheet, wherein the transparent resin layer comprises a first transparent resin layer and a second transparent resin layer from the base sheet side, and the first transparent resin layer contains ammonium polyphosphate.

2. The decorative sheet according to claim 1, wherein the ratio of the thickness of the first transparent resin layer to the thickness of the second transparent resin layer (thickness of the first transparent resin layer:thickness of the second transparent resin layer) is 1:1 to 12:

1.

3. The decorative sheet according to claim 1, wherein the ratio of the thickness of the first transparent resin layer to the thickness of the second transparent resin layer (thickness of the first transparent resin layer:thickness of the second transparent resin layer) is 1:1 to 8:

1.

4. The decorative sheet according to claim 1, wherein the thickness of the transparent resin layer is 200 μm or more and 280 μm or less.

5. The decorative sheet according to claim 1, wherein the transparent resin layer consists of three or more layers, from the base sheet side, having a first transparent resin layer and a second transparent resin layer, and the thickness of the transparent resin layer is 200 μm or more and 280 μm or less.

6. The decorative sheet according to claim 1, wherein the transparent resin layer comprises a transparent resin layer A, a first transparent resin layer, and a second transparent resin layer from the base sheet side, and the transparent resin layer A comprises a resin layer containing a polyolefin resin.

7. The decorative sheet according to claim 6, wherein the polyolefin resin is a maleic acid-modified polypropylene resin.

8. The decorative sheet according to claim 1, wherein the ammonium polyphosphate content is 9.0% by mass or more and 16.0% by mass or less, based on 100% by mass of the total mass of the first transparent resin layer.

9. The decorative sheet according to claim 1, wherein the ammonium polyphosphate content is 4.5% by mass or more and 9.6% by mass or less, based on 100% by mass of the total mass of the transparent resin layers.

10. The decorative sheet according to claim 1, wherein the base sheet, the first transparent resin layer, and the second transparent resin layer contain a thermoplastic resin.

11. The decorative sheet according to claim 1, further comprising a pattern layer between the base sheet and the transparent resin layer.

12. The decorative sheet according to claim 1, wherein the transparent resin layer side has an embossed shape.

13. The decorative sheet according to claim 1, wherein the outermost surface has a surface protective layer.

14. A decorative panel having a decorative sheet according to any one of claims 1 to 13 on a decorative panel substrate.

15. The decorative panel according to claim 14, wherein the decorative panel base material is at least one selected from the group consisting of wood-based base materials, resin-based base materials, and metal-based base materials.

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