JP2020100115A - Decorative sheet - Google Patents

Abstract

To provide a decorative sheet with improved scratch resistance under a high-load condition.SOLUTION: A decorative sheet includes a raw fabric layer 7, a transparent resin layer 1 and surface protective layers 4 in this order. The surface protective layers 4 are composed as a multilayer. If a surface protective layer located on an outermost surface among the surface protective layers 4 is a surface protective layer 4b, and a surface protective layer located in a lower layer of the surface protective layer 4b is a surface protective layer 4a, an erosion rate E of the surface protective layer 4b measured using polygonal alumina powder with an average particle diameter (D50) of 1.2 μm is within a range of 0.1-0.4 μm/g.SELECTED DRAWING: Figure 1

Description

The present invention relates to a decorative sheet.

In recent years, for example, as shown in Patent Documents 1 to 3, as a decorative sheet replacing a decorative sheet made of polyvinyl chloride, many decorative sheets using an olefin resin have been proposed.
However, since these decorative sheets do not use vinyl chloride resin, the generation of toxic gases and the like during incineration is suppressed, but, for example, when a general polypropylene sheet or a soft polypropylene sheet is used, Scratch resistance (scratch resistance) tends to deteriorate. Therefore, a decorative sheet using an olefin resin may be inferior in scratch resistance to a conventional polyvinyl chloride decorative sheet.

Japanese Patent No. 3271022 Japanese Patent No. 3861472 Japanese Patent No. 3772634

In order to improve the scratch resistance of the decorative sheet, a method of coating and curing an ionizing radiation curable resin on the surface protective layer is known. However, there is a problem that the decorative sheet is not scratched at all, and that when the scratch resistance test is performed under a high load condition, the decorative sheet may be scratched.
Therefore, in order to improve scratch resistance under high load conditions, it has been proposed to make the surface protective layer harder and thicker, but if the surface protective layer is made too hard, the surface protective layer becomes brittle and falls. There are also problems that impact resistance to objects and the like may deteriorate, weather resistance may deteriorate, and costs may increase.

Further, in order to improve scratch resistance under high load conditions, it has been proposed to add an inorganic filler to the surface protective layer, but when the inorganic filler is added to the surface protective layer, the inorganic filler added to the surface protective layer When the surface protection layer has a large protrusion or there is a void at the interface with the surface protection layer, the inorganic filler is damaged during the scratch resistance test, or the inorganic filler is missing from the surface protection layer, causing gloss change. There was also the problem that things happened.
The present invention has been made in view of the above points, and an object thereof is to provide a decorative sheet having improved scratch resistance under a high load condition.

As a result of earnest studies to achieve the above-mentioned object, the present inventors have found that the above-mentioned problems can be solved by forming a surface protective layer having a specific erosion rate on a decorative sheet.
A decorative sheet according to one aspect of the present invention is a decorative sheet that includes a raw fabric, a transparent resin layer, and a surface protective layer in this order, wherein the surface protective layer is composed of a plurality of layers, and among the surface protective layers, When the surface protective layer located on the outermost surface is the first surface protective layer and the surface protective layer located under the first surface protective layer is the second surface protective layer, the first surface protective layer The erosion rate E measured using a polygonal alumina powder having an average particle diameter (D ₅₀ ) of 1.2 μm is in the range of 0.1 μm/g or more and 0.4 μm/g or less. ..

According to the decorative sheet according to one aspect of the present invention, it is possible to provide a decorative sheet having excellent scratch resistance even under a high load condition.

It is sectional drawing which shows an example of embodiment of the decorative sheet of this invention.

The decorative sheet according to the embodiment of the present invention will be described in detail below with reference to FIG.
Here, the drawings are schematic, and the relationship between the thickness and the plane dimension, the thickness ratio of each layer, and the like are different from the actual ones. Further, the embodiments described below exemplify a configuration for embodying the technical idea of the present invention, and the technical idea of the present invention is that the material, shape, structure, etc. of the components are as follows. It is not specific to a thing. Various changes can be added to the technical idea of the present invention within the technical scope defined by the claims described in the claims.

(Measurement of erosion rate E)
First, the "erosion rate E" defined in this embodiment will be described.
The erosion rate E in the present embodiment is, for example, a material surface precision tester (micro slurry jet erosion tester, hereinafter MSE tester, manufactured by PALMESO CO., LTD./apparatus name: nano MSE/model N-MSE). -A) is a value measured using. The specific method for measuring the erosion rate E is as follows.

Polygonal alumina powder having an average particle diameter D ₅₀ =1.2 μm is dispersed in water to prepare a slurry containing 3% by mass of polygonal alumina powder with respect to the total mass of the slurry. The decorative sheet is fixed to a table, and the projection distance between the decorative sheet and the nozzle for spraying the slurry is set to 4 mm. The nozzle diameter is 1 mm×1 mm. A slurry containing polygonal alumina powder is jetted from a nozzle, and the decorative sheet fixed to the table is sequentially cut from the surface protective layer. The injection intensity at this time is a standard projection from the existing Si wafer cut under similar experimental conditions in advance and the scraped displacement with respect to the injection amount of the slurry (that is, the depth cut when 1 g of the slurry is sprayed). The force X is calculated and determined based on the value. In the present embodiment using the polygonal alumina powder, the projection force when the existing Si wafer is shaving 6.360 μm/g is set as the standard projection force X.

In this embodiment, in the case of polygonal alumina powder, X=1/100 projection force (projection force when scraping 0.064 μm/g on an existing Si wafer).
After washing the cut portion with water, the cutting depth, that is, the erosion depth Z is measured. The erosion depth Z is, for example, a stylus type surface shape measuring instrument (manufactured by Kosaka Laboratory Ltd./model PU-EU1/tip of a stylus R=2 μm/load 100 μN/measurement magnification 10,000/measurement length 4 mm/measurement The speed is 0.2 mm/sec). In the present embodiment, the erosion rate E [μm/g] is calculated by using the projected particle amount X′ [g] calculated from the above-mentioned projection force and the erosion depth Z [μm].
It is known that the erosion rate E is not affected by the magnitude of the erosion rate E of the lower layer existing in the depth direction when the erosion rate E is measured. Therefore, when measuring the erosion rate E, the MSE test was performed in order from the first surface protective layer located on the outermost surface.

(Structure of makeup sheet)
Below, each structure of the decorative sheet of this embodiment is demonstrated. In addition, in this embodiment, the case where the surface protective layer has two layers will be described.
The decorative sheet shown in FIG. 1 has a surface protective layer (first surface protective layer) 4b, a surface protective layer (second surface protective layer) 4a, a transparent resin layer 1, and an adhesive resin layer 8 in order from the upper side of the drawing. An adhesive layer 6 (a heat-sensitive adhesive layer, an anchor coat layer, a dry laminating adhesive layer), a pattern layer 2, an original layer 7, and a primer layer 5. More specifically, the decorative sheet of the present embodiment has a structure in which the pattern layer 2 and the hiding layer 3 are provided on one surface of the transparent resin layer 1 and the surface protective layer 4 is provided on the other surface of the transparent resin layer 1. It is a makeup sheet.

An embossed pattern 1a may be appropriately provided on the surface of the transparent resin layer 1 on the surface protective layer 4 side in order to improve the design.
Further, the total thickness of the decorative sheet may be in the range of 80 μm or more and 250 μm or less.
Further, the decorative sheet of the present embodiment preferably does not contain a vinyl chloride resin. By using a decorative sheet made of a non-vinyl chloride resin, there is no fear of generating toxic gas or the like during incineration.
Hereinafter, details of each layer constituting the decorative sheet of the present embodiment will be described.

<Fabric layer>
The original fabric layer (original fabric) 7 is, for example, paper such as thin paper, titanium paper, resin-impregnated paper, polyethylene, polypropylene when the decorative sheet has designability, scratch resistance and post-processing resistance. , Polystyrene, polybutylene, polycarbonate, polyester, polyethylene terephthalate, polybutylene terephthalate, polyamide, ethylene-vinyl acetate copolymer, polyvinyl alcohol, synthetic resins such as acrylic, or foams of these synthetic resins, ethylene-propylene copolymer rubber, Ethylene-propylene-diene copolymer rubber, styrene-butadiene-styrene block copolymer rubber, rubber such as polyurethane, organic or inorganic non-woven fabric, synthetic paper, metal foil such as aluminum, iron, gold, silver, etc. You may use it. The original fabric layer 7 may be a sheet made of the same resin composition as the transparent resin layer 1. Of the above, polyolefin-based materials such as polypropylene and polyethylene are preferable.

Examples of the polyolefin-based resin contained in the raw fabric layer 7 include, in addition to polypropylene, polyethylene, polybutene, and the like, α-olefins (eg, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1- Octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene, 3- Methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-pentene, 4- Ethyl-1-hexene, 3-ethyl-1-hexene, 9-methyl-1-decene, 11-methyl-1-dodecene, 12-ethyl-1-tetradecene, etc.) were homopolymerized or copolymerized with two or more kinds. Ethylene, vinyl acetate copolymer, ethylene/vinyl alcohol copolymer, ethylene/methyl methacrylate copolymer, ethylene/ethyl methacrylate copolymer, ethylene/butyl methacrylate copolymer, ethylene/methyl acrylate copolymer , Ethylene/ethyl acrylate copolymer, ethylene/butyl acrylate copolymer, and the like, copolymerized with ethylene or α-olefin and other monomer.

When a substrate having an inactive surface such as a polyolefin-based material is used as the raw fabric layer 7, for example, corona treatment, plasma treatment, ozone treatment, electron beam treatment, ultraviolet treatment is applied to the front and back of the raw fabric layer 7. It is desirable to perform dichromic acid treatment. Furthermore, a primer layer (not shown) may be provided between the original fabric layer 7 and the pattern layer 2 in order to ensure close contact.
When it is desired to impart a concealing property to the decorative sheet, a concealing colored sheet may be used for the original fabric layer 7, or a concealing layer 3 may be provided above the original fabric layer 7 and below the pattern layer 2. May be. When a colored sheet is used as the raw fabric layer 7, a coloring agent can be added to the resin material forming the raw fabric layer 7 for coloring. As the colorant, for example, an inorganic pigment (titanium oxide, carbon black, or the like), an organic pigment (phthalocyanine blue, or the like), or a dye can be used. The colorant of the present embodiment can be used by selecting one kind or two or more kinds from publicly known or commercially available colorants, and the addition amount can be adjusted so that desired hiding property and designability can be obtained. ..
In the raw fabric layer 7, if necessary, for example, a filler, a foaming agent, a flame retardant, a lubricant, an antistatic agent, an antioxidant, a crystal nucleating agent, an ultraviolet absorber, a light stabilizer, a heat stabilizer, a coloring agent. Various additives such as agents and matting agents may be added.
The thickness of the raw fabric layer 7 is preferably in the range of 30 μm or more and 150 μm or less in consideration of printing workability and cost.

<Picture layer/Hiding layer>
As a method for providing the pattern layer 2 and the hiding layer 3, for example, gravure printing, offset printing, screen printing, flexographic printing, electrostatic printing, ink jet printing or the like may be performed on the raw fabric layer 7 or the transparent resin layer 1. is there. Further, particularly when the hiding layer 3 is applied, for example, a comma coater, a knife coater, a lip coater, a metal vapor deposition method or a sputtering method may be used. The hiding layer 3 is generally provided on the original fabric layer 7 and the lower layer of the pattern layer 2.

When an ink is used to form the pattern layer 2, the binder contained in the ink is, for example, nitrified cotton, cellulose, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, polyurethane, acrylic, polyester or the like alone or It may be appropriately selected from each modified product. These may be aqueous, solvent-based, or emulsion type, and may be arbitrarily selected from a one-pack type and a two-pack type using a curing agent.
Further, it is also possible to cure the ink by irradiating it with ultraviolet rays or electron beams. Among them, the most general method is a method of curing with an isocyanate using a urethane-based ink.

In addition to the above-mentioned binder, pigments, colorants such as dyes, extender pigments, solvents, and various additives contained in ordinary ink may be added. Particularly frequently used pigments include, for example, condensed azo, insoluble azo, quinacridone, isoindoline, anthraquinone, imidazolone, cobalt, phthalocyanine, carbon, titanium oxide, iron oxide, pearl pigments such as mica. In addition to the ink application, it is also possible to apply a design by vapor deposition or sputtering of various metals.
The material used for the hiding layer 3 may be basically the same as the material for the pattern layer 2. Since the hiding layer 3 needs to have hiding properties for its purpose, it is preferable to use, for example, an opaque pigment, titanium oxide, iron oxide or the like as the pigment. Further, in order to improve the hiding property, it is possible to add a metal such as gold, silver, copper or aluminum. Generally, flake-shaped aluminum is often added. When the coating thickness, that is, the thickness of the hiding layer 3 is less than 2 μm, it is difficult to impart the hiding property, and when it exceeds 10 μm, the cohesive force of the resin layer becomes weak. Therefore, it is appropriate that the thickness of the hiding layer 3 is in the range of 2 μm or more and 10 μm or less.

<Adhesive layer>
Any material can be selected for the adhesive layer 6, and examples of the bonding method using the adhesive layer 6 include thermal lamination, extrusion lamination, and dry lamination. The adhesive contained in the adhesive layer 6 can be selected from acrylic, polyester, polyurethane, and other materials. The adhesive contained in the adhesive layer 6 is usually a two-component curing type due to its cohesive force, and it is particularly preferable to use a urethane-based material obtained by a reaction with a polyol using an isocyanate.

<Adhesive resin layer>
An adhesive resin layer 8 may be provided between the adhesive layer 6 and the transparent resin layer 1. The adhesive resin layer 8 may be provided especially when further laminating strength is required in the extrusion laminating method. The transparent resin layer 1 and the adhesive resin layer 8 are generally laminated and formed by a coextrusion method.
The resin contained in the adhesive resin layer 8 is preferably, for example, a resin such as polypropylene, polyethylene, or acrylic resin that has been subjected to acid modification, and its thickness is preferably 2 μm or more for the purpose of improving adhesive strength. When the thickness of the adhesive resin layer 8 is less than 2 μm, it is difficult to obtain a sufficient adhesive force. In addition, if the thickness of the adhesive resin layer 8 is too thick, the adhesive resin layer 8 itself has a softness even if the surface hardness is improved by the transparent resin layer 1 having high crystallinity. Since it is affected, 20 μm or less is desirable.

<Transparent resin layer>
The transparent resin layer 1 is formed on the adhesive resin layer 8, and the thickness thereof is in the range of 40 μm or more and 170 μm or less. If the thickness of the transparent resin layer is less than 40 μm, the weather resistance and scratch resistance may decrease. When the thickness of the transparent resin layer exceeds 170 μm, the manufacturing cost may increase and the flexibility may decrease.
The transparent resin layer 1 may be a sheet formed by film formation, or may be a laminate of already formed sheets. The transparent resin layer 1 is made of, for example, a highly crystalline polypropylene resin.

Further, one surface or both surfaces of the transparent resin layer 1 may be activated by, for example, corona treatment, plasma treatment, electron beam treatment, ultraviolet ray treatment, dichromic acid treatment or the like, if necessary. If there is a problem with the adhesiveness of the concealing layer 3 to the base material (base material such as wooden boards, inorganic boards, metal plates to which the above decorative sheet is attached), the primer layer 5 may be appropriately provided in layers. I don't care.
When the transparent resin layer 1 is formed into a sheet by film formation, for example, a method using an extruder is generally used.

When the transparent resin layer 1 is laminated and molded, there is no particular restriction, and for example, a method applying heat and pressure, an extrusion laminating method, a dry laminating method or the like is generally used. When the embossed pattern 1a is applied, for example, a sheet which has been laminated by various methods is embossed by hot pressing afterwards, or an uneven pattern is provided on a cooling roll, and extrusion lamination is performed using the cooling roll. There is a method of embossing at the same time. More specifically, the embossed pattern 1a is directly applied to the transparent resin layer 1, for example, a highly crystalline polypropylene sheet, and the method is to use an embossed plate having an uneven pattern on the formed sheet by heat and pressure. There are a method of providing an embossed pattern, a method of providing an embossed film at the same time as cooling by using a cooling roll having an uneven pattern when forming a film using an extruder. Here, it is also possible to embed ink in the embossed pattern 1a as the embossed portion to further improve the design.
The embossed pattern 1a may be provided if necessary, and may be omitted if unnecessary.

In the transparent resin layer 1, if necessary, for example, a heat stabilizer, a flame retardant, an ultraviolet absorber, a light stabilizer, an antiblocking agent, a catalyst scavenger, and within a range that does not impair the characteristics of the present embodiment, For example, various additives such as a colorant, a light scattering agent, and a gloss adjusting agent can be added.
As the heat stabilizer, for example, phenol-based, sulfur-based, phosphorus-based, hydrazine-based, etc., as the flame retardant, aluminum hydroxide, magnesium hydroxide, etc., as the ultraviolet absorber, for example, benzotriazole-based, benzoate-based, As a light stabilizer such as a benzophenone-based or triazine-based light stabilizer, for example, a hindered amine-based light stabilizer or the like is generally added in an arbitrary combination. In particular, when it is used for this purpose, it is necessary to consider the weather resistance, and in that case, an ultraviolet absorber and a light stabilizer may be added to the transparent resin layer 1, and the addition amount is 100% in the transparent resin layer 1 respectively. An appropriate amount is within a range of 0.1% by weight or more and 2.0% by weight or less.
The transparent resin layer 1 may include a crystal nucleating agent (nanosize nucleating agent) that has been vesicle-treated by a supercritical reverse phase evaporation method.

The concrete vesicle treatment by the supercritical reverse phase evaporation method is carried out by injecting an aqueous phase into a mixed fluid of supercritical carbon dioxide, phospholipid as a dispersant, and an additive as an encapsulating substance, and then stirring the supercritical fluid. An emulsion of carbon dioxide and an aqueous phase is formed. Then, when the pressure is reduced, carbon dioxide expands and evaporates to cause phase inversion, and phospholipids form nanocapsules in which the surfaces of the additive particles are covered with a monolayer film. By using this supercritical reverse phase evaporation method, unlike the conventional encapsulation method in which the dispersant is a multi-layered film on the surface of the additive particles, it is possible to easily form a single-layer film capsule, so that a smaller diameter Capsules can be prepared. When it is desired to form a multi-layered capsule, it can be easily produced by injecting supercritical carbon dioxide into a mixed fluid of phospholipid, an additive and an aqueous phase. Examples of the phospholipid used in preparing the vesicles include phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidic acid, phosphatidylglycerrol, phosphatidylinositol, cardiopine, yolk egg lecithin, hydrogenated egg yolk lecithin, soybean lecithin, water. Examples thereof include glycerophospholipids such as added soybean lecithin, sphingolipids such as sphingomyelin, ceramide phosphorylethanolamine, and ceramide phosphorylglycerol. The vesicle can realize excellent compatibility with the resin material by including the outer membrane made of phospholipid.

When the transparent resin layer 1 is composed of the resin layer containing the nano-sized nucleating agent described above, the crystalline polypropylene resin is contained as a main component in the range of 90% by weight or more and 100% by weight or less, and the addition of the nano-sized particles is added. It is important to include nucleating agents as agents. More preferably, the nano-sized additive is contained in a vesicle state (nucleating agent vesicle). In this case, the nucleating agent vesicles preferably have an average particle size of 1/2 or less of the wavelength of visible light. Specifically, since the wavelength region of visible light is 400 to 750 nm, the average particle size of the nano-sized nucleating agent is preferably 375 nm or less. In such a transparent resin layer 1, by adjusting the cooling conditions at the time of film formation, the haze value is 15% or less, more preferably 10% or less, and the tensile elastic modulus is in the range of 800 MPa or more and 2,000 MPa or less, It is important that the tensile elongation at break is 200% or more.

The crystalline polypropylene resin can be designed by appropriately selecting from isotactic polypropylene, syndiotactic polypropylene, random polypropylene, block polypropylene, and a mixture thereof having different pentad fractions. More preferably, the crystalline polypropylene resin is a highly crystalline homopolypropylene resin which is a homopolymer of propylene having an isotactic pentad fraction (mmmm fraction) of 95% or more, more preferably 96% or more, that is, a homopolymer. It is important that The resin other than the crystalline polypropylene that constitutes the transparent resin layer 1 can be appropriately selected depending on the purpose of its blending as long as it does not significantly affect the physical properties of the crystalline polypropylene. However, in order to maintain the V-groove bending suitability, it is preferable that the compatibility with the crystalline polypropylene resin forming the transparent resin layer 1 is good.
It is preferable that the transparent resin layer 1 has a thickness of 20 μm or more and 250 μm or less. More preferably, it is in the range of 40 μm or more and 170 μm or less.

Since the particle size of the nano-sized nucleating agent is as small as nano size, the number of nucleating agents present per unit volume and the surface area increase in inverse proportion to the cube of the particle diameter. As a result, the distance between the nucleating agent particles becomes close, so when the crystal growth occurs from the surface of one nucleating agent particle added to the polypropylene resin, the end portion where the crystal is growing immediately, In contact with the ends of the crystals that had grown from the surface of the other nucleating agent particles adjacent to the nucleating agent particles, because the end of each crystal inhibits the growth and the growth of each crystal stops, the crystal The average particle size of spherulites in the crystalline part of the crystalline polypropylene resin can be made extremely small.
Therefore, by containing a nano-sized nucleating agent in the transparent resin layer 1, finer and larger amounts of crystal nuclei are generated in the resin as compared with the conventional nucleating agent, and as a result, crystals are formed. We succeeded in shortening the distance between crystal nuclei in the part, suppressing the growth of individual crystals, and making the average particle diameter of spherulites extremely small. And, in such a crystalline polypropylene resin, an extremely high transparency with a haze value of 15% or less is realized.

Furthermore, by incorporating the nano-sized nucleating agent in the form of vesicles, that is, as the nucleating agent vesicles, the nucleating agents are prevented from aggregating with each other and high dispersibility in the resin material is realized. In the resin composition, the outer membrane of the nucleating agent vesicles is partially collapsed and the nucleating agent is exposed, and in the crystallization process of the resin material, the nano-sized nucleating agent particles form crystal nuclei. Spherulites are formed.
At this time, in particular, the nucleating agent vesicles obtained by the supercritical reverse phase evaporation method have an extremely small size. Therefore, the average particle size of the spherulites in the crystal part of the crystalline polypropylene resin can be made extremely small, and the crystallinity of the crystal part can be dramatically improved.

In the decorative sheet of the present embodiment, the transparent resin layer 1 contains a nano-sized nucleating agent, and more preferably, the vesicles of the nucleating agent are contained so that the spherulite in the crystal part of the crystalline polypropylene resin is The average particle size is extremely small to achieve excellent scratch resistance. In particular, by incorporating the nucleating agent vesicles in the transparent resin layer 1, the nucleating agent is uniformly dispersed in the crystalline polypropylene resin, and the crystallinity of the crystalline polypropylene is controlled to control the hardness of the transparent resin layer 1. And toughness can be adjusted to be optimal. In addition, by including the nucleating agent vesicles in the transparent resin layer 1, excellent tensile resistance in the range of 800 MPa or more and 2000 MPa or less and tensile break elongation of 200% or more, excellent scratch resistance and post-processability. Can be realized.

The terms used in the above description will be briefly described below.
The nucleating agent is added to promote the generation of crystal nuclei during crystallization of the resin, or the nucleating agent itself serves as crystal nuclei. The nucleating agent is a melting type that melts into the resin of the base material and precipitates again to generate crystal nuclei when added, or the nucleating agent added to the base material turns into crystal nuclei with the same particle size without melting. There are mold nucleating agents. Examples of the nucleating agent for polypropylene resin include phosphoric acid ester metal salts, benzoic acid metal salts, pimelic acid metal salts, rosin metal salts, benzylidene sorbitol, quinacridone, cyanine blue and talc. In particular, in the present embodiment, in order to maximize the effect of the nano-formation treatment, a non-melting type, which can be expected to have good transparency, a phosphoric acid ester metal salt, a benzoic acid metal salt, a pimelic acid metal salt, a rosin metal. Although salt is preferably used, colored quinacridone, cyanine blue, talc, and the like can also be used when transparency can be obtained by nano treatment. Further, a melt type benzylidene sorbitol may be appropriately mixed and used with a non-melt type nucleating agent.

The haze value is the light ray emitted from the other surface from the integrated value (total light transmittance) of the light ray emitted from the other surface when the light incident from one surface of the object is emitted to the other surface. Of these, the value obtained by subtracting the integrated value (linear transmittance) of only the linear component (diffuse transmittance) from the total light transmittance is the value expressed as a percentage. Therefore, the smaller the haze value, the higher the transparency. This haze value is determined by the internal haze determined by the internal state of the object such as crystallinity and spherulite size in the crystal part, and the external haze determined by the surface state of the object such as the presence or absence of irregularities on the incident surface and the exit surface. Be decided. In the present embodiment, when simply referred to as a haze value, it means a value determined by the internal haze and the external haze.

Isotactic pentad fraction (mmmm fraction) is a resin that constitutes the transparent resin layer 1 by a ¹³ C-NMR measurement method (nuclear magnetic resonance measurement method) using carbon C (nuclide) having a mass number of 13. It is calculated from the numerical value (electromagnetic wave absorption rate) obtained by resonating the material at a predetermined resonance frequency, and defines the atomic arrangement, electronic structure, and molecular fine structure in the resin material. The isotactic pentad fraction of a polypropylene resin is a ratio of 5 propylene units arranged by ¹³ C-NMR and is used as a measure of crystallinity or stereoregularity. And, such an isotactic pentad fraction is one of the important factors that mainly determines the scratch resistance of the surface, and basically, the higher the isotactic pentad fraction is, the more the crystallization of the sheet becomes. The scratch resistance is improved due to the higher degree.

<Surface protection layer>
The surface protective layer 4 of this embodiment includes a surface protective layer 4a and a surface protective layer 4b. When the surface protective layer 4b has a specific erosion rate E, it becomes possible to provide a decorative sheet having excellent surface scratch resistance.
Further, the surface protective layer 4b of the present embodiment is more excellent because the surface protective layer 4b further has a specific coating film thickness and a static friction coefficient, and contains an inorganic filler having a hydrophobic treatment and strengthening the bond with the surface protective layer 4b. It is possible to provide a decorative sheet having surface scratch resistance.

Hereinafter, the surface protection layer 4 will be described in detail.
The surface protective layer 4 is composed of multiple layers. When the surface protective layer located on the outermost surface of the surface protective layer 4 is referred to as "surface protective layer 4b" and the surface protective layer located below the surface protective layer 4b is referred to as "surface protective layer 4a", the surface protective layer 4b The erosion rate E measured using a polygonal alumina powder having an average particle diameter (D ₅₀ ) of 1.2 μm is in the range of 0.1 μm/g or more and 0.4 μm/g or less. When the erosion rate E of the surface protective layer 4b is less than 0.1 μm/g, the erosion rate E is small and the adhesion with the surface protective layer 4a may be reduced. Therefore, impact resistance may decrease. When the erosion rate E of the surface protective layer 4b exceeds 0.4 μm/g, the scratch resistance tends to be poor. The surface protective layer 4a and the surface protective layer 4b may be made of different resins.

The thickness of the surface protective layer 4b may be in the range of 2 μm or more and 7 μm or less. When the thickness of the surface protective layer 4b is less than 2 μm, the coating method is limited and stable production becomes difficult, which may reduce the productivity. In addition, weather resistance and scratch resistance may decrease, and variations may increase. When the thickness of the surface protective layer 4b exceeds 7 μm, the balance between performance and cost may be lost and the cost may increase. In addition, flexibility may decrease.
The thickness of the surface protective layer 4a may be in the range of 2 μm or more and 14 μm or less. When the thickness of the surface protective layer 4a is less than 2 μm, the coating method is limited and stable production becomes difficult, which may reduce the productivity. In addition, weather resistance and scratch resistance may decrease, and variations may increase. If the thickness of the surface protective layer 4a exceeds 14 μm, the balance between performance and cost may be lost and the cost may increase. In addition, flexibility may decrease.

The thickness of the entire surface protective layer 4 may be in the range of 4 μm or more and 21 μm or less. When the thickness of the entire surface protective layer 4 is less than 4 μm, the coating method is limited and stable production becomes difficult, which may reduce productivity. In addition, weather resistance and scratch resistance may decrease, and variations may increase. If the total thickness of the surface protective layer 4 exceeds 21 μm, the balance between performance and cost may be lost, and the cost may increase. In addition, flexibility may decrease.
The static friction coefficient μs (according to JIS K7 125) of the decorative sheet of the present embodiment, that is, the surface protective layer 4b may be in the range of 0.25 or more and 0.5 or less. When the coefficient of static friction μs of the surface protective layer 4b is less than 0.25, the surface of the surface protective layer 4b, which is the outermost layer of the decorative sheet, slides well, so that scratches are less likely to occur even under high load conditions. It may not be appropriate because it increases the risk of people falling when used as a material. When the coefficient of static friction μs of the surface protective layer 4b exceeds 0.5, the friction between the sheet surface and an object in contact with the sheet surface increases, and the surface is easily scratched under high load conditions.

The method of providing the surface protective layer 4 is the same as the method of providing the concealing layer 3 and the pattern layer 2, and is not specified at all.
The material used for the surface protective layer 4 is not particularly limited, and examples include polyurethane-based, acrylic-based, acryl-silicone-based, fluorine-based, epoxy-based, vinyl-based, polyester-based, melamine-based, aminoalkyd-based, and urea-based materials. It can be selected appropriately. The form may be any of aqueous, emulsion and solvent systems, and the curing may be a one-pack type or a two-pack type using a curing agent. Among them, urethane-based top coats utilizing the isocyanate reaction are desirable from the viewpoints of workability, cost, cohesive force of the resin itself, and the like.

Examples of the isocyanate include tolylene diisocyanate (TDI), xylylene diisocyanate (XDI), hexamethylene diisocyanate (HMDI), diphenylmethane diisocyanate (MDI), lysine diisocyanate (LDI), isophorone diisocyanate (IPDI), bis (isocyanate methyl). It can be appropriately selected and used from curing agents such as adducts, burettes, isocyanurates and various prepolymers, which are derivatives such as cyclohexane (HXDI) and trimethylhexamethylene diisocyanate (TMDI), but considering weather resistance. It is preferable to use a curing agent based on hexamethylene diisocyanate (HMDI) or isophorone diisocyanate (IPDI) having a linear molecular structure.

In order to further improve the hardness of the surface of the decorative sheet, it is desirable to use, as the surface protective layer 4, a resin that is cured by irradiation with ultraviolet rays or electron beams, that is, an ionizing radiation curable resin. The content of the ionizing radiation-curable resin may be in the range of 65 parts by mass or more and 100 parts by mass or less in 100 parts by mass of the resin constituting the surface protection layer 4, particularly the surface protection layer 4b. When the content of the ionizing radiation curable resin is less than 65 parts by mass, the erosion rate E may increase and the scratch resistance may decrease.
Resins other than the ionizing radiation curable resin, for example, thermosetting resins, have a larger erosion rate E than the ionizing radiation curable resin.

Further, in order to improve weather resistance, an ultraviolet absorber and a light stabilizer may be appropriately added to the surface protective layer 4, particularly the surface protective layer 4b. Further, functional additives such as an antibacterial agent and an antifungal agent may be optionally added to impart various functions.
As the photocurable resin, for example, a polyester acrylate type, an epoxy acrylate type, a urethane acrylate type, an acrylic acrylate type or the like can be appropriately selected and used, and in particular, a urethane acrylate having good weather (light) resistance. It is preferable to use a system and an acrylic acrylate system. As a method for curing the photocurable resin, curing with active energy rays such as ultraviolet rays and electron beams is preferable from the viewpoint of workability.

Regarding the mixture of the thermosetting resin and the photocurable resin, for example, a urethane resin obtained by reacting an acrylic polyol as a thermosetting resin and an isocyanate, and a urethane acrylate resin as a photocurable resin It is preferable to use them by mixing. By using the mixture of the thermosetting resin and the photocurable resin, it is possible to improve the surface hardness, suppress the curing shrinkage, and improve the adhesion with the inorganic fine particles (inorganic filler).
As the electron beam source, for example, a light source such as an ultrahigh pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc lamp, a black light, and a metal halide lamp can be used. The wavelength of ultraviolet rays is preferably 180 nm to 400 nm.
It is desirable to add an inorganic filler to the surface protective layer 4 for the purpose of improving the scratch resistance of the surface or adjusting the gloss accompanying the design property.

Examples of the inorganic filler include alumina, silica, boehmite, iron oxide, magnesium oxide, aluminosilicate, diamond, silicon nitride, silicon carbide, glass beads, calcium titanate, barium titanate, magnesium pyroporate, zinc oxide, silicon nitride. Zirconium oxide, chromium oxide, iron oxide, glass fiber, etc. may be added. As the inorganic filler, inorganic fine particles having an average particle diameter in the range of 1 μm or more and 30 μm or less can be used, and particularly, inorganic fine particles in the range of 1 μm or more and 10 μm or less are suitable. If the average particle size of the inorganic filler is less than 1 μm, it tends to be difficult to obtain a matting effect. This is because, in order to exert the matte effect, it is ideal that the particle size is as large as or larger than the thickness of the film (layer) to which the inorganic filler is added. If the average particle size of the inorganic filler is less than 30 μm, and more certainly less than 10 μm, the inorganic filler tends to fall off from the surface protective layer 4 under high load conditions, and the gloss tends to change and the surface tends to deteriorate. is there.

For example, when gravure printing is selected, a proper coating thickness for one layer is usually 2 μm to 12 μm. In this case, as described above, it is preferable to select an inorganic filler having a similar average particle diameter from the thickness that can be applied at one time or less. However, when the surface protective layer 4 is composed of a plurality of layers, it is also possible to add an inorganic filler having an average particle diameter larger than the film thickness of the surface protective layer 4a located below.
The content of the inorganic filler may be in the range of 1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the resin forming the surface protective layer 4b. If the content of the inorganic filler is less than 1 part by mass, the scratch resistance may decrease. When the content of the inorganic filler exceeds 20 parts by mass, the gloss of the surface is significantly reduced, which may impair the design. In addition, weather resistance and stain resistance may decrease.

It is desirable to apply a surface treatment to the inorganic filler. By subjecting the inorganic filler to a surface treatment, it is possible to strengthen the bond with the surface protective layer. An inorganic filler whose surface is untreated may be added to the lower surface protective layer 4 such as the surface protective layer 4b.
In addition, when the surface treatment is performed, it is desirable to have a functional group that imparts hydrophobicity to the surface of the inorganic filler and reactivity with the surface protective layer 4.
The method for carrying out the surface treatment of the inorganic filler is not particularly limited, and a known method can be selected.

As the surface treatment agent used for the surface treatment of the inorganic filler, at least one of a surfactant, a fatty acid metal salt, a silane coupling agent, silicone, wax, and a modified resin can be used. Examples of the surface treatment agent of this embodiment include silicone oil-based, alkylsilazane-based, trimethylsilylating agent, alkoxysilane-based, siloxane and unknown coupling agents, as well as titanium coupling agents and phosphoric acid-fatty acid-based interfaces. An activator or the like can be selected, and one kind or a combination of plural kinds may be used.
Examples of the silicone oil type treating agent include straight silicone oil (dimethyl silicone oil, methylphenyl silicone oil, etc.) and modified silicone oil (amino modified, epoxy modified, carboxyl modified, carbinol modified, methacryl modified, mercapto modified, phenol modified). , One-end reactive modification, different functional group modification, polyether modification, methylstyryl modification, alkyl modification, higher fatty acid ester modification, hydrophilic special modification, higher alkoxy modification, higher fatty acid-containing modification, fluorine modified silicone oil, etc.) can do.

As the alkylsilazane-based treating agent, for example, hexamethyldisilazane, vinylsilazane or the like can be selected.
As the silane coupling agent, for example, methyltrimethoxysilane, dimethyldimethoxysilane, trimethylmethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, trimethylethoxysilane, n-hexyltrimethoxysilane, n-hexyltriethoxysilane, n-hexyltriethoxysilane, n-octyltriethoxysilane, n-hexyltriethoxysilane, decyltriethoxysilane, phenyltriethoxysilane, benzyltriethoxysilane, propyltrimethoxysilane, propyltriethoxysilane, diethoxymethylphenyl Alkoxysilane compounds such as silane, allyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, aminopropyltriethoxysilane, aminopropyltrimethoxysilane and chlorosilane compounds such as trimethylchlorosilane and diethyldichlorosilane can be selected. ..

As the trimethylsilylating agent, an alkoxysilane compound in the silane coupling agent can be selected.
Examples of titanate coupling agents include isopropyl tridecyl benzene sulfonyl titanate, isopropyl tris(dioctyl pyrophosphate) titanate, tetraisopropyl bis(dioctyl phosphite) titanate, tetraoctyl bis(ditridecyl phosphite) titanate, tetra (2,2 diallyloxymethyl-1-butyl)bis(ditridecyl)phosphite titanate, bis(dioctyl pyrophosphate)oxyacetate titanate, etc. can be selected.

As the aluminate-based coupling agent, for example, acetoalkoxy aluminum diisopropylate can be selected.
As the surfactant, anionic, cationic, nonionic or amphoteric surfactant can be selected.
The above-mentioned surface treatment agent is subjected to vesicle treatment by the above-mentioned supercritical reverse phase evaporation method and dispersed, and then used for the surface treatment, whereby the reaction rate at the time of the surface treatment is improved.
An excellent surface-treated filler can be obtained by performing surface treatment by a known method using the surface-treating agent treated by the supercritical reverse phase evaporation method.

As described above, one of the features (the invention specifying matter) of the decorative sheet of the present embodiment is that "the surface treatment agent for treating the surface of the inorganic filler includes the surface treatment agent in the vesicle by the supercritical reverse phase evaporation method. It is a vesicle containing a surface treatment agent. Then, by reacting the surface treatment agent with the inorganic filler in a state of being encapsulated in vesicles, the effect of dramatically improving the reactivity between the surface treatment agent and the inorganic filler is achieved, but its characteristics have been completed. It can be said that it is impractical to directly specify the structure and characteristics of the object in the state of the decorative sheet, which may be difficult depending on the situation. The reason is as follows. The surface treatment agent added in the vesicle state has a high dispersibility and is in a dispersed state, and reacts with the inorganic filler with a high reaction probability. However, after the surface treatment agent is reacted with the inorganic filler in the state of vesicles to form the surface protective layer, in the process of producing the decorative sheet, various treatments such as compression treatment and curing treatment for the laminate are usually performed. However, it is highly possible that the outer membrane of the vesicle containing the surface treatment agent is crushed or chemically reacted by such a treatment, and the surface treatment agent is not included in the outer membrane (foreskin). This is because the state in which the film is crushed or chemically reacts varies depending on the treatment process of the decorative sheet. In such a situation that the surface treatment agent is not included in the outer membrane, it is difficult to specify the physical properties themselves within the numerical range, and whether the crushed outer membrane constituent material is the outer membrane of the vesicles. It may be difficult to determine whether the material is a material added separately from the surface treatment agent. As described above, the present invention is different from the conventional one in that the reactivity between the surface treatment agent and the inorganic filler is dramatically improved, but is added in the state of vesicles containing the surface treatment agent. In some cases, it may be impractical to specify the structure and characteristics of the decorative sheet within the range of numerical values analyzed based on the measurement.

The method of surface treatment of the inorganic filler is not particularly limited. As the surface treatment method, any of a dry method, a wet method, and an integral blending method can be generally used. In the dry method, a surface-treating agent diluted with water or an organic solvent is added to an inorganic filler whose surface is not treated by spraying or the like, followed by stirring/curing and the like, and the reaction is allowed to proceed to obtain a surface-treated filler.
Further, when the surface of the transparent resin layer 1 on the surface protection layer 4 side is provided with the embossed pattern 1a, the ink forming the surface protective layer 4b is embedded in the embossed pattern 1a by wiping to improve the design. It is also possible to improve.

From the viewpoint of weather resistance, there is also a method of imparting weather resistance to the surface protective layer 4 and the transparent resin layer 1 as described above, in order to protect the transparent resin layer 1 as the base material. In addition to that, there is also a method of adding an ultraviolet absorber and a light stabilizer to the adhesive resin layer 8, the adhesive layer 6, and the pattern layer 2 itself in order to protect the pattern layer 2.
The addition amount of the photoinitiator is not particularly limited, and is preferably about 0.1 to 15 parts by mass with respect to 100 parts by mass of the base resin.

The type of photoinitiator is not particularly limited. In the case of a resin system having a radically polymerizable unsaturated group, examples of the photoinitiator include acetophenone system, benzophenone system, thioxanthones, benzoin, benzoin methyl ether, Michler benzoyl benzoate, Michler's ketone, diphenyl sulfide, dibenzyl disulfide. , Diethyl oxide, triphenylbiimidazole, isopropyl-N,N dimethylaminobenzoate and the like can be selected. Preferably, it is desirable to design by combining a plurality of types according to the light source and the production environment.
Further, in the case of a resin system having a cationically polymerizable functional group, as a photoinitiator, for example, an aromatic diazonium salt, an aromatic sulfonium salt, a metallocene compound, a benzoin sulfonate ester, a fryloxysulfoxonium diallyl iodosyl salt. At least one of these can be selected.

<Primer layer>
The material used for the primer layer 5 may be basically the same as the material for the pattern layer 2 and the hiding layer 3. Further, considering that the web is wound on the back surface of the decorative sheet, in order to avoid blocking and enhance the adhesion with the adhesive, the primer layer 5 is made of, for example, silica, alumina, magnesia. Inorganic fillers such as titanium oxide and barium sulfate may be added. The coating thickness, that is, the thickness of the primer layer 5 is intended to ensure close contact with the raw material layer 7 which is a base material, and therefore, it is appropriate that the thickness is within a range of 0.1 μm or more and 10.0 μm or less, and more preferable. Is in the range of 0.1 μm or more and 3.0 μm or less.
The primer layer 5 is necessary when the surface of the raw fabric layer 7 is inactive such as an olefin-based material, but is not particularly necessary when the surface is a base material having an active surface.

[Example]
Hereinafter, specific examples of the decorative sheet of the present invention will be examined.
<Common materials>
In Examples 1 to 10 and Comparative Examples 1 and 2, the same material was used except for the surface protective layer 4b.
<Preparation of transparent resin layer>
A decorative sheet having the structure shown in FIG. 1 was produced. Specifically, a highly crystalline homopolymer having an isotactic pentad fraction of 97.8%, an MFR (melt flow rate) of 15 g/10 min (230° C.) and a molecular weight distribution MWD (Mw/Mn) of 2.3. Hindered phenolic antioxidant (IRGANOX 1010: manufactured by Ciba Specialty Chemicals Co., Ltd.) of 500 PPM and benzotriazole ultraviolet absorber (Tinuvin 328: manufactured by Ciba Specialty Chemicals Co., Ltd.) of 2,000 PPM and a hindered amine system of polypropylene resin. A thickness in which a light stabilizer (Kimasorb 944: manufactured by Ciba Specialty Chemicals) and 2,000 PPM and a nano-nucleating agent 1,000 PPM are extruded using a melt extruder and used as the transparent resin layer 1 A 100 μm highly crystalline polypropylene transparent resin sheet was formed into a film. Subsequently, corona treatment was performed on both surfaces of the formed transparent resin sheet to adjust the surface wetting tension to 40 dyn/cm or more. The haze value of the crystalline polypropylene resin of the film-formed transparent resin sheet was 8.5% by controlling the cooling conditions during the extrusion film formation.

<Nucleation treatment of nucleating agent using supercritical reverse phase evaporation method>
A method for nanonizing the nucleating agent using the supercritical reverse phase evaporation method in this example will be described below.
First, 100 parts by weight of methanol, 82 parts by weight of a phosphoric acid ester metal salt-based nucleating agent (Adeka Stab NA-11, manufactured by ADEKA), and 5 parts by weight of phosphatidylcholine were placed in a high-pressure stainless steel container kept at 60° C. and sealed, Carbon dioxide was injected so as to have a pressure of 20 MPa to make a supercritical state. Then, 100 parts by weight of ion-exchanged water was injected with vigorous stirring and mixing. After stirring for 15 minutes while maintaining the temperature and pressure in the container, carbon dioxide is discharged and returned to atmospheric pressure to obtain a nucleating agent vesicle having an outer membrane made of a phospholipid encapsulating the nucleating agent. It was

<Preparation of pattern layer/concealment layer>
The obtained transparent resin sheet was used as the transparent resin layer 1, and one surface of the transparent resin layer 1 was subjected to pattern printing with a two-component curing type urethane ink (V351: manufactured by Toyo Ink Mfg. Co., Ltd.) to obtain a pattern layer. 2 is formed, and then a two-component curing type urethane ink (V351: manufactured by Toyo Ink Mfg. Co., Ltd.) having a hiding property is applied to the pattern layer 2 at a coating amount of 6 g/m ² to form the hiding layer 3. did.
<Preparation of primer layer>
In addition, a two-component curing type urethane ink (PET-E, Regiuser: manufactured by Dainichiseika Co., Ltd.) was applied as a primer coat on the concealing layer 3 at a coating amount of 1 g/m ² to form a primer layer 5. Formed.

<Preparation of embossed pattern>
Next, the other surface of the transparent resin layer 1 was pressed using a die roll for embossing to give an embossed pattern 1a.
<Preparation of surface protection layer 4a>
A two-component curing type urethane top coat (TD365UR varnish, Z202 curing agent: both manufactured by Toyo Ink Co., Ltd.) was applied on the surface of the embossed pattern 1a at a coating amount of 10 g/m ² .

<Production of surface treatment filler>
The surface-treated inorganic fine particles NVC-X1 used in each of the examples and each of the comparative examples were obtained by using an inorganic fine particle (L-121: manufactured by AGC SITEC Co., Ltd.) by using a surface-treating agent having an OH group at the end. Obtained by processing.
The surface treatment was performed by a dry method. Specifically, 100 parts by weight of L-121 (inorganic fine particles) was charged into a Henschel mixer having a nozzle port capable of spraying, and 10 parts by weight of a surface treatment agent was sprayed while stirring to obtain inorganic fine particles. The surface treatment agent was reacted.

<Preparation of surface protective layers 4a and 4b>
The surface protective layer 4b was formed by using top coat agents A to D.
<Top coat agent used for surface protective layer 4b>
Topcoat agents are Topcoat A agent, B agent, C agent and D agent.
Top coat agents A and B are mainly composed of ionizing radiation curable resins W and X, and top coat agents C and D are mainly composed of thermosetting resins Y and Z, respectively. ing.

The base material W is a polyfunctional urethane acrylate oligomer having a functional group of 3 to 15, and the base material X is a polyfunctional urethane acrylate oligomer having a functional group of 2 to 9.
The main agent Y is an acrylic polyol having a glass transition temperature of about 100° C., a weight average molecular weight Mw of about 50,000 and a hydroxyl value of 15, and the main agent Z has a glass transition temperature of about 45° C. and a weight average molecular weight Mw of It is an acrylic polyol having a hydroxyl value of about 150,000 and 15.
In the top coat agents A, B, C, and D, 5 parts of Tinuvin 479 (manufactured by BASF Corp.) as an ultraviolet absorber and 100 parts of each of the main ingredients W, X, Y, and Z are used as a light stabilizer. When using 3 parts of Tinuvin 123 (manufactured by BASF Co., Ltd.), 50 parts of ethyl acetate as a diluent solvent, and further using Topcoat C agent and D agent, Duranate TAP-100 (manufactured by Asahi Kasei Co., Ltd.) is further used as a curing agent. 5 parts were added and blended.

<Topcoat E Agent Used for Surface Protective Layer 4a>
The top coat agent used for the surface protective layer 4a is referred to as a top coat E agent.
The top coat E agent is mainly composed of a thermosetting resin N.
The base agent N is an acrylic polyol having a glass transition temperature of about 100° C., a weight average molecular weight Mw of about 40,000 and a hydroxyl value of 12.
In the top coat E agent, with respect to 100 parts of the main agent N, 5 parts of Tinuvin 479 (manufactured by BASF Ltd.) as an ultraviolet absorber, 3 parts of Tinuvin 123 (manufactured by BASF Ltd.) as a light stabilizer, and ethyl acetate as a diluting solvent. 50 parts, 15 parts of an inorganic filler L-121 (manufactured by AGC SITEC Co., Ltd.) as a gloss adjusting agent, and 5 parts of Duranate TAP-100 (manufactured by Asahi Kasei Corporation) as a curing agent were mixed and adjusted.

<Example 1>
On the surface of the surface protective layer 4a, an ionizing radiation-curable top coat agent A and agent B were mixed at 50:50, and 8 parts of surface-treated inorganic fine particles NVC-X1 having an average particle diameter of 5 μm were added. The liquid was applied at a coating amount of 5 g/m ² . Thus, the surface protective layer 4b of Example 1 was formed.
<Example 2>
On the surface of the surface protective layer 4a, an ionizing radiation-curable top coat agent A, agent B and agent C were blended at 40:40:20, and surface treated inorganic fine particles NVC-X1 having an average particle diameter of 5 μm were added. The coating liquid added in parts was coated at a coating amount of 5 g/m ² . Thus, the surface protective layer 4b of Example 2 was formed.

<Comparative Example 1>
On the surface of the surface protective layer 4a, an ionizing radiation-curable top coat agent A, agent B and agent D were mixed at 40:40:20, and surface-treated inorganic fine particles NVC-X1 having an average particle diameter of 5 μm were added. The coating liquid added in parts was coated at a coating amount of 5 g/m ² . Thus, the surface protective layer 4b of Comparative Example 1 was formed.
<Comparative example 2>
On the surface of the surface protective layer 4a, the ionizing radiation-curable top coat agent A, agent B and agent C were blended at 30:30:40, and surface-treated inorganic fine particles NVC-X1 having an average particle diameter of 5 μm were added. The coating liquid added in parts was coated at a coating amount of 5 g/m ² . Thus, the surface protective layer 4b of Comparative Example 2 was formed.

<Example 3>
On the surface of the surface protective layer 4a, an ionizing radiation-curable top coat agent A and agent B were blended at 25:75, and a coating liquid containing no inorganic fine particles was applied at a coating amount of 5 g/m ² . .. Thus, the surface protective layer 4b of Comparative Example 2 was formed. Thus, the surface protective layer 4b of Example 3 was formed.
<Example 4>
On the surface of the surface protective layer 4a, a coating composition was prepared by mixing the ionizing radiation-curable top coat agents A and B at 25:75 and adding 10 parts of surface-treated inorganic fine particles NVC-X1 having an average particle diameter of 5 μm. The liquid was applied at a coating amount of 5 g/m ² . Thus, the surface protective layer 4b of Example 4 was formed.

<Example 5>
On the surface of the surface protective layer 4a, an ionizing radiation-curable top coat agent A and agent B were mixed at 25:75, and 10 parts of surface-treated inorganic fine particles NVC-X1 having an average particle diameter of 8 μm were added. The liquid was applied at a coating amount of 5 g/m ² . Thus, the surface protective layer 4b of Example 5 was formed.
<Example 6>
On the surface of the surface protective layer 4a, an ionizing radiation-curable top coat agent A and agent B were mixed at 25:75, and 10 parts of surface-treated inorganic fine particles NVC-X1 having an average particle diameter of 17 μm were added. The liquid was applied at a coating amount of 5 g/m ² . Thus, the surface protective layer 4b of Example 6 was formed.

<Example 7>
On the surface of the surface protective layer 4a, an ionizing radiation-curable top coat agent A and agent B were blended at 25:75, and 10 parts of inorganic fine particles L-121 having an average particle diameter of 5 μm and not surface-treated were added. The coating solution was applied at a coating amount of 5 g/m ² . Thus, the surface protective layer 4b of Example 7 was formed.
<Example 8>
On the surface of the surface protective layer 4a, a coating composition was prepared by blending the ionizing radiation-curable top coat agents A and B at 25:75 and adding 5 parts of surface-treated inorganic fine particles NVC-X1 having an average particle diameter of 5 μm. The liquid was applied at a coating amount of 5 g/m ² . Thus, the surface protective layer 4b of Example 8 was formed.

<Example 9>
On the surface of the surface protective layer 4a, coatings were prepared by blending the ionizing radiation-curable top coat agents A and B at 25:75, and adding 20 parts of surface-treated inorganic fine particles NVC-X1 having an average particle diameter of 5 μm. The liquid was applied at a coating amount of 5 g/m ² . Thus, the surface protective layer 4b of Example 9 was formed.

<Example 10>
A coating in which 35 parts of inorganic fine particles NVC-X1 having an average particle diameter of 5 μm, which are prepared by blending the ionizing radiation-curable top coat agents A and B in a ratio of 25:75 on the surface of the surface protective layer 4a, are applied. The liquid was applied at a coating amount of 5 g/m ² . Thus, the surface protective layer 4b of Example 10 was formed.

The method for measuring the erosion rate E of each decorative sheet obtained in Examples 1 to 10 and Comparative Examples 1 and 2 will be described below.
Polygonal alumina powder having an average particle diameter D ₅₀ =1.2 μm was dispersed in water to prepare a slurry containing 3% by mass of polygonal alumina powder with respect to the total mass of the slurry. The decorative sheet was fixed to a table, and the projection distance between the decorative sheet and the nozzle for spraying the slurry was set to 4 mm. The nozzle diameter was 1 mm x 1 mm. A slurry containing polygonal alumina powder was jetted from a nozzle, and the decorative sheet fixed to the table was sequentially cut from the surface protective layer. The injection intensity at this time is a standard projection from the existing Si wafer cut under similar experimental conditions in advance and the scraped displacement with respect to the injection amount of the slurry (that is, the depth cut when 1 g of the slurry is sprayed). The force X was determined and determined based on that value. In this example using polygonal alumina powder, the projection force when the existing Si wafer was shaving 6.360 μm/g was defined as the standard projection force X.

In this example, in the case of polygonal alumina powder, X=1/100 projection force (projection force when scraping 0.064 μm/g on an existing Si wafer).
After washing the cut portion with water, the cutting depth, that is, the erosion depth Z was measured.
The erosion depth Z is a stylus type surface shape measuring instrument (manufactured by Kosaka Laboratory Ltd./model PU-EU1/tip of the stylus R=2 μm/load 100 μN/measurement magnification 10,000/measurement length 4 mm/measurement speed 0 The value is measured at 0.2 mm/sec). More specifically, first, the inclination correction was performed using the both end reference areas A and B that were not worn in the measurement length. Next, the step from the regression line serving as the reference to the wear scar center portion C (average value of 50 μm width) was measured. Next, the difference between the step data for 0 g projection and the step data for each projection amount was taken to obtain the erosion depth Z. An erosion progress graph and an erosion rate distribution graph were created from the acquired data of each amount of projection-erosion depth Z. In this way, the erosion depth Z was specified.

In the present example, the erosion process and the shape measurement by the shape measuring instrument were repeated a set number of times (N times), and the shape measurement data for N times was acquired.
Further, in this embodiment, the erosion rate E [μm/g] was calculated using the projected particle amount X′ [g] and the erosion depth Z [μm] calculated from the above-mentioned projection force.
In addition, each of the decorative sheets obtained in Examples 1 to 10 and Comparative Examples 1 and 2 was attached to a wood base material using an urethane-based adhesive, and then subjected to a coin scratch test, a Hoffman scratch test, and a steel wool abrasion. The surface hardness was determined by the test. Moreover, the degree of whitening of the surface of each of the decorative sheets obtained in Examples 1 to 10 and Comparative Examples 1 and 2 was evaluated. The evaluation results are shown in Tables 1 to 4 below.

The test method of each evaluation test will be briefly described below.
<Hoffman scratch test>
The Hoffman scratch test is performed by using a Hoffman scratch hard nester (manufactured by BYK-Gardner) at a constant speed of 200 g for each 200 g and a test length of 5 cm for each load of 200 g to 2000 g. The load at which scratches and scratches on the surface of the decorative sheet occurred was shown.
◎: Hoffman scratch over 1600g ○: Hoffman scratch 1200g
Δ: Hoffman scratch 800 g or more ×: Hoffman scratch less than 600 g In addition, in this Hoffman scratch test, “⊚”, “◯”, and “Δ” were passed.

<Coin scratch test>
In the coin scratch test, a 100-yen or 10-yen coin is used, the angle of the coin is fixed to 45±1° with respect to the decorative sheet, and the coin is 1 kg to 5 kg (1 to 4 kg is 10 yen coin, 5 kg is 100 It is determined whether or not a scratch of 3 mm or more is formed on the decorative sheet by sliding it for 5 cm with a load of (yen coin) applied, and the load at which the scratch is formed is shown as the surface hardness of the decorative sheet.
◎: Coin scratch 3kg or more ○: Coin scratch 2kg
△: Coin scratch 1kg
×: less than 1 kg of coin scratches In this coin scratch test, “⊚”, “◯”, and “Δ” were passed.

<Steel wool rubbing test>
The steel wool rubbing test is carried out by fixing a surface of each decorative sheet attached to a wooden base material with a jig while the steel wool is in contact with the surface, and applying a load of 500 g/cm ^{2 to} the jig. The surface of the decorative sheet was visually inspected for scratches by rubbing it at a constant speed and a distance of 50 mm for 50 reciprocations. As the steel wool, Bonster #0 (manufactured by Japan Steel Wool Co., Ltd.) was rolled into a 1 cm square and used.
⊚: No gloss change and scratches ◯: Slight gloss change can be confirmed, but no scratches Δ: Gloss change causes slight scratches ×: Gloss change causes numerous scratches In the steel wool rubbing test , "◎", "○", "△" were passed.

<Whitening measurement>
For the whitening measurement, a gloss value on the surface of the decorative sheet was measured under the condition of an incident angle of 60° using a handy gloss meter <Gloss Checker> IG-320 manufactured by Horiba Ltd.
◯: No whitening (gloss value less than 1.0)
×: Whitened (gloss value of 1.0 or more)
In addition, in this whitening measurement, “◯” was passed.

As is clear from Tables 1 to 4, the decorative sheets according to Examples 1 to 10 of the present invention have excellent balance of scratch resistance.
When the resin composition of the surface protective layer 4b contains ionizing radiation curable resin in an amount of 65% or more or when it contains a thermosetting resin having a rigid skeleton, the erosion rate E is small, and the Hoffman scratch or steel wool rubbing test is particularly excellent. Became.
Further, when the inorganic filler added to the surface protective layer 4b is surface-treated and the average particle diameter is appropriate or the addition amount is appropriate, the static friction coefficient is small and the resistance is small. The steel wool rubbing test gave excellent results.
Further, the condition that the surface protective layer 4b contains the inorganic fine particles resulted in excellent Hoffman scratch.

Note that the decorative sheets according to Examples 1 to 9 of the present invention have excellent scratch resistance and can reduce whitening of the surface.
The decorative sheet of the present invention is not limited to the above-described embodiments and examples, and various modifications can be made without departing from the features of the invention.

DESCRIPTION OF SYMBOLS 1 Transparent resin layer 1a Embossed pattern 2 Pattern layer 3 Concealment layer 4a Surface protection layer 4b Surface protection layer 5 Primer layer 6 Adhesive layer 7 Raw fabric layer 8 Adhesive resin layer

Claims (12)

A decorative sheet comprising an original fabric, a transparent resin layer, and a surface protective layer in this order,
The surface protective layer is composed of a plurality of layers,
The surface protective layer located on the outermost surface of the surface protective layer is a first surface protective layer,
When the surface protective layer located below the first surface protective layer is used as the second surface protective layer,
The erosion rate E of the first surface protective layer measured using a polygonal alumina powder having an average particle diameter (D ₅₀ ) of 1.2 μm is in the range of 0.1 μm/g or more and 0.4 μm/g or less. A decorative sheet characterized by being. The thickness of the first surface protective layer is in the range of 2 μm or more and 7 μm or less,
The thickness of the second surface protective layer is in the range of 2 μm or more and 14 μm or less,
The decorative sheet according to claim 1, wherein the thickness of the entire surface protective layer is in the range of 4 μm or more and 21 μm or less. The static friction coefficient μs (according to JIS K7 125) of the decorative sheet is in the range of 0.25 or more and 0.5 or less, and the decorative sheet according to claim 1 or claim 2. The decorative sheet according to any one of claims 1 to 3, wherein the transparent resin layer has a thickness of 40 µm or more and 170 µm or less. The surface protective layer contains an inorganic filler,
The average particle diameter of the inorganic filler is in the range of 1 μm or more and 10 μm or less, and the inorganic filler is at least one of alumina, silica, aluminosilicate, glass, boehmite, iron oxide, magnesium oxide, and diamond. The decorative sheet according to any one of claims 1 to 4, wherein: The cosmetic according to claim 5, wherein the content of the inorganic filler is within a range of 1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the resin forming the first surface protective layer. Sheet. 7. The decorative sheet according to claim 5, wherein the inorganic filler is surface-treated. The surface treating agent for treating the surface of the inorganic filler is at least one of a surfactant, a fatty acid metal salt, a silane coupling agent, a silicone, a wax, and a modified resin. Makeup sheet. The surface treatment agent for treating the surface of the inorganic filler has a reactive group that reacts with a main resin that constitutes the first surface protection layer, according to any one of claims 5 to 8. The described decorative sheet. 10. The decorative sheet according to claim 9, wherein the surface treatment agent for treating the surface of the inorganic filler is a surface treatment agent-encapsulated vesicle obtained by encapsulating the surface treatment agent in a vesicle by a supercritical reverse phase evaporation method. The decorative sheet according to claim 1, wherein the decorative sheet does not contain a vinyl chloride resin. The content of the ionizing radiation curable resin in 100 parts by mass of the resin forming the first surface protection layer is in the range of 65 parts by mass or more and 100 parts by mass or less. Item 12. The decorative sheet according to any one of items 11.

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