Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B27/00—Layered products comprising a layer of synthetic resin
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B3/00—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar shape; Layered products comprising a layer having particular features of form
  • B32B3/26—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar shape; Layered products comprising a layer having particular features of form characterised by a particular shape of the outline of the cross-section of a continuous layer; characterised by a layer with cavities or internal voids ; characterised by an apertured layer
  • B32B3/30—Layered products comprising a layer with external or internal discontinuities or unevennesses, or a layer of non-planar shape; Layered products comprising a layer having particular features of form characterised by a particular shape of the outline of the cross-section of a continuous layer; characterised by a layer with cavities or internal voids ; characterised by an apertured layer characterised by a layer formed with recesses or projections, e.g. hollows, grooves, protuberances, ribs
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B33/00—Layered products characterised by particular properties or particular surface features, e.g. particular surface coatings; Layered products designed for particular purposes not covered by another single class
• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04F—FINISHING WORK ON BUILDINGS, e.g. STAIRS, FLOORS
  • E04F13/00—Coverings or linings, e.g. for walls or ceilings
  • E04F13/07—Coverings or linings, e.g. for walls or ceilings composed of covering or lining elements; Sub-structures therefor; Fastening means therefor
• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04F—FINISHING WORK ON BUILDINGS, e.g. STAIRS, FLOORS
  • E04F13/00—Coverings or linings, e.g. for walls or ceilings
  • E04F13/07—Coverings or linings, e.g. for walls or ceilings composed of covering or lining elements; Sub-structures therefor; Fastening means therefor
  • E04F13/08—Coverings or linings, e.g. for walls or ceilings composed of covering or lining elements; Sub-structures therefor; Fastening means therefor composed of a plurality of similar covering or lining elements

Definitions

• the present invention relates to a decorative sheet.
• Decorative sheets are used to decorate the surfaces of interior and exterior materials such as building fixtures, furniture, fixtures, and flooring, for the purpose of imparting design and durability to these components.
• Decorative sheets are generally widely used as decorative panels that are attached via adhesives to the surface of substrates such as wood, wood boards, metal plates, non-flammable boards, paper substrates, and resin substrates.
• Designs can be added by using various printing methods to create patterns such as wood grain or stone grain. Plain decorative sheets without patterns are sometimes preferred. The choice of whether or not to have a pattern and the type of pattern varies depending on the application and preference.
• the glossiness of the surface is also important to the design of decorative sheets.
• decorative sheets There are a variety of decorative sheets to choose from, depending on the application and preference, ranging from high-gloss, mirror-like finishes to low-gloss finishes that do not reflect light at all.
• durability is an important function of decorative sheets, along with providing design. Durability is a comprehensive assessment of scratch resistance, stain resistance, and whether these properties can be maintained over the long term. Requirements vary depending on the environment and situation in which the decorative sheet is used, but there is always a demand for decorative sheets with high performance.
• a surface protective layer on the outermost surface of the decorative sheet. Furthermore, to adjust the aforementioned gloss, particularly to achieve a low gloss, it is common to add a gloss adjuster (matt additive) to the surface protective layer.
• one example of a decorative sheet that takes into consideration design (low gloss), scratch resistance, and stain resistance is the decorative sheet described in Patent Document 1.
• the object of the present invention is to provide a decorative sheet that gives the feel of cool wood.
• One aspect of the present invention provides a decorative sheet comprising a base fabric layer and a surface protective layer provided on one surface of the base fabric layer, wherein the surface of the surface protective layer has an uneven structure, and the uneven structure of the surface protective layer has a load length ratio Rmr(10%) at a cutting level of 10% of 0.4 or more and 0.7 or less, a root mean square slope Rdq of 0.15 or more and 0.4 or less, and a root mean square height Rq of 2.3 ⁇ m or more and 5.6 ⁇ m or less.
• a decorative sheet according to the above aspect in which the gloss level of the surface protective layer is less than 10.
• a decorative sheet according to any of the above aspects, wherein the surface protective layer contains a cured resin and particles.
• a decorative sheet according to the above aspect wherein the particles have an average particle size of 3 ⁇ m or more.
• a decorative sheet according to the above aspect, wherein the particles have an average particle size of 3 ⁇ m or more and 11 ⁇ m or less.
• a decorative sheet according to any of the above aspects, wherein the particles are contained in the surface protective layer in an amount of 3 to 11 parts by weight per 100 parts by weight of the resin.
• a decorative sheet according to any of the above aspects, wherein the resin is an ionizing radiation curable resin.
• a decorative sheet according to any of the above aspects, wherein the resin is an acrylate.
• a decorative sheet according to the above aspect, in which the resin is a trifunctional acrylate containing a repeating structure, and the number of repetitions of the repeating structure is 9 or more and 15 or less.
• a decorative sheet according to the above aspect, in which the resin is a tetrafunctional acrylate containing a repeating structure, and the number of repetitions of the repeating structure is 20 or more and 25 or less.
• a decorative sheet according to any of the above aspects, wherein the thickness t of the surface protective layer is 9 ⁇ m or more and 14 ⁇ m or less.
• a decorative sheet according to the above aspect, further comprising a pattern layer between the base fabric layer and the surface protective layer.
• a decorative sheet relating to the above aspect, in which the pattern layer has a wood grain pattern.
• a decorative material comprising a decorative sheet according to any of the above aspects and a substrate to which the decorative sheet is attached.
• the present invention provides a decorative sheet that gives the feel of cool wood.
• FIG. 1 is a cross-sectional view of a decorative material including a decorative sheet according to one embodiment of the present invention.
• FIG. 2 is a cross-sectional view of a surface protective layer included in the decorative sheet of FIG.
• FIG. 3 is a microscope image of a surface protective layer included in a decorative sheet according to one example of the present invention.
• Decorative material and decorative sheet Fig. 1 is a cross-sectional view of a decorative material including a decorative sheet according to one embodiment of the present invention.
• Fig. 2 is a cross-sectional view of a surface protective layer included in the decorative sheet of Fig. 1.
• Fig. 3 is a micrograph of a surface protective layer included in a decorative sheet according to one example of the present invention.
• the micrograph in Figure 3 is a planar photograph taken with a laser microscope (OLS-4000, manufactured by Olympus Corporation).
• the decorative material 11 shown in Figure 1 includes a substrate B and a decorative sheet 1 attached thereto.
• the decorative material 11 is a decorative board.
• the decorative board may be a flat plate, or may be curved or folded.
• the decorative material 11 may have a shape other than a plate.
• the substrate B is a plate material.
• the plate material is, for example, a wood board, an inorganic board, a metal plate, or a composite board made of multiple materials.
• the substrate B may also have a shape other than a plate.
• the decorative sheet 1 includes a base fabric layer 2, a design layer 3, a transparent resin layer 4, a surface protective layer 5, an adhesive layer 7, a primer layer 6, and a concealing layer 8.
• the design layer 3, adhesive layer 7, transparent resin layer 4, and surface protective layer 5 are provided in this order from the base fabric layer 2 side on the surface of the base fabric layer 2 opposite the surface facing the substrate B.
• the concealing layer 8 and primer layer 6 are provided in this order from the base fabric layer 2 side on the surface of the base fabric layer 2 facing the substrate B.
• One or more of the design layer 3, transparent resin layer 4, primer layer 6, adhesive layer 7, and concealing layer 8 may be omitted. The elements included in the decorative sheet 1 are explained below in order.
• the raw fabric layer 2 or its material can be any material selected from, for example, paper, synthetic resin, synthetic resin foam, rubber, nonwoven fabric, synthetic paper, metal foil, etc.
• paper include tissue paper, titanium paper, and resin-impregnated paper.
• synthetic resins include polyethylene, polypropylene, polybutylene, polystyrene, polycarbonate, polyester, polyamide, ethylene-vinyl acetate copolymer, polyvinyl alcohol, and acrylic.
• Examples of rubber include ethylene-propylene copolymer rubber, ethylene-propylene-diene copolymer rubber, styrene-butadiene copolymer rubber, styrene-isoprene-styrene block copolymer rubber, styrene-butadiene-styrene block copolymer rubber, and polyurethane.
• Examples of nonwoven fabric include organic and inorganic nonwoven fabrics.
• Examples of metals for the metal foil include aluminum, iron, gold, and silver.
• the thickness of the base fabric layer 2 is preferably in the range of 20 ⁇ m to 250 ⁇ m, taking into consideration printing workability and costs.
• Primer Layer When an olefin-based resin is used as the material of the raw fabric layer 2, the surface of the raw fabric layer 2 is often in an inactive state. Therefore, in this case, it is preferable to provide a primer layer 6 between the raw fabric layer 2 and the substrate B.
• the primer layer 6 may be omitted, and the raw fabric layer 2 may be subjected to a surface modification treatment such as corona treatment, plasma treatment, ozone treatment, electron beam treatment, ultraviolet treatment, or dichromate treatment in order to improve the adhesion between the raw fabric layer 2 and the substrate B.
• the materials used for the primer layer 6 can be, for example, the materials described below for the design layer 3. Since the primer layer 6 is applied to the back surface of the decorative sheet 1, and considering that the decorative sheet 1 will be wound into a web, an inorganic filler may be added to the primer layer 6 to avoid blocking and increase adhesion to the adhesive.
• inorganic fillers include silica, alumina, magnesia, titanium oxide, and barium sulfate.
• a colored sheet is used as the base layer 2, or an opaque concealing layer 8 is provided.
• the concealing layer 8 can be made of, for example, the same material as that used for the design layer 3, which will be described later.
• an opaque pigment titanium oxide, iron oxide, or the like, as the pigment.
• metals such as gold, silver, copper, and aluminum can also be added to the material of the concealing layer 8. Generally, flake-shaped aluminum pieces are often added.
• the design layer 3 is a layer formed by printing a design onto the base layer 2 using ink.
• ink binders include soluble nitrocellulose, cellulose, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, polyurethane, acrylic, polyesters, and modified versions thereof, either alone or in combination.
• the binder may be aqueous, solvent-based, or emulsion-based, and may be a one-component type or a two-component type incorporating a curing agent.
• the design layer 3 may be formed by curing a layer formed with a curable ink by exposure to ultraviolet light, electron beams, or the like.
• the most common method is to use a urethane-based ink that is cured with an isocyanate.
• the ink used to form the design layer 3 may further contain, in addition to the binder, pigments and colorants such as dyes, extender pigments, solvents, and various additives typically found in inks.
• pigments and colorants such as dyes, extender pigments, solvents, and various additives typically found in inks.
• versatile pigments include condensed azo, insoluble azo, quinacridone, isoindoline, anthraquinone, imidazolone, cobalt, phthalocyanine, carbon, titanium oxide, iron oxide, and pearl pigments such as mica.
• the ink contains a light stabilizer. This prevents deterioration of the decorative sheet 1 itself due to light degradation of the ink, thereby extending the life of the decorative sheet 1.
• the pattern layer 3 is provided between the base fabric layer 2 and the adhesive layer 7, but it can be provided at any position between the base fabric layer 2 and the surface protection layer 5.
• the pattern layer 3 preferably has a wood grain pattern. If the pattern layer 3 has a wood grain pattern, the user will be able to easily sense the texture of wood from the visual information.
• the pattern layer 3 may also be omitted.
• Adhesive Layer 7 is also called a heat-sensitive adhesive layer, an anchor coat layer, or a dry lamination adhesive layer.
• the resin material for the adhesive layer 7 is not particularly limited, and can be appropriately selected from acrylic, polyester, polyurethane, epoxy, and other resin materials. Furthermore, an ethylene-vinyl acetate copolymer resin adhesive can also be used as the resin material for the adhesive layer 7.
• the coating method can be appropriately selected depending on the viscosity of the adhesive. Generally, gravure coating is used, and the adhesive layer 7 is formed on the upper surface of the design layer 3 by gravure coating, and then the transparent resin layer 4 is laminated. The adhesive layer 7 can be omitted if sufficient adhesive strength can be obtained between the transparent resin layer 4 and the design layer 3.
• An olefin-based resin is preferably used as the resin material for the transparent resin layer 4.
• the olefin-based resin include polypropylene, polyethylene, polybutene, and the like, as well as ⁇ -olefins (e.g., 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
• the resin for the transparent resin layer 4.
• various additives such as heat stabilizers, light stabilizers, antiblocking agents, catalyst scavengers, colorants, light scattering agents, and gloss adjusters can also be added to the transparent resin layer 4 as needed.
• Phenol-based, sulfur-based, phosphorus-based, and hydrazine-based heat stabilizers are commonly used, while hindered amine-based and other light stabilizers are commonly used, each added in any combination.
• the surface protection layer 5 includes a core portion 5A and a plurality of ridge portions 5B each protruding in a ridge shape from one surface of the core portion 5A. These ridge portions 5B form an uneven structure.
• the term "ridge-like” refers to a convex shape that is linear in plan view.
• the ridge portions 5B may be curved or linear in plan view, but curved shapes are preferable from the standpoint of the fingerprint resistance of the decorative sheet 1.
• Each ridge portion 5B may or may not be branched in plan view.
• the ridge portions 5B refer to, for example, the portion from the lowest point to the tip of the uneven shape provided on the surface of the surface protective layer 5, and the core portion 5A refers to the portion of the surface protective layer 5 excluding the ridge portions 5B.
• the ridge portions 5B are each curved, and at least some of them are adjacent to each other in the width direction.
• the cross section of the surface protection layer 5 parallel to this width direction and the thickness direction of the surface protection layer 5 has a wave shape, such as a sine wave shape, in the portion where the uneven structure is provided, as shown in Figure 2.
• the surface protective layer 5 covers the entire upper surface of the underlying layer (transparent resin layer 4 in this embodiment) that contacts the surface protective layer 5.
• the underlying layer i.e., transparent resin layer 4
• the surface protective layer 5 is not exposed on the surface.
• the uneven structure of the surface protection layer 5 has a load length ratio Rmr(10%) of 0.4 or more and 0.7 or less at a cutting level of 10%.
• the load length ratio Rmr(10%) is preferably 0.45 or more and 0.65 or less, and more preferably 0.5 or more and 0.6 or less.
• the load length ratio Rmr (10%) is the ratio of the load length of the roughness curve at a cutting level of 10% to the evaluation length.
• the cutting level of 10% is the level at which the depth from the highest point on the roughness curve is 10% of the maximum cross-sectional height Rt.
• the load length ratio Rmr (10%) correlates with the amount of contact between the finger and the convex portion when the user lightly touches the textured structure with their finger.
• the load length ratio Rmr (10%) and the maximum cross-sectional height Rt are surface texture parameters specified in JIS B0601:2013. A contact-type surface roughness gauge can be used to measure the roughness curve.
• the load length ratio Rmr (10%) is expressed by the following formula 1.
• the uneven structure of the surface protection layer 5 has a root-mean-square slope Rdq of 0.15 or more and 0.4 or less.
• the root-mean-square slope Rdq is preferably 0.2 or more and 0.35 or less, and more preferably 0.25 or more and 0.3 or less.
• Root-mean-square slope Rdq is the root-mean-square of the local slope of a roughness curve over a reference length. Root-mean-square slope Rdq is a parameter that can be used to evaluate the magnitude of the local slope angle. Specifically, root-mean-square slope Rdq is a numerical representation of the steepness of the convex or concave portions contained in an uneven structure. Root-mean-square slope Rdq is a surface texture parameter specified in JIS B0601:2013.
• the root mean square slope Rdq is expressed by the following equation 2.
• the uneven structure has a root mean square height Rq of 2.3 ⁇ m or more and 5.6 ⁇ m or less.
• the root mean square height Rq is preferably 3 ⁇ m or more and 5 ⁇ m or less, and more preferably 3.5 ⁇ m or more and 4.5 ⁇ m or less.
• the root mean square height Rq is the root mean square of the ordinate value Z(x) of the roughness curve over the reference length l.
• the root mean square height Rq is a parameter that can be used to evaluate the height-wise size of the convex or concave portions contained in the uneven structure.
• the root mean square height Rq is a surface texture parameter specified in JIS B0601:2013.
• the root mean square height Rq is expressed by the following equation 3.
• the thickness t of the surface protective layer 5 is preferably 9 ⁇ m or more and 14 ⁇ m or less. It is more preferable that the thickness t of the surface protective layer 5 is 10 ⁇ m or more and 13 ⁇ m or less. If the thickness of the surface protective layer 5 is too small or too large, it becomes difficult to achieve the "cool feel of wood.” Furthermore, if the thickness of the surface protective layer 5 is too large, it becomes difficult to achieve high fingerprint resistance, high stain resistance, and high scratch resistance. Fingerprint resistance, stain resistance, and scratch resistance will be described later.
• the thickness of the surface protective layer 5 is determined by observing the cross section with a scanning electron microscope and averaging the values at 25 points. Specifically, the thickness of the surface protective layer 5 can be determined as described in the examples below. Note that if the surface protective layer coating liquid described below does not contain a solvent, the thickness of the coating film made from the surface protective layer coating liquid will be equal to the thickness of the surface protective layer 5.
• the surface protective layer 5 preferably contains a cured resin and particles.
• the resin contained in the surface protection layer 5 is preferably an ionizing radiation curable resin.
• ionizing radiation refers to a charged particle beam such as an electron beam.
• the ionizing radiation curable resin is cured by irradiation with ionizing radiation.
• the ionizing radiation curable resin can also be cured by irradiation with ultraviolet light.
• the ionizing radiation curable resin used here is cured by irradiation with light having a wavelength of 200 nm or less, and has a large absorption coefficient for this light.
• the amount of cured ionizing radiation curable resin in the surface protective layer 5 is preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more.
• the ionizing radiation curable resin may be any known resin, such as various monomers or commercially available oligomers. For example, (meth)acrylic resins, silicone resins, polyester resins, urethane resins, amide resins, or epoxy resins may be used.
• the ionizing radiation curable resin may be either an aqueous resin or a non-aqueous (organic solvent-based) resin.
• the main component of the ionizing radiation curable resin is preferably an acrylate.
• the main component of the ionizing radiation curable resin means a component that accounts for 60% or more by mass in the ionizing radiation curable resin.
• the ionizing radiation curable resin preferably contains 70 parts by mass or more of acrylate, and more preferably 80 parts by mass or more.
• the ionizing radiation curable resin is more preferably an acrylate.
• the acrylate is preferably a trifunctional or higher acrylate, and more preferably a tetrafunctional or higher acrylate.
• the acrylate is preferably trifunctional or higher.
• the acrylate preferably contains a repeating structure.
• This repeating structure is, for example, an ethylene oxide (EO) structure, a propylene oxide (PO) structure, or an ⁇ -caprolactone (CL) structure.
• the repeating structure is preferably ethylene oxide or propylene oxide.
• the repeating structure may be in an open ring state and interposed between the acryloyl group and the methylol group.
• the number of repetitions of the repeating structure is 9 or more. If an acrylate with a high number of repetitions is used, the cured film is more likely to expand in the plane during the second irradiation step described below, and therefore wrinkles corresponding to the ridge portions 5B are more likely to appear on the surface of the coating film. Furthermore, if an acrylate with a high number of repetitions is used, the gloss value tends to decrease and the design tends to improve. However, if the number of repetitions is increased, the crosslinking density decreases and the scratch resistance of the surface protective layer decreases. Furthermore, if an acrylate with a low number of repetitions is used, it may be difficult to achieve high processability.
• the ionizing radiation curable resin is a trifunctional acrylate containing a repeating unit.
• trifunctional acrylates containing a repeating unit include EO-modified, PO-modified, or CL-modified trimethylolpropane triacrylate, glycerin triacrylate, isocyanurate triacrylate, or pentaerythritol triacrylate.
• the number of repeating units is preferably 9 or more and 15 or less.
• the ionizing radiation curable resin is a tetrafunctional acrylate containing a repeating unit.
• the tetrafunctional acrylate containing a repeating unit is, for example, EO-modified, PO-modified, or CL-modified pentaerythritol tetraacrylate.
• the number of repeating units is preferably 20 or more and 25 or less.
• the number of repetitions of the above repeating structure can be analyzed using MALDI-TOF-MS.
• Ionizing radiation curable resins may have a molecular weight distribution. If there is a molecular weight distribution, the above number of repetitions should be the number of repetitions corresponding to the molecular weight with the strongest peak in the MALDI-TOF-MS mass spectrum.
• the particles contained in the surface protective layer 5 can be, for example, particles made of organic materials such as polyethylene (PE) wax, polypropylene (PP) wax, and resin beads, or particles made of inorganic materials such as silica, glass, alumina, titania, zirconia, calcium carbonate, and barium sulfate.
• PEO polyethylene
• PP polypropylene
• resin beads or particles made of inorganic materials such as silica, glass, alumina, titania, zirconia, calcium carbonate, and barium sulfate.
• the particles preferably have an average particle size (D50) of 3 ⁇ m or more.
• the average particle size (D50) of the particles is more preferably 3 ⁇ m or more and 11 ⁇ m or less, and even more preferably 3 ⁇ m or more and 8 ⁇ m or less.
• the surface protective layer 5 contains particles, wrinkles can be more uniformly formed on the coating surface in the second irradiation step described below.
• the average particle size (D50) of the particles increases, there is a tendency for the user to feel a stronger sense of particle unevenness. For this reason, if the average particle size (D50) is too large, it can be difficult to achieve the "cold wood feel.” Furthermore, if the average particle size (D50) of the particles is large, the particles are more likely to fall off from the surface protective layer 5, making it difficult to achieve high scratch resistance. Furthermore, if the particles are small, the effect of forming wrinkles uniformly can be reduced. Furthermore, if the particles are small, it can be difficult to impart the cold wood feel.
• average particle size (D50) refers to the median size (D50) measured using a laser diffraction/scattering particle size distribution analyzer. If the coating liquid for the surface protective layer contains particles, the surface protective layer 5 obtained from this coating liquid will also contain particles. The average particle size of the particles contained in the surface protective layer 5 can be determined by observing the cross section of the layer and averaging the particle sizes of multiple particles. The value obtained in this manner is essentially the same as the median size (D50) measured using a laser diffraction/scattering particle size distribution analyzer. Therefore, the above-mentioned range of average particle sizes can also be interpreted as the range of average particle sizes of the particles contained in the surface protective layer 5.
• the particles are preferably contained in the surface protection layer 5 in an amount of 3 to 11 parts by weight per 100 parts by weight of resin. It is more preferable that the amount of particles added is 4 to 8 parts by weight per 100 parts by weight of resin. Note that "100 parts by weight of resin” refers to the parts by weight of the solid content of the resin.
• the glossiness of the surface protective layer 5 is preferably less than 10.0.
• the glossiness of the surface protective layer 5 is preferably 5 or less.
• glossiness is the measured value when measured at an angle of incidence of 60 degrees using a glossmeter conforming to JIS Z8741:1997.
• the decorative sheet 1 is manufactured, for example, by the following method.
• explanations of the design layer 3, transparent resin layer 4, primer layer 6, adhesive layer 7, and hiding layer 8 are omitted here.
• a coating liquid for the surface protective layer is prepared and stirred.
• the coating liquid for the surface protective layer contains, for example, the resin and particles described above.
• the main component of the resin is acrylate.
• the particles may appear to be mixed uniformly at first glance, but particle aggregation and other factors can cause uneven particle dispersion in microscopic areas. In this case, wrinkles are less likely to form uniformly on the surface of the surface protective layer 5.
• the load length ratio Rmr (10%) of the uneven structure is likely to be small.
• the above-mentioned unevenness can be eliminated by stirring the coating liquid for the surface protective layer more strongly or for a longer period of time than with a typical stirring method. In this case, the load length ratio Rmr (10%) can be increased.
• the coating liquid for the surface protective layer may further contain a solvent and additives to improve the functionality of the final product, such as antibacterial agents and antifungal agents.
• the coating liquid for the surface protective layer may further contain other additives such as ultraviolet absorbers and light stabilizers.
• ultraviolet absorbers examples include benzotriazoles, benzoates, benzophenones, and triazines.
• light stabilizers examples include hindered amines.
• a surface protective layer 5 with low gloss can be formed without the use of gloss adjusters (matt additives).
• the surface protective layer coating liquid further contains a photoinitiator.
• the photoinitiator is not particularly limited, but examples include benzophenone-based, acetophenone-based, benzoin ether-based, and thioxanthone-based photoinitiators.
• a coating film made from a surface protection layer coating liquid is formed on one surface of the raw fabric layer 2.
• This coating film can be formed by various printing methods, such as gravure printing, offset printing, screen printing, electrostatic printing, and inkjet printing, or various coating methods, such as roll coating, knife coating, microgravure coating, and die coating.
• the first irradiation step is carried out.
• the coating film is irradiated with light having a wavelength of approximately 200 nm or more and 400 nm or less (hereinafter referred to as first radiation).
• first radiation This semi-cures the coating film.
• first radiation By semi-curing the coating film through the first irradiation step, it is possible to uniformly create a wrinkled uneven structure (texture) that will be produced in the second irradiation step described below.
• the light source used in the first irradiation step can be selected from, for example, a high-pressure mercury lamp, a metal halide lamp, and a single-wavelength LED lamp emitting light with a wavelength of 200 nm or more and 400 nm or less.
• the cumulative light dose in the first irradiation step is preferably 2 mJ/cm2 or more and 100 mJ/cm2 or less, more preferably 10 mJ/ cm2 or more and 80 mJ/ cm2 or less, and even more preferably 20 mJ/ cm2 or more and 60 mJ/ cm2 or less. If the cumulative light dose is too small, the effect of the first irradiation step described above will not be achieved. If the cumulative light dose is too large, the coating film will be completely cured, and wrinkles will not be formed in the subsequent second irradiation step.
• the second irradiation step is carried out.
• the coating film is irradiated with light having a wavelength of 200 nm or less (hereinafter referred to as second radiation).
• the ionizing radiation curable resin contained in the coating liquid for the surface protective layer has a large absorption coefficient for the second irradiation light. Therefore, the second irradiation light incident on the coating film can only reach a position several tens to several hundred nm away from the outermost surface. Therefore, in the second irradiation step, the crosslinking reaction proceeds in the surface region of the coating film, forming an extremely thin cured film, while in other regions the crosslinking reaction does not proceed and the coating remains semi-cured.
• the coating film After the second irradiation step, the coating film has wrinkles on its surface that correspond to the ridge portions 5B.
• the second radiation can only reach a position tens to hundreds of nanometers away from the outermost surface of the coating film.
• the crosslinking reaction of the ionizing radiation curable resin caused by irradiation with the second radiation only occurs on the surface of the coating film, and areas more than tens to hundreds of nanometers away from the outermost surface are partially uncured, resulting in the presence of highly fluid molecules.
• These highly fluid molecules swell the cured film, increasing its volume. The increase in volume in the in-plane direction generates in-plane compressive stress, causing the cured film to buckle, resulting in wrinkles on the surface of the coating film.
• the second radiation is usually applied from a vertical direction, the increase in the in-plane volume of the cured film is greater in areas with a nearly horizontal surface than in areas with an inclined surface. In other words, the rate of increase in the in-plane volume of the cured film is greater at the tops of the convex portions and the bottoms of the concave portions than in other parts.
• mass transfer occurs within the coating film from areas corresponding to the concave portions of the wrinkles to areas corresponding to the convex portions of the wrinkles, causing the thickness of the coating film to decrease in the areas that will become concave portions and increase in the areas that will become convex portions. If the coating film is irradiated with the first radiation prior to irradiation with the second radiation, mass transfer within the coating film that accompanies an increase in the in-plane volume of the cured film is moderated.
• the convex portions experience a high rate of volume increase in the in-plane direction of the cured film and are prone to deformation. Therefore, when irradiation with the second radiation continues, the ridge-like convex portions that appear on the surface of the coating film expand, for example, so that the portion of the cross section perpendicular to its length that corresponds to the surface of the coating film takes on a convex curve, and their width also increases.
• the convex portions expand to have the above-mentioned cross-sectional shape and the distance between the convex portions shortens, the amount of light of the second radiation reaching the concave portions decreases. Therefore, in the concave portions, the rate at which the volume of the cured film increases in the in-plane direction decreases.
• a surface protection layer 5 is obtained that has surface properties characterized by the parameters described above.
• the uniformity of particle distribution in the coating film affects the uniformity of the distribution of convex and concave portions, and therefore affects the surface properties of the surface protective layer 5. Therefore, in the above method, the coating liquid for the surface protective layer is stirred more strongly or for a longer period of time than in conventional stirring methods, eliminating non-uniform particle dispersion.
• the second radiation can be extracted from excimer VUV (Vacuum Ultra Violet) light.
• Excimer VUV light can be produced from lamps that use rare gases or rare gas halide compounds. When high-energy electrons are supplied from the outside to a lamp filled with rare gases or rare gas halide compounds, a large number of discharge plasmas (dielectric barrier discharges) are generated. This plasma discharge excites the atoms of the discharge gas (rare gas), which momentarily enter an excimer state. When returning from this excimer state to the ground state, light is emitted in a wavelength range specific to that excimer.
• the gas used in excimer lamps can be any conventional gas that emits light of 200 nm or less.
• gases that can be used include rare gases such as Xe, Ar, and Kr, and mixed gases of rare gases such as ArBr and ArF with halogen gas.
• Excimer lamps have different wavelengths (center wavelengths) depending on the gas used, such as approximately 172 nm (Xe), approximately 126 nm (Ar), approximately 146 nm (Kr), approximately 165 nm (ArBr), and approximately 193 nm (ArF).
• a xenon lamp that emits excimer light with a central wavelength of 172 nm as the light source. Also, considering the cost of maintaining the equipment and the availability of materials, it is preferable to use a xenon lamp as the light source.
• the second irradiation step is carried out in an atmosphere with a low oxygen concentration.
• Oxygen has a high absorption coefficient for light of 200 nm or less. Therefore, the second irradiation step is preferably carried out in, for example, a nitrogen gas atmosphere.
• the oxygen concentration in the gas phase during the second irradiation step i.e., the residual oxygen concentration in the reaction atmosphere, is preferably 2000 ppm or less, and more preferably 1000 ppm or less.
• oxygen in the atmosphere inhibits radical polymerization. Therefore, the residual oxygen concentration in the reaction atmosphere affects the formation of wrinkles on the coating surface. Therefore, changing the residual oxygen concentration in the reaction atmosphere can also change the surface properties of the surface protective layer 5.
• the cumulative light dose of the second radiation is preferably 0.5 mJ/ cm2 or more and 200 mJ/ cm2 or less, more preferably 1 mJ/ cm2 or more and 100 mJ/cm2 or less , even more preferably 3 mJ/ cm2 or more and 50 mJ/ cm2 or less, and most preferably 5 mJ/ cm2 or more and 30 mJ/ cm2 or less. If the cumulative light dose is reduced, the expansion of the cured film in the in-plane direction will be reduced. If the cumulative light dose is increased, the surface condition of the coating film will deteriorate.
• the third irradiation step is carried out.
• the coating film is irradiated with a third radiation to harden the entire coating film. This results in the surface protection layer 5.
• the third radiation is ionizing radiation such as an electron beam, or ultraviolet radiation, which has a longer wavelength than the first radiation.
• the cumulative light amount of the third radiation is preferably 10 mJ/ cm2 or more and 500 mJ/ cm2 or less, more preferably 50 mJ/ cm2 or more and 400 mJ/cm2 or less , and even more preferably 100 mJ/ cm2 or more and 300 mJ/ cm2 or less.
• the decorative sheet 1 can be manufactured, for example, by the method described above.
• the decorative sheet 1 may also be manufactured by other methods.
• a plate may be formed using the method described above for the surface protective layer 5, and the surface protective layer 5 having a relief structure on its surface may be formed by transfer using this plate.
• the decorative sheet 1 described with reference to Figures 1 to 3 has the surface properties of the surface protective layer 5 described above.
• the decorative sheet 1 gives the user the "cool feel of wood.”
• This decorative sheet 1 not only has a low gloss and excellent design, but also has an excellent feel. This feel will be explained below.
• the load length ratio Rmr (10%) of the uneven structure of the surface protection layer 5 is within the above-mentioned range. Therefore, when a user lightly touches the uneven structure with their finger, the contact area between the finger and the protrusions is relatively large. Furthermore, when the decorative sheet 1 is placed at room temperature, the temperature of the surface of the decorative sheet 1 is typically lower than the user's body temperature. Therefore, when a user touches the decorative sheet 1 with their finger, the user's heat is easily conducted to the decorative sheet 1, and the decorative sheet 1 gives the user a cool feeling to the touch.
• the decorative sheet 1 described above has a root-mean-square slope Rdq of the uneven structure that falls within the range described above. Furthermore, the decorative sheet 1 described above has a root-mean-square height Rq of the uneven structure that falls within the range described above.
• the convex portions that form this uneven structure are moderately steep and have a moderate size in the height direction. Therefore, when a user runs their finger over the surface of the surface protection layer 5, the decorative sheet 1 stimulates the user's finger, giving the user a feeling of moderate roughness, i.e., a wood-like feel.
• the decorative sheet 1 gives the user a cool feel
• the decorative sheet 1 gives the user a wood-like feel. Therefore, the decorative sheet 1 gives the user a feel that combines these two feel, i.e., the "feel of cool wood.”
• an uneven structure in which the peaks of the convex portions are steep will have a smaller load length ratio Rmr (10%) than an uneven structure in which the peaks of the convex portions are gentle. In this case, it is possible to distinguish between the two using only the parameter of the load length ratio Rmr (10%).
• an uneven structure in which the peaks of the convex portions are steep and the frequency of unevenness is high may have the same load length ratio Rmr (10%) as an uneven structure in which the peaks of the convex portions are gentle and the frequency of unevenness is low. In this case, it is not possible to distinguish between the two using only the parameter of the load length ratio Rmr (10%).
• the surface protective layer 5 of the decorative sheet 1 has the surface properties described above, and therefore can achieve a low gloss level even without containing a gloss adjuster (matt additive).
• Gloss adjusters reduce the oil repellency of layers formed from resin materials, making surface protective layers 5 containing gloss adjusters more susceptible to fingerprints.
• Surface protective layers 5 that do not contain gloss adjusters are less likely to absorb oil and therefore less likely to be marked with fingerprints.
• surface protective layers 5 with excellent oil repellency are less likely to develop oil stains or adsorb contaminants.
• gloss adjuster particles do not fall off, and therefore decorative sheets 1 containing such surface protective layers 5 are less likely to develop gloss changes or scratches.
• the surface protective layer 5 can achieve a low gloss. In this case, it is possible to reduce the reflection of external light on the surface of the surface protective layer 5. Therefore, for example, if the pattern layer 3 has a wood grain pattern, the wood grain pattern can be visually recognized as a clear pattern. In this case, it is particularly easy to give the user the "feel of cool wood.” Note that while the above parameters are related to low gloss, parameters other than the above are also involved in achieving low gloss. For this reason, a low-gloss decorative sheet does not necessarily meet the requirements of the above parameters.
• Oxygen in the gas phase during the second irradiation step not only absorbs short-wavelength ultraviolet light, but also inhibits radical polymerization.
• the effect of oxygen contained in the gas phase on radical polymerization is greatest in the portions of the coating film made of ionizing radiation-curable resin that are adjacent to the gas phase, and decreases as the distance from the coating film surface increases. Therefore, by changing the oxygen concentration in the gas phase during the second irradiation step, it is possible to change the relationship between the distance from the coating film surface and the progress of the crosslinking reaction.
• the thickness of the cured film formed on the surface of the coating by the second irradiation process and the degree of in-plane expansion of the cured film as the crosslinking reaction progresses will change.
• the thickness of the cured film and the degree of in-plane expansion of the cured film are also affected by the integrated light dose in the first and second irradiation processes.
• the thickness of the cured film and the degree of in-plane expansion of the cured film also affect the surface properties of the surface protective layer.
• the particle size and amount of particles added in the coating film, as well as the thickness of the coating film also affect the formation of wrinkles.
• the stirring method for the coating liquid for the surface protective layer by appropriately setting the stirring method for the coating liquid for the surface protective layer, the composition of the ionizing radiation curable resin, the particle size and amount added, the thickness of the coating film, the oxygen concentration in the gas phase in the second irradiation step, and the integrated light amount in the first and second irradiation steps, it is possible to obtain a surface protective layer with the desired surface properties.
• Example 1 The decorative sheet 1 described with reference to Figures 1 to 3 was produced by the following method: In this example, the transparent resin layer 4, primer layer 6, adhesive layer 7, and masking layer 8 were omitted.
• an impregnated paper (GFR-506, manufactured by Kohjin Co., Ltd.) with a basis weight of 50 g/ m2 was prepared as the raw fabric layer 2.
• a design layer 3 was formed using an oil-based nitrocellulose resin gravure printing ink (PCNT (PCRNT) various colors, manufactured by Toyo Ink Co., Ltd.).
• PCNT nitrocellulose resin gravure printing ink
• the design pattern of the design layer was a wood grain pattern.
• a coating liquid for a surface protective layer was prepared, which was prepared by blending the following particles with the following ionizing radiation curable resin.
• - Ionizing radiation curable resin Type Trimethylolpropane EO modified triacrylate (EO 15 moles added)
• Particle size 5 ⁇ m Blending: 2 parts by mass
• the coating liquid for forming the surface protective layer was stirred. Stirring was carried out as follows. First, the coating liquid for the surface protective layer was placed in a stirring vessel.
• the stirring vessel used was a ZT-20 (manufactured by Satake Multinics Co., Ltd.).
• a Satake Multi A Mixer AT14-VPR-0.09BI manufactured by Satake Multinics Co., Ltd. was used for stirring.
• the stirring method was centripetal stirring.
• the power for stirring the coating liquid for the surface protective layer was 0.75 kW, and the stirring time was 5 minutes.
• a surface protective layer coating liquid was applied onto the design layer 3.
• a coating film made from the surface protective layer coating liquid was formed to a thickness of 11.58 ⁇ m.
• a first irradiation step was carried out. Specifically, in the atmosphere, the surface of the coating film made of the coating liquid for surface protective layer was irradiated with ultraviolet light using a high-pressure mercury lamp emitting ultraviolet light with a dominant wavelength of 365 nm, so that the cumulative light amount was 50 mJ/ cm2 . This resulted in semi-curing of the coating film.
• a second irradiation step was carried out. Specifically, under atmospheric pressure in a nitrogen gas atmosphere with an oxygen concentration of 500 ppm, the surface of the coating film made of the coating liquid for surface protective layer was irradiated with ultraviolet light having a wavelength of 172 nm using a Xe excimer lamp so that the cumulative light amount was 50 mJ/ cm2 . This caused wrinkles to form on the surface of the coating film.
• the third irradiation step was carried out. Specifically, the coating film was irradiated with ionizing radiation to cure the entire coating film, thereby forming the surface protective layer 5. In this manner, a decorative sheet 1 was obtained.
• Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points. That is, in this example, the blending amount of particles was set to 3 parts by mass. Then, a coating film made of the surface protective layer coating liquid was formed to a thickness of 10.31 ⁇ m.
• Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points. That is, in this example, the blending amount of particles was 4 parts by mass. Then, a coating film made of the surface protective layer coating liquid was formed to a thickness of 12.51 ⁇ m.
• Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points. That is, in this example, the blending amount of particles was set to 5 parts by mass. Then, a coating film made of the surface protective layer coating liquid was formed to a thickness of 10.28 ⁇ m.
• Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points. That is, in this example, the blending amount of particles was set to 9.1 parts by mass. Then, a coating film made of the surface protective layer coating liquid was formed to a thickness of 11.08 ⁇ m.
• Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points. That is, in this example, the blending amount of particles was set to 10.9 parts by mass. Then, a coating film made of the surface protective layer coating liquid was formed to a thickness of 10.36 ⁇ m.
• Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points. That is, in this example, the blending amount of particles was set to 12.1 parts by mass. Then, a coating film made of the surface protective layer coating liquid was formed to a thickness of 10.23 ⁇ m.
• Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points. That is, in this example, particles were not blended. Then, a coating film made of the surface protective layer coating liquid was formed to a thickness of 11.18 ⁇ m.
• Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points. That is, in this example, the blending amount of particles was set to 5 parts by mass. Then, a coating film made of the coating liquid for surface protective layer was formed to a thickness of 10.88 ⁇ m. The power for stirring the coating liquid for surface protective layer was set to 0.3 kW.
• Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points. That is, in this example, the blending amount of particles was set to 5 parts by mass. Then, a coating film made of the surface protective layer coating liquid was formed to a thickness of 2.94 ⁇ m.
• Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points. That is, in this example, the blending amount of particles was set to 5 parts by mass. Then, a coating film made of the surface protective layer coating liquid was formed to a thickness of 6.02 ⁇ m.
• Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points. That is, in this example, the blending amount of particles was set to 5 parts by mass. Then, a coating film made of the surface protective layer coating liquid was formed to a thickness of 10.57 ⁇ m.
• Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points. That is, in this example, the blending amount of particles was set to 5 parts by mass. Then, a coating film made of the surface protective layer coating liquid was formed to a thickness of 13.08 ⁇ m.
• Comparative Example 5 Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points. That is, in this example, the blending amount of particles was set to 5 parts by mass. Then, a coating film made of the surface protective layer coating liquid was formed to a thickness of 16.23 ⁇ m.
• Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points: In this example, the following particles were added to the coating liquid for the surface protective layer.
• Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points: In this example, the following particles were added to the coating liquid for the surface protective layer.
• Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points: In this example, the following particles were added to the coating liquid for the surface protective layer. Particles Product name: Sylysia 450 (Fuji Silysia Chemical Ltd.) Particle size: 8 ⁇ m Blending ratio: 5 parts by mass Then, a coating film made of the coating liquid for surface protection layer was formed to a thickness of 10.98 ⁇ m.
• Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points: In this example, the following particles were added to the coating liquid for the surface protective layer. Particles Product name: Sylysia 882 (Fuji Silysia Chemical Ltd.) Particle size: 10 ⁇ m Blending ratio: 5 parts by mass Then, a coating film made of the coating liquid for surface protection layer was formed to a thickness of 11.80 ⁇ m.
• Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points: In this example, the following particles were added to the coating liquid for the surface protective layer. Particles Product name: Sylysia 780 (Fuji Silysia Chemical Ltd.) Particle size: 11 ⁇ m Blending ratio: 5 parts by mass Then, a coating film made of the coating liquid for surface protection layer was formed to a thickness of 10.00 ⁇ m.
• Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points: In this example, the following particles were added to the coating liquid for the surface protective layer.
• Particles Product name sicastar 43-00-154 (manufactured by Corefront Co., Ltd.) Particle size: 14 ⁇ m Blending ratio: 5 parts by mass Then, a coating film made of the coating liquid for surface protection layer was formed to a thickness of 12.80 ⁇ m.
• Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points:
• the following ionizing radiation curable resin was used.
• - Ionizing radiation curable resin Type Trimethylolpropane triacrylate
• the amount of the particles was set to 5 parts by mass.
• a coating film made of the coating liquid for surface protection layer was formed to a thickness of 10.97 ⁇ m, and then the coating film was cured only by the third irradiation step without performing the first irradiation step and the second irradiation step.
• Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points:
• the following ionizing radiation curable resin was used.
• - Ionizing radiation curable resin Type Trimethylolpropane EO modified triacrylate (EO 3 moles added)
• a coating film made of the coating liquid for forming a surface protective layer was formed to a thickness of 11.48 ⁇ m.
• Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points:
• the following ionizing radiation curable resin was used.
• - Ionizing radiation curable resin Type Trimethylolpropane EO modified triacrylate (EO 6 moles added)
• a coating film made of the coating liquid for forming a surface protective layer was formed to a thickness of 11.19 ⁇ m.
• Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points:
• the following ionizing radiation curable resin was used.
• - Ionizing radiation curable resin Type Trimethylolpropane EO modified triacrylate (EO 9 moles added)
• the amount of the particles was set to 5 parts by mass.
• a coating film made of the coating liquid for forming a surface protective layer was formed to a thickness of 12.07 ⁇ m.
• Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points:
• the following ionizing radiation curable resin was used.
• - Ionizing radiation curable resin Type Trimethylolpropane EO modified triacrylate (EO 20 moles added)
• a coating film made of the coating liquid for forming a surface protective layer was formed to a thickness of 12.79 ⁇ m.
• Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points:
• the following ionizing radiation curable resin was used.
• - Ionizing radiation curable resin Type Ethoxylated pentaerythritol tetraacrylate (EO 20 moles added) The amount of the particles was set to 5 parts by mass.
• a coating film made of the coating liquid for forming a surface protective layer was formed to a thickness of 13.11 ⁇ m.
• a shaping mold was prepared.
• the shaping mold was prepared in the same manner as the manufacturing method of the decorative sheet according to Example 16, except for the following points. That is, in preparing the shaping mold, a coating film made of the surface protective layer coating liquid was formed to a thickness of 12.28 ⁇ m.
• this mold was used to transfer the surface shape of the mold as a template onto the surface protection layer on the decorative sheet.
• the transfer was carried out using the following method.
• a UV-curable polydimethylsiloxane liquid (Agent A: X-34-4184A, Agent B: X-34-4184B, manufactured by Shin-Etsu Chemical Co., Ltd.) was diluted with decamethylcyclopentasiloxane (KF-995, manufactured by Shin-Etsu Chemical Co., Ltd.) and mixed at weight ratios of 1:1:7 and 1:1:8, respectively, to prepare a polydimethylsiloxane mixture.
• the polydimethylsiloxane liquid was then applied to the molding die at a coating weight of 10 g/ m2 to form a coating film.
• a 15 ⁇ m-thick PET film was then pressed onto the coating film.
• the molding die After curing the polydimethylsiloxane mixture by UV irradiation, the molding die was peeled off from the UV-cured film of the polydimethylsiloxane mixture.
• This UV-cured film of the polydimethylsiloxane mixture is referred to as the primary transfer film.
• the textured surface of the above primary transfer film was subjected to UV ozone treatment, after which the surface was modified with perfluorodecyltriethoxysilane using a gas-phase deposition method, and the reaction was completed in an oven at 100°C.
• the above polydimethylsiloxane mixture was then coated onto the above primary transfer film in the same amount as above, and a 15 ⁇ m thick PET film was pressed against the coating.
• This polydimethylsiloxane mixture was hardened by UV irradiation, and this is called the secondary transfer film. By peeling this secondary transfer film from the primary transfer film, a mold for forming the textured structure of the surface protection layer was formed.
• a coating film composed of the surface protective layer coating liquid used in Example 16 was prepared by applying the surface protective layer coating liquid to the pattern layer 3 using the same procedure as in Example 16. A mold was pressed onto the prepared coating film, and then the PET film was irradiated twice with ionizing radiation similar to the ionizing radiation irradiation performed in the third irradiation step of Example 16, thereby curing the coating film. The secondary transfer film was then peeled off to form a surface protective layer. In this manner, a decorative sheet was obtained.
• Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points:
• the following ionizing radiation curable resin was used.
• - Ionizing radiation curable resin Type Ethoxylated pentaerythritol tetraacrylate (EO 35 moles added)
• the amount of the particles was 5 parts by mass.
• a coating film made of the coating liquid for forming a surface protective layer was formed to a thickness of 9.85 ⁇ m.
• Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points:
• the following ionizing radiation curable resin was used.
• - Ionizing radiation curable resin Type Trimethylolpropane EO modified triacrylate (EO 6 moles added)
• a coating film made of the coating liquid for forming a surface protective layer was formed to a thickness of 11.28 ⁇ m.
• Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points:
• the following ionizing radiation curable resin was used.
• - Ionizing radiation curable resin Type Ethylene glycol diacrylate (EO 9 moles added)
• Product name Light Acrylate 9EG-A (Kyoeisha Chemical Co., Ltd.)
• the amount of the particles was set to 5 parts by mass.
• a coating film made of the coating liquid for forming a surface protective layer was formed to a thickness of 10.38 ⁇ m.
• Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points:
• the following ionizing radiation curable resin was used.
• - Ionizing radiation curable resin Type Ethoxylated dipentaerythritol hexaacrylate (EO 12 moles added)
• the amount of the particles was set to 5 parts by mass.
• a coating film made of the coating liquid for forming a surface protective layer was formed to a thickness of 11.20 ⁇ m.
• Decorative sheet 1 was produced in the same manner as in Example 1, except for the following points:
• the following ionizing radiation curable resin was used.
• - Ionizing radiation curable resin Type Pentaerythritol tetraacrylate
• Product name NK Ester A-TMMT (manufactured by Shin-Nakamura Chemical Co., Ltd.)
• the amount of the particles was 5 parts by mass.
• a coating film made of the coating liquid for forming a surface protective layer was formed to a thickness of 10.71 ⁇ m.
• the thickness of the surface protective layer was measured as follows. After embedding the decorative sheet 1 in a resin such as a cold-curing epoxy resin or a UV-curable resin and allowing it to fully harden, the decorative sheet 1 was cut to reveal its cross section and mechanically polished to obtain a measurement surface. The thickness of the surface protective layer was then measured using a SIGMA 500 scanning electron microscope manufactured by Carl Zeiss Microscopy. Measurements were performed at 25 random points, and the average measurement value for the 25 points was defined as the "thickness t of the surface protective layer.” The measurement conditions were an acceleration voltage of 0.5 keV (low acceleration voltage), an SE2 mode, and a magnification of 2000x. No sputtering was performed on the measurement sample. The "thickness t of the surface protective layer" was equal to the thickness of the coating film made from the surface protective layer coating liquid.
• the skin feeling was evaluated by the following method. First, preliminary preparations were made to ensure that the evaluation criteria for the tactile sensation related to surface roughness were consistent among the evaluators. Specifically, three standard test pieces with different surface properties (a test piece with an Rdq of less than 0.15, a test piece with an Rdq in the range of 0.15 to 0.4, and a test piece with an Rdq of more than 0.4) were prepared. Next, five evaluators were blindfolded and asked to slide their fingers over the surface of the standard test piece while pressing it with their fingers, and then to classify the tactile sensation related to surface roughness into the following three groups. Group 1: There was little sense of roughness, and the feel was like that of a flat plastic plate. Group 2: It felt moderately rough, giving it a wood-like feel. Group 3: The roughness was felt strongly, and the texture was like that of a file.
• a preliminary preparation was conducted in the same manner as for the tactile sensation related to surface roughness to ensure that the evaluation criteria were consistent among the evaluators.
• three standard test pieces with different surface properties were prepared: a test piece with an Rmr (10%) of greater than 0.35 and less than 0.4, a test piece with an Rmr (10%) in the range of 0.4 to 0.7, and a test piece with an Rmr (10%) in the range of greater than 0.7.
• five evaluators were blindfolded and asked to slide their fingers over the surface of the standard test piece while pressing it with their fingers, and then to classify the tactile sensation related to temperature sensation into the following three groups.
• Group a A lukewarm feel was obtained.
• Group B A cold sensation was felt.
• Group c The touch felt too cold.
• each of the evaluators was blindfolded and asked to slide their fingers over the surface of the surface protective layer while pressing it with their fingers, and then to classify the tactile sensations related to surface roughness and temperature sensation into the three groups mentioned above. This procedure was repeated until the evaluations by each evaluator were consistent three or more times in a row, and the evaluation results between the evaluators were consistent three or more times in a row. From these results, the skin feel was evaluated according to the following criteria.
• A cold wood feel
• B feel other than cold wood feel
• the ease of wiping off fingerprints was evaluated. Specifically, first, the 60-degree gloss of the surface of each decorative sheet was measured, and this 60-degree gloss was taken as the initial gloss. Next, a fingerprint-resistant evaluation liquid was applied to the surface protective layer, and the fingerprint-resistant evaluation liquid applied to the surface of the decorative sheet was wiped off. Here, a higher fatty acid was used as the fingerprint-resistant evaluation liquid. Thereafter, the 60-degree gloss of the portion from which the fingerprint-resistant evaluation liquid had been wiped off was measured, and this 60-degree gloss was taken as the gloss after wiping.
• Fingerprint wiping rate (%) (glossiness after wiping/initial glossiness) x 100
• the evaluation criteria were as follows: AA: 70% or more and less than 250% A: 50% or more and less than 70%, or 250% or more and less than 300% B: Less than 50%, or 300% or more
• Stain Resistance To evaluate stain resistance, the Stain A test specified in the Japanese Agricultural Standards (JAS) was carried out. That is, 10 mm wide lines were drawn on the surface protective layer of each decorative sheet using blue ink, black quick-drying ink, and red crayon, and the sheets were left for 4 hours. Thereafter, the blue ink, black quick-drying ink, and red crayon lines were wiped off with a cloth soaked in ethanol.
• JS Japanese Agricultural Standards
• the evaluation criteria were as follows: AA: No scratches or changes in gloss occurred on the surface. A: Minor scratches or changes in gloss occurred on the surface. B: Significant scratches or changes in gloss occurred on the surface.
• Load length ratio Rmr (10%), root mean square slope Rdq, and root mean square height Rq The load length ratio Rmr (10%), root mean square slope Rdq, and root mean square height Rq were determined as described in the detailed description section.
• the roughness curve used to calculate Rmr (10%), Rdq, and Rq was measured using a small surface roughness tester SJ-210 (manufactured by Mitutoyo Corporation) (a contact-type surface roughness meter). Measurements were taken at five locations with no overlapping, and the average value was used.
• the internal settings were: roughness standard "JIS 2001,” evaluation curve “R curve,” filter “GAUSS,” cutoff values ⁇ s “8 ⁇ m,” ⁇ c “2.5 mm,” number of sections “5,” forward/backward run “OFF,” measurement speed “0.5 mm/s,” and measurement range “AUTO.”
• the cut level standard for calculating the load length ratio was set to "peak”, and the cut level was set to include at least "10%”.
• Tables 1 to 5 The evaluation results are shown in Tables 1 to 5.
• Tables 1 to 5 if the same stirring method as that used for decorative sheet 1 in Example 1 was used in the manufacturing process of decorative sheet 1, this is indicated by entering the letter A in the "Stirring method” column, and if the same stirring method as that used for decorative sheet 1 in Comparative Example 2 was used, this is indicated by entering the letter B in the “Stirring method” column.
• “Cutting level ( ⁇ m)” indicates the cutting level when the load length ratio Rmr (10%) is determined.
• the decorative sheets of Examples 1 to 17 gave the evaluators the feel of cool wood. Furthermore, the decorative sheets of Examples 1 to 5, 8, 10 to 12, and 15 to 17 had low gloss and excellent fingerprint resistance, stain resistance, and scratch resistance. On the other hand, the decorative sheets of Comparative Examples 1 to 15 did not give the evaluators the feel of cool wood.

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