Decorative sheet and decorative member

Abstract

To provide a decorative sheet which hardly causes changes in appearance when subjected to a stretching load.SOLUTION: There is provided a decorative sheet comprising at least a colored resin layer, a printing layer and a transparent resin layer in this order, which satisfies all of the following conditions (1) to (3). (1) Both of the colored resin layer and the transparent resin layer are an olefin-based thermoplastic resin layer. (2) At least one or both of the colored resin layer and the transparent resin layer contain a fibrous material composed mainly of cellulose. (3) The aspect ratio defined by the (average fiber length / average fiber diameter) of the fibrous material is 10 to 1000.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a decorative sheet and a decorative member. [Background technology]

[0002] Decorative sheets used for the surface decoration of building materials may be subjected to stretching stresses through processes such as V-cut bending (a bending process in which the decorative sheet is attached to a base material, and then a V-shaped groove is formed on the side of the base material opposite the decorative sheet) and wrapping. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4248728 Summary of the Invention [Problem to be solved by the invention]

[0004] When a stretching load is applied to a decorative sheet, changes in the appearance of the decorative sheet may occur, such as stretching of the pattern, etc. To prevent these changes in appearance, methods have been proposed to make the decorative sheet more flexible, but this has the problem of reducing scratch resistance.

[0005] The present invention has been devised to solve such problems, and has as its object to provide a decorative sheet that is less likely to change in appearance when a stretching load is applied to the decorative sheet. [Means for solving the problem]

[0006] [1] A decorative sheet comprising at least a colored resin layer, a printed layer, and a transparent resin layer in this order, A decorative sheet that meets all of the following conditions (1) to (3). (1) Both the colored resin layer and the transparent resin layer are olefin-based thermoplastic resin layers. (2) At least one of the colored resin layer and the transparent resin layer or both of them contains a fibrous material whose main component is cellulose. (3) The aspect ratio of the fibrous material, defined as (average fiber length / average fiber diameter), is 10 to 1,000. [2] The decorative sheet according to [1], wherein only the colored resin layer of the colored resin layer and the transparent resin layer contains the fibrous material whose main component is cellulose. [3] The decorative sheet according to [1] or [2], wherein the colored resin layer contains the fibrous material in a concentration of 0.1 to 5.0% by mass. [4] At least one of the colored resin layer and the transparent resin layer containing the fibrous material contains a polyolefin graft-polymerized with a carboxylic acid anhydride. The decorative sheet according to any one of [1] to [3]. [5] The decorative sheet according to [4], wherein the carboxylic acid anhydride is maleic anhydride. [6] The decorative sheet according to any one of [1] to [5], wherein at least one of the colored resin layer and the transparent resin layer containing the fibrous material is molded by an inflation method. [7] A decorative member comprising a substrate and the decorative sheet according to any one of [1] to [6] attached onto the substrate. [Effects of the Invention]

[0007] According to the present invention, a decorative sheet is provided which is less susceptible to changes in appearance when subjected to a stretching load. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view illustrating a decorative sheet according to one embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] (decorative sheet) An example of the decorative sheet of the present invention will be described with reference to FIG.

[0010] As shown in FIG. 1, the decorative sheet 100 comprises at least a colored resin layer 10, a printed layer 20, and a transparent resin layer 30 in this order.

[0011] (Colored resin layer 10) The colored resin layer 10 is an olefin-based thermoplastic resin layer. An olefin-based thermoplastic resin is a resin whose main component is polyolefin. Examples of polyolefins include polyethylene, polypropylene, polybutene, copolymers of ethylene and one or more α-olefins, and copolymers of two or more α-olefins. Examples of α-olefins include 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, and 12-ethyl-1-tetradecene.

[0012] "Polyolefin as the main component" means that polyolefin is the largest component, and the amount of polyolefin may be 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, or 90% by mass or more.

[0013] The colored resin layer 10 may contain multiple types of polyolefins. For example, the colored resin layer 10 may contain a polyolefin having an MFR of less than 1 and a polyolefin having an MFR of 10 or more.

[0014] The colored resin layer 10 may contain a polyolefin graft-polymerized with a carboxylic acid anhydride. An example of the carboxylic acid anhydride is maleic anhydride. The amount of the polyolefin graft-polymerized with the carboxylic acid anhydride may be 0.1% by mass or more and 20% by mass or less of the total polyolefin.

[0015] When the colored resin layer contains a polyolefin graft-polymerized with a carboxylic acid anhydride, the compatibility between the polyolefin and the fibrous material containing cellulose as the main component is improved, and whitening due to stretching is suppressed.

[0016] The colored resin layer 10 contains a colorant such as a pigment. Examples of the pigment include inorganic pigments such as metal oxides, such as titanium oxide and iron oxide, and composite oxides, such as iron-zinc oxide, chromium-antimony oxide, and iron-aluminum oxide. The hue of the base color of the printed layer 20 can be selected appropriately depending on the type of colorant.

[0017] The amount of colorant in the colored resin layer 10 may be 0.1% by mass or more and 30% by mass or less.

[0018] (fibrous material whose main component is cellulose) The colored resin layer 10 contains a fibrous material whose main component is cellulose.

[0019] Examples of fibrous materials whose main component is cellulose include plant fibers, recycled fibers, acetate-based fibers (diacetate and triacetate), pulp fibers, and cellulose fibers.

[0020] Examples of plant fibers include cotton and hemp.

[0021] Examples of acetate-based fibers include acetate fibers, diacetate fibers, and triacetate fibers.

[0022] Examples of regenerated fibers include rayon and cupra.

[0023] Pulp fibers are fibers obtained by removing lignin and hemicellulose from plant fibers.

[0024] The cellulose fibers are fibers obtained by defibrating pulp fibers. The diameter of the cellulose fibers may be 1 μm or more, or may be less than 1 μm. The diameter of the cellulose fibers may be 3 nm to 10 μm.

[0025] The cellulose in the fibrous material may be modified with a hydrophobic functional group such as fluorene.

[0026] Fibers containing cellulose as a main component, such as cellulose fibers, may contain at least one of hemicellulose and lignin in addition to cellulose. Cellulose may account for 50% by mass or more, or 70% by mass or more, of the fibrous material.

[0027] The aspect ratio of the fibrous material containing cellulose as a main component is 10 to 1000. The aspect ratio may be 20 or more, 50 or more, 100 or more, 150 or more, or 200 or more. The aspect ratio may be 500 or less.

[0028] The aspect ratio of a fibrous material whose main component is cellulose is defined as (average fiber length / average fiber diameter). Specifically, the fiber diameter and fiber length of any 20 fibers in a transmission electron microscope image of the colored resin layer are obtained, and the aspect ratio can be calculated as the ratio of the average fiber length to the average fiber diameter.

[0029] The aspect ratio of the fibrous material in the colored resin layer can vary not only depending on the aspect ratio of the fibrous material at the raw material stage of resin production, but also on the kneading conditions during production of the colored resin layer.

[0030] When polyolefin, colorant, and fibrous material are melt-kneaded in a twin-screw extruder, the aspect ratio of the fibrous material in the colored resin layer can be maintained large without being excessively small compared to the raw material stage by using a polyolefin with a large MFR and setting the kneading temperature relatively high.

[0031] The diameter of the fibrous material may be 0.003 to 10 μm.

[0032] The amount of fibrous material containing cellulose as a main component in the colored resin layer may be 0.1% by mass or more, 0.2% by mass or more, 0.5% by mass or more, 0.7% by mass or more, 1.0% by mass or more, 10% by mass or less, 7.0% by mass or less, 6.0% by mass or less, or 5.0% by mass or less. By setting the amount of cellulose-based fiber material to 0.1 parts by mass or more, it is possible to effectively suppress changes in appearance during stretching, while by setting it to 5.0 parts by mass or less, it is possible to suppress discoloration and deterioration of processability due to excessive stiffening.

[0033] The types and compositions of the polyolefin, colorant, and fibrous material in the colored resin layer can be appropriately selected in consideration of ease of sheeting, printability, and suitability for bending.

[0034] The thickness of the colored resin layer 10 may be 3 μm or more, 20 μm or more, 60 μm or less, or 110 μm or less.

[0035] The colored resin layer may be formed by any method, for example, an extrusion molding method such as T-die molding or inflation molding. Among them, inflation molding is preferred. The inflation molding method reduces anisotropy, making it easier to suppress necking when bending in any direction.

[0036] (Printing layer) The printed layer 20 is a layer that forms a picture pattern to impart design to the decorative sheet 100. Various known printing methods can be used to form the printed layer 20. The printing method is not particularly limited, but gravure printing is preferred in consideration of productivity and pattern quality. Furthermore, for example, if the colored resin layer 10 can be prepared in a rolled state, the printed layer 20 can be formed using a roll-to-roll printing device. Other printing methods include, for example, offset printing, screen printing, flexographic printing, electrostatic printing, inkjet printing, and transfer printing from a transfer sheet. When using such a printing method, the picture pattern of the printing layer 20 can be formed by multi-color printing using the usual process colors of yellow, red, blue, and black, or by multi-color printing using special colors in which plates of the individual colors that make up the picture pattern are prepared.

[0037] The pattern of the printed layer 20 can be any pattern depending on the design of the flooring material or fitting. For example, a marble grain pattern can be used to evoke the image of a stone floor such as marble. Furthermore, for example, if a wood-based pattern is desired, various wood grains or cork can be used as the pattern. Furthermore, in addition to patterns of natural materials, artificial patterns based on these motifs or geometric patterns can also be used. In addition to these, other examples of pattern designs include wood grain patterns composed of spring wood and autumn wood regions in the cross section of tree rings, vessel parts, etc., leather (grain) patterns, stone grain patterns on the surface of stone materials such as marble, granite, and sandstone, sand grain patterns, tile patterns, brickwork patterns, fabric patterns, geometric shapes, letters, symbols, abstract patterns, floral patterns, landscapes, characters, etc.

[0038] The ink for forming the print layer is a mixture of a solvent and solid components such as a colorant and a binder resin.

[0039] Examples of solvents include petroleum-based organic solvents such as hexane, heptane, octane, toluene, xylene, ethylbenzene, cyclohexane, and methylcyclohexane; ester-based organic solvents such as ethyl acetate, butyl acetate, 2-methoxyethyl acetate, and 2-ethoxyethyl acetate; alcohol-based organic solvents such as methyl alcohol, ethyl alcohol, normal propyl alcohol, isopropyl alcohol, isobutyl alcohol, ethylene glycol, and propylene glycol; ketone-based organic solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone; ether-based organic solvents such as diethyl ether, dioxane, and tetrahydrofuran; chlorine-based organic solvents such as dichloromethane, carbon tetrachloride, trichloroethylene, and tetrachloroethylene; and inorganic solvents such as water. The solvents may be used alone or in combination of two or more.

[0040] Examples of binder resins include chlorine-based resins, urethane resins, acrylic urethane resins, acrylic resins, polyester resins, polyamide resins, butyral resins, polystyrene resins, nitrocellulose resins (nitrocellulose), and cellulose acetate resins. Examples of chlorine-based resins include polyvinyl chloride resins such as polyvinyl chloride, chlorinated polyethylene, polyvinylidene chloride, ethylene-vinyl chloride copolymer, vinyl chloride-vinyl acetate copolymer, and vinyl chloride-vinyl acetate-(meth)acrylic copolymer, as well as polypropylene chloride and chlorinated polypropylene, where (meth)acrylic means acrylic or methacrylic. The binder resin may be a single type or a combination of two or more types.

[0041] Examples of colorants include inorganic pigments such as carbon black, iron black, titanium white (titanium oxide), antimony white, yellow lead, titanium yellow, red iron oxide, cadmium red, ultramarine blue, and cobalt blue; and organic pigments such as quinacridone red, isoindolinone yellow, and phthalocyanine blue. The colorant may be one type alone or two or more types in combination. The solvent contained in the printing ink will eventually volatilize, so the printed layer 20 is formed mainly from solid components such as colorants and binder resins.

[0042] The printing ink may also contain other components such as a stabilizer, a plasticizer, a catalyst, and a curing agent. The printing ink may be selected in accordance with the printing method, taking into consideration in particular the adhesion to the colored resin layer 10, printability, and weather resistance as a flooring material or fitting. The thickness of the printed layer 20 can be adjusted as appropriate, taking into consideration the decorative properties required of the printed layer 20, the three-dimensional formability of the decorative sheet 100, etc. The thickness of the printed layer 20 is usually 1 μm or more and 1 mm or less, preferably 2 μm or more and 0.1 mm or less, and more preferably 2 μm or more and 50 μm or less.

[0043] (adhesive layer 25) For the purpose of improving the adhesion between the printing layer 20 and the transparent resin layer 30, an adhesive layer 25 may be provided on the surface of the printing layer 20 that comes into contact with the transparent resin layer 30. By strengthening this adhesion, it may become easier to impart bending processability to the decorative sheet 100 so that it can follow curved surfaces and right-angled surfaces. The resin used for the adhesive layer 25 is not particularly limited. For example, a two-component curing urethane resin can be used. Alternatively, the adhesive layer can be formed by adhering an adhesive resin to the printing layer 20 with a urethane adhesive. For example, a coating device or a gravure printing device can be used to apply the resin used for the adhesive layer 25. The thickness of adhesive layer 25 may be 0.1 μm or more, 1 μm or more, 5 μm or less, or 15 μm or less.

[0044] (Transparent resin layer) The transparent resin layer 30 is a resin layer that not only adds thickness and depth for design purposes, but also protects the printed layer 20 and imparts good surface properties to improve the weather resistance and abrasion resistance of the decorative sheet 100. The transparent resin layer 30 is an olefin-based thermoplastic resin layer. An olefin-based thermoplastic resin is a resin whose main component is polyolefin. Examples of polyolefins include polyethylene, polypropylene, polybutene, copolymers of ethylene and one or more α-olefins, and copolymers of two or more α-olefins. Examples of α-olefins include 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, and 12-ethyl-1-tetradecene.

[0045] "Polyolefin as the main component" means that polyolefin is the largest component, and the amount of polyolefin may be 50% by mass or more, 60% by mass or more, 70% by mass or more, 80% by mass or more, or 90% by mass or more.

[0046] The transparent resin layer 30 may contain multiple types of polyolefins.

[0047] The transparent resin layer 30 may contain a polyolefin graft-polymerized with a carboxylic acid anhydride. An example of the carboxylic acid anhydride is maleic anhydride. The amount of the polyolefin graft-polymerized with the carboxylic acid anhydride may be 0.1% by mass or more and 20% by mass or less of the total polyolefin.

[0048] The transparent resin layer 30 may contain a fibrous material whose main component is cellulose. The type and concentration of the fibrous material whose main component is cellulose may be the same as those described for the colored resin layer 10. It is preferable that the transparent resin layer 30 does not contain a fibrous material whose main component is cellulose. By including a fibrous material whose main component is cellulose in the colored resin layer but not in the transparent resin layer, discoloration of the transparent resin layer caused by organic materials can be suppressed. Specifically, it is thought that discoloration due to thermal decomposition of cellulose, lignin residue, or hemicellulose residue can be suppressed.

[0049] The transparent resin layer 30 does not contain a colorant such as a pigment, for example, titanium oxide.

[0050] The thickness of the transparent resin layer 30 may be 20 μm or more, 50 μm or more, 70 μm or less, or 120 μm or less.

[0051] A lamination method can be used as a method for forming the transparent resin layer 30. Furthermore, for example, when the transparent resin layer 30 and the adhesive layer 25 are formed simultaneously, a method can be used in which they are formed by co-extrusion.

[0052] (Surface protective layer 40) The surface protective layer 40 is a layer that provides surface properties such as abrasion resistance to the decorative sheet 100. The surface protective layer 40 also serves to adjust the gloss of the surface of the decorative sheet 100. The surface protective layer 40 may be a single layer or multiple layers. For example, the surface protective layer 40 may be formed by providing two layers, a first surface protective layer and a second surface protective layer, in this order on the transparent resin layer 30 . When providing a surface protection layer 40 consisting of a first surface protection layer and a second surface protection layer, each layer may be applied and the coating film may be hardened using a known coating device, heat drying device, or ionizing radiation irradiation device depending on the type of curable resin. Preferably, the surface protective layer 40 is primarily composed of a curable resin, i.e., the resin component of the surface protective layer 40 is substantially composed of a curable resin. "Substantially" refers to, for example, 80 parts by mass or more when the total resin is 100 parts by mass. The surface protective layer 40 may contain weathering agents, plasticizers, stabilizers, fillers, dispersants, colorants such as dyes and pigments, solvents, etc., as needed.

[0053] For example, an ionizing radiation curable resin or a two-component curable urethane resin can be used as the material of the surface protection layer 40. The ionizing radiation curable resin is not particularly limited. For example, a transparent resin can be used whose main component is a prepolymer (including oligomer) and / or monomer containing a radically polymerizable double bond in the molecule that can undergo polymerization and crosslinking reaction upon irradiation with ionizing radiation such as infrared rays, ultraviolet rays, or electron beams. These prepolymers or monomers can be used alone or in combination. Specific examples of prepolymers or monomers include compounds having radically polymerizable unsaturated groups such as (meth)acryloyl groups and (meth)acryloyloxy groups, and cationically polymerizable functional groups such as epoxy groups in the molecule. Also preferred is a polyene / thiol-based prepolymer obtained by combining a polyene with a polythiol. Here, the (meth)acryloyl group means an acryloyl group or a methacryloyl group.

[0054] Examples of prepolymers having a radically polymerizable unsaturated group include polyester (meth)acrylate, urethane (meth)acrylate, epoxy (meth)acrylate, melamine (meth)acrylate, triazine (meth)acrylate, silicone (meth)acrylate, etc. The molecular weight of these is preferably about 250 to 100,000. Furthermore, examples of the monomer having a radically polymerizable unsaturated group include monofunctional monomers such as methyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and phenoxyethyl (meth)acrylate. Examples of polyfunctional monomers include diethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, trimethylpropane tri(meth)acrylate, trimethylolpropane ethylene oxide tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, and dipentaerythritol hexa(meth)acrylate.

[0055] Examples of prepolymers having a cationically polymerizable functional group include prepolymers of epoxy resins such as bisphenol-type epoxy resins and novolac-type epoxy compounds, and vinyl ether resins such as fatty acid vinyl ethers and aromatic vinyl ethers. Furthermore, examples of polyene-based prepolymers include those in which allyl alcohol is added to both ends of polyurethane made from diol and diisocyanate. Examples of thiol-based prepolymers include polythiols such as trimethylolpropane trithioglycolate and pentaerythritol tetrathioglycolate.

[0056] The ionizing radiation may be, for example, electromagnetic waves or charged particles having enough energy to cause a curing reaction of molecules in the ionizing radiation curable resin (composition). Examples of the curing reaction include crosslinking curing reactions. The ultraviolet light source may be, for example, an ultra-high pressure mercury lamp, a high pressure mercury lamp, a low pressure mercury lamp, a carbon arc lamp, a black light, or a metal halide lamp. The wavelength of the ultraviolet light is preferably, for example, 190 nm or more and 380 nm or less. As the electron beam source, for example, an electron beam accelerator such as a Cockcroft-Walton type, a Van de Graaff type, a resonant transformer type, an insulating core transformer type, a linear type, a dynamitron type, a high frequency type, etc. is usable. In particular, one that can irradiate electrons having an energy of 100 keV or more and 1000 keV or less (more preferably, electrons having an energy of 100 keV or more and 300 keV or less) is preferred.

[0057] The two-component curing urethane resin is not particularly limited. For example, it may contain a polyol component having OH groups as the main component and an isocyanate component as the curing agent. Examples of the polyol component having OH groups include acrylic polyol, polyester polyol, polyether polyol, and epoxy polyol. Examples of the isocyanate component include tolylene diisocyanate, hexamethylene diisocyanate, and metaxylene diisocyanate.

[0058] The thickness of the surface protection layer 40 may be 3 μm or more, 9 μm or more, 12 μm or less, or 21 μm or less.

[0059] (Primer coating layer 50) The primer coat layer 50 can be provided on the side of the colored resin layer 10 opposite the printed layer 20. The primer coat layer 50 is a layer for improving adhesion and corrosion resistance with a substrate (not shown) to which the decorative sheet 100 is attached.

[0060] The primer coating layer 50 is formed using, for example, a polyester resin, an organic additive, a pigment, etc. The primer coating layer 50 may contain an anti-rust pigment to improve corrosion resistance. The thickness of the primer coating layer 50 is, for example, in the range of 1 μm to 10 μm.

[0061] (Transformation mode) In the above embodiment, the colored resin layer 10 contains a fibrous material whose main component is cellulose, but the colored resin layer 10 may not contain a fibrous material whose main component is cellulose, and instead the transparent resin layer 30 may contain a fibrous material whose main component is cellulose.

[0062] (Action and effect) The decorative sheet according to this embodiment is less likely to change in appearance when a stretching load is applied to the decorative sheet. The reason for this is not clear, but the following is thought to be the reason: At least one of the colored resin layer and the transparent resin layer contains a fibrous material whose main component is cellulose, and the aspect ratio of the fibrous material is 10 to 1000, which suppresses necking (local elongation) of the decorative sheet when stretched and makes the decorative sheet more likely to elongate overall, thereby suppressing whitening and cracking of the pattern on the printed layer.

[0063] (decorative materials) The decorative member according to this embodiment includes a substrate and the decorative sheet described above attached to the substrate. Examples of the substrate are not particularly limited, and include plywood (such as linden, oak, and lauan), MDF (medium density fiberboard), etc. The decorative sheet may be attached to the substrate using various adhesives. [Example]

[0064] Examples 1 to 4 Random PP (a blend of Prime Polymer's S235WC (MFR=11) and B241 (MFR=0.5)), titanium oxide (Ishihara Sangyo Kaisha CR-63), maleic acid-modified PP (Sanyo Chemical Industry's Umex 1001), and fluorene-modified cellulose fiber PP masterbatch (Osaka Gas Chemicals: cellulose concentration 30% by mass) were mixed and pelletized using a twin-screw extruder at a set temperature of 150°C, according to the mass composition shown in Table 1. The mixture was then extruded at a temperature of 200°C and formed into a film with a thickness of 60 μm, producing a colored resin layer containing cellulose fiber.

[0065] The aspect ratio of the cellulose fibers in the colored resin layer after production was determined by obtaining the fiber diameters and fiber lengths of 20 randomly selected fibers using a transmission electron microscope and calculating the ratio of average fiber length to average fiber diameter.

[0066] After corona treatment was performed on both sides of this colored resin layer, a wood grain pattern printing layer was applied using an inkjet printer (PerformanceJet PJ-2508UF manufactured by Muto Industries).

[0067] Next, a transparent resin layer (thickness 100 μm) of homo PP resin (F-300SP: MFR=3 manufactured by Prime Polymer) prepared separately by T-die extrusion film production was subjected to corona treatment on both sides, and an isocyanate-curing polyester adhesive (Tomoflex TM593: base agent, CAT-RA85: hardener, both manufactured by Toyo-Morton) was applied using a wire bar at a coating amount of 5 g / m2 (after drying), and the printed layer side of the previously prepared colored resin layer was then laminated.

[0068] Next, a UV-curable acrylic resin coating agent was applied to the outermost surface of the transparent resin layer using a wire bar at a coating amount of 10 g / m2 (after drying), and then cured with LED-type UV light to create a surface protection layer.

[0069] On the outermost surface of the colored resin layer, a pigment-free medium ink (V350 manufactured by Toyo Ink) was applied with a wire bar to a coating thickness of 1 g / m2 (after drying) as a primer coating layer, to obtain decorative sheets of Examples 1 to 4.

[0070] (Examples 5 to 8) Decorative sheets of Examples 5 to 8 were obtained in the same manner as in Examples 1 to 4, except that the colored resin layer was produced by inflation film formation instead of T-die extrusion film formation.

[0071] (Comparative Example 1) A decorative sheet of Comparative Example 1 was obtained with the composition shown in Table 2 in the same manner as in Example 1, except that the fluorene-modified cellulose fiber masterbatch was not added when producing the colored resin layer.

[0072] (Comparative Examples 2 to 5) Random PP B241 (Prime Polymer: MFR = 0.5), titanium oxide (Ishihara Sangyo Kaisha CR-63), maleic acid-modified PP (Sanyo Chemical Industry: Umex 1001), and fluorene-modified cellulose fiber masterbatch (Osaka Gas Chemicals) were mixed in the mass composition shown in Table 2 using a twin-screw extruder at a set temperature of 130°C. The screw rotation speed was increased to its maximum to apply shear to the mixed resin and produce pellets. The mixed resin pellets and random PP (Prime Polymer S235WC) pellets were then dry-blended to the mass composition shown in Table 2 and extruded at 200°C using a T-die extruder to produce a film with a thickness of 60 μm, producing a colored resin layer containing cellulose fiber. Otherwise, decorative sheets for Comparative Examples 2 to 5 were obtained using the same methods as in Examples 1 to 4.

[0073] The aspect ratio of the cellulose fibers in the resulting colored resin layer was reduced to about 7 to 9 due to the breakage of the cellulose fibers caused by kneading the high viscosity PP resin with high shear force.

[0074] (Evaluation method) Vinyl acetate emulsion adhesive (Konishi Wood Bond CH18) at 60g / m 2 The decorative sheets of the Examples and Comparative Examples were attached to a piece of MDF (medium density fiberboard) that had been uniformly coated with (wet) primer, pressed and cured, with the primer coating side facing up. Then, a V-groove was cut from the MDF side to a depth that did not reach the sheet, and the sheet was bent in a 0°C environment, and the appearance of the bent part was evaluated.

[0075] The conditions and evaluation are shown in Tables 1 and 2.

[0076] [Table 1]

[0077] [Table 2] [Explanation of symbols]

[0078] 20...printed layer, 10...colored resin layer, 30...transparent resin layer, 100...decorative sheet.

Claims

1. A decorative sheet comprising at least a colored resin layer, a printed layer, and a transparent resin layer in this order, A decorative sheet that satisfies all of the following conditions (1) to (3): (1) Both the colored resin layer and the transparent resin layer are olefin-based thermoplastic resin layers. (2) At least one of or both of the colored resin layer and the transparent resin layer contains a fibrous material whose main component is cellulose. (3) The aspect ratio of the fibrous material, defined as (average fiber length / average fiber diameter), is 10 to 1,000.

2. 2. The decorative sheet according to claim 1, wherein only the colored resin layer of the colored resin layer and the transparent resin layer contains the fibrous material containing cellulose as a main component.

3. 3. The decorative sheet according to claim 1, wherein the colored resin layer contains the fibrous material in a concentration of 0.1 to 5.0% by mass.

4. 3. The decorative sheet according to claim 1, wherein at least one of the colored resin layer and the transparent resin layer containing the fibrous material contains a polyolefin graft-polymerized with a carboxylic acid anhydride.

5. 5. The decorative sheet according to claim 4, wherein said carboxylic acid anhydride is maleic anhydride.

6. 3. The decorative sheet according to claim 1, wherein at least one of the colored resin layer and the transparent resin layer containing the fibrous material is formed by an inflation method.

7. A decorative member comprising a substrate and the decorative sheet according to claim 1 or 2 attached to the substrate.

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