Decorative sheet and decorative laminate

Abstract

To provide a decorative sheet and a decorative laminate capable of suppressing decrease of adhesion strength of a decorative sheet with the lapse of time.SOLUTION: A decorative sheet 10 includes a substrate resin layer 20 and a colored layer 40 laminated on one surface of the substrate resin layer 20. The colored layer 40 includes a resin and a pigment, and a content of the pigment to 100 pts.mass of the resin is 200 pts.mass or over and 380 pts.mass or under. In the colored layer 40, by restraining the content of the pigment to 100 pts.mass of the resin in 200 pts.mass or over and 380 pts.mass or under, failures such as cohesive failure in the colored layer 40 caused by the high pigment concentration is suppressed, and decrease in adhesion strength of the decorative sheet 10 along with failures of the colored layer 40 is suppressed.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a decorative sheet and a decorative board.

Background Art

[0002] Among decorative sheets for building materials, there are some that require high concealment in order to make the base material to which the decorative sheet is to be attached and the intermediate layer of the decorative sheet itself invisible. In addition, due to the increasing concern about environmental problems, thinning of the decorative sheet such as resin reduction is desired. As a method of forming a sheet having high concealment and a thin sheet, there is a method of forming a sheet including a layer coated with a paint containing a high-concentration pigment. The paint containing a high-concentration pigment in this way is likely to cause ink cracking. This ink cracking not only impairs the appearance, but also causes a problem that the barrier performance against various liquids and chemicals is reduced, leading to a reduction in physical properties.

[0003] In order to solve such problems, a method of eliminating ink cracking has been proposed by adjusting the ratio of the pigment to the resin and the thickness of the sheet within an appropriate range (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, decorative sheets for building materials are usually used by being attached to a base material such as a wood material, a metal, or a resin. The inventors have found that in a decorative sheet having a colored concealment layer using a paint, when the pigment contained in the paint is at a high concentration, the adhesion strength of the decorative sheet to the base material decreases over time after the base material and the decorative sheet are bonded together. An object of the present invention is to provide a cosmetic sheet and a decorative board capable of suppressing a decrease in the adhesion strength of the cosmetic sheet over time. **Means for Solving the Problems**

[0006] A cosmetic sheet according to one aspect of the present invention is a cosmetic sheet including a base resin layer and a colored layer laminated on one surface of the base resin layer, wherein the colored layer contains a resin and a pigment, and the content of the pigment with respect to 100 parts by mass of the resin is 200 parts by mass or more and 380 parts by mass or less. Further, a decorative board according to another aspect of the present invention includes the cosmetic sheet of the above aspect and a substrate provided on the colored layer side of the cosmetic sheet. **Advantages of the Invention**

[0007] According to one aspect of the present invention, it is possible to suppress a decrease in the adhesion strength of the cosmetic sheet over time. **Brief Description of the Drawings**

[0008]

Figure 1

Figure 2

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Here, the drawings are schematic, and the relationship between the thickness and the planar dimensions, the ratio of the thickness of each layer, etc. are different from the actual ones. Further, the embodiments shown below are examples of configurations for embodying the technical idea of the present invention, and the technical idea of the present invention is not specified by the materials, shapes, structures, etc. of the constituent parts as follows. The technical idea of the present invention can be variously modified within the technical scope defined by the claims described in the claims.

[0010] Figure 1 is a cross-sectional view schematically showing a cosmetic sheet according to an embodiment of the present invention. In Figure 1, reference numeral 10 denotes a cosmetic sheet. Although not shown, for example, it is used indoors and is adhered to the surface of a base material such as a wood material, metal, or resin, such as furniture (interior doors, entrance storage), millwork (partitions, moldings, baseboards, window frames, door frames), etc., and is used by matching the patterns of furniture and millwork for each house or room.

[0011] The cosmetic sheet 10 includes the following layers, and each layer is provided in order from (1). Note that the following (1) to (6) will be described later. (1) Primer layer 30 (2) Barrier layer 35 (3) Coloring layer 40 (4) Printed pattern layer 50 (5) Base resin layer 20 (6) Top coat layer 60

[0012] Note that each layer of the cosmetic sheet 10 is not limited to the above (1) to (6). As shown in Figure 1, a substrate 70 may be adhered to the side of the primer layer 30 to form a decorative board 11. Also, although not shown, an adhesive layer and a release paper may be added to the side of the primer layer 30 in this order to form a cosmetic tack sheet.

[0013] Also, in Figure 1, the top coat layer 60, printed pattern layer 50, barrier layer 35, and primer layer 30 do not necessarily have to be provided and may be provided as necessary. "If the barrier layer 35 has the function of a primer layer, the primer layer 30 can be omitted. Since there is also a white single-color cosmetic sheet 10, the printed pattern layer 50 may be provided as necessary.

[0014] (Main features of the cosmetic sheet 10) The main features of the cosmetic sheet 10 according to this embodiment are as follows.

[0015] (1) The decorative sheet 10 according to this embodiment is a single-layer film composed of a transparent olefin sheet. On one surface side of the base resin layer 20, a printed pattern layer 50 with a pattern printed thereon, a coloring layer 40, a barrier layer 35, and a primer layer 30 are sequentially formed. Further, on the other surface side of the base resin layer 20, a top coat layer 60 is formed, and it is a decorative sheet that does not have a laminate layer made of another film on either the front surface side or the back surface side of the base resin layer 20. A dispersant as a nano-sized additive is added to the base resin layer 20. Furthermore, the coloring layer 40 is formed by containing 200 parts by mass or more and 380 parts by mass or less of a pigment with respect to 100 parts by mass of the resin.

[0016] According to this embodiment, when manufacturing the decorative sheet 10, since there is no lamination process for other sheets, the manufacturing process from printing to applying the top coat layer 60 can be performed in one-step inline. Also, since the upper limit of the pigment content in the coloring layer 40 is restricted, it is possible to suppress the decrease in the adhesion strength over time due to the high concentration of the pigment, and it is possible to suppress peeling or the like of the decorative sheet caused by the decrease in the adhesion strength after the decorative sheet is attached to the target base material.

[0017] Furthermore, according to this embodiment, in the case of a conventional multi-layer decorative sheet, there was a problem that it was impossible to obtain the limit in film formation and the hardness of the sheet when thinning the sheet. However, since the decorative sheet 10 according to this embodiment is single-layer, it is easy to thin, and by using a nano-sized additive, the sheet can be made hard even if it is thin.

[0018] (2) In the decorative sheet 10 according to this embodiment, in addition to a dispersant as a nano-sized additive, an inorganic filler is added. Therefore, it is possible to further thin the film and improve the scratch-resistant performance.

[0019] (3) Since the substrate 70 is adhered to the side of the primer layer 30 in the decorative board according to this embodiment, it can be easily and quickly used as the decorative board 11. In addition, by providing an adhesive layer and a release paper on the side of the primer layer 30 of the cosmetic sheet 10, a cosmetic tack sheet can be easily realized and adhered quickly.

[0020] (Base resin layer 20) The base resin layer 20 serves as a support for the cosmetic sheet 10 and is made of, for example, a transparent olefin sheet. The base resin layer 20 is formed as a single layer, and a dispersant as a nano-sized additive and an inorganic filler are added. Since the base resin layer 20 is a single layer, it is easy to make it thinner, and by using nano-sized additives, the sheet can be made hard even if it is thin. Details of the base resin layer 20 will be described later.

[0021] (Primer layer 30) As shown in FIG. 1, the primer layer 30 is located on the back side of the base resin layer 20 and is mainly provided for the purpose of improving adhesiveness. In addition to improving adhesiveness, the functions of the primer layer 30 also include surface stabilization after surface treatment, corrosion prevention of the metal surface, imparting tackiness, and preventing deterioration of the adhesive. The primer layer 30 is formed by coating a urethane resin so that the solid content is 1 g / m 2 by, for example, the gravure printing method.

[0022] (Barrier layer 35) The barrier layer 35 is a layer having a function of preventing indoor odors and liquids that cause odors from penetrating into concrete or boards (hereinafter also referred to as "substrate") that make up the building wall surface or building floor surface to which the cosmetic sheet 10 is attached, and preventing various chemical substances from diffusing from the substrate into the room.

[0023] (Coloring layer 40) As shown in FIG. 1, the coloring layer 40 is located on the surface side of the primer layer 30 and is formed using a printing method. It is a concealment layer mainly provided for the purpose of imparting concealment. The coloring layer 40 may be a solid layer. The colored layer 40 is printed with a two-component urethane resin by, for example, the gravure printing method.

[0024] The colored layer 40 is formed of a resin with a pigment added thereto at a ratio such that the pigment is 200 parts by mass or more and 380 parts by mass or less with respect to 100 parts by mass of the resin. As the pigment, titanium oxide is preferable due to its high hiding power. Also, as the pigment, a white paint (such as zirconium oxide, zinc white, etc.) can be applied, and there is no particular limitation as long as it is a pigment used as a coloring material. As the resin to which the pigment is added, a urethane resin is preferable from the viewpoint of adhesion to the printed pattern layer 50, but it is not limited to the urethane resin, and any resin used for paints such as acrylic, epoxy, polyester, ester, fluorine, etc. is not particularly limited.

[0025] (Printed pattern layer 50) As shown in FIG. 1, the printed pattern layer 50 is located on the surface of the colored layer 40, is formed using a printing method, and is provided for the purpose of imparting design properties to the decorative sheet 10. The printed pattern layer 50 is, for example, a pattern printed with a urethane resin by the gravure printing method. As the printing method, for example, the gravure printing method is exemplified, but it is not limited thereto, and various printing methods such as an offset printing method, a letterpress printing method, a flexographic printing method, a screen printing method, an inkjet printing method, an electrostatic printing method, etc. can be applied.

[0026] The type of pattern of the printed pattern layer 50 is arbitrary depending on the purpose of use, the preference of the user, etc., and for example, a wood grain pattern, a stone grain pattern, an abstract pattern, etc. are common. The type of pattern is not limited to the types exemplified above, and for example, full-surface solid printing etc. may be used. As the printing ink used in the printing method, for example, vinyl chloride-based inks (cyan, magenta, yellow) are used.

[0027] In addition, although urethane resins were exemplified as the printing ink, the present invention is not limited thereto, and for example, colorants such as organic or inorganic dyes or pigments may be used. Further, the printing ink may be a composition in which appropriate additives such as fillers, tackifiers, plasticizers, stabilizers, dispersants, defoamers, leveling agents, surfactants, and desiccants, and solvents or diluents are dispersed in a binder made of a synthetic resin or the like.

[0028] (Topcoat layer 60) As shown in FIG. 1, the topcoat layer 60 is located on the surface side of the base resin layer 20 and is formed by a printing method for the purpose of imparting surface physical properties such as abrasion resistance, water resistance, and weather resistance. The topcoat layer 60 is formed, for example, by applying an acrylic two-component curable resin (acrylic urethane resin manufactured by DIC Graphic Co., Ltd.) to a thickness of about 6 μm.

[0029] Note that the topcoat layer 60 is not limited to a single layer as shown in FIG. 1. For example, the topcoat layer 60 may be formed of a high-gloss layer applied to the surface of the base resin layer 20 and a low-gloss layer applied to the surface of the high-gloss layer, so as to produce a pattern due to a difference in gloss. In this case, the pattern may be synchronized with the pattern of the printed pattern layer 50.

[0030] (Details of the base resin layer 20) The base resin layer 20 is a single-layer film composed of a transparent olefin sheet. A dispersant is added to the base resin layer 20 as a nano-sized additive. In addition, a weathering agent is blended in the base resin layer 20. Further, an inorganic filler is added to the base resin layer 20. Note that the inorganic filler does not necessarily have to be added. The base resin layer 20 is formed by extrusion molding using, for example, a transparent polypropylene-based thermoplastic resin. The film thickness of the base resin layer 20 is 50 μm or more and 120 μm or less.

[0031] (Nano-sized additives (nucleating agents), etc.) The base resin layer 20 contains an inorganic filler in addition to a dispersant as a nano-sized additive. Hereinafter, the nano-sized additive is also referred to as a "nano-sized nucleating agent".

[0032] The nano-sized nucleating agent is preferably added to and used in the polypropylene resin in the form of a nucleating agent vesicle encapsulated in a vesicle having an outer membrane of a single-layer film. Also, in the present Embodiment 1, the nucleating agent in the resin constituting the base resin layer 20 may be encapsulated in a vesicle with a part of the nucleating agent exposed. Since the base resin layer 20 contains a nucleating agent, the crystallinity can be improved, and the scratch resistance (scratch resistance) of the decorative sheet 10 can be improved.

[0033] (Particle size of the nano-sized nucleating agent) The nano-sized nucleating agent preferably has an average particle size of 1 / 2 or less of the wavelength region of visible light. Specifically, since the wavelength region of visible light is 400 nm or more and 750 nm or less, the average particle size is preferably 375 nm or less.

[0034] Since the nano-sized nucleating agent has an extremely small particle size, the number and surface area of the nucleating agents present per unit volume increase in inverse proportion to the cube of the particle diameter. As a result, the distance between each nucleating agent particle becomes close. When crystal growth occurs from the surface of one nucleating agent particle added to the resin, the end of the growing crystal immediately contacts the end of the crystal growing from the surface of another nucleating agent particle adjacent to the one nucleating agent particle, and the growth of each crystal is inhibited by the mutual inhibition of the growth of the crystal ends, and the growth of each crystal stops. Therefore, the average particle diameter of the spherulites in the crystalline part of the crystalline resin can be reduced, for example, the spherulite size can be reduced to 1 μm or less.

[0035] As a result, a high-hardness resin film with high crystallinity can be obtained, and since the stress concentration between spherulites generated during bending processing is efficiently dispersed, a resin film that suppresses cracking and whitening during bending processing can be realized. When the nucleating agent is simply added, the nucleating agent in the resin undergoes secondary aggregation, resulting in an increase in particle size. On the one hand, when adding the nucleating agent vesicles, the dispersibility in the resin is improved, so the number of crystal nuclei with respect to the amount of the added nucleating agent increases significantly compared to the case of simply adding the nucleating agent.

[0036] Therefore, the average particle size of spherulites in the crystalline part of the resin becomes smaller, and the occurrence of cracks and whitening during bending processing can be suppressed. Thus, by adding the nucleating agent vesicles, the crystallinity can be further increased, and it becomes possible to better balance the improvement of the elastic modulus and the processability. The base resin layer 20 is formed of, for example, a resin material in which a nucleating agent is added in the range of preferably 0.05 parts by mass or more and 0.5 parts by mass or less, more preferably 0.1 parts by mass or more and 0.3 parts by mass or less, with respect to 100 parts by mass of a polypropylene resin as the main component.

[0037] When using the nucleating agent vesicles, the addition amount of the nucleating agent to the resin material is the addition amount converted to the nucleating agent in the nucleating agent vesicles. When the addition amount of the nucleating agent is less than 0.05 parts by mass, the crystallinity of polypropylene may not be sufficiently improved, and the scratch resistance of the base resin layer 20 may not be sufficiently improved.

[0038] Also, when the addition amount of the nucleating agent exceeds 0.5 parts by mass, due to excessive crystal nuclei, the spherulite growth of polypropylene is conversely inhibited, and as a result, the crystallinity of polypropylene may not be sufficiently improved, and the scratch resistance of the base resin layer 20 may not be sufficiently improved. Here, the "main component" refers to a resin material that occupies 50% by mass or more of the resin material constituting the base resin layer 20.

[0039] (Method for nano-sizing the nucleating agent) Also, as a method for nano-sizing the nucleating agent, for example, a solid phase method in which mainly mechanical grinding is performed on the nucleating agent to obtain nano-sized particles, a liquid phase method in which synthesis and crystallization of nano-sized particles are performed in a solution in which the nucleating agent or the nucleating agent is dissolved, a gas phase method in which synthesis and crystallization of nano-sized particles are performed from a gas or vapor composed of the nucleating agent or the nucleating agent, etc. can be appropriately used.

[0040] Examples of the solid-phase method include a ball mill, bead mill, rod mill, colloid mill, conical mill, disk mill, hammer mill, jet mill, etc. Examples of the liquid-phase method include a crystallization method, coprecipitation method, sol-gel method, liquid-phase reduction method, hydrothermal synthesis method, etc. Further, examples of the gas-phase method include an electric furnace method, chemical flame method, laser method, thermal plasma method, etc.

[0041] (Supercritical reverse phase evaporation method) As a method for nanosizing a nucleating agent, the supercritical reverse phase evaporation method is preferable. The supercritical reverse phase evaporation method is a method for creating a capsule (nanosized vesicle) encapsulating a target substance using carbon dioxide under supercritical state or temperature conditions or pressure conditions above the critical point.

[0042] Supercritical carbon dioxide means carbon dioxide in a supercritical state at a critical temperature (30.98 °C) and a critical pressure (7.3773 ± 0.0030 MPa) or higher, and carbon dioxide under temperature conditions or pressure conditions above the critical point means carbon dioxide under conditions where only the temperature or only the pressure exceeds the critical conditions. Also, as a specific nanosizing treatment by the supercritical reverse phase evaporation method, first, an aqueous phase is injected into a mixed fluid of supercritical carbon dioxide, a phospholipid as an outer membrane-forming substance, and a nucleating agent as an encapsulating substance, and stirred to generate an emulsion of supercritical carbon dioxide and the aqueous phase.

[0043] Next, by reducing the pressure, carbon dioxide expands and evaporates, causing a phase inversion to generate a nanocapsule (nanovesicle) in which the phospholipid covers the surface of the nucleating agent particles with a monolayer film. By using this supercritical reverse phase evaporation method, unlike the conventional encapsulation method in which the outer membrane becomes a multilayer film on the surface of the nucleating agent particles, a capsule with a monolayer film can be easily generated, so that a capsule with a smaller diameter can be prepared.

[0044] The nucleating agent vesicles are prepared, for example, by the Bangham method, the extrusion method, the hydration method, the surfactant dialysis method, the reverse evaporation method, the freeze-thaw method, the supercritical reverse evaporation method, etc. Among them, the nucleating agent vesicles are preferably prepared using the supercritical reverse evaporation method in particular.

[0045] (Outer membrane constituting the nucleating agent vesicle) The outer membrane constituting the nucleating agent vesicle is composed of, for example, a single-layer membrane. Also, the outer membrane is composed of a substance containing a biological lipid such as a phospholipid, for example.

[0046] In this specification, a nucleating agent vesicle whose outer membrane is composed of a substance containing a biological lipid such as a phospholipid is referred to as a nucleating agent liposome.

[0047] Examples of the phospholipid constituting the outer membrane include glycerophospholipids such as phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidic acid, phosphatidylglycerol, phosphatidylinositol, cardiolipin, egg yolk lecithin, hydrogenated egg yolk lecithin, soybean lecithin, hydrogenated soybean lecithin, and sphingolipids such as sphingomyelin, ceramide phosphorylethanolamine, and ceramide phosphorylglycerol.

[0048] (Other substances serving as the outer membrane) Examples of other substances serving as the outer membrane of the vesicle include nonionic surfactants and dispersants such as a mixture of this and cholesterol or triacylglycerol.

[0049] Among these, examples of nonionic surfactants include one or more of polyglycerin ethers, dialkyl glycerins, polyoxyethylene hydrogenated castor oil, polyoxyethylene alkyl ethers, polyoxyethylene sorbitan fatty acid esters, sorbitan fatty acid esters, polyoxyethylene polyoxypropylene copolymers, polybutadiene-polyoxyethylene copolymers, polybutadiene-poly(2-vinylpyridine), polystyrene-polyacrylic acid copolymers, polyethylene oxide-polyethyl ethylene copolymers, polyoxyethylene-polycaprolactam copolymers, etc. Examples of cholesterol compounds include cholesterol, α-cholestanol, β-cholestanol, cholestane, desmosterol (5,24-cholestadien-3β-ol), sodium cholate, or colecalciferol, etc.

[0050] Also, the outer membrane of the liposome may be formed from a mixture of phospholipids and a dispersant. In the cosmetic sheet 10 of the present embodiment, it is preferable that the nucleating agent vesicle be a radical scavenging agent liposome having an outer membrane made of phospholipids. By configuring the outer membrane from phospholipids, the compatibility between the resin material, which is the main component of the cosmetic sheet 10, and the vesicle can be made good.

[0051] The nucleating agent is not particularly limited as long as it is a substance that serves as a crystallization starting point when the resin crystallizes. Examples of nucleating agents include metal phosphate esters, metal benzoates, metal pimelates, metal rosins, benzylidene sorbitol, quinacridone, cyanine blue, and talc. In particular, in order to maximize the effect of the nanosizing treatment, it is preferable to use metal phosphate esters, metal benzoates, metal pimelates, and metal rosins, which are non-melting types and can be expected to have good transparency. However, when the material itself can be made transparent by the nanosizing treatment, colored quinacridone, cyanine blue, talc, etc. can also be used. Also, for non-melting type nucleating agents, melting type benzylidene sorbitol may be appropriately mixed and used.

[0052] (Features of the base resin layer 20) As described above, in the decorative sheet 10 of the present embodiment, the base resin layer 20 contains a resin material and a nucleating agent.

[0053] Further, in the decorative sheet 10 of the present embodiment, when forming the base resin layer 20, a nucleating agent encapsulated in vesicles is added to the resin material to crystallize the resin material. By adding the nucleating agent encapsulated in vesicles to the resin composition, the dispersibility of the nucleating agent in the resin material, that is, in the base resin layer 20, is dramatically improved. On the other hand, it is assumed that in some cases, it is difficult or impractical to directly identify the nucleating agent encapsulated in vesicles based on the structure and properties of the object in the state of the completed decorative sheet 10. The reasons are as follows.

[0054] The nucleating agent added in the state of vesicles is in a dispersed state with high dispersibility, and is highly dispersed in the base resin layer 20 even in the state of the laminate which is the precursor of the produced decorative sheet 10.

[0055] However, in the manufacturing process of the decorative sheet 10, usually, various processes such as compression treatment and curing treatment are performed on the laminate, and in such processes, the outer membrane of the vesicles encapsulating the nucleating agent may be crushed or a chemical reaction may occur.

[0056] For this reason, due to the processing steps of the decorative sheet 10, the state of the outer membrane of the nucleating agent in the completed decorative sheet 10 being crushed or undergoing a chemical reaction varies, and there is also a high possibility that the nucleating agent is not encapsulated (covered) by the outer membrane. And when the nucleating agent is not encapsulated by the outer membrane, it is difficult to specify the physical properties of the nucleating agent itself within a numerical range, and it is also assumed that it is difficult to determine whether the constituent material of the crushed outer membrane is the outer membrane of the vesicles or a material added separately from the nucleating agent.

[0057] As described above, although the present disclosure differs from the prior art in that the nucleating agent is highly dispersed in the cosmetic sheet 10, it is assumed that it may not be practical to specify, within a numerical range obtained by analyzing the structure and properties based on measurements, whether this is because the nucleating agent was added in the form of vesicles encapsulating the nucleating agent, in the state of the cosmetic sheet 10.

[0058] (Method for manufacturing the cosmetic sheet 10) The cosmetic sheet 10 has the configuration described above, and its manufacturing method has the following first to third steps and is manufactured inline.

[0059] Here, "inline" means that since there is no lamination step for laminating films together, printing, which usually consists of multiple steps, can be processed on one line, that is, one single line. That is, the manufacturing process from printing to applying the top coat layer 60 can be carried out in one inline step.

[0060] (1) First step The first step is a step of manufacturing the base resin layer 20, which is a single-layer film, by extrusion molding a transparent polypropylene-based thermoplastic resin.

[0061] (2) Second step The second step is a step of sequentially forming a printed pattern layer 50, a colored layer 40, a barrier layer 35, and a primer layer 30 on the back side of the base resin layer 20 manufactured in the first step. Note that the layers formed in the second step are not limited to the four layers of the printed pattern layer 50, the colored layer 40, the barrier layer 35, and the primer layer 30. For example, it may be only one layer including at least the colored layer 40, or two layers including the primer layer 30 in addition to the colored layer 40. Any layer may be formed as long as it includes the base resin layer 20 and the colored layer 40.

[0062] (3) Third step The third step is a step of forming a top coat layer 60 on the front side of the base resin layer 20 manufactured in the first step after the second step or prior to the second step. The order of the above steps has two patterns: the order of the first step, the second step, and the third step, and the order of the first step, the third step, and the second step.

[0063] (Decorative board 11) As shown in FIG. 1, the decorative board 11 is obtained by adhering a substrate 70 to the side of the primer layer 30 of the decorative sheet 10 having the above-described configuration using an adhesive or the like. Further, the decorative board 11 can also be configured by providing an adhesive layer on the side of the primer layer 30 and directly adhering the substrate 70 to this adhesive layer. Here, the substrate 70 may be made of any type such as wood, steel, resin, etc., and for example, it may be composed of a steel plate with a non-combustible specification or a non-combustible material defined in Notification No. 1400 of the Ministry of Construction.

[0064] (Decorative tack sheet) Although not shown in the figure, the decorative tack sheet is a decorative sheet 10 having the above-described configuration, and an adhesive layer and a release paper are attached to the side of its primer layer 30.

[0065] (Effects of the embodiment) In the decorative sheet 10 according to the present embodiment, the colored layer 40 is formed of a resin in which a pigment is added at a ratio of 200 parts by mass or more and 380 parts by mass or less with respect to 100 parts by mass of the resin. That is, an upper limit is provided for the concentration of the pigment contained in the colored layer 40. In the case of the decorative sheet 10 having the colored layer 40 containing a pigment, when the ratio of the pigment contained in the colored layer 40 is large, when this decorative sheet 10 is attached to a substrate, thereafter, with the passage of time, the adhesion strength of the decorative sheet 10 to the substrate may decrease. In the present embodiment, an upper limit is provided for the concentration of the pigment contained in the colored layer 40. Therefore, after the decorative sheet 10 is attached to the substrate, it is possible to suppress the gradual decrease in the adhesion strength of the decorative sheet 10 to the substrate.

[0066] When attaching the cosmetic sheet 10 to the base material, an adhesive is applied to the surface of the base material or the back surface of the cosmetic sheet 10 by a laminator, a wrapping device, manual work, etc., and pressure is applied to the cosmetic sheet 10 with a roller or the like and attached to the base material, thereby closely adhering the cosmetic sheet 10 to the base material. In the base material with the sheet attached, shrinkage occurs due to the volatilization of the solvent or moisture of the adhesive, and in addition, in the case of a two-component mixed adhesive, further shrinkage occurs due to the progress of the cross-linking reaction over time. Also, the base material may be deformed by containing moisture or the like. In this way, stress associated with the deformation of the adhesive and the base material is applied to the cosmetic sheet 10 over time, and the colored layer 40 is compressed or stretched. At this time, in the case of the colored layer 40 containing a high-concentration pigment, the strength of the colored layer 40 cannot resist the stress, and for example, destruction of the colored layer 40 such as cohesive failure or delamination occurs. Due to this destruction of the colored layer 40, the adhesive strength between the colored layer 40 and the barrier layer 35 of the cosmetic sheet 10, and further, between the colored layer 40 and the base material or the like through the barrier layer 35 and the primer layer 30 decreases.

[0067] In the present embodiment, considering the decrease in the adhesion strength between the cosmetic sheet 10 and the base material caused by the destruction of the colored layer 40 when the cosmetic sheet 10 is attached to the base material, the concentration of the pigment in the colored layer 40 is determined. Therefore, it is possible to suppress not only cracking but also a decrease in the adhesion strength between the cosmetic sheet 10 and the base material, and it is possible to provide a cosmetic sheet 10 that does not peel off from the base material and does not impair the aesthetic appearance.

[0068] In addition, if the proportion of the pigment contained in the colored layer 40 is small, when this cosmetic sheet 10 is attached to the substrate, the concealability is insufficient, and depending on the substrate, the color of the substrate may partially show through, making it impossible to express the originally intended design. In the present embodiment, since a lower limit is provided for the concentration of the pigment contained in the colored layer 40, concealability can be ensured. Also, if the coating amount is increased to enhance the concealability of the colored layer 40 in order to ensure concealability, problems such as an increase in cost and drying issues will occur, and in addition, thinning cannot be achieved. In the present embodiment, since the lower limit value of the pigment contained in the colored layer 40 is restricted to a certain value, it is possible to achieve ensuring concealability and thinning without an increase in cost.

[0069] Moreover, the cosmetic sheet 10 according to the present embodiment does not have a lamination process. Therefore, a series of processes from the first process of forming the base resin layer 20, the second process of forming the printed pattern layer 50, the colored layer 40, the barrier layer 35, and the primer layer 30, and further to the third process of forming the top coat layer 60 can be performed in one inline process. In addition, the base resin layer 20 is formed of a resin containing a nano-sized additive in which a dispersant is added as a nano-sized nucleating agent. By adding the nucleating agent, the base resin layer 20 becomes hard, making it difficult for it to expand and contract.

[0070] Therefore, in the process of forming the printed pattern layer 50, the colored layer 40, the barrier layer 35, and the primer layer 30 on the back side of the base resin layer 20, and in the process of forming the top coat layer 60 on the front side of the base resin layer 20, the expansion and contraction of the base resin layer 20 caused by forming various layers with tension applied to the base resin layer 20, or the expansion and contraction of the base resin layer 20 due to the temperature applied to the base resin layer 20 when drying the ink printed for forming the printed pattern layer 50 after printing the ink for forming the printed pattern layer 50 when forming each layer such as the printed pattern layer 50 can be suppressed.

[0071] (Modification example) In the above embodiment, the case of forming a single-layer base resin layer 20 has been described, but the base resin layer 20 may be composed of two types and three layers.

[0072] That is, as shown in FIG. 2, the base resin layer 20 is formed of two types and three layers in the order of a transparent skin layer 21, a transparent core layer 22 made of transparent polypropylene, and a transparent skin layer 21. In FIG. 2, the base resin layer 20 is represented such that the transparent core layer 22 and the transparent skin layer 21 form separate layers, but actually, the transparent core layer 22 and the transparent skin layer 21 are continuous and it is a single-layer sheet without an interface.

[0073] The base resin layer 20 is co-extruded so that the transparent skin layer 21:transparent core layer 22:transparent skin layer 21 has a thickness ratio of 0.5:9:0.5, and is made to have a total thickness of 50 μm or more and 120 μm or less.

Example

[0074] Hereinafter, examples and comparative examples of the cosmetic sheet according to the present invention will be described. (Example 1) A cosmetic sheet having a colored layer and a base resin layer was prepared by the following procedure using the following materials. First, a weathering agent, a dispersant as a nano-sized additive, etc. were added to a transparent polypropylene resin, and extrusion molding was performed using the transparent polypropylene resin to which these were added to prepare a base resin layer.

[0075] Second, using a bar coater, a pattern layer was printed on the back side of the base resin layer using a urethane-based resin ink. Third, using a bar coater, on the surface of the pattern layer opposite to the base resin layer, a two-component urethane-based resin ink adjusted so that titanium oxide becomes a predetermined weight part (334 mass parts) with respect to 100 mass parts of the resin, and the solid content is 18 g / m 2 was used to form a colored layer.

[0076] Fourth, an acrylic two-component curable resin was applied as a barrier layer using a bar coater so that the solid content became 3 g / m 2 Thereby, the cosmetic sheet 10 of Example 1 was prepared.

[0077] (Example 2) Example 2 was prepared in the same procedure as Example 1 using the same materials as Example 1, except that the colored layer was formed using a two-component urethane resin ink adjusted so that the amount of titanium oxide was 344 parts by mass with respect to 100 parts by mass of the resin.

[0078] (Example 3) Example 3 was prepared in the same procedure as Example 1 using the same materials as Example 1, except that the colored layer was formed using a two-component urethane resin ink adjusted so that the amount of titanium oxide was 377 parts by mass with respect to 100 parts by mass of the resin.

[0079] (Comparative Example 1) Comparative Example 1 was prepared in the same procedure as Example 1 using the same materials as Example 1, except that the colored layer was formed using a two-component urethane resin ink adjusted so that the amount of titanium oxide was 395 parts by mass with respect to 100 parts by mass of the resin.

[0080] (Comparative Example 2) Comparative Example 2 was prepared in the same procedure as Example 1 using the same materials as Example 1, except that the colored layer was formed using a two-component urethane resin ink adjusted so that the amount of titanium oxide was 415 parts by mass with respect to 100 parts by mass of the resin.

[0081] (Comparative Example 3) Comparative Example 3 was prepared in the same procedure as Example 1 using the same materials as Example 1, except that the colored layer was formed using a two-component urethane resin ink adjusted so that the amount of titanium oxide was 435 parts by mass with respect to 100 parts by mass of the resin.

[0082] (Comparative Example 4) Comparative Example 4 was prepared in the same procedure as Example 1 using the same materials as Example 1, except that the colored layer was formed using a two-component urethane resin ink adjusted so that the amount of titanium oxide was 483 parts by mass with respect to 100 parts by mass of the resin.

[0083] (Performance Evaluation Method) As an evaluation of the cosmetic sheet, evaluation of the substrate adhesion strength and visual inspection were performed.

[0084] (Evaluation of Substrate Adhesion Strength) A two-component water-based urethane adhesive was applied to form an adhesive layer (80 g / m 2 ) on a 3 mm thick medium density fiberboard (MDF), which was then pasted onto the back surface of each cosmetic sheet of Examples 1 to 4 and Comparative Examples 1 to 4 and compression-fixed (11 g / cm 2 × 3 days and 11 g / cm 2 × 6 days) to form a decorative board.

[0085] For each of these decorative boards, a cut was made in a 1-inch width from the surface of the decorative board (cosmetic sheet side), and the cosmetic sheet was peeled off from the substrate by 180° peeling at a speed of 50 mm / min using a tensile tester. The strength (kgf / inch) at that time was measured as the adhesion strength. The measurement was carried out at a temperature of 23 ± 2°C. Then, for each of Examples 1 to 3 and Comparative Examples 1 to 4, based on the adhesion strength of the decorated body compressed for 3 days and the adhesion strength of the decorated body compressed for 6 days, the adhesion strength reduction rate was calculated from the following formula.

[0086] Adhesion Strength Reduction Rate = [(Adhesion strength of the decorated body compressed for 6 days) - (Adhesion strength of the decorated body compressed for 3 days)] / (Adhesion strength of the decorated body compressed for 3 days)

[0087] (Visual Inspection) For each cosmetic sheet, visual inspection was carried out to check for ink cracking. The evaluation results are shown in Table 1. In Table 1, the case without ink cracking is marked as 〇, and the case with ink cracking is marked as ×.

[0088]

Table 1

[0089] As shown in Table 1, in the case of Comparative Examples 1 to 4 where the content of titanium oxide with respect to 100 parts by mass of the resin is 395 parts by mass or more, the adhesion strength reduction rate is 29% or more. However, in the case of Examples 1 to 3 where the content of titanium oxide is 377 parts by mass or less, it was confirmed that the adhesion strength reduction rate is 7% or less. Further, in the case of Comparative Examples 1 to 4 where the content of titanium oxide with respect to 100 parts by mass of the resin is 395 parts by mass or more, cracks occurred, but in the case of Examples 1 to 3 where the content is 377 parts by mass or less, it was confirmed that no cracks occurred.

[0090] Further, as shown in Comparative Examples 1 and 2, at the initial stage after attaching the substrate, such as 3 days after attaching the substrate, even if the initial strength is a relatively large value, the substrate adhesion strength significantly decreases 6 days after attaching the substrate. On the other hand, in Examples 1 to 3 where the upper limit of the pigment concentration in the colored layer 40 is limited, if the initial strength is a relatively large value, it can be seen that the substrate adhesion strength only decreases to some extent and is maintained at a relatively large value.

[0091] Note that the present invention can have, for example, the following configurations. (1) A decorative sheet including a base resin layer and a colored layer laminated on one surface of the base resin layer, wherein the colored layer contains a resin and a pigment, and the content of the pigment with respect to 100 parts by mass of the resin is 200 parts by mass or more and 380 parts by mass or less. The decorative sheet is characterized by this. (2) The decorative sheet according to (1) above, wherein the reduction rate of the adhesion strength between the decorative sheet and an object adhered to the decorative sheet is 7% or less. (3) The decorative sheet according to (1) or (2) above, further comprising a top coat layer on the surface of the base resin layer opposite to the colored layer. (4) The decorative sheet according to any one of (1) to (3) above, further comprising a printed pattern layer between the base resin layer and the colored layer. (5) The decorative sheet according to any one of (1) to (4) above, characterized in that a barrier layer is provided on the side of the colored layer opposite to the base resin layer. (6) The decorative sheet according to any one of (1) to (5) above, characterized in that a primer layer is provided on the side of the colored layer opposite to the base resin layer. (7) The decorative sheet according to any one of (1) to (6) above, and a substrate provided on the colored layer side of the decorative sheet, a decorative panel characterized by comprising.

Explanation of symbols

[0092] 10 Decorative sheet 20 Base resin layer 21 Transparent skin layer 22 Transparent core layer 30 Primer layer 35 Barrier layer 40 Colored layer 50 Printed pattern layer 60 Top coat layer

Claims

1. A decorative sheet comprising a base resin layer and a colored layer laminated on one surface of the base resin layer, The colored layer contains a resin and a pigment, A decorative sheet characterized in that the content of the pigment with respect to 100 parts by mass of the resin is 200 parts by mass or more and 380 parts by mass or less.

2. The decorative sheet according to claim 1, characterized in that the reduction rate of the adhesion strength between the decorative sheet and an object adhered to the decorative sheet is 7% or less.

3. The decorative sheet according to claim 1 or claim 2, characterized in that a top coat layer is provided on the surface of the base resin layer opposite to the colored layer.

4. The decorative sheet according to claim 1 or claim 2, characterized in that a printed pattern layer is provided between the base resin layer and the colored layer.

5. The decorative sheet according to claim 1 or claim 2, characterized in that a barrier layer is provided on the side of the colored layer opposite to the base resin layer.

6. The decorative sheet according to claim 1 or claim 2, characterized in that a primer layer is provided on the side of the colored layer opposite to the base resin layer.

7. A decorative board comprising the decorative sheet according to claim 1 or claim 2, and a substrate provided on the colored layer side of the decorative sheet.

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