Decorative sheets and panels made from biomass-derived polyethylene

Abstract

To provide a decorative sheet or the like in which biomass-derived polyethylene is used and which enables color loss of pattern design to be minimized and also exhibits excellent durability.SOLUTION: The present invention provides a decorative sheet in which biomass-derived polyethylene is used, comprising: a base material sheet which contains biomass-derived polyethylene and which has a first surface and a second surface; a pattern auxiliary layer which is laminated on the first surface side of the base material sheet so as to cover the entirety of the first surface of the base material sheet; and a pattern design layer which is laminated on the surface of the pattern auxiliary layer on the side opposite to the base material sheet, so as to form a pattern design. The base material sheet contains a phenolic antioxidant.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to decorative sheets and decorative boards in which biomass-derived polyethylene is used. [Background technology]

[0002] 2. Description of the Related Art When it is desired to decorate components used in building materials, furniture, home appliances, and the like, decorative panels having a decorative sheet with a design attached thereto are generally used.

[0003] For example, Patent Document 1 discloses a decorative sheet having at least a surface protective layer on a base sheet, the surface protective layer being characterized in that the surface protective layer is made of a resin composition containing an ionizing radiation curable resin, an aldehyde adsorbent, and a non-photocatalyst. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2013-063635 A Summary of the Invention [Problem to be solved by the invention]

[0005] The base sheet of the decorative sheet used for building materials, etc., is mainly made of plastic. Petroleum-derived plastics are widely used for this plastic, but they are not preferable from the viewpoint of reducing the environmental load. Therefore, biomass-derived plastics, which are made from renewable biological resources, are known as materials that have less environmental load than petroleum-derived plastics.

[0006] The present inventors have conducted extensive research into the introduction of biomass-derived polyethylene films into decorative sheets for building materials and the like, and have found that biomass-derived polyethylene films contain more impurities than petroleum-derived polyethylene films, and are therefore prone to defects caused by the inclusion of impurities, known as fisheyes. Areas where fisheyes exist have a problem of reduced adhesion to resins compared to areas where fisheyes do not exist.

[0007] Therefore, it was found that when biomass-derived polyethylene film is used as a base material for a decorative sheet, the effect of fish eyes causes discoloration of the pattern applied to the pattern layer, etc., resulting in a poor appearance and preventing the sheet from fulfilling its role as a decorative sheet.

[0008] In order to form a wide variety of patterns, the pattern layer must have colors (colored inks containing colorants) arranged partially and overlappingly, and there are edge regions of the colored portions (portions where colored inks are arranged) and overlapping regions between colored portions (portions where colored inks are arranged). When such regions overlap with fisheyes that have low adhesion, color loss is particularly likely to occur, but defects in the pattern are extremely noticeable, and this significantly impairs the quality of the decorative sheet.

[0009] The present inventors have found that the effect of fish eyes can be suppressed by adding an antioxidant to biomass-derived polyethylene. However, although the effect of fisheyes is suppressed when biomass-derived polyethylene contains only a phosphorus-based antioxidant, the inventors have also found a new problem in that when this is used as a base sheet for a decorative sheet, the durability of the decorative sheet decreases.

[0010] Therefore, the present disclosure is intended to solve the above-mentioned problems that have been found when introducing biomass-derived polyethylene into decorative sheets for building materials and the like. [Means for solving the problem]

[0011] By laminating a pattern auxiliary layer in which a base sheet containing biomass-derived polyethylene contains a phenolic antioxidant and covers the entire first surface of the base sheet, it is possible to suppress a decrease in durability of the decorative sheet and to suppress color fading of the pattern in the pattern layer laminated on the first surface side of the base sheet.

[0012] That is, the present disclosure provides a decorative sheet comprising a base sheet containing biomass-derived polyethylene and having a first side and a second side, a pattern auxiliary layer laminated on the first side of the base sheet and covering the entire first side of the base sheet, and a pattern layer constituting a pattern laminated on the side of the pattern auxiliary layer opposite the base sheet, wherein the base sheet is made of biomass-derived polyethylene containing a phenol-based antioxidant.

[0013] In the decorative sheet using biomass-derived polyethylene according to the present disclosure, the base sheet preferably further contains a phosphorus-based antioxidant. In the base sheet, the mass ratio of the phenol-based antioxidant to the phosphorus-based antioxidant is preferably 1:1 to 1:2. The pattern auxiliary layer preferably has a thickness of 1 μm or more and 5 μm or less. The picture auxiliary layer is preferably subjected to a smoothing treatment. It is preferable that the sheet has a back surface adhesive auxiliary layer laminated on the second surface side of the base sheet and covering the entire second surface of the base sheet. The back surface adhesive auxiliary layer preferably contains soluble nitrocellulose in an amount of 5% by mass or less. It is preferable that the picture design layer has a transparent resin layer laminated on the side opposite to the picture auxiliary layer. The transparent resin layer preferably has a thickness of 40 μm or more and 100 μm or less. The transparent resin layer is preferably made of an olefin-based resin. The present disclosure also relates to a decorative sheet in which an adherend is laminated on the second surface side of the base sheet of the decorative sheet using the biomass-derived polyethylene. Effect of the Invention

[0014] The present disclosure can provide a decorative sheet using biomass-derived polyethylene that is capable of suppressing color loss in a design pattern due to fisheyes and also has excellent durability. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a cross-sectional view that illustrates a schematic diagram of a preferred example of a decorative sheet that uses the biomass-derived polyethylene of the present disclosure. [Diagram 2] FIG. 2 is a cross-sectional view that illustrates a schematic diagram of a preferred example of a decorative sheet that uses the biomass-derived polyethylene of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] <Decorative sheet made from biomass-derived polyethylene> The decorative sheet using the biomass-derived polyethylene of the present disclosure will be described below.

[0017] The decorative sheet using the biomass-derived polyethylene of the present disclosure comprises a base sheet containing biomass-derived polyethylene and having a first side and a second side, a pattern auxiliary layer laminated on the first side of the base sheet and covering the entire first side of the base sheet, and a pattern layer constituting a pattern laminated on the side of the pattern auxiliary layer opposite the base sheet, wherein the base sheet contains a phenol-based antioxidant.

[0018] FIG. 1 is a cross-sectional view that illustrates a schematic diagram of a preferred example of a decorative sheet that uses the biomass-derived polyethylene of the present disclosure. As shown in FIG. 1, a decorative sheet 10 using biomass-derived polyethylene according to the present disclosure has a picture pattern layer 3 laminated on the first surface side of a base sheet 1. It also has a base sheet 1, a picture auxiliary layer 2 laminated on the first surface side of the base sheet 1 and covering the entire first surface of the base sheet 1, and a picture pattern layer 3 laminated on the surface side of the picture auxiliary layer 2 opposite the base sheet 1. It is also preferable that the sheet has a back surface adhesion auxiliary layer 4 laminated on the second surface side of the base sheet 1 and covering the entire second surface of the base sheet 1 .

[0019] Fig. 2 is a cross-sectional view for explaining a preferred example of a decorative sheet using the biomass-derived polyethylene of the present disclosure. As shown in Fig. 2, in addition to the layers shown in Fig. 1, the decorative sheet 10 may have a back surface adhesive auxiliary layer 4 laminated on the second surface side of the base sheet 1, and an adhesive layer 5, a transparent resin layer 6, a front surface adhesive auxiliary layer 7, and a front surface protective layer 8 laminated on the picture pattern layer 3 in this order.

[0020] (Base sheet) The decorative sheet uses a base sheet that contains biomass-derived polyethylene and has a first side and a second side. The first side is the side of the base sheet on which the pattern layer is formed (also called the front side), and the second side is the side of the base sheet opposite the first side (the side on which the adherend is laminated, also called the back side).

[0021] "Biomass-derived polyethylene" means that at least a portion of the raw materials used are biomass-derived, but does not mean that all of the raw materials are biomass-derived. Whether or not raw materials derived from biomass are used can be determined by radiocarbon (C14) measurements, which will be described in the "Biomass Degree" section below.

[0022] The base sheet contains, for example, biomass polyethylene, which is a polymer of monomers containing ethylene derived from biomass.

[0023] The base sheet preferably has a biomass ratio of 15% or more. A biomass ratio of 15% or more makes it possible to suitably reduce the use of raw materials derived from fossil fuels and to suitably reduce the environmental load. From the viewpoint of further suitably reducing the environmental load, the biomass degree is more preferably 30% or more, further preferably 45% or more, and particularly preferably 60% or more. The upper limit of the biomass ratio is, for example, 70%, from the viewpoint that the base sheet contains additives and the like, which will be described later.

[0024] "Biomass ratio" (biomass-derived carbon concentration in a base sheet containing biomass-derived polyethylene) is a value measured by measuring the amount of biomass-derived carbon by radiocarbon (C14) measurement. Carbon dioxide in the atmosphere contains a certain percentage (105.5 pMC) of C14, and it is known that the C14 content in plants that grow by absorbing carbon dioxide from the atmosphere, such as corn, is also about 105.5 pMC. It is also known that fossil fuels contain very little C14. Therefore, the percentage of biomass-derived carbon can be calculated by measuring the percentage of C14 in the total carbon atoms in the polyethylene. That is, the content of C14 in polyethylene is P C14 The content of carbon derived from biomass, P bio It can be calculated as follows: P bio (%)=P C14 / 105.5×100

[0025] The base sheet may be made of at least one selected from the group consisting of high-density polyethylene, medium-density polyethylene, low-density polyethylene, and linear low-density polyethylene, or may be made of a mixture of two or more selected from the group consisting of high-density polyethylene, medium-density polyethylene, low-density polyethylene, and linear low-density polyethylene.

[0026] The base sheet contains a phenol-based antioxidant. By having a base sheet containing a phenol-based antioxidant and a pattern auxiliary layer laminated on the first surface side of the base sheet and covering the entire first surface of the base sheet, defects caused by fisheyes in the base sheet can be reduced and color fading in the pattern can be suppressed.

[0027] Examples of the phenol-based antioxidant include hindered phenol-based antioxidants, and specific examples thereof include pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, thiodiethylene bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], N,N'-hexane-1,6-diylbis[3-(3,5-di-tert-butyl-4-hydroxyphenylpropionamide)], 2,4-dimethyl-6-(1-methylpentadecyl)phenol, diethyl[[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]phosphonate, 3,3',3'',5,5',5''-hexa-tert-butyl 4,6-bis(octylthiomethyl)-o-cresol, ethylene bis(oxyethylene) bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate], hexamethylene bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 1,3,5-tris(3,5-di -tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, 2,6-di-tert-butyl-4-(4,6-bis(octylthio)-1,3,5-triazin-2-ylamino)phenol, 2-[1-(2-hydroxy-3,5-di-tert-pentylphenyl)ethyl]-4,6-di-tert-pentylphenyl acrylate, and the like.

[0028] The base sheet may contain an antioxidant other than the phenol-based antioxidant. Examples of such antioxidants include amine-based, sulfur-based and phosphorus-based antioxidants. Furthermore, if the base sheet contains a phenol-based antioxidant, discoloration may occur. From the viewpoint of suppressing such discoloration, it is more preferable that the base sheet further contains a phosphorus-based antioxidant.

[0029] Examples of phosphorus-based antioxidants include triphenyl phosphite, tris(2,4-t-butylphenyl)phosphite, bis[2,4 bis(1,1-dimethylethyl)-6-methylphenyl]ethyl ester phosphorous acid, bis(2,4-t-butylphenyl)pentaerythritol diphosphite, tetrakis(2,4-di-t-butylphenyl)[1,1 biphenyl]-4,4'-diyl bisphosphonite, tetra(C12 to C15 alkyl)-4,4'-isopropylidenediphenyl diphosphite, 3,9-bis(2,6-t-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5,5 undecane], 1,1'-biphenyl-4,4'-diylbis[bis(2,4-di-t-butylphenyl)]phosphonite, and the like.

[0030] The content of the antioxidant is preferably 0.01% by mass or more and 0.2% by mass or less based on the mass of the base sheet. The content of the antioxidant in the base sheet can be confirmed by, for example, liquid chromatography.

[0031] When a phenol-based antioxidant and a phosphorus-based antioxidant are used in combination, the mass ratio of the phenol-based antioxidant to the phosphorus-based antioxidant (phenol-based antioxidant:phosphorus-based antioxidant) is preferably 1:1 or more and 1:2 or less, which can suitably reduce defects in the base sheet due to fisheyes and suitably suppress discoloration of the base sheet.

[0032] The base sheet may contain various additives, such as colorants, fillers, matting agents, foaming agents, flame retardants, lubricants, antistatic agents, ultraviolet absorbing agents, and light stabilizers, as necessary. The content of the additives used as necessary is preferably 20% by mass or more and 40% by mass or less based on the mass of the base sheet.

[0033] The substrate sheet preferably has a thickness of 50 μm or more and 100 μm or less. By making the thickness 50 μm or more, the ratio of biomass-derived raw materials in the decorative sheet using biomass-derived polyethylene can be sufficiently ensured, which makes it possible to suitably reduce the environmental impact. In addition, it is also possible to suppress shrinkage when forming the later-described picture auxiliary layer and picture pattern layer. Furthermore, by making the thickness 100 μm or less, the amount of raw materials derived from fossil fuels used for the base sheet can be reduced, and the environmental load can be reduced in an optimal manner. The thickness is more preferably 60 μm or more and 80 μm or less.

[0034] The specific method for forming a film (sheeting) of the base sheet is not particularly limited, and examples thereof include the T-die method in which molten resin is extruded and laminated using a T-die, the calendar method, the circular die method (inflation method, tubular method), etc. Among these, the T-die method is preferred when improving production efficiency (production speed) and alleviating internal stress during sheeting. The calendar method is preferred when making the thickness of the base sheet uniform and reducing foreign matter defects.

[0035] (Picture support layer) The decorative sheet has a base sheet and a pattern auxiliary layer laminated on the first surface side of the base sheet and covering the entire first surface of the base sheet. By having such a picture auxiliary layer, fish eyes on the first surface side of the base sheet can be suitably repaired, and color loss of the picture pattern of the picture design layer laminated on the picture auxiliary layer can be suppressed. Note that the picture auxiliary layer only needs to uniformly cover the entire first surface, and body The pattern auxiliary layer does not necessarily have to completely cover the area. The pattern auxiliary layer may have small defects such as pinholes that are unavoidable during the formation of the pattern auxiliary layer.

[0036] The pattern auxiliary layer covering the entire first surface of the base sheet can be formed by solid printing using a gravure printing method with an intaglio roll. The ink used to form the pattern auxiliary layer contains a resin component and a liquid component. The ink may be appropriately mixed with colorants such as pigments and dyes, extender pigments, stabilizers, plasticizers, catalysts, hardeners, etc.

[0037] The resin component is not particularly limited, and may be any one selected from, for example, urethane resins, acrylic resins, ester resins, amide resins, butyral resins, styrene resins, cellulose acetate resins, acrylic-urethane resins, vinyl chloride-vinyl acetate copolymer resins, vinyl chloride-vinyl acetate-acrylic copolymer resins, chlorinated polypropylene resins, etc., either alone or in combination. As the liquid component, for example, organic solvents such as methyl ethyl ketone, toluene, cyclohexanone, ethyl acetate alcohol, ethanol, and methanol, or water, may be used.

[0038] The pattern auxiliary layer is preferably subjected to a smoothing treatment using a smoothing roll after solid printing using an intaglio roll. Alternatively, the pattern auxiliary layer is preferably subjected to a smoothing treatment by making the conveying speed of the base sheet and the peripheral rotation speed of the intaglio roll different. By performing the smoothing treatment, a more uniform pattern auxiliary layer can be formed.

[0039] The pattern auxiliary layer preferably has a thickness of 1 μm or more and 5 μm or less. Since defects due to fish eyes in the base sheet can be suitably repaired, color loss of the pattern in the pattern layer can be suitably suppressed. The pattern auxiliary layer more preferably has a thickness of 1.5 μm or more and 3 μm or less.

[0040] (Pattern layer) The decorative sheet has a picture pattern layer constituting a picture pattern, laminated on the side of the picture auxiliary layer opposite to the base sheet.

[0041] The picture pattern layer is for imparting a desired picture pattern (design) to the decorative sheet, and the type of picture pattern is not limited. Examples of the picture pattern include wood grain, stone grain, sand grain, tiled pattern, brickwork pattern, fabric pattern, leather pattern, geometric figures, letters, symbols, and abstract patterns.

[0042] The ink used to form the picture pattern layer contains a colorant component, a resin component, and a liquid component. The ink may contain an extender pigment, a solvent, a stabilizer, a plasticizer, a catalyst, a hardener, etc., as appropriate.

[0043] Examples of the colorant component include inorganic pigments such as carbon black (ink), iron black, titanium white, antimony white, yellow lead, titanium yellow, red iron oxide, cadmium red, ultramarine blue, and cobalt blue; organic pigments or dyes such as quinacridone red, isoindolinone yellow, and phthalocyanine blue; scaly foil metal pigments such as aluminum and brass; and scaly foil pearlescent (pearl) pigments such as titanium dioxide-coated mica and basic lead carbonate. The resin component is not particularly limited, and may be any one selected from urethane-based resins, acrylic-based resins, ester-based resins, amide-based resins, butyral-based resins, styrene-based resins, nitrocellulose (nitrocellulose)-based resins, cellulose acetate-based resins, acrylic-urethane-based resins, vinyl chloride-vinyl acetate copolymer resins, vinyl chloride-vinyl acetate-acrylic copolymer resins, and chlorinated polypropylene-based resins, either alone or in combination. As the liquid component, for example, an organic solvent such as methyl ethyl ketone, toluene, cyclohexanone, ethyl acetate alcohol, ethanol, or methanol, or water can be used.

[0044] The picture pattern layer constituting the picture pattern can be formed by partially printing an ink containing a colorant component, a resin component, and a liquid component onto the picture auxiliary layer by a gravure printing method using an intaglio roll. The picture pattern layer may be formed by partially printing ink of the same or different composition in different regions and / or by overlapping the same region multiple times.

[0045] The thickness of the picture pattern layer is preferably, for example, 0.1 μm or more and 5 μm or less, which can improve the film quality and adhesion. The thickness of the picture pattern layer is more preferably 0.5 μm or more and 3 μm or less.

[0046] (back adhesive auxiliary layer) The decorative sheet preferably has a back surface adhesive auxiliary layer laminated on the second surface side of the base sheet and covering the entire second surface of the base sheet. By having such a back surface adhesive auxiliary layer, fish eyes on the second surface side of the base sheet can be repaired and poor adhesion to the adherend can be suppressed. Note that it is sufficient for the back surface adhesive auxiliary layer to uniformly cover the entire second surface, and body It is not necessary for the back surface adhesive auxiliary layer to completely cover the back surface. The back surface adhesive auxiliary layer may have small defects such as pinholes that are unavoidable during the formation of the back surface adhesive auxiliary layer.

[0047] The back adhesive auxiliary layer covering the entire second surface of the base sheet can be formed by solid printing using a gravure printing method with an intaglio roll. The ink used to form the back adhesive auxiliary layer contains a resin component and a liquid component. The ink may be appropriately mixed with a colorant such as a pigment or dye, an extender pigment, a stabilizer, a plasticizer, a catalyst, a hardener, etc.

[0048] Examples of the resin component include urethane resin, acrylic resin, ester resin, amide resin, butyral resin, styrene resin, urethane-acrylic copolymer, polycarbonate acrylic-urethane copolymer (urethane-acrylic copolymer derived from a polymer (polycarbonate polyol) having a carbonate bond in the polymer main chain and having two or more hydroxyl groups at the end and side chain), vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-vinyl acetate-acrylic copolymer resin, chlorinated propylene resin, nitrocellulose resin (nitrocellulose), and cellulose acetate resin. Examples of the liquid component include organic solvents such as methyl ethyl ketone, toluene, cyclohexanone, ethyl acetate alcohol, ethanol, and methanol, and water.

[0049] From the viewpoint of improving adhesion to the adherend, the back surface adhesive auxiliary layer preferably contains a urethane resin, and the polyurethane resin is more preferably an ester polyurethane.

[0050] An ester-based polyurethane resin is a cured product of a composition that contains a polyol (polyhydric alcohol) as a main component and an isocyanate as a crosslinking agent (curing agent). The polyol has two or more hydroxyl groups in the molecule, and examples of the polyol that can be used include polyethylene glycol, polypropylene glycol, acrylic polyol, polyester polyol, and polyether polyol. As the isocyanate, a polyvalent isocyanate having two or more isocyanate groups in the molecule is used. For example, aromatic isocyanates such as 2-4 tolylene diisocyanate, xylene diisocyanate, and 4-4 diphenylmethane diisocyanate, and aliphatic (or alicyclic) isocyanates such as hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, and hydrogenated diphenylmethane diisocyanate can be used.

[0051] From the viewpoint of suitably improving the adhesion to the adherend, the content of the resin component is more preferably 40 mass % or more, and even more preferably 50 mass % or more, based on the mass of the back surface adhesive auxiliary layer.

[0052] In order to improve drying properties, it is preferable that the back adhesive auxiliary layer contains soluble nitrocellulose (nitrocellulose resin) (more than 0% by mass), but in order to suppress discoloration of decorative sheets that use biomass-derived polyethylene, the soluble nitrocellulose content is preferably 5% by mass or less. The content of soluble nitrocellulose is more preferably 3% by mass or less, and even more preferably 1% by mass or less, based on the mass of the back surface adhesive auxiliary layer.

[0053] The back surface adhesive auxiliary layer is preferably subjected to a smoothing treatment using a smoothing roll after solid printing using an intaglio roll. Alternatively, the back surface adhesive auxiliary layer is preferably subjected to a smoothing treatment by making the conveying speed of the base sheet and the outer circumferential rotation speed of the intaglio roll different. By performing the smoothing treatment, a more homogeneous back surface adhesive auxiliary layer can be formed.

[0054] The thickness of the back surface adhesive auxiliary layer is preferably 1 μm or more and 10 μm or less, which can effectively repair defects in the base sheet due to fish eyes, and can effectively prevent poor adhesion to the adherend. The back surface adhesion auxiliary layer more preferably has a thickness of 1.5 μm or more and 5 μm or less.

[0055] (Transparent resin layer) The decorative sheet preferably has a transparent resin layer laminated on the side of the picture design layer opposite the picture auxiliary layer. By providing the transparent resin layer, the picture design layer can be protected, and the scratch resistance of the decorative sheet can be improved, thereby imparting durability. In addition, the term "transparency" refers to a range in which the picture pattern layer can be visually recognized, and the picture pattern layer may be semi-transparent or colored.

[0056] The transparent resin layer may be made of, for example, an ester-based resin, an olefin-based resin, an acrylic-based resin, a carbonate-based resin, a urethane-based resin, a styrene-based resin, a vinyl chloride-based resin, a vinyl acetate-based resin, a vinyl chloride-vinyl acetate copolymer resin, etc. From the viewpoint of improving moldability and scratch resistance, an ester-based resin or an olefin-based resin such as polypropylene or polyester is preferred.

[0057] From the viewpoint of imparting durability more favorably, the transparent resin layer preferably contains an ultraviolet absorber and a light stabilizer. Examples of the ultraviolet absorbing agent include a benzotriazole-based ultraviolet absorbing agent, a benzophenone-based ultraviolet absorbing agent, a salicylic acid ester-based ultraviolet absorbing agent, and a triazine-based ultraviolet absorbing agent. Among these, triazine-based ultraviolet absorbers are preferred from the viewpoint of suitably imparting weather resistance, design properties, bleeding suppression, etc. The content of the ultraviolet absorber is preferably 0.1% by mass or more and 1% by mass or less based on the mass of the transparent resin layer.

[0058] As the light stabilizer, a hindered amine-based light stabilizer can be suitably used. The content of the light stabilizer is preferably 1.5% by mass or more and 3% by mass or less based on the mass of the transparent resin layer.

[0059] The transparent resin layer may further contain various additives as necessary, such as lubricants such as silicone resins, waxes, and fluororesins, and colorants such as dyes and pigments.

[0060] The transparent resin layer has a thickness of 40 μm or more and 100 μm or less. By having the thickness of the transparent resin layer fall within the above range, the amount of polyethylene derived from fossil fuels in the entire decorative sheet can be suitably reduced, and the environmental load can be suitably reduced. The transparent resin layer preferably has a thickness of 50 μm or more and 80 μm or less.

[0061] The method for laminating the transparent resin layer is not limited as long as it is a common method, and examples thereof include a dry lamination method and an extrusion lamination method in which a molten resin is extruded using a T-die to perform lamination. A T-die or the like capable of extruding molten resin can be used as the extrusion mechanism described above.

[0062] The transparent resin layer may be subjected to a surface treatment such as a saponification treatment, a glow discharge treatment, a corona discharge treatment, a plasma discharge treatment, an ultraviolet (UV) treatment, or a flame treatment.

[0063] (Surface protective layer) The decorative sheet may have a surface protective layer on the side of the transparent resin layer opposite the picture design layer. The surface protective layer can provide durability (scratch resistance, stain resistance, weather resistance, etc.).

[0064] The surface protective layer may contain, for example, a cured product of a thermosetting component or a cured product of an ionizing radiation curable component as a main component. The cured product is preferably transparent. The surface protective layer preferably contains an ultraviolet absorbing agent and a light stabilizer. The ultraviolet absorbing agent and the light stabilizer may be the same as those used in the transparent resin layer.

[0065] Examples of the cured product of the thermosetting component include ester-based urethane and acrylic-based urethane.

[0066] Examples of the cured product of the ionizing radiation curable component include a cured product of an oligomer and / or monomer having a radical polymerizable unsaturated bond or a cationic polymerizable functional group in the molecule. The ionizing radiation means electromagnetic waves or charged particles having energy capable of polymerizing or crosslinking molecules, and generally includes electron beams (EB) or ultraviolet rays (UV). The method for forming the surface protective layer is not particularly limited, and known methods can be used.

[0067] As the oligomer having a radical polymerizable unsaturated group in the molecule, for example, oligomers such as urethane (meth)acrylate, polyester (meth)acrylate, epoxy (meth)acrylate, melamine (meth)acrylate, triazine (meth)acrylate, etc. can be preferably used, and urethane (meth)acrylate oligomer is more preferable. As the molecular weight, those of about 250 or more and 100,000 or less are usually used.

[0068] As the monomer having a radically polymerizable unsaturated group in the molecule, for example, a polyfunctional monomer is preferable, and a polyfunctional (meth)acrylate is more preferable. Examples of polyfunctional (meth)acrylates include diethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, bisphenol A ethylene oxide modified di(meth)acrylate, trimethylolpropane tri(meth)acrylate, trimethylolpropane ethylene oxide tri(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate {pentafunctional (meth)acrylate}, dipentaerythritol hexa(meth)acrylate {hexafunctional (meth)acrylate}, etc. Monofunctional monomers may also be used as appropriate.

[0069] The ionizing radiation curable component preferably contains a urethane acrylate oligomer and a polyfunctional monomer in a mass ratio of urethane acrylate oligomer / polyfunctional monomer in the range of 6 / 4 or more and 9 / 1 or less.

[0070] When the ionizing radiation curable resin is crosslinked by ultraviolet light, it is preferable to use a photopolymerization initiator. The amount of the photopolymerization initiator added is, for example, 0.1 to 10 parts by mass per 100 parts by mass of the ionizing radiation curable component.

[0071] The surface protective layer preferably has a gloss / matte effect, so that even if a color loss occurs in the picture pattern formed by the picture pattern layer due to fisheyes, the color loss can be made less noticeable. The gloss matte effect refers to a design effect that makes glossy areas stand out and non-glossy areas appear recessed. The method of imparting the matte gloss effect is not particularly limited, and may include a gloss regulator in the surface protective layer, or may be realized by the uneven shape described later. The uneven shape may have a maximum height Rz of 10 μm or more and 60 μm or less. The pattern formed by the matte gloss effect of the surface protective layer may or may not be in harmony with the whole or part of the pattern formed by the pattern layer. A non-synchronized (not in sync) pattern is preferable, since it can be made less noticeable even if color loss occurs in the pattern formed by the pattern layer due to fisheyes.

[0072] The thickness of the surface protective layer is not particularly limited, but is, for example, 1 μm or more and 50 μm or less. If the thickness of the surface protective layer is less than 1 μm, sufficient durability (scratch resistance, stain resistance, weather resistance, etc.) may not be imparted, and if it exceeds 50 μm, the transmittance may decrease, and the visibility of the pattern of the pattern layer may decrease. The thickness of the surface protective layer may be 3 μm or more and 40 μm or less, or 5 μm or more and 35 μm or less.

[0073] (adhesive layer) The decorative sheet may have an adhesive layer between the picture pattern layer and the transparent resin layer. The adhesive layer is preferably transparent. As the adhesive of the adhesive layer, for example, a urethane adhesive such as an ester urethane or an acrylic urethane, an acrylic adhesive, an epoxy adhesive, or a rubber adhesive can be used. The thickness of the adhesive layer is, for example, 0.1 to 30 μm.

[0074] (Surface adhesion auxiliary layer) The decorative sheet may have a surface adhesion auxiliary layer between the transparent resin layer and the surface protective layer. The surface adhesion auxiliary layer functions as a primer layer or an easy-adhesion layer for the surface protective layer. The surface adhesion auxiliary layer is preferably transparent. For example, a urethane adhesive such as an ester-based urethane or an acrylic-based urethane, an acrylic adhesive, an epoxy adhesive, or a rubber adhesive can be used as the adhesive of the surface adhesion auxiliary layer. The surface adhesion auxiliary layer preferably contains an ultraviolet absorber and a light stabilizer. The ultraviolet absorber and the light stabilizer can be the same as those of the transparent resin layer. The thickness of the surface adhesion auxiliary layer is, for example, 0.1 to 30 μm.

[0075] (Method of manufacturing decorative sheets) In the manufacturing method of the decorative sheet of the present disclosure, the order of each step is not particularly important. For example, the steps can be performed in the order of picture auxiliary layer, back surface adhesive auxiliary layer, and picture pattern layer, or the order of picture auxiliary layer, picture pattern layer, and back surface adhesive auxiliary layer, or the order of back surface adhesive auxiliary layer, picture auxiliary layer, and picture pattern layer. In addition, each step does not need to be performed consecutively, and other steps or treatments may be performed between these steps.

[0076] <Decorative board> The decorative board of the present disclosure has an adherend laminated on the second surface side of a base sheet of a decorative sheet that uses biomass-derived polyethylene. Examples of the adherend include a wood board, a gypsum board, a cement board, a ceramic board, a metal board, a resin board, and a fiber-reinforced plastic board. For example, the adherend may be laminated on the second surface side of the base sheet using an adhesive. EXAMPLES

[0077] The present invention will now be described in more detail with reference to examples, but the present disclosure is not limited to these examples.

[0078] Example 1 A biomass-derived polyethylene with a biomass content of 15% [a colored polyethylene film having a thickness of 80 μm, containing 0.05% by mass of a phenolic antioxidant (Irganox 1010, manufactured by BASF Japan Ltd.)] was prepared and used as a base sheet. A back adhesive auxiliary layer (containing 53% by mass of ester-based polyurethane resin and 5% by mass of soluble nitrocellulose) was formed on one side of the base sheet so as to cover the entire surface by solid printing with an ink containing an organic solvent using a gravure printing method with an intaglio roll. On the other side of the base sheet, a 2 μm thick picture auxiliary layer mainly composed of an acrylic-urethane resin was formed by solid printing with an ink containing an organic solvent using a gravure printing method with an intaglio roll so as to cover the entire surface, and then a 2 μm thick picture pattern layer (wood grain pattern) mainly composed of an acrylic-urethane resin was formed by partially printing with an ink containing a colorant and an organic solvent using a gravure printing method with an intaglio roll. An ester-based polyurethane was applied to the side of the picture pattern layer opposite the picture auxiliary layer to form a 10 μm thick adhesive layer, and a 60 μm thick transparent olefin sheet was dry laminated onto the adhesive layer to form a transparent resin layer. Furthermore, a surface adhesion auxiliary layer made of an acrylic-urethane copolymer resin having a thickness of 2 μm was formed on the side of the transparent resin layer opposite the adhesive layer, and a coating agent (urethane acrylate-based ionizing radiation curable resin composition) was applied onto the surface adhesion auxiliary layer by gravure coating. After that, the coating agent was cured by irradiating with ionizing radiation to form a surface protection layer having a thickness of 5 μm. Finally, the surface having the surface protective layer was embossed with heat and pressure to form a concave-convex shape, thereby producing a decorative sheet.

[0079] Example 2 A biomass-derived polyethylene with a biomass content of 15% [a colored polyethylene film with a thickness of 80 μm, containing 0.05 mass% of a phenol-based antioxidant (Irganox 1010, manufactured by BASF Japan Ltd.) and 0.05 mass% of a phosphorus-based antioxidant (Irgafos 168, manufactured by BASF Japan Ltd.)] was prepared and used as a base sheet. A back adhesive auxiliary layer (containing 53% by mass of ester-based polyurethane resin and 0% by mass of soluble nitrocellulose) was formed on one side of the base sheet so as to cover the entire surface by solid printing with an ink containing an organic solvent using a gravure printing method with an intaglio roll. On the other side of the base sheet, a 2 μm thick picture auxiliary layer mainly composed of an acrylic-urethane resin was formed by solid printing with an ink containing an organic solvent using a gravure printing method with an intaglio roll so as to cover the entire surface, and then a 2 μm thick picture pattern layer (wood grain pattern) mainly composed of an acrylic-urethane resin was formed by partially printing with an ink containing a colorant and an organic solvent using a gravure printing method with an intaglio roll. An ester-based polyurethane was applied to the side of the picture pattern layer opposite the picture auxiliary layer to form a 10 μm thick adhesive layer, and a 60 μm thick transparent olefin sheet was dry laminated onto the adhesive layer to form a transparent resin layer. Furthermore, a surface adhesion auxiliary layer made of an acrylic-urethane copolymer resin having a thickness of 2 μm was formed on the side of the transparent resin layer opposite the adhesive layer, and a coating agent (urethane acrylate-based ionizing radiation curable resin composition) was applied onto the surface adhesion auxiliary layer by gravure coating. After that, the coating agent was cured by irradiating with ionizing radiation to form a surface protection layer having a thickness of 5 μm. Finally, the surface having the surface protective layer was embossed with heat and pressure to form a concave-convex shape, thereby producing a decorative sheet.

[0080] Example 3 A biomass-derived polyethylene with a biomass content of 15% [a colored polyethylene film having a thickness of 80 μm, containing 0.05% by mass of a phenolic antioxidant (Irganox 1010, manufactured by BASF Japan Ltd.)] was prepared and used as a base sheet. A back adhesive auxiliary layer (containing 53% by mass of ester-based polyurethane resin and 10% by mass of soluble nitrocellulose) was formed on one side of the base sheet so as to cover the entire surface by solid printing with an ink containing an organic solvent using a gravure printing method with an intaglio roll. On the other side of the base sheet, a 2 μm thick picture auxiliary layer mainly composed of an acrylic-urethane resin was formed by solid printing with an ink containing an organic solvent using a gravure printing method with an intaglio roll so as to cover the entire surface, and then a 2 μm thick picture pattern layer (wood grain pattern) mainly composed of an acrylic-urethane resin was formed by solid printing with an ink containing an organic solvent using a gravure printing method with an intaglio roll. An ester-based polyurethane was applied to the side of the picture pattern layer opposite the picture auxiliary layer to form a 10 μm thick adhesive layer, and a 60 μm thick transparent olefin sheet was dry laminated onto the adhesive layer to form a transparent resin layer. Furthermore, a surface adhesion auxiliary layer made of an acrylic-urethane copolymer resin having a thickness of 2 μm was formed on the side of the transparent resin layer opposite the adhesive layer, and a coating agent (urethane acrylate-based ionizing radiation curable resin composition) was applied onto the surface adhesion auxiliary layer by gravure coating. After that, the coating agent was cured by irradiating with ionizing radiation to form a surface protection layer having a thickness of 5 μm. Finally, the surface having the surface protective layer was embossed with heat and pressure to form a concave-convex shape, thereby producing a decorative sheet.

[0081] Comparative Example 1 A biomass-derived polyethylene with a biomass content of 15% [a colored polyethylene film with a thickness of 80 μm, containing no antioxidant] was prepared and used as a base sheet. A back adhesive auxiliary layer (containing 53% by mass of ester-based polyurethane resin and 5% by mass of soluble nitrocellulose) was formed on one side of the base sheet so as to cover the entire surface by solid printing with an ink containing an organic solvent using a gravure printing method with an intaglio roll. On the other side of the base sheet, a 2 μm thick picture auxiliary layer mainly composed of an acrylic-urethane resin was formed by solid printing with an ink containing an organic solvent using a gravure printing method with an intaglio roll so as to cover the entire surface, and then a 2 μm thick picture pattern layer (wood grain pattern) mainly composed of an acrylic-urethane resin was formed by solid printing with an ink containing an organic solvent using a gravure printing method with an intaglio roll. An ester-based polyurethane was applied to the side of the picture pattern layer opposite the picture auxiliary layer to form a 10 μm thick adhesive layer, and a 60 μm thick transparent olefin sheet was dry laminated onto the adhesive layer to form a transparent resin layer. Furthermore, a surface adhesion auxiliary layer made of an acrylic-urethane copolymer resin having a thickness of 2 μm was formed on the side of the transparent resin layer opposite the adhesive layer, and a coating agent (urethane acrylate-based ionizing radiation curable resin composition) was applied onto the surface adhesion auxiliary layer by gravure coating. After that, the coating agent was cured by irradiating with ionizing radiation to form a surface protection layer having a thickness of 5 μm. Finally, the surface having the surface protective layer was embossed with heat and pressure to form a concave-convex shape, thereby producing a decorative sheet.

[0082] Comparative Example 2 A biomass-derived polyethylene with a biomass content of 15% [a colored polyethylene film having a thickness of 80 μm, containing 0.05% by mass of a phosphorus-based antioxidant (Irgafos 168, manufactured by BASF Japan Ltd.)] was prepared and used as a substrate sheet. A back adhesive auxiliary layer (containing 53% by mass of ester-based polyurethane resin and 5% by mass of soluble nitrocellulose) was formed on one side of the base sheet so as to cover the entire surface by solid printing with an ink containing an organic solvent using a gravure printing method with an intaglio roll. On the other side of the base sheet, a 2 μm thick picture auxiliary layer mainly composed of an acrylic-urethane resin was formed by solid printing with an ink containing an organic solvent using a gravure printing method with an intaglio roll so as to cover the entire surface, and then a 2 μm thick picture pattern layer (wood grain pattern) mainly composed of an acrylic-urethane resin was formed by solid printing with an ink containing an organic solvent using a gravure printing method with an intaglio roll. An ester-based polyurethane was applied to the side of the picture pattern layer opposite the picture auxiliary layer to form a 10 μm thick adhesive layer, and a 60 μm thick transparent olefin sheet was dry laminated onto the adhesive layer to form a transparent resin layer. Furthermore, a surface adhesion auxiliary layer made of an acrylic-urethane copolymer resin having a thickness of 2 μm was formed on the side of the transparent resin layer opposite the adhesive layer, and a coating agent (urethane acrylate-based ionizing radiation curable resin composition) was applied onto the surface adhesion auxiliary layer by gravure coating. After that, the coating agent was cured by irradiating with ionizing radiation to form a surface protection layer having a thickness of 5 μm. Finally, the surface having the surface protective layer was embossed with heat and pressure to form a concave-convex shape, thereby producing a decorative sheet.

[0083] <Evaluation method> (1) Color loss in the design The decorative sheets using biomass-derived polyethylene produced in the Examples and Comparative Examples were visually inspected from a position 50 cm away from the decorative sheet under a light source of 500 lux or more to see if the pattern in the design layer had come off (whether there was color loss in the design), and were evaluated according to the following criteria. The results are shown in Table 1. <Evaluation criteria> +: No color loss was observed in the design. -: Colour loss in the design was observed.

[0084] (2)Durability The decorative sheets using the biomass-derived polyethylene produced in the Examples and Comparative Examples were subjected to the following accelerated weathering test using a black panel temperature of 63°C and an illuminance of 100mW / cm 2 The cycle of irradiating the sheet with ultraviolet light for 20 hours under the above conditions and then condensing for 4 hours was repeated. After 300 hours had passed, the appearance of the decorative sheet was visually evaluated. The results are shown in Table 1. <Ultra-accelerated weather resistance test equipment> Ultra-accelerated weather resistance test equipment (product name: "Eye Super UV Tester SUV-W161", manufactured by Iwasaki Electric Co., Ltd.) equipped with a UV lamp (product name: M04-L21WB / SUV, manufactured by Iwasaki Electric Co., Ltd.), a lamp jacket (product name: WJ50-SUV, manufactured by Iwasaki Electric Co., Ltd.), and an illuminometer (product name: UVD-365PD, manufactured by Iwasaki Electric Co., Ltd.) <Evaluation criteria> +: No cracks occurred. -: Cracks have occurred.

[0085] (3) Discoloration (pinking) The decorative sheets using the biomass-derived polyethylene produced in Examples 1 to 3 were placed in a sealed container and stored at 60°C for two weeks, and the color difference on the back surface of the decorative sheet before and after storage was measured and evaluated according to the following criteria. The results are shown in Table 2. The color difference was measured using a spectrophotometer CR-400 (manufactured by Konica Minolta Japan, Inc.). <Evaluation criteria> +: The color difference Δa before and after the test was less than 0.2. -: The color difference Δa before and after the test was 0.2 or more.

[0086] [Table 1]

[0087] [Table 2]

[0088] From the examples, it was confirmed that by laminating a pattern auxiliary layer in which the base sheet contains a phenolic antioxidant and covers the entire first surface of the base sheet, color fading of the pattern due to fisheyes can be suppressed and durability is also excellent. Furthermore, a comparison between Example 1 and Example 3 confirmed that discoloration of the decorative sheet could be suppressed by setting the content of soluble nitrocellulose in the back surface adhesive auxiliary layer to 5 mass % or less. On the other hand, in Comparative Example 1, since the base sheet did not contain an antioxidant, discoloration of the design pattern occurred due to fish eyes, and durability decreased due to deterioration of the base sheet. In Comparative Example 2, the phosphorus-based antioxidant contained in the base sheet was hydrolyzed and lost its function as an antioxidant, resulting in a decrease in durability. [Explanation of symbols]

[0089] 1 Base sheet 2. Picture support layer 3. Pattern layer 4 Back adhesive auxiliary layer 5 Adhesive layer 6 Transparent resin layer 7 Surface adhesion auxiliary layer 8 Surface protective layer 10 Decorative sheets made from biomass-derived polyethylene

Claims

1. A base sheet comprising biomass-derived polyethylene and having a first surface and a second surface; A pattern auxiliary layer is laminated on the first surface side of the base sheet and covers the entire first surface of the base sheet; A picture pattern layer constituting a picture pattern is laminated on the surface of the picture auxiliary layer opposite to the base sheet; A transparent resin layer is laminated on the side of the picture design layer opposite to the picture auxiliary layer; A surface protective layer is laminated on the transparent resin layer on the side opposite to the picture pattern layer, The base sheet contains a phenol-based antioxidant. A decorative sheet made from biomass-derived polyethylene.

2. 2. The decorative sheet using biomass-derived polyethylene according to claim 1, wherein the base sheet further contains a phosphorus-based antioxidant.

3. 3. The decorative sheet using biomass-derived polyethylene according to claim 2, wherein in the base sheet, the mass ratio of the phenol-based antioxidant to the phosphorus-based antioxidant is 1:1 to 1:

2.

4. The decorative sheet using the biomass-derived polyethylene according to any one of claims 1 to 3, wherein the pattern auxiliary layer has a thickness of 1 μm or more and 5 μm or less.

5. The decorative sheet using the biomass-derived polyethylene according to any one of claims 1 to 4, wherein the picture auxiliary layer has been subjected to a smoothing treatment.

6. A decorative sheet using the biomass-derived polyethylene according to any one of claims 1 to 5, comprising a back adhesive auxiliary layer laminated on the second surface side of the base sheet and covering the entire second surface of the base sheet.

7. 7. The decorative sheet using biomass-derived polyethylene according to claim 6, wherein the back adhesive auxiliary layer has a soluble nitrocellulose content of 5% by mass or less.

8. The decorative sheet using the biomass-derived polyethylene according to any one of claims 1 to 7, wherein the transparent resin layer has a thickness of 40 µm or more and 100 µm or less.

9. The decorative sheet using the biomass-derived polyethylene according to any one of claims 1 to 8, wherein the transparent resin layer is made of an olefin-based resin.

10. The base sheet is a decorative sheet using biomass-derived polyethylene described in any one of claims 1 to 9, having a biomass content of 15% or more and 70% or less.

11. A decorative sheet comprising a base sheet and an adhesive laminated on the second surface side of the base sheet of a decorative sheet using the biomass-derived polyethylene according to any one of claims 1 to 10.

Images