Cosmetic sheets and panels made with bio-derived polyethylene.

Abstract

The present invention provides a cosmetic sheet or the like made of bio-derived polyethylene, which can suppress the fading of patterns and has excellent durability. The cosmetic sheet of the present invention using bio-derived polyethylene comprises: a substrate sheet comprising bio-derived polyethylene and having a first side and a second side; a pattern auxiliary layer deposited on the first side of the substrate sheet, covering the entire first side of the substrate sheet; and a pattern pattern layer constituting a pattern pattern and deposited on the side of the pattern auxiliary layer opposite to the substrate sheet; and the substrate sheet contains a phenolic antioxidant.

Description

Technical Field

[0001] This invention relates to a cosmetic sheet and cosmetic plate using bio-derived polyethylene. Prior Technology

[0002] In building materials, furniture, and home appliances, when it is desired to decorate the components used, decorative panels with decorative patches attached are generally used.

[0003] For example, Patent Document 1 discloses a cosmetic sheet characterized in that it is a cosmetic sheet having at least a surface protective layer on a substrate sheet, and the surface protective layer is composed of a resin composition containing an ionizing radiation-curing resin, an aldehyde adsorbent, and a photocatalyst-free resin. Previous technical documents Patent documents

[0004] Patent Document 1: Japanese Patent Application Publication No. 2013-063635 Summary of the Invention

[0005] [The problem the invention aims to solve]

[0006] The substrate sheet for cosmetic films used in building materials, etc., uses plastic as its main component. This plastic is generally derived from petroleum, but it is not ideal from the perspective of reducing environmental impact. Therefore, as a material with a lower environmental impact than petroleum-derived plastics, biomass-derived plastics are known, which use renewable resources derived from biological sources as raw materials.

[0007] The inventors have repeatedly studied the application of biomass-derived polyethylene films to cosmetic sheets used in building materials, and found that biomass-derived polyethylene films contain more impurities than petroleum-derived polyethylene films, making them prone to defects caused by the inclusion of impurities such as "fish eyes." Areas with fish eyes exhibit reduced adhesion to resin compared to areas without fish eyes.

[0008] Therefore, it was found that if a biomaterial-derived polyethylene film is used as the substrate for cosmetic films, the following problems exist: the fisheye effect causes the patterns applied to the patterned layer to fade, resulting in poor appearance and failure to function as a cosmetic film.

[0009] For pattern layers used to create a wide variety of designs, the colors (coloring inks containing colorants) must be applied locally and overlapping, resulting in overlapping areas between colored portions (areas containing coloring ink). If these areas overlap with fisheye patterns that have low adhesion, fading is particularly likely to occur, and defects in the pattern become more noticeable, thus severely damaging the quality of the cosmetic film.

[0010] The inventors have discovered that by including antioxidants in biodegradable polyethylene, the effects of fish eyes can be suppressed. However, when biodegradable polyethylene contains only phosphorus-based antioxidants, although the effect of fish eyes is suppressed, a new problem arises when it is used as a substrate for cosmetic films: the durability of the cosmetic films decreases.

[0011] Therefore, the present invention is intended to solve the aforementioned problems discovered when introducing bio-derived polyethylene into cosmetic sheets for building materials, etc. [Technical means to solve the problem]

[0012] By using a substrate sheet containing phenolic antioxidants derived from biomass and a patterned auxiliary layer that is laminated over the entire first side of the substrate sheet, the durability of cosmetic films can be suppressed, and the fading of the patterned pattern layer laminated on the first side of the substrate sheet can be suppressed.

[0013] That is, the present invention is a cosmetic sheet using bio-derived polyethylene, comprising: a substrate sheet comprising bio-derived polyethylene and having a first side and a second side; a pattern auxiliary layer deposited on the first side of the substrate sheet, covering the entire first side of the substrate sheet; and a pattern pattern layer constituting a pattern pattern and deposited on the side of the pattern auxiliary layer opposite to the substrate sheet; and the substrate sheet contains a phenolic antioxidant.

[0014] In the present invention, the use of cosmetic sheets derived from biomass polyethylene is preferably made of hindered phenolic antioxidants. Preferably, the aforementioned substrate sheet contains a phosphorus-based antioxidant. Preferably, in the above-mentioned substrate sheet, the mass ratio of the phenolic antioxidant to the phosphorus antioxidant is 1:1 to 1:2. Preferably, the thickness of the above-mentioned pattern auxiliary layer is more than 1 μm and less than 5 μm. Preferably, the above-mentioned pattern auxiliary layer is smoothed. Preferably, it has a back-side bonding auxiliary layer, which is deposited on the second side of the substrate sheet and covers the entire second side of the substrate sheet. Preferably, the content of nitrocellulose in the back-side auxiliary layer is less than 5% by mass. Preferably, the transparent resin layer is deposited on the side opposite to the pattern auxiliary layer of the pattern layer, and the thickness of the transparent resin layer is more than 40 μm and less than 100 μm. Preferably, the transparent resin layer is composed of an olefin-based resin. This invention is also a cosmetic sheet, wherein the second side-layer of the substrate sheet of the cosmetic sheet using bio-derived polyethylene has an adhesive material. [Effects of the Invention]

[0015] The present invention provides a cosmetic sheet using biodegradable polyethylene, which can suppress the fading of patterns caused by fisheye even when using biodegradable polyethylene, and also has excellent durability. Simple Explanation of the Diagram

[0016] Figure 1 is a cross-sectional view illustrating a preferred example of the use of a cosmetic sheet derived from biomass polyethylene according to the present invention. Figure 2 is a cross-sectional view illustrating a preferred example of the use of a cosmetic sheet derived from biomass polyethylene in this invention. Implementation

[0017] <Cosmetic sheets made from bio-derived polyethylene> The following describes the use of cosmetic sheets derived from biomass polyethylene in this invention.

[0018] The cosmetic sheet of the present invention using bio-derived polyethylene comprises: a substrate sheet comprising bio-derived polyethylene and having a first side and a second side; a pattern auxiliary layer deposited on the first side of the substrate sheet, covering the entire first side of the substrate sheet; and a pattern pattern layer constituting a pattern pattern and deposited on the side of the pattern auxiliary layer opposite to the substrate sheet; and the substrate sheet contains a phenolic antioxidant.

[0019] Figure 1 is a cross-sectional view illustrating a preferred example of the use of a cosmetic sheet derived from biomass polyethylene according to the present invention. As shown in Figure 1, the cosmetic sheet 10 of the present invention, which is derived from biomass polyethylene, has a patterned layer 3 on the first side of the substrate sheet 1. Furthermore, it comprises: a substrate sheet 1; a pattern auxiliary layer 2, which is deposited on the first side of the substrate sheet 1 and covers the entire first side of the substrate sheet 1; and a pattern pattern layer 3, which is deposited on the side of the pattern auxiliary layer 2 opposite to the substrate sheet 1. Furthermore, it is preferable to have a back-side bonding auxiliary layer 4, which is deposited on the second side of the substrate sheet 1 and covers the entire second side of the substrate sheet 1.

[0020] Figure 2 is a cross-sectional view illustrating a preferred example of the use of a cosmetic sheet derived from biomass polyethylene according to the present invention. As shown in Figure 2, in the cosmetic sheet 10, in addition to the layers shown in Figure 1, a back adhesion auxiliary layer 4 may be deposited on the second side of the substrate sheet 1, and an adhesive layer 5, a transparent resin layer 6, a surface adhesion auxiliary layer 7, and a surface protective layer 8 may be sequentially deposited on the pattern layer 3.

[0021] (Substrate sheet) The cosmetic sheet uses a substrate sheet containing bio-derived polyethylene and having a first side and a second side. The first side is the side of the substrate sheet on which the pattern layer is formed (also called the surface), and the second side is the side of the substrate sheet opposite to the first side (the side on which the substrate layer is bonded, also called the back side).

[0022] The term "biologically derived polyethylene" means that at least a portion of the raw materials are derived from biomass, not that all of the raw materials are derived from biomass. Furthermore, the use of biomass-derived raw materials can be determined by the radiocarbon (C14) measurement recorded in the "Biomass Quality" section described later.

[0023] The substrate sheet may include, for example, biopolymer polyethylene, which is a polymer containing monomers derived from biopolymer ethylene.

[0024] The substrate sheet should ideally have a biomass of 15% or higher. By achieving a biomass content of 15% or higher, the amount of raw materials derived from fossil fuels can be appropriately reduced, thus appropriately reducing the environmental impact. From the perspective of further appropriately reducing environmental impact, the biomass is preferably 30% or higher, even better is 45% or higher, and ideally it is 60% or higher. Furthermore, based on the view that the substrate sheet contains additives as described later, the upper limit of the biomass is, for example, 70%.

[0025] "Biomass content" (including the biomass-derived carbon concentration in the substrate sheet of polyethylene) is the value of biomass-derived carbon measured by radiocarbon dating (C14). It is known that atmospheric carbon dioxide contains a certain proportion (105.5 pMC) of C14, therefore, plants that absorb atmospheric carbon dioxide for growth, such as corn, also have a C14 content of approximately 105.5 pMC. Furthermore, it is known that fossil fuels contain almost no C14. Therefore, by measuring the proportion of C14 contained in all carbon atoms in polyethylene, the proportion of biomass-derived carbon can be calculated. That is, when the C14 content in polyethylene is set as P C14, the carbon content derived from biomass, P bio, can be calculated as follows. P bio(%) = P C14 / 105.5 × 100

[0026] The substrate sheet may be, for example, at least one selected from the group consisting of high-density polyethylene, medium-density polyethylene, low-density polyethylene, or linear low-density polyethylene. Alternatively, two or more selected from the group consisting of high-density polyethylene, medium-density polyethylene, low-density polyethylene, or linear low-density polyethylene may be mixed together.

[0027] The substrate sheet contains phenolic antioxidants. By using a substrate sheet containing phenolic antioxidants and having a patterned auxiliary layer deposited on the first side of the substrate sheet, covering the entire first side, defects caused by fisheyes in the substrate sheet can be reduced, and color fading of the pattern can be inhibited. Free radicals are generated during the molding of the substrate sheet due to heat, which initiates oxidation reactions, leading to gelation or coking, thus causing fisheyes in the substrate sheet. Since phenolic antioxidants can inhibit oxidation by capturing free radicals, they effectively reduce defects caused by fisheyes in the substrate sheet.

[0028] The aforementioned phenolic antioxidants are preferably composed of hindered phenolic antioxidants. Since the polyethylene constituting the substrate sheet has a relatively slow oxidation reaction rate, hindered phenolic antioxidants, which react slowly with free radicals, are effective in inhibiting the aforementioned oxidation. Examples of hindered phenolic antioxidants include: pentaerythritol tetrakis[3-(3,5-ditert-butyl-4-hydroxyphenyl)propionate], octadecyl 3-(3,5-ditert-butyl-4-hydroxyphenyl)propionate, thiodiethylbis[3-(3,5-ditert-butyl-4-hydroxyphenyl)propionate], N,N'-hexane-1,6-dimethylbis[3-(3,5-ditert-butyl-4-hydroxyphenylpropionamine)], 2,4-dimethyl-6-(1-methylpentadecanyl)phenol, [[3,5-bis(1,1-dimethylethyl)-4-hydroxyphenyl]methyl]phosphonate diethyl ester, 3,3',3'',5,5',5''-hexa-tert-butyl-α, a',a''-(1,3,5-trimethylbenzyl-2,4,6-triyl)tri-p-cresol, 4,6-bis(octylthiomethyl)o-cresol, ethyl bis(oxyethyl)bis[3-(5-tert-butyl-4-hydroxym-tolyl)propionate], hexamethylene bis[3-(3,5-ditert-butyl-4-hydroxyphenyl)propionate], 1,3,5-tris(3,5-ditert-butyl-4-hydroxybenzyl)-1,3,5-tris(2,4,6(1H,3H,5H)-trione), 2,6-ditert-butyl-4-(4,6-bis(octylthio)-1,3,5-tris(2,4,6)-amino)phenol, 2-[1-(2-hydroxy-3,5-ditert-pentylphenyl)ethyl]-4,6-ditert-pentylphenyl ester, etc.

[0029] The substrate sheet may contain antioxidants other than phenolic antioxidants. Examples of such antioxidants include amine-based, sulfur-based, and phosphorus-based antioxidants. Furthermore, if the substrate contains phenolic antioxidants, discoloration may sometimes occur due to the oxidation of phenolic antioxidants. However, by further containing phosphorus-based antioxidants, the oxidation of phenolic antioxidants can be inhibited, thereby suppressing discoloration.

[0030] Examples of phosphorus-based antioxidants include: triphenyl phosphite, tris(2,4-tert-butylphenyl) phosphite, bis[2,4-bis(1,1-dimethylethyl)-6-methylphenyl]ethyl phosphite, pentaerythritol diphosphite, tetra(2,4-ditert-butylphenyl)[1,1-biphenyl]-4,4'-diyl phosphite, tetra(alkyl(C12 or more, C15 or less))-4,4'-isopropyldiphenyl phosphite, 3,9-bis(2,6-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5,5-undecane], and 1,1'-biphenyl-4,4'-diylbis[bis(2,4-ditert-butylphenyl) phosphite].

[0031] The antioxidant content, based on the mass of the substrate sheet, is preferably between 0.01% and 0.2% by mass. Furthermore, liquid chromatography can be used, for example, to confirm the presence of antioxidants in the substrate sheet.

[0032] When using both phenolic and phosphorus-based antioxidants, the preferred mass ratio of phenolic to phosphorus-based antioxidants (phenolic antioxidant: phosphorus-based antioxidant) is 1:1 to 1:2 or less. This can appropriately reduce defects caused by fisheyes in the substrate and appropriately suppress discoloration of the substrate.

[0033] The substrate sheet may also contain various additives such as colorants, fillers, matting agents, foaming agents, flame retardants, lubricants, antistatic agents, ultraviolet absorbers, and light stabilizers, as needed. Furthermore, the content of additives to be used as needed is preferably between 20% and 40% by mass, based on the weight of the substrate sheet.

[0034] The thickness of the substrate sheet is preferably between 50 μm and 100 μm. By using a thickness of 50 μm or more, the proportion of bio-derived raw materials in cosmetic sheets made from bio-derived polyethylene can be adequately ensured, thus appropriately reducing environmental impact. Furthermore, shrinkage during the formation of the patterned auxiliary layer or patterned layer described later can be suppressed. Furthermore, by using a thickness of less than 100 μm, the amount of raw materials derived from fossil fuels used in the substrate sheet can be reduced, thus appropriately reducing the environmental impact. The thickness is preferably between 60 μm and 80 μm.

[0035] There are no particular limitations on the specific method for forming a film (sheet) of substrate material. Examples include the T-die method, which uses a T-die to extrude molten resin for lamination; calendering; and circular die method (blowing, tubular). Among these, the T-die method is preferred when it is necessary to improve production efficiency (production speed) or alleviate internal stress during sheet formation. Calendering is preferred when it is necessary to make the thickness of the substrate sheet more uniform or reduce foreign matter defects.

[0036] (Pattern auxiliary layer) The cosmetic piece has: a substrate sheet; and a patterned auxiliary layer, which is deposited on the first side of the substrate sheet and covers the entire first side of the substrate sheet. By employing this patterned auxiliary layer, fisheye defects on the first side of the substrate can be appropriately repaired, while suppressing color fading of the pattern layer deposited on the patterned auxiliary layer. Furthermore, the patterned auxiliary layer only needs to uniformly cover the entire first side, rather than completely covering it. For example, unavoidable minor defects such as pinholes may sometimes occur during the formation of the patterned auxiliary layer.

[0037] The patterned auxiliary layer on the entire first side of the coated substrate sheet can be formed by full-page printing using a gravure printing method with a gravure roller. The ink used to form the patterned auxiliary layer contains resin components and liquid components. Pigments or dyes, extender pigments, stabilizers, plasticizers, catalysts, hardeners, etc., may also be appropriately mixed into the ink.

[0038] There are no particular restrictions on the resin components. For example, any one of the following resins can be used alone or in combination of two or more: carbamate resins, acrylic resins, ester resins, amide resins, butyraldehyde resins, styrene resins, cellulose acetate resins, acrylate-carbamate resins, vinyl chloride-vinyl acetate copolymer resins, vinyl chloride-vinyl acetate-acrylic copolymer resins, chlorinated polypropylene resins, etc. As liquid components, organic solvents such as methyl ethyl ketone, toluene, cyclohexanone, ethyl acetate alcohol, ethanol, methanol, or water can be used.

[0039] The pattern auxiliary layer is preferably smoothed using a smoothing roll after full-page printing with a gravure roller. Alternatively, the pattern auxiliary layer is preferably smoothed by making the substrate sheet transport speed different from the outer peripheral rotation speed of the gravure roller. By performing a smoothing treatment, a more homogeneous pattern auxiliary layer can be formed.

[0040] The thickness of the pattern auxiliary layer is preferably between 1 μm and 5 μm. Because it can appropriately repair defects caused by fisheyes in the substrate sheet, it can appropriately suppress the fading of the pattern on the pattern layer. More preferably, the thickness of the pattern auxiliary layer is between 1.5 μm and 3 μm.

[0041] (Pattern layer) The cosmetic piece has a patterned layer that forms a pattern and is deposited on the side of the patterned auxiliary layer opposite to the substrate.

[0042] The aforementioned pattern layer refers to the design of the desired patterns on the cosmetic film, and there are no restrictions on the types of patterns. Examples include: wood grain patterns, stone grain patterns, sand grain patterns, tile patterns, stacked brick structure patterns, fabric patterns, leather embossing patterns, geometric shapes, text, symbols, abstract patterns, etc.

[0043] Inks used to form patterned layers contain colorant components, resin components, and liquid components. Extender pigments, solvents, stabilizers, plasticizers, catalysts, hardeners, etc., may also be appropriately mixed into the ink.

[0044] As a coloring agent, for example, inorganic pigments such as carbon black, iron black, titanium dioxide, antimony white, chrome yellow, titanium yellow, red lead, cadmium red, ultramarine, and cobalt blue can be used; organic pigments or dyes such as quinacridone red, isoindolinone yellow, and phthalocyanine blue can be used; metallic pigments of aluminum, brass, and other flake-shaped foils can be used; and pearlescent (pearl) pigments of titanium dioxide coated with mica and basic lead carbonate can be used. As a resin component, there are no particular restrictions. For example, any of the following resins can be used alone or in combination of two or more: carbamate resins, acrylic resins, ester resins, amide resins, butyraldehyde resins, styrene resins, nitrocellulose (nitrocellulose) resins, cellulose acetate resins, acrylate-carbamate resins, vinyl chloride-vinyl acetate copolymer resins, vinyl chloride-vinyl acetate-acrylic copolymer resins, and chlorinated polypropylene resins can be used. As a liquid component, organic solvents such as methyl ethyl ketone, toluene, cyclohexanone, ethyl acetate alcohol, ethanol, methanol, or water can be used.

[0045] The pattern layer constituting the pattern can be formed by gravure printing using a gravure roller, where ink containing colorant, resin, and liquid components is partially printed onto the pattern auxiliary layer. The pattern layer can also be formed by dividing inks of the same or different compositions into different areas, and / or by overlapping the same areas multiple times for partial printing.

[0046] The thickness of the pattern layer is preferably 0.1 μm to 5 μm. This results in good film quality and adhesion. More preferably, the thickness of the pattern layer is 0.5 μm to 3 μm.

[0047] (Auxiliary layer attached to the back) The cosmetic sheet preferably has a back adhesion aid layer, which is deposited on the second side of the substrate sheet, covering the entire second side of the substrate sheet. By having this back adhesion aid layer, fisheye defects on the second side of the substrate sheet can be repaired, thus suppressing poor adhesion with the substrate. Furthermore, the back adhesion aid layer only needs to uniformly cover the entire second side, rather than completely covering the entire second side. For example, the back adhesion aid layer may sometimes have unavoidable minor defects such as pinholes during its formation.

[0048] The back-adhesive layer on the entire second side of the coated substrate can be formed by full-page printing using a gravure printing method with a gravure roller. The ink used to form the back-adhesive layer contains resin and liquid components. Pigments or dyes, extender pigments, stabilizers, plasticizers, catalysts, hardeners, etc., may also be appropriately mixed into the ink.

[0049] As a resin component, for example, urethane resins, acrylic resins, ester resins, amide resins, butyraldehyde resins, styrene resins, urethane-acrylic acid copolymers, polycarbonate-acrylic acid-urethane copolymers (derived from polymers with carbonate bonds in the polymer backbone and two or more hydroxyl groups at the ends and side chains (polycarbonate polyols)), vinyl chloride-vinyl acetate copolymer resins, vinyl chloride-vinyl acetate-acrylic acid copolymer resins, chlorinated propylene resins, nitrocellulose resins (nitrocellulose), cellulose acetate resins, etc., can be used. As a liquid component, for example, organic solvents such as methyl ethyl ketone, toluene, cyclohexanone, ethyl acetate alcohol, ethanol, methanol, or water can be used.

[0050] From the viewpoint of improving adhesion to the substrate, the back bonding auxiliary layer preferably contains a polyurethane resin, and the polyurethane resin is more preferably an ester-based polyurethane.

[0051] The term "ester-based polyurethane resin" refers to a cured product of a composition that uses polyol as the main component and isocyanate as a crosslinking agent (curing agent). As a polyol, it refers to a molecule with two or more hydroxyl groups, such as polyethylene glycol, polypropylene glycol, acrylic polyol, polyester polyol, polyether polyol, etc. As an isocyanate, a polyisocyanate having two or more isocyanate groups in its molecule is used. For example, aromatic isocyanates such as 2,4-toluene diisocyanate, xylene diisocyanate, and 4,4-diphenylmethane diisocyanate, or aliphatic (or alicyclic) isocyanates such as hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated toluene diisocyanate, and hydrogenated diphenylmethane diisocyanate can be used.

[0052] From the viewpoint of appropriately improving the adhesion to the substrate, the content of the resin component is preferably 40% by mass or more, and more preferably 50% by mass or more, based on the mass of the back bonding auxiliary layer.

[0053] From the perspective of improving dryness, the backing auxiliary layer preferably contains nitrocellulose (nitrocellulose resin) (more than 0% by mass), but from the perspective of inhibiting discoloration of cosmetic sheets made of bio-derived polyethylene, the content of nitrocellulose is preferably less than 5% by mass. The content of nitrocellulose is based on the mass of the backing auxiliary layer, preferably 3% by mass or less, and even more preferably 1% by mass or less.

[0054] The back-adhesive auxiliary layer is preferably applied after full-page printing using a gravure roller, followed by a smoothing treatment using a smoothing roller. Alternatively, the back-adhesive auxiliary layer is preferably applied by applying a smoothing treatment at a different speed between the substrate sheet's transport speed and the outer circumferential rotation speed of the gravure roller. This smoothing treatment results in a more homogeneous back-adhesive auxiliary layer.

[0055] The thickness of the back-side bonding auxiliary layer is preferably between 1 μm and 10 μm. This allows for the appropriate repair of defects caused by fisheyes in the substrate, thus effectively suppressing poor adhesion to the substrate. The thickness of the auxiliary layer on the back side is preferably between 1.5 μm and 5 μm.

[0056] (Transparent resin layer) The cosmetic patch preferably has a transparent resin layer, which is deposited on the side of the pattern layer opposite to the pattern auxiliary layer. The transparent resin layer protects the pattern layer, improving the durability of the cosmetic piece by enhancing its scratch resistance. Furthermore, the so-called "transparency" can be semi-transparent or colored, as long as the area of ​​the pattern layer is visible.

[0057] Regarding the transparent resin layer, in addition to ester-based resins and olefin-based resins, acrylic resins, carbonate resins, carbamate resins, styrene resins, vinyl chloride resins, vinyl acetate resins, and vinyl chloride-vinyl acetate copolymer resins can also be used. From the viewpoint of improving molding processability and scratch resistance, ester-based resins and olefin-based resins are preferred, and polypropylene or polyester olefin-based resins are even more preferred.

[0058] From the viewpoint of further suitably imparting durability, the transparent resin layer is preferably one containing ultraviolet absorbers and light stabilizers. Examples of UV absorbers include: benzotriazole UV absorbers, benzophenone UV absorbers, salicylate UV absorbers, triterpenoid UV absorbers, etc. Among these, a triterpenoid UV absorber is preferred from the perspective of appropriately imparting weather resistance or design properties and inhibiting exudation. The content of the UV absorber, based on the mass of the transparent resin layer, is preferably 0.1% by mass or more and 1% by mass or less.

[0059] Hindered amine light stabilizers can be used appropriately as light stabilizers. The content of light stabilizer is based on the mass of the transparent resin layer, preferably between 1.5% and 3% by mass.

[0060] The transparent resin layer may also contain various additives as needed. These include lubricants such as silicone resin, wax, and fluororesin, or colorants such as dyes and pigments.

[0061] The thickness of the transparent resin layer is between 40 μm and 100 μm. By using the thickness of the transparent resin layer within the aforementioned range, the amount of polyethylene derived from fossil fuels in the cosmetic piece can be appropriately reduced, thereby appropriately reducing the environmental impact. The thickness of the transparent resin layer is preferably between 50 μm and 80 μm.

[0062] There are no limitations on the method of laminating transparent resin layers, as long as it is a general method. Examples include dry lamination and extrusion lamination, which uses a T-die to extrude molten resin for lamination. Furthermore, T-die or similar devices that can extrude molten resin can be used as the aforementioned extrusion mechanism.

[0063] The transparent resin layer can also be subjected to surface treatments such as saponification, glow discharge, corona discharge, plasma discharge, ultraviolet (UV) treatment, and flame treatment.

[0064] (Surface protective layer) In cosmetic films, a protective layer may also be provided on the side of the transparent resin layer opposite to the patterned layer. By having a surface protective layer, durability (scratch resistance, stain resistance, weather resistance, etc.) can be provided.

[0065] The surface protective layer may, for example, contain a thermosetting or radiation-curing material as its main component. The curing material is preferably transparent. The surface protective layer preferably contains ultraviolet absorbers and light stabilizers. The ultraviolet absorbers or light stabilizers may be the same as those used in the transparent resin layer.

[0066] Examples of thermosetting components that are hardened include ester-based urethanes or acrylate-based urethanes.

[0067] Examples of hardened materials that are hardened by ionizing radiation include, for instance, oligomers and / or monomers with free radical polymerizable unsaturated bonds or cationic polymerizable functional groups in their molecules. Ionizing radiation refers to electromagnetic waves or charged particles with energy capable of polymerizing or cross-linking molecules; generally, this includes electron beams (EB) or ultraviolet light (UV). There are no particular limitations on the method for forming the surface protective layer; known methods can be used.

[0068] As oligomers containing unsaturated groups with free radical polymerizability in their molecules, urethane (meth)acrylates, polyester (meth)acrylates, epoxy (meth)acrylates, melamine (meth)acrylates, trimethylolpropene (meth)acrylates, and other oligomers are preferred, with urethane (meth)acrylate oligomers being even more preferred. As for molecular weight, those in the range of 250 to 100,000 are typically used.

[0069] As a monomer with an unsaturated group that has free radical polymerization in the molecule, it is preferably a multifunctional monomer, and more preferably a multifunctional (meth)acrylate. Examples of polyfunctional (meth)acrylates include: diethylene glycol dimethacrylate, propylene glycol dimethacrylate, bisphenol A ethylene oxide modified dimethacrylate, trimethylolpropane trimethacrylate, trimethylolpropane ethylene oxide trimethacrylate, dipentaerythritol tetramethacrylate, dipentaerythritol pentamethacrylate (pentafunctional (meth)acrylate), and dipentaerythritol hexamethacrylate (hexafunctional (meth)acrylate). Furthermore, monofunctional monomers may also be appropriately used.

[0070] The preferred curing component for ionizing radiation is one with a mass ratio of urethane acrylate oligomer to polyfunctional monomer ranging from 6 / 4 to 9 / 1, including both urethane acrylate oligomer and polyfunctional monomer.

[0071] When crosslinking ionizing radiation-curing resins using ultraviolet light, it is preferable to use a photopolymerization initiator. The amount of photopolymerization initiator added is, for example, 0.1 to 10 parts by mass relative to 100 parts by mass of the ionizing radiation-curing component.

[0072] The surface protective layer preferably has a high-gloss / low-gloss effect. This makes it less noticeable even if the pattern formed by the pattern layer fades due to fisheye. The so-called high-gloss / low-gloss effect refers to a design effect that makes the glossy parts stand out while making the low-gloss parts appear recessed. There are no particular limitations on the method for imparting a high-gloss / low-gloss effect. The surface protective layer can contain a gloss modifier, or it can be achieved through the uneven shape described later. For example, the uneven shape can have a maximum height Rz of 10 μm to 60 μm. The pattern formed by the high-gloss / low-gloss effect of the surface protective layer can be in the same tone as all or part of the pattern formed by the pattern layer, or they can be different tone. Since even if the pattern formed by the pattern layer fades due to fisheye, it can be made less noticeable, it is preferable to have a different tone (different color) pattern.

[0073] There is no particular limitation on the thickness of the surface protective layer, for example, it can be between 1 μm and 50 μm. If the thickness of the surface protective layer is less than 1 μm, it may not adequately impart durability (scratch resistance, stain resistance, weather resistance, etc.). If it exceeds 50 μm, the transmittance may decrease, and the visibility of the pattern layer may decrease. The thickness of the surface protective layer can be between 3 μm and 40 μm, or between 5 μm and 35 μm.

[0074] (Adhesive layer) Cosmetic films may also have an adhesive layer between the patterned layer and the transparent resin layer. The adhesive layer is preferably transparent. Adhesives used for the adhesive layer may include, for example, urethane adhesives such as ester-based or acrylic-based urethane adhesives, acrylic adhesives, epoxy adhesives, and rubber adhesives. The thickness of the adhesive layer may be, for example, 0.1 μm to 30 μm.

[0075] (Auxiliary layer attached to the surface) Cosmetic films may also have a surface adhesion aid layer between the transparent resin layer and the surface protective layer. The surface adhesion aid layer functions as a base coat or easy-to-bond layer for the surface protective layer. The surface adhesion aid layer is preferably transparent. Adhesives used in the surface adhesion aid layer may include, for example, urethane adhesives such as ester-based or acrylate-based urethane adhesives, acrylic adhesives, epoxy adhesives, and rubber adhesives. The surface adhesion aid layer preferably contains a UV absorber and a light stabilizer. The UV absorber or light stabilizer may be the same as that used in the transparent resin layer. The thickness of the surface adhesion aid layer is, for example, 0.1 μm to 30 μm.

[0076] (Manufacturing Method of Cosmetic Films) In the manufacturing method of the cosmetic sheet of the present invention, the order of each step is not particularly limited. For example, it can be performed in the order of patterned auxiliary layer, back-adhesion auxiliary layer, and patterned pattern layer; or in the order of patterned auxiliary layer, patterned pattern layer, and back-adhesion auxiliary layer; or in the order of back-adhesion auxiliary layer, patterned auxiliary layer, and patterned pattern layer. Furthermore, the steps do not need to be performed consecutively, and other steps or processes can be performed between these steps.

[0077] <Cosmetic Board> The cosmetic sheet of the present invention has an adhesive material on the second side layer of a substrate sheet made of bio-derived polyethylene. Examples of substrate materials include: wood-based panels, gypsum board, cement board, ceramic board, metal board, resin board, and fiber-reinforced plastic board. As for the lamination method of the substrate materials, for example, simply using an adhesive to laminate the substrate materials onto the second side of the substrate sheet.

[0078] The following matters are disclosed in this specification. The present invention (1) is a cosmetic sheet using bio-derived polyethylene, comprising: a substrate sheet containing bio-derived polyethylene and having a first side and a second side; a pattern auxiliary layer deposited on the first side of the substrate sheet, covering the entire first side of the substrate sheet; and a pattern pattern layer constituting a pattern pattern and deposited on the side of the pattern auxiliary layer opposite to the substrate sheet; and the substrate sheet containing a phenolic antioxidant. The present invention (2) is a cosmetic sheet using bio-derived polyethylene as described in the present invention (1), wherein the phenolic antioxidant is composed of hindered phenolic antioxidant. The present invention (3) is a cosmetic sheet using bio-derived polyethylene as described in the present invention (2), wherein the substrate sheet further contains a phosphorus-based antioxidant. The present invention (4) is a cosmetic sheet using biodegradable polyethylene as described in the present invention (3), wherein the mass ratio of the phenolic antioxidant to the phosphorus antioxidant in the substrate sheet is 1:1 to 1:2. The present invention (5) is a cosmetic sheet using bio-derived polyethylene as described in any one of the present invention (1) to (4), wherein the thickness of the above-mentioned pattern auxiliary layer is more than 1 μm and less than 5 μm. The present invention (6) is a cosmetic sheet using bio-derived polyethylene as described in any one of the present invention (1) to (5), wherein the above-mentioned pattern auxiliary layer is subjected to a smoothing treatment. The present invention (7) is a cosmetic sheet using bio-derived polyethylene as described in any one of the present invention (1) to (6), having a back-adhesion auxiliary layer, which is deposited on the second side of the substrate sheet and covers the entire second side of the substrate sheet. The present invention (8) is a cosmetic sheet using bio-derived polyethylene as described in any one of the present invention (1) to (7), wherein the content of the nitrocellulose adhering to the back auxiliary layer is 5% by mass or less. The present invention (9) is a cosmetic sheet using bio-derived polyethylene as described in any one of the present invention (1) to (8), having a transparent resin layer deposited on the side opposite to the pattern layer of the pattern layer, and the thickness of the transparent resin layer being 40 μm or more and 100 μm or less. The present invention (10) is a cosmetic sheet using biodegradable polyethylene as described in the present invention (9), wherein the transparent resin layer is composed of an olefin resin. The present invention (11) is a cosmetic sheet having an adhesive material on the second side-layer of the substrate sheet of the cosmetic sheet using bio-derived polyethylene as described in any one of the present invention (1) to (10). Example

[0079] The present invention will now be described in more detail by way of examples, but the present invention is not limited to these examples.

[0080] (Example 1) Prepare a substrate sheet from a 15% biomass-derived polyethylene [80 μm thick colored polyethylene film containing 0.05% by mass of phenolic antioxidant (Irganox 1010, manufactured by BASF Japan Co., Ltd.)]. On one side of the substrate sheet, an ink containing organic solvent is printed on the entire surface using a gravure printing method with a gravure roller, thereby forming a back-adhesive auxiliary layer (containing 53% by mass of ester-based polyurethane resin and 5% by mass of nitrocellulose). On the other side of the substrate sheet, an ink containing organic solvent is printed on the entire surface using gravure printing with a gravure roller, thereby forming a 2 μm thick pattern auxiliary layer with acrylate resin as the main component. Then, an ink containing colorant and organic solvent is printed on the partial surface using gravure printing with a gravure roller, thereby forming a 2 μm thick pattern layer (wood grain pattern) with acrylate resin as the main component. An ester-based polyurethane is coated on the side opposite to the pattern auxiliary layer to form an adhesive layer with a thickness of 10 μm. A transparent olefin sheet with a thickness of 60 μm is then dry-laminated onto the adhesive layer to form a transparent resin layer. Furthermore, a 2 μm thick surface adhesive auxiliary layer composed of acrylate-urethane copolymer resin is formed on the side opposite to the adhesive layer of the transparent resin layer. A coating agent (urethane acrylate ionizing radiation curable resin composition) is applied to the surface adhesive auxiliary layer by gravure coating, and then ionizing radiation is irradiated to harden the coating agent, thereby forming a 5 μm thick surface protective layer. Finally, the protective surface layer is embossed by hot pressing to form a raised or recessed shape, thus producing a cosmetic piece.

[0081] (Example 2) Prepare a substrate sheet from a 15% biomass-derived polyethylene [a colored polyethylene film with a thickness of 80 μm, containing 0.05% by mass of phenolic antioxidant (Irganox 1010, manufactured by BASF Japan Co., Ltd.) and 0.05% by mass of phosphorus antioxidant (Irgafos 168, manufactured by BASF Japan Co., Ltd.)]. On one side of the substrate sheet, an ink containing organic solvent is printed on the entire surface using a gravure printing method with a gravure roller, thereby forming a back-adhesive auxiliary layer (containing 53% by mass of ester-based polyurethane resin and 0% by mass of nitrocellulose). On the other side of the substrate sheet, an ink containing organic solvent is printed on the entire surface using gravure printing with a gravure roller, thereby forming a 2 μm thick pattern auxiliary layer with acrylate resin as the main component. Then, an ink containing colorant and organic solvent is printed on the partial surface using gravure printing with a gravure roller, thereby forming a 2 μm thick pattern layer (wood grain pattern) with acrylate resin as the main component. An ester-based polyurethane is coated on the side opposite to the pattern auxiliary layer to form an adhesive layer with a thickness of 10 μm. A transparent olefin sheet with a thickness of 60 μm is then dry-laminated onto the adhesive layer to form a transparent resin layer. Furthermore, a 2 μm thick surface adhesive auxiliary layer composed of acrylate-urethane copolymer resin is formed on the side opposite to the adhesive layer of the transparent resin layer. A coating agent (urethane acrylate ionizing radiation curable resin composition) is applied to the surface adhesive auxiliary layer by gravure coating, and then ionizing radiation is irradiated to harden the coating agent, thereby forming a 5 μm thick surface protective layer. Finally, the protective surface layer is embossed by hot pressing to form a raised or recessed shape, thus producing a cosmetic piece.

[0082] (Example 3) Prepare a substrate sheet from a 15% biomass-derived polyethylene [80 μm thick colored polyethylene film containing 0.05% by mass of phenolic antioxidant (Irganox 1010, manufactured by BASF Japan Co., Ltd.)]. On one side of the substrate sheet, an ink containing organic solvent is printed on the entire surface using a gravure printing method with a gravure roller, thereby forming a back-adhesive auxiliary layer (containing 53% by mass of ester-based polyurethane resin and 10% by mass of nitrocellulose). On the other side of the substrate sheet, an ink containing organic solvent is printed on the entire surface using gravure printing with a gravure roller, thereby forming a 2 μm thick pattern auxiliary layer with acrylic-urethane resin as the main component. Then, an ink containing organic solvent is printed on the entire surface using gravure printing with a gravure roller, thereby forming a 2 μm thick pattern layer (wood grain pattern) with acrylic-urethane resin as the main component. An ester-based polyurethane is coated on the side opposite to the pattern auxiliary layer to form an adhesive layer with a thickness of 10 μm. A transparent olefin sheet with a thickness of 60 μm is then dry-laminated onto the adhesive layer to form a transparent resin layer. Furthermore, a 2 μm thick surface adhesive auxiliary layer composed of acrylate-urethane copolymer resin is formed on the side opposite to the adhesive layer of the transparent resin layer. A coating agent (urethane acrylate ionizing radiation curable resin composition) is applied to the surface adhesive auxiliary layer by gravure coating, and then ionizing radiation is irradiated to harden the coating agent, thereby forming a 5 μm thick surface protective layer. Finally, the protective surface layer is embossed by hot pressing to form a raised or recessed shape, thus producing a cosmetic piece.

[0083] (Comparative Example 1) Prepare a biodegradable polyethylene film (80 μm thick, colored polyethylene film without antioxidants) with a biodegradation of 15% and fabricate it into a substrate sheet. On one side of the substrate sheet, an ink containing organic solvent is printed on the entire surface using a gravure printing method with a gravure roller, thereby forming a back-adhesive auxiliary layer (containing 53% by mass of ester-based polyurethane resin and 5% by mass of nitrocellulose). On the other side of the substrate sheet, an ink containing organic solvent is printed on the entire surface using gravure printing with a gravure roller, thereby forming a 2 μm thick pattern auxiliary layer with acrylic-urethane resin as the main component. Then, an ink containing organic solvent is printed on the entire surface using gravure printing with a gravure roller, thereby forming a 2 μm thick pattern layer (wood grain pattern) with acrylic-urethane resin as the main component. An ester-based polyurethane is coated on the side opposite to the pattern auxiliary layer to form an adhesive layer with a thickness of 10 μm. A transparent olefin sheet with a thickness of 60 μm is then dry-laminated onto the adhesive layer to form a transparent resin layer. Furthermore, a 2 μm thick surface adhesive auxiliary layer composed of acrylate-urethane copolymer resin is formed on the side opposite to the adhesive layer of the transparent resin layer. A coating agent (urethane acrylate ionizing radiation curable resin composition) is applied to the surface adhesive auxiliary layer by gravure coating, and then ionizing radiation is irradiated to harden the coating agent, thereby forming a 5 μm thick surface protective layer. Finally, the protective surface layer is embossed by hot pressing to form a raised or recessed shape, thus producing a cosmetic piece.

[0084] (Comparative Example 2) Prepare a substrate sheet from bio-derived polyethylene with a biomass content of 15% [a colored polyethylene film with a thickness of 80 μm, containing 0.05% by mass of phosphorus-based antioxidant (Irgafos 168, manufactured by BASF Japan Co., Ltd.)]. On one side of the substrate sheet, an ink containing organic solvent is printed on the entire surface using a gravure printing method with a gravure roller, thereby forming a back-adhesive auxiliary layer (containing 53% by mass of ester-based polyurethane resin and 5% by mass of nitrocellulose). On the other side of the substrate sheet, an ink containing organic solvent is printed on the entire surface using gravure printing with a gravure roller, thereby forming a 2 μm thick pattern auxiliary layer with acrylic-urethane resin as the main component. Then, an ink containing organic solvent is printed on the entire surface using gravure printing with a gravure roller, thereby forming a 2 μm thick pattern layer (wood grain pattern) with acrylic-urethane resin as the main component. An ester-based polyurethane is coated on the side opposite to the pattern auxiliary layer to form an adhesive layer with a thickness of 10 μm. A transparent olefin sheet with a thickness of 60 μm is then dry-laminated onto the adhesive layer to form a transparent resin layer. Furthermore, a 2 μm thick surface adhesive auxiliary layer composed of acrylate-urethane copolymer resin is formed on the side opposite to the adhesive layer of the transparent resin layer. A coating agent (urethane acrylate ionizing radiation curable resin composition) is applied to the surface adhesive auxiliary layer by gravure coating, and then ionizing radiation is irradiated to harden the coating agent, thereby forming a 5 μm thick surface protective layer. Finally, the protective surface layer is embossed by hot pressing to form a raised or recessed shape, thus producing a cosmetic piece.

[0085] <Evaluation Methods> (1) Fading of patterns For the cosmetic sheets made using bio-derived polyethylene prepared in the examples and comparative examples, under a light source of 500 lux or higher, the pattern of the pattern layer was visually inspected to confirm whether the pattern had peeled off from a position 50 cm away from the cosmetic sheet (whether there was color fading of the pattern), and the evaluation was carried out according to the following criteria. The results are shown in Table 1. <Evaluation Criteria> +: No color fading of the pattern has been confirmed. -: The pattern has been confirmed to have faded.

[0086] (2) Durability For the cosmetic sheets made using bio-derived polyethylene prepared in the examples and comparative examples, the following ultra-accelerated weathering resistance testing apparatus was used. After irradiating with ultraviolet light for 20 hours at a black panel temperature of 63°C and an illuminance of 100 mW / cm², the sheets were allowed to condense for 4 hours, and the above cycle was repeated. After 300 hours, the appearance of the cosmetic sheets was evaluated visually. The results are shown in Table 1. <Super-enhanced Weather Resistance Testing Device> EYE SUPER UV TESTER SUV-W161 (manufactured by Iwasaki Electric) is an ultra-fast weathering resistance testing device equipped with a UV lamp (product name: M04-L21WB / SUV, manufactured by Iwasaki Electric), a light source housing (product name: WJ50-SUV, manufactured by Iwasaki Electric), and an illuminometer (product name: UVD-365PD, manufactured by Iwasaki Electric). <Evaluation Criteria> +: No cracks were found. -: Cracks appear.

[0087] (3) Discoloration (reddish tinge) The cosmetic sheets made from bio-derived polyethylene prepared in Examples 1-3 were placed in a sealed container and stored at 60°C for 2 weeks. The color difference on the back of the cosmetic sheets before and after storage was measured and evaluated according to the following criteria. The results are shown in Table 2. Furthermore, the color difference was measured using a spectrophotometer CR-400 (manufactured by Konica Minolta Japan Co., Ltd.). <Evaluation Criteria> +: The color difference Δa before and after the test did not reach 0.2. -: The color difference Δa before and after the test is greater than 0.2.

[0088] [Table 1] Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Phenolic antioxidants have have have none none Phosphorus-free antioxidants none have none none have Evaluation methods Pattern fading + + + - + Durability + + + - -

[0089] [Table 2] Example 1 Example 2 Example 3 Phenolic antioxidants have have have Content (mass%) of nitrocellulose in the back auxiliary layer 5 0 10 Evaluation methods Color change + + -

[0090] According to the embodiments, it was confirmed that by using a substrate sheet containing phenolic antioxidants and laminating a pattern auxiliary layer covering the entire first side of the substrate sheet, the fading of the pattern due to fisheyes can be suppressed, and the durability is also excellent. Furthermore, based on a comparison of Example 1 and Example 3, it was confirmed that by having a content of nitrocellulose of 5% by mass or less in the auxiliary layer attached to the back side, discoloration of the cosmetic sheet can be suppressed. On the other hand, in Comparative Example 1, since the substrate does not contain antioxidants, the pattern fades due to fisheye defects, and the deterioration of the substrate leads to a decrease in durability. Furthermore, in Comparative Example 2, the durability decreased because the phosphorus-based antioxidant contained in the substrate sheet was deactivated due to hydrolysis.

[0091] 1: Substrate sheet 2: Pattern auxiliary layer 3: Pattern layer 4: The back is connected to the auxiliary layer. 5: Adhesive layer 6: Transparent resin layer 7: Surface is attached with an auxiliary layer 8: Surface protective layer 10: Use cosmetic sheets made of bio-derived polyethylene.

Claims

1. A cosmetic sheet using bio-derived polyethylene, comprising: a substrate sheet containing bio-derived polyethylene and having a first side and a second side; a pattern auxiliary layer deposited on the first side of the substrate sheet, covering the entire first side of the substrate sheet; and a pattern pattern layer constituting a pattern pattern and deposited on the side of the pattern auxiliary layer opposite to the substrate sheet; wherein the substrate sheet contains a phenolic antioxidant.

2. As in claim 1, the use of cosmetic sheets made of bio-derived polyethylene, wherein the aforementioned phenolic antioxidant is composed of hindered phenolic antioxidants.

3. As in claim 1 or 2, the use of a cosmetic sheet made of bio-derived polyethylene, wherein the substrate sheet further contains a phosphorus-based antioxidant.

4. As in claim 3, the use of bio-derived polyethylene cosmetic sheets, wherein the mass ratio of the phenolic antioxidant to the phosphorus antioxidant in the substrate sheet is 1:1 to 1:

2.

5. If cosmetic sheets of bio-derived polyethylene are used as requested in item 1 or 2, the thickness of the aforementioned patterned auxiliary layer is more than 1 μm and less than 5 μm.

6. As in claim 1 or 2, cosmetic sheets made of bio-derived polyethylene, wherein the aforementioned patterned auxiliary layer is subjected to a smoothing treatment.

7. As claimed in claim 1 or 2, a cosmetic sheet made of bio-derived polyethylene has a back-adhesion auxiliary layer that is deposited on the second side of the substrate sheet and covers the entire second side of the substrate sheet.

8. As requested in item 7, the cosmetic sheet is made of bio-derived polyethylene, wherein the content of the nitrocellulose adhering to the back auxiliary layer is 5% by mass or less.

9. The cosmetic sheet made of bio-derived polyethylene, as claimed in claim 1 or 2, has a transparent resin layer deposited on the side opposite to the pattern layer of the patterned layer, and the thickness of the transparent resin layer is 40 μm or more and 100 μm or less.

10. As claimed in claim 9, use of cosmetic sheets made of bio-derived polyethylene, wherein the aforementioned transparent resin layer is composed of an olefin-based resin.

11. A cosmetic sheet having an adhesive layer on the second side of the substrate sheet of a cosmetic sheet made of bio-derived polyethylene as claimed in claim 1 or 2.

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