JP7298761B2 - Decorative sheet and board using biomass-derived polyethylene - Google Patents

Description

TECHNICAL FIELD The present disclosure relates to decorative sheets and boards using biomass-derived polyethylene.

BACKGROUND ART When it is desired to decorate members used in building materials, furniture, home electric appliances, etc., a decorative board to which a decorative sheet having a design is adhered is generally used.

For example, Patent Document 1 describes a decorative sheet having at least a surface protective layer on a base sheet, wherein the surface protective layer is made of a resin composition containing an ionizing radiation-curable resin, an aldehyde adsorbent and a non-photocatalyst. Disclosed is a decorative sheet characterized by:

JP 2013-063635 A

Plastics are used as the main component of base sheets of decorative sheets used for building materials and the like. Although petroleum-derived plastics are widely used as this plastic, they are not preferable from the viewpoint of reducing the burden on the environment. Therefore, biomass-derived plastics using renewable biological resources as raw materials are known as materials that have less environmental impact than petroleum-derived plastics.

The inventors of the present invention have repeatedly studied the introduction of biomass-derived polyethylene films into decorative sheets for building materials and the like. , it was found that a defect called a fish eye is likely to occur due to the contamination of impurities or the like. Locations where fisheyes are present pose a problem of lower adhesion to resin than locations where fisheyes are not present.

Therefore, when biomass-derived polyethylene film is used as a base material for decorative sheets, the effect of fisheyes causes color loss in the patterned pattern layer, etc., resulting in a poor appearance and a loss of role as a decorative sheet. I found that there was a problem that I could not fulfill.

The pattern layer for forming a wide variety of patterns requires that colors (colored inks containing colorants) be arranged partially and superimposed, and the edges of the colored parts (the parts where the colored inks are arranged) There are overlapping regions between regions and color portions (portions where colored ink is placed). If such a region overlaps with fisheyes having low adhesion, color loss is particularly likely to occur, but defects in the pattern are conspicuous, and the quality of the decorative sheet is greatly impaired.

Therefore, the present disclosure solves the above-described problems found when introducing biomass-derived polyethylene into decorative sheets for building materials and the like.

It was found that the size and number of fish eyes are less dependent on the thickness of biomass-derived polyethylene, and that the greater the thickness, the less affected by fish eyes.

Even if a base sheet containing biomass-derived polyethylene having a biomass degree of 50% or more is used, the pattern auxiliary layer has a thickness of 80 μm to 100 μm and covers the entire first surface of the base sheet. By laminating the above, it is possible to alleviate the adverse effects of defects caused by fisheyes in the base sheet, so that the color loss of the picture pattern of the picture pattern layer laminated on the first surface side of the base sheet can be suppressed.

That is, the present disclosure includes a base sheet comprising biomass-derived polyethylene and having a first side and a second side; and a picture pattern layer that constitutes a picture pattern and is laminated on the side of the picture auxiliary layer opposite to the base sheet, the base sheet comprising The decorative sheet has a biomass degree of 50% or more and a thickness of 80 μm or more and 100 μm or less, and uses biomass-derived polyethylene.

In the decorative sheet using the biomass-derived polyethylene of the present disclosure, the base sheet preferably contains an antioxidant.
The design auxiliary layer preferably has a thickness of 1 μm or more and 5 μm or less.
It is preferable that the pattern auxiliary layer is subjected to a smoothing treatment.
It is preferable to have a transparent resin layer laminated on the side opposite to the picture auxiliary layer of the picture pattern 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 resin.
The present disclosure is also 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.

INDUSTRIAL APPLICABILITY The present disclosure can provide a decorative sheet or the like using biomass-derived polyethylene capable of suppressing color fading of a pattern.

FIG. 1 is a cross-sectional view schematically illustrating a preferred example of a decorative sheet using the biomass-derived polyethylene of the present disclosure. FIG. 2 is a cross-sectional view schematically illustrating a preferred example of a decorative sheet using the biomass-derived polyethylene of the present disclosure.

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

The decorative sheet using biomass-derived polyethylene of the present disclosure includes a base sheet containing biomass-derived polyethylene and having a first side and a second side, and a base sheet laminated on the first side of the base sheet, A pattern auxiliary layer covering the entire first surface of the base sheet; and a pattern layer forming a pattern, laminated on the side of the pattern auxiliary layer opposite to the base sheet. The base sheet has a biomass degree of 50% or more and a thickness of 80 μm or more and 100 μm or less.

FIG. 1 is a cross-sectional view schematically illustrating a preferred example of a decorative sheet using the biomass-derived polyethylene of the present disclosure.
As shown in FIG. 1 , a decorative sheet 10 using the biomass-derived polyethylene of the present disclosure has a pattern layer 3 laminated on the first surface side of a base sheet 1 .
In addition, the base sheet 1, the pattern 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 the base sheet of the pattern auxiliary layer 2 It has a picture pattern layer 3 laminated on the side opposite to 1.

FIG. 2 is a cross-sectional view schematically illustrating a preferred example of a decorative sheet using the biomass-derived polyethylene of the present disclosure. As shown in FIG. 2, in the decorative sheet 10, in addition to the layers shown in FIG. Furthermore, an adhesive layer 5, a transparent resin layer 6, a surface adhesion auxiliary layer 7, and a surface protective layer 8 may be laminated in this order.

(base material sheet)
The decorative sheet uses a base sheet containing biomass-derived polyethylene and having a first side and a second side.
The first surface is the surface of the base sheet on which the pattern layer is formed (also referred to as the surface), and the second surface is the surface opposite to the first surface of the base sheet (the adherend is laminated). It is the surface on the side to be done, and is also called the back surface).

The term "biomass-derived polyethylene" means that at least a part of the raw material is a biomass-derived raw material, and does not mean that the entire raw material is biomass-derived.
It should be noted that whether or not biomass-derived raw materials are used can be determined by radiocarbon (C14) measurement described in the later-described "biomass degree".

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

The base sheet has a biomass degree of 50% or more.
Normally, the higher the biomass degree, the larger the number of fish eyes. The adverse effects of fisheye defects in the material sheet can be mitigated.
In addition, since the biomass degree is 50% or more, it is possible to reduce the amount of raw materials derived from fossil fuels and suitably reduce the environmental load.
The upper limit of the biomass degree is, for example, 70% from the viewpoint of containing additives and the like.

“Biomass degree” (concentration of biomass-derived carbon in a base sheet containing biomass-derived polyethylene) is a value obtained by measuring the content of biomass-derived carbon by radioactive carbon (C14) measurement. Since carbon dioxide in the atmosphere contains a certain proportion of C14 (105.5 pMC), the C14 content in plants that grow by taking in carbon dioxide in the atmosphere, such as corn, is also about 105.5 pMC. It is known. It is also known that fossil fuels contain almost no C14. Therefore, by measuring the ratio of C14 contained in the total carbon atoms in polyethylene, the ratio of biomass-derived carbon can be calculated.
That is, when the content of C14 in polyethylene is defined as P _C14 , the biomass-derived carbon content P _bio can be obtained as follows.
P _bio (%) = P _C14 /105.5 x 100

At least one selected from the group consisting of, for example, high-density polyethylene, medium-density polyethylene, low-density polyethylene, and linear low-density polyethylene can be used for the base sheet. Also, 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.

The base sheet preferably contains an antioxidant.
Examples of antioxidants include phenol-based, amine-based, sulfur-based, and phosphorus-based antioxidants.
Among these, phenolic antioxidants are preferable from the viewpoint of reducing fisheyes in the base sheet and suppressing color loss of the pattern and poor adhesion to the adherend. Phenolic antioxidants are less likely to be hydrolyzed, and are therefore preferable as antioxidants for use in base sheets of decorative sheets that require durability.

Examples of phenolic antioxidants include hindered phenolic antioxidants, specific examples of which include pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl ) propionate], octadecyl-3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate, thiodiethylenebis[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]phosphoate, 3,3′,3″,5,5′,5″-hexa-tert -butyl-a,a',a''-(mesitylene-2,4,6-triyl)tri-p-cresol, 4,6-bis(octylthiomethyl)-o-cresol, ethylenebis(oxyethylene) bis[3-(5-tert-butyl-4-hydroxy-m-tolyl)propionate], hexamethylenebis[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.

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. It can be confirmed by, for example, liquid chromatography that the base sheet contains an antioxidant.

When the base sheet contains a phenolic antioxidant, discoloration may occur. From the viewpoint of suppressing such discoloration, it is more preferable to use a phenolic antioxidant and a phosphorus antioxidant together.
Phosphorus antioxidants include triphenylphosphite, tris(2,4-t-butylphenyl)phosphite, bis[2,4bis(1,1-dimethylethyl)-6-methylphenyl]ethyl ester Phosphoric acid, bis(2,4-t-butylphenyl)pentaerythritol diphosphite, tetrakis(2,4-di-t-butylphenyl)[1,1biphenyl]-4,4'-diylbisphosphonate night, tetra(C12-C15 alkyl)-4,4'-isopropylidene diphenyl 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)phosphonous acid] and the like. be done.

When a phenolic antioxidant and a phosphorus antioxidant are used in combination, the mass ratio of the phenolic antioxidant and the phosphorus antioxidant (phenolic antioxidant: phosphorus antioxidant) is 1: It is preferably 1 or more and 1:2 or less. Defects due to fisheyes in the base sheet can be suitably reduced, and discoloration of the base sheet can be suitably suppressed.

The base sheet contains various additives such as colorants, fillers, matting agents, foaming agents, flame retardants, lubricants, antistatic agents, ultraviolet absorbers, light stabilizers, etc., as required. good too.
The content of 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.

The base sheet has a thickness of 80 µm or more and 100 µm or less.
Even if a base sheet with a high biomass degree of 50% or more is used, the thickness of the base sheet is set in the above range, and the pattern auxiliary layer that covers the entire first surface of the base sheet described later is provided. As a result, it is possible to alleviate the adverse effects of defects caused by fisheyes in the base sheet, thereby suppressing color loss of the picture pattern of the picture pattern layer.
In addition, since the thickness is 100 μm or less, it is possible to reduce the amount of raw materials derived from fossil fuels used for the base material sheet, so that the environmental load can be reduced.

The specific method for forming a film (sheeting) of the base sheet is not particularly limited, and may be a T-die method or a calendar method in which a T-die is used to extrude and laminate a molten resin, a circular die method (inflation method, tubular method ), etc. Among them, the T-die method is preferable in order to improve the production efficiency (production speed) or to relax the internal stress during sheeting. A calendering method is preferably used to make the thickness of the base sheet uniform or to reduce foreign matter defects.

(Picture auxiliary layer)
The decorative sheet has a base sheet and a design 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 pattern auxiliary layer, fish eyes on the first surface side of the base material sheet can be suitably repaired, and color loss of the pattern of the pattern layer laminated on the pattern auxiliary layer can be suppressed. . The design auxiliary layer may cover the entire first surface uniformly, and does not need to completely cover the entire first surface. The pattern auxiliary layer may have, for example, micro defects such as pinholes that are unavoidable during formation.

The pattern auxiliary layer covering the entire first surface of the base sheet can be formed by solid printing by a gravure printing method using an intaglio roll. The ink used for forming the pattern auxiliary layer contains a resin component and a liquid component. The ink may be appropriately mixed with coloring agents such as pigments and dyes, extender pigments, stabilizers, plasticizers, catalysts, curing agents, and the like.

The resin component is not particularly limited, and examples include urethane-based resins, acrylic-based resins, ester-based resins, amide-based resins, butyral-based resins, styrene-based resins, cellulose acetate-based resins, acrylic-urethane-based resins, and vinyl chloride-acetic acid. Optional resins selected from vinyl copolymer resins, vinyl chloride-vinyl acetate-acrylic copolymer resins, chlorinated polypropylene resins, and the like can be used singly or in combination of two or more. Examples of the liquid component include organic solvents such as methyl ethyl ketone, toluene, cyclohexanone, ethyl acetate alcohol, ethanol, and methanol, and water.

The pattern auxiliary layer is preferably subjected to smoothing treatment using a smoothing roll after solid printing with an intaglio roll. Alternatively, the design auxiliary layer is preferably subjected to smoothing treatment by differentiating the conveying speed of the base sheet from the rotation speed of the outer periphery of the intaglio roll. A more homogeneous pattern auxiliary layer can be formed by performing the smoothing treatment.

The design auxiliary layer preferably has a thickness of 1 μm or more and 5 μm or less. Since fish-eye defects of the base sheet can be suitably repaired, color loss of the picture pattern of the picture pattern layer can be suitably suppressed. More preferably, the design auxiliary layer has a thickness of 1.5 μm or more and 3 μm or less.

(Pattern layer)
The decorative sheet has a picture pattern layer that forms a picture pattern and is laminated on the side of the picture auxiliary layer opposite to the base sheet.

The pattern layer imparts a desired pattern (design) to the decorative sheet, and the type of pattern is not limited. Examples include wood grain patterns, stone grain patterns, grain patterns, tiling patterns, brickwork patterns, texture patterns, leather striped patterns, geometric figures, characters, symbols, abstract patterns, and the like.

The ink used for forming the pattern layer contains a colorant component, a resin component and a liquid component. The ink may be appropriately mixed with extender pigments, solvents, stabilizers, plasticizers, catalysts, curing agents, and the like.

Examples of colorant components 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, quinacridone red, and isoindolinone. Use organic pigments or dyes such as yellow and phthalocyanine blue, metal pigments of scale-like foils such as aluminum and brass, pearlescent (pearl) pigments of scale-like foils such as titanium dioxide-coated mica, basic lead carbonate, etc. can be done. The resin component is not particularly limited, and examples include 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, Any one selected from acrylic-urethane resin, vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-vinyl acetate-acrylic copolymer resin, chlorinated polypropylene resin, etc. The above can be mixed and used. As the liquid component, for example, organic solvents such as methyl ethyl ketone, toluene, cyclohexanone, ethyl acetate alcohol, ethanol, and methanol, and water can be used.

The picture pattern layer forming the picture pattern can be formed by partially printing an ink containing a colorant component, a resin component and a liquid component on the picture auxiliary layer by a gravure printing method using an intaglio roll. The patterned layer may be formed by partial printing of inks of the same or different composition in different areas and/or overlapping the same area multiple times.

The thickness of the pattern layer is preferably, for example, 0.1 μm or more and 5 μm or less. Good film quality and adhesion can be achieved.
More preferably, the thickness of the pattern layer is 0.5 μm or more and 3 μm or less.

(Back side adhesion auxiliary layer)
The decorative sheet may have a backside adhesion assisting layer laminated to the second side of the base sheet and covering the entire second side of the base sheet. By having such a back surface adhesion auxiliary layer, fish eyes on the second surface side of the base sheet can be repaired, and adhesion failure to the adherend can be suppressed. The back adhesion auxiliary layer may cover the entire second surface uniformly, and does not need to completely cover the entire second surface. The backside adhesion auxiliary layer may have micro defects such as pinholes that are unavoidable during formation, for example.

The back adhesion auxiliary layer covering the entire second surface of the base sheet can be formed by solid printing by a gravure printing method using an intaglio roll. The ink used for forming the back adhesion auxiliary layer contains a resin component and a liquid component. The ink may be appropriately mixed with coloring agents such as pigments and dyes, extender pigments, stabilizers, plasticizers, catalysts, curing agents, and the like.

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

From the viewpoint of improving adhesion to the adherend, the back adhesion auxiliary layer preferably contains a urethane-based resin, and the urethane-based resin is more preferably ester-based polyurethane.

Ester-based polyurethane is a cured product of a composition containing polyol (polyhydric alcohol) as a main component and isocyanate as a cross-linking agent (curing agent).
Polyols that have two or more hydroxyl groups in the molecule can be used, for example, polyethylene glycol, polypropylene glycol, acrylic polyol, polyester polyol, polyether polyol, and the like.
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, or aliphatic (or alicyclic) isocyanates such as hexamethylene diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate, and hydrogenated diphenylmethane diisocyanate ) isocyanate and the like can be used.

The content of the resin component is more preferably 40% by mass or more, more preferably 50% by mass or more, based on the mass of the back adhesion auxiliary layer, from the viewpoint of suitably improving the adhesion to the adherend. is more preferred.

The back adhesion auxiliary layer preferably contains nitrocellulose (nitrocellulose resin) (more than 0% by mass) from the viewpoint of improving drying properties, but suppresses discoloration of the decorative sheet using biomass-derived polyethylene. From a viewpoint, the content of nitrocellulose is preferably 5% by mass or less.
The content of nitrocellulose (nitrocellulose resin) is more preferably 3% by mass or less, still more preferably 1% by mass or less, based on the mass of the back adhesion auxiliary layer.

The back adhesion auxiliary layer is preferably subjected to smoothing treatment using a smoothing roll after solid printing with an intaglio roll. Alternatively, the back adhesion auxiliary layer is preferably subjected to a smoothing treatment by setting the conveying speed of the base sheet and the rotation speed of the intaglio roll at different speeds. A more uniform back adhesion auxiliary layer can be formed by performing the smoothing treatment.

The back adhesion auxiliary layer preferably has a thickness of 1 μm or more and 10 μm or less. Since fish-eye defects of the base sheet can be suitably repaired, poor adhesion to the adherend can be suitably suppressed.
More preferably, the back adhesion auxiliary layer has a thickness of 1.5 μm or more and 5 μm or less.

(Transparent resin layer)
The decorative sheet preferably has a transparent resin layer laminated on the side of the picture pattern layer opposite to the picture auxiliary layer.
By having the transparent resin layer, it is possible to protect the picture pattern layer, improve the scratch resistance of the decorative sheet, and impart durability.
The “transparency” may be translucent or colored as long as the pattern layer can be visually recognized.

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 A polymer resin or the like can be used. From the viewpoint of improving moldability and scratch resistance, ester-based resins and olefin-based resins are preferable, and olefin-based resins such as polypropylene and polyester are more preferable.

The transparent resin layer preferably contains an ultraviolet absorber and a light stabilizer from the viewpoint of more preferably imparting durability.
Examples of the ultraviolet absorber include benzotriazole-based ultraviolet absorbers, benzophenone-based ultraviolet absorbers, salicylic acid ester-based ultraviolet absorbers, and triazine-based ultraviolet absorbers.
Among these, triazine-based ultraviolet absorbers are preferred from the viewpoint of favorably imparting weather resistance, design properties, bleeding suppression, and the like. 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.

As the light stabilizer, a hindered amine light stabilizer can be preferably 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.

The transparent resin layer may further contain various additives as necessary. For example, lubricants such as silicone resins, waxes, and fluorine resins, and coloring agents such as dyes and pigments.

The transparent resin layer has a thickness of 40 μm or more and 100 μm or less.
When the thickness of the transparent resin layer is within the above range, the amount of polyethylene derived from fossil fuels can be suitably reduced in the decorative sheet as a whole, 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.

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

The transparent resin layer may be subjected to surface treatment such as saponification treatment, glow discharge treatment, corona discharge treatment, plasma discharge treatment, ultraviolet (UV) treatment, and flame treatment.

(Surface protective layer)
The decorative sheet may have a surface protective layer on the side opposite to the pattern layer of the transparent resin layer.
Durability (scratch resistance, stain resistance, weather resistance, etc.) can be imparted by having the surface protective layer.

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 absorber and a light stabilizer. The same ultraviolet absorbers and light stabilizers as used in the transparent resin layer can be used.

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

Examples of cured products of ionizing radiation-curable components include cured products of oligomers and/or monomers having radically polymerizable unsaturated bonds or cationic polymerizable functional groups in the molecule. Ionizing radiation refers to electromagnetic waves or charged particles with energy capable of polymerizing or cross-linking molecules, typically electron beams (EB) or ultraviolet rays (UV). A method for forming the surface protective layer is not particularly limited, and a known method can be used.

Examples of oligomers having a radically polymerizable unsaturated group in the molecule include oligomers such as urethane (meth)acrylate, polyester (meth)acrylate, epoxy (meth)acrylate, melamine (meth)acrylate, and triazine (meth)acrylate. It can be used preferably, and urethane (meth)acrylate oligomer is more preferable. As for the molecular weight, those having a molecular weight of about 250 to 100,000 are generally used.

As the monomer having a radically polymerizable unsaturated group in the molecule, for example, polyfunctional monomers are preferable, and polyfunctional (meth)acrylates are 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, and 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. is mentioned. In addition, you may use a monofunctional monomer suitably.

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.

A photopolymerization initiator is preferably used when the ionizing radiation-curable resin is crosslinked with ultraviolet light. The amount of the photopolymerization initiator to be added is, for example, 0.1 to 10 parts by mass with respect to 100 parts by mass of the ionizing radiation-curable component.

The surface protective layer preferably has a gloss matte effect. Even if the picture pattern formed by the picture pattern layer due to fish-eye color loss occurs, it can be made inconspicuous.
The term "gloss matte effect" means a design effect in which a glossy portion is made to stand out and a dull portion appears to be recessed.
The method for imparting a gloss matte effect is not particularly limited, and a glossiness adjusting agent may be contained in the surface protective layer, or the surface protective layer may be provided with an irregular shape, which will be described later. The uneven shape can have, for example, a maximum height Rz of 10 μm or more and 60 μm or less. The picture pattern formed by the gloss matte effect of the surface protective layer may or may not be in synchronism with the whole or part of the picture pattern formed by the picture pattern layer. A non-synchronized (non-synchronized) pattern is preferable because it can be made inconspicuous even when color loss occurs in the pattern formed by the pattern layer due to fish eyes.

Although the thickness of the surface protective layer is not particularly limited, it is, for example, 1 μm or more and 50 μm or less. When 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. The visibility of the pattern of the layer may deteriorate. The thickness of the surface protective layer may be 3 μm or more and 40 μm or less, or may be 5 μm or more and 35 μm or less.

(adhesive layer)
The decorative sheet may have an adhesive layer between the pattern layer and the transparent resin layer. The adhesive layer is preferably transparent. As the adhesive for the adhesive layer, for example, urethane-based adhesives such as ester-based urethane and acrylic urethane, acrylic-based adhesives, epoxy-based adhesives, and rubber-based adhesives can be used. The thickness of the adhesive layer is, for example, 0.1 or more and 30 μm or less.

(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 and an easy adhesion layer for the surface protective layer. The surface adhesion auxiliary layer is preferably transparent. As the adhesive for the auxiliary surface adhesion layer, for example, urethane-based adhesives such as ester-based urethane and acrylic urethane, acrylic-based adhesives, epoxy-based adhesives, and rubber-based adhesives can be used. The surface adhesion auxiliary layer preferably contains an ultraviolet absorber and a light stabilizer. The same ultraviolet absorbers and light stabilizers as used in the transparent resin layer can be used. The thickness of the surface adhesion auxiliary layer is, for example, 0.1 or more and 30 μm or less.

(Manufacturing method of decorative sheet)
In the manufacturing method of the decorative sheet of the present disclosure, the order of progress of each step is not particularly limited. For example, the order of pattern auxiliary layer, back adhesion auxiliary layer, pattern pattern layer, the order of pattern auxiliary layer, pattern layer, back adhesion auxiliary layer, or the order of back adhesion auxiliary layer, pattern auxiliary layer, pattern pattern layer. can. Also, each step does not have to proceed in succession, and other steps or treatments may be performed between these steps.

<Decorative board>
In the decorative sheet of the present disclosure, an adherend is laminated on the second surface side of the base sheet of the decorative sheet using biomass-derived polyethylene.
Examples of the adherend include wood board, gypsum board, cement board, ceramic board, metal board, resin board, and fiber-reinforced plastic board. As a method for laminating the adherend, for example, the adherend may be laminated on the second surface side of the base sheet using an adhesive.

EXAMPLES Next, the present invention will be described in more detail with reference to examples, but the present disclosure is not limited by these examples.

(Example 1)
Biomass-derived polyethylene with a biomass degree of 50% [a colored polyethylene film with a thickness of 80 μm, containing 0.05% by mass of a phenolic antioxidant (Irganox 1010, manufactured by BASF Japan Co., Ltd.), a phosphorus antioxidant (Irgafos 168, manufactured by BASF Japan Ltd.)] was prepared and used as a base sheet.
A gravure printing method using an intaglio roll is applied to one side of the base sheet so as to cover the entire surface with a back adhesion auxiliary layer (containing 53% by mass of ester polyurethane resin and 3% by mass of nitrocellulose). It was formed by solid printing with an ink containing an organic solvent.
On the other side of the base sheet, a pattern auxiliary layer with a thickness of 2 μm containing acrylic-urethane resin as a main component is applied so as to cover the entire surface by a gravure printing method using an intaglio roll, and an organic solvent is applied. After forming by solid printing the ink containing, a 2 μm thick picture pattern layer (wood grain pattern) mainly composed of acrylic-urethane resin is applied by a gravure printing method using an intaglio roll with a coloring agent and an organic solvent. It was formed by partially printing the ink containing.
Ester-based polyurethane is applied to the side of the pattern layer opposite to the pattern auxiliary layer to form an adhesive layer with a thickness of 10 μm, and a transparent olefin sheet with a thickness of 60 μm is dry-laminated on the adhesive layer to make it transparent. A flexible resin layer was formed.
Furthermore, on the side opposite to the adhesive layer of the transparent resin layer, a surface adhesion auxiliary layer made of acrylic-urethane copolymer resin having a thickness of 2 μm is formed, and the surface adhesion auxiliary layer is coated with a coating agent by gravure coating. After applying (urethane acrylate ionizing radiation-curable resin composition), ionizing radiation was applied to cure the coating agent to form a surface protective layer having a thickness of 5 μm.
Finally, the side having the surface protective layer was embossed by hot pressing to form an uneven shape, thereby producing a decorative sheet.

(Examples 2-3, Comparative Examples 1-2)
A decorative sheet was produced in the same manner as in Example 1, except that the biomass degree and thickness of the base sheet were changed as shown in Table 1.

<Evaluation method>
(color loss of pattern)
Regarding the decorative sheet using biomass-derived polyethylene produced in Examples and Comparative Examples, under a light source of 500 lux or more, whether the pattern of the pattern layer is missing from a position 50 cm away from the decorative sheet (color of the pattern) omission) was visually confirmed and evaluated according to the following criteria. The results are shown in Table 1.
+: Color omission of the pattern was not observed.
-: Color omission of the pattern was confirmed.

From the examples, even if the biomass degree of the base sheet containing biomass-derived polyethylene is high (even if it is 50% or more), the base sheet has a predetermined thickness and the first surface of the base sheet It was confirmed that by laminating the design auxiliary layer covering the entire surface, it is possible to alleviate the adverse effects of defects caused by fisheyes, thereby suppressing color fading of the design.
On the other hand, in Comparative Examples 1 and 2, since the thickness of the base sheet is insufficient, defects due to fisheyes do not occur even if the pattern auxiliary layer covering the entire first surface of the base sheet is laminated. The adverse effects could not be sufficiently alleviated, and the color loss of the pattern could not be sufficiently suppressed.

1 base sheet 2 picture auxiliary layer 3 picture pattern layer 4 back adhesion auxiliary layer 5 adhesive layer 6 transparent resin layer 7 surface adhesion auxiliary layer 8 surface protective layer 10 decorative sheet using biomass-derived polyethylene

Claims (6)

a base sheet comprising biomass-derived polyethylene and having a first side and a second side;
a pattern auxiliary layer laminated on the first surface side of the base sheet and covering the entire first surface of the base sheet;
a pattern layer forming a pattern, laminated on the side of the pattern auxiliary layer opposite to the base sheet;
a transparent resin layer laminated on the side opposite to the picture auxiliary layer of the picture pattern layer;
a surface protective layer laminated on the surface of the transparent resin layer opposite to the pattern layer,
The base sheet has a biomass degree of 50% or more and 70% or less and a thickness of 80 μm or more and 100 μm or less ,
The transparent resin layer is made of an olefin resin,
A decorative sheet that uses biomass-derived polyethylene. The decorative sheet using the biomass-derived polyethylene according to claim 1, wherein the base sheet contains an antioxidant. 3. The decorative sheet using biomass-derived polyethylene according to claim 1, wherein the pattern auxiliary layer has a thickness of 1 μm or more and 5 μm or less. The decorative sheet using biomass-derived polyethylene according to any one of claims 1 to 3, wherein the pattern auxiliary layer is smoothed. The decorative sheet using biomass-derived polyethylene according to any one of claims 1 to 4, wherein the transparent resin layer has a thickness of 40 µm or more and 100 µm or less. 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 according to any one of claims 1 to 5 .

Images