JP6459340B2 - Mirror surface decorative sheet and mirror surface decorative plate using the same - Google Patents

Description

  The present invention relates to a mirror surface decorative sheet and a mirror surface decorative sheet using the same.

Conventionally, a decorative sheet that has been given a beauty by using a plastic sheet as a base material, and giving it a color, pattern, or unevenness, is a metal plate, an inorganic plate (such as a plaster board), a wooden plate (MDF, particle board, And laminated on a substrate such as a laminated board, etc., and used for various members such as interior and exterior of buildings, building materials, furniture, or home appliances. Such decorative sheets, especially decorative sheets used for interior materials such as kitchen doors for kitchen products, are expected to have a high-class feeling in addition to cleanliness and design, due to the recent trend toward consumer luxury goods. Rarely, the specularity is also an important requirement for decorative sheets.
In order to obtain the specularity of various members as described above, it is a matter of course that the specularity of the decorative sheet to be used is important, but it is possible to prevent the specularity from being deteriorated by attaching the decorative sheet to the member substrate. It is also important. That is, in order to maintain the specularity when the decorative sheet is bonded to the member substrate, the decorative sheet itself needs to have a concealing property corresponding to the color tone variation of the member substrate, and at the same time, adhesive (adhesive) In order to prevent a decrease in specularity due to picking up so-called duck, such as uneven coating on the surface of the member substrate, or the like, measures by thickness, hardness, and layer configuration are indispensable and important.

  As such a decorative sheet having a specularity, a decorative sheet having a polyester film as a base material and a surface protective layer obtained by crosslinking and curing an ionizing radiation curable resin composition has been proposed (for example, Patent Documents). 1). One means for improving the specularity is to make the surface protective layer thicker. However, by increasing the thickness of the surface protective layer, there was a tendency for cracks to easily occur on the surface when bending, V-cutting, or lapping, which is required for bonding to the substrate for members with an adhesive, was performed. .

  In addition, the mirror surface decorative sheet is generally applied with a masking film to prevent scratches during transportation and construction, including when processing into a member substrate. The surface cracks generated during processing such as processing are generally confirmed for the first time when a member is applied and the masking film is peeled off. And by peeling a masking film, the stress concerning the surface of a mirror surface decorative sheet is released, and the problem that cracks spread over time due to surface cracks generated during processing tends to occur. For this reason, the mirror surface decorative sheet is required to be free from surface cracks due to aging after processing, such as during bending of the member substrate.

  Such a request can be met by using a soft resin for forming the surface protective layer of the mirror surface decorative sheet. However, various members as described above are also required to have surface characteristics such as contamination resistance, scratch resistance, water resistance, chemical resistance, and weather resistance, and the surface protective layer is required to have a certain level of hardness. ing. In other words, it can be said that it is necessary to simultaneously satisfy the contradictory performances of preventing generation of cracks during processing and cracking after construction and satisfying surface characteristics.

  In addition, in order to ensure the specularity, it is necessary for the decorative sheet to have a certain level of hardness, but on the other hand, if it has more than necessary hardness, it is referred to as a springback during processing into a member substrate. Another problem is that peeling of the end face tends to occur.

  By the way, the interior and exterior of the above building, building materials, furniture, and various parts such as for home appliances, especially the storage and doors of kitchen products in kitchens and bathrooms are heated above normal room temperature. In particular, in the case of kitchen components, heated pans and kettles may be placed directly through the pan or directly, so the decorative sheet may require heat resistance as a surface property. .

JP 2007-204966 A

  Under such circumstances, an object of the present invention is to provide a specular decorative sheet having excellent specularity and having excellent surface characteristics and processing characteristics, and a specular decorative sheet using the same.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that the problem can be solved by the following invention. That is, this invention provides the following mirror surface decorative sheet and the mirror surface decorative board using the same.

1. It has a base material layer having a support resin layer and a base resin layer, and a surface protective layer, the thickness of the support resin layer is 60 to 160 μm, and the hardness measured by the following method is 300 to 300 1000 MPa, the thickness of the base resin layer is 100 to 300 μm, the hardness measured by the following method is 600 to 1900 MPa, and the total thickness of the support resin layer and the base resin layer is 200. The surface protective layer is a layer provided by crosslinking and curing the ionizing radiation curable resin composition on the base resin layer side of the base material layer, and the thickness thereof is 2 to 15 μm. Makeup sheet.
(Measurement method of hardness)
Prepare a test piece punched into a dumbbell shape conforming to JIS K7127, and measure it under a temperature environment of 25 ° C. using a tensile tester under the conditions of a tensile speed of 50 mm / min, a distance between chucks of 80 mm, and a width of 10 mm. E (tensile modulus) calculated from the following formula from the initial direct portion of the obtained tensile stress-strain curve was defined as hardness.
Tensile modulus = Δρ / Δε
Δρ: Stress difference due to the original average cross-sectional area between two points on a straight line Δε: Strain difference between the same two points A specular decorative board comprising a substrate, an adhesive layer, and the specular decorative sheet according to 1 above in that order.

  ADVANTAGE OF THE INVENTION According to this invention, the mirror surface decorative sheet which has the outstanding mirror surface property and has the outstanding surface characteristic and processing characteristic, and the mirror surface decorative board using this decorative sheet can be obtained.

It is a schematic diagram which shows the cross section of one aspect of the mirror surface decorative sheet of this invention. It is a schematic diagram which shows the cross section of one aspect of the mirror surface decorative sheet of this invention. It is a schematic diagram which shows the cross section of one aspect of the mirror surface decorative board of this invention.

[Mirror makeup sheet]
The mirror surface decorative sheet of the present invention has a base material layer having a support resin layer and a base resin layer, and a surface protective layer, and the thickness of the support resin layer is 60 to 160 μm. The measured hardness is 300 to 1000 MPa, the thickness of the base resin layer is 100 to 300 μm, the hardness measured by the following method is 600 to 1900 MPa, and the support resin layer and the base resin The total thickness of the layers is 200 to 460 μm, and the surface protective layer is a layer provided by crosslinking and curing an ionizing radiation curable resin composition on the base resin layer side of the base material layer. Is 2 to 15 μm. The mirror surface decorative sheet of the present invention will be described with reference to FIGS.

  1 and 2 are schematic views showing a cross section of a preferred embodiment of the specular decorative sheet of the present invention. A mirror surface decorative sheet 10 shown in FIG. 1 includes a base material layer 1 having a support resin layer 1a and a base resin layer 1b, and a surface protective layer 2. Moreover, the mirror surface decorative sheet 10 shown in FIG. 2 has a base material layer 1 having a support resin layer 1a and a base resin layer 1b, a primer layer 3, a surface protective layer 2, and a masking film 5 in this order. In addition, the back surface primer layer 4 is provided on the side opposite to the side having the surface protective layer 2 of the base material layer 1 (hereinafter sometimes simply referred to as a back surface).

The mirror surface decorative sheet of the present invention has the thickness and hardness of the support resin layer and the base resin layer constituting the decorative sheet within a predetermined range, and the total thickness of the support resin layer and the base resin layer is predetermined. And a mirror-coated decorative sheet obtained by setting the thickness of the surface protective layer, which is a cross-linked cured product of the ionizing radiation curable resin composition, within a predetermined range.
The specularity in the present invention is a performance having a predetermined glossiness and smoothness. Specifically, the glossiness (incident angle 60 °) is 40 or more and the center line average roughness (Ra) is 1 μm. It means the following. Here, the center line average roughness (Ra) is measured at 12 measurement points according to JIS B0601-1994, for example, using a contact-type surface roughness meter, and the maximum value and the minimum value are bracketed. A value obtained by calculating an average value of 10 points is defined as a center line average roughness (Ra).

(Base material layer)
The base material layer 1 has a support resin layer 1a and a base resin layer 1b, and has a thickness of 200 to 460 μm. And this support body resin layer 1a requires that the thickness is 60-160 micrometers, and the hardness measured by the predetermined method mentioned later is 300-1000 MPa, This base resin layer 1b This is a layer having a thickness of 100 to 300 μm and a hardness measured by a predetermined method described later of 600 to 1900 MPa. When the support resin layer and the base resin layer satisfy the above conditions, it is possible to obtain excellent specularity, excellent surface characteristics and processing characteristics.

Here, for the hardness of the support resin layer and the base resin layer in the present invention, a test piece punched into a dumbbell shape in accordance with JIS K7127 is prepared, and a tensile tester is used in a temperature environment of 25 ° C. E (tensile modulus) calculated by the following equation from the initial direct portion of the tensile stress-strain curve obtained by measurement under the conditions of a tensile speed of 50 mm / min, a distance between chucks of 80 mm, and a width of 10 mm.
Tensile modulus = Δρ / Δε
Δρ: Stress difference due to the original average cross-sectional area between two points on a straight line Δε: Strain difference between the same two points

  From the viewpoint of obtaining excellent specularity and excellent surface characteristics and processing characteristics, the total thickness of the support resin layer and the base resin layer is preferably 230 to 430 μm, and more preferably 250 to 400 μm. The thickness of the support resin layer is preferably 80 to 155 μm, more preferably 80 to 150 μm, and the thickness of the base resin layer is preferably 120 to 270 μm, more preferably 150 to 250 μm.

From the viewpoint of obtaining excellent specularity, excellent surface characteristics and processing characteristics, the hardness of the support resin layer is preferably 400 to 1000 MPa, more preferably 500 to 900 MPa, and the hardness of the base resin layer is It is preferable that it is 700-1600 MPa, More preferably, it is 800-1500 MPa.
The base resin layer is preferably harder than the support resin layer. By providing a harder base resin layer closer to the surface layer, the hardness of the decorative sheet can be improved, and by providing a support resin layer softer than the base resin layer near the substrate, the unevenness of the substrate Absorbs the shape and the like, and as a result, excellent specularity can be obtained.

  Moreover, 700-2100 MPa is preferable, as for the hardness as a base material layer which has a support body resin layer and a base resin layer, 900-2050 MPa is more preferable, More preferably, it is 1150-2000 MPa. When the hardness of the substrate layer is within the above range, excellent specularity, excellent surface characteristics and processing characteristics can be obtained.

The resin material for forming the support resin layer and the base resin layer is preferably a crystalline resin. The crystalline resin has a stable crystal structure as long as it is below the melting point (Tm) even in the temperature range higher than the glass transition temperature (Tg), so the temperature dependence of flexibility is low and uneven temperature due to local heating occurs. Even so, excellent specularity is maintained.
In the present invention, the crystalline resin preferably has a glass transition point (Tg) of −50 to 130 ° C. and a melting point (Tm) of 130 to 300 ° C. When the resin satisfies the glass transition point (Tg) and the melting point (Tm) at the same time, the temperature dependency of flexibility is suppressed, and excellent specularity can be obtained even if temperature unevenness occurs due to local overheating. Is obtained. From the same viewpoint, that is, from the viewpoint of obtaining excellent heat resistance and specularity, the glass transition point (Tg) is more preferably -20 to 100 ° C, and further preferably -20 to 50 ° C. The melting point (Tm) is more preferably 130 to 220 ° C, and further preferably 130 to 200 ° C.

Here, the glass transition point (Tg) is a value measured according to JIS K7121-1987. Specifically, using the base sheet as a test piece, the test piece is heated from room temperature at a rate of 20 ° C./min, the calorific value is measured with a differential scanning calorimeter (DSC), and an endothermic curve diagram or exotherm. A curve diagram was created, and an extension line was drawn on each of the straight lines before and after the inflection point, and the intersection of the 1/2 straight line between the two extension lines and the endothermic curve or exothermic curve was defined as Tg.
The melting point (Tm) is a value measured according to JIS K7121-1987. Specifically, using the base sheet as a test piece, the test piece was heated from room temperature at a rate of 10 ° C./min, heated to a temperature 30 ° C. higher than the end of the melting peak, held for 10 minutes, and then 10 In the DSC curve obtained by cooling at 40 ° C./min to 40 ° C. and repeating the same heating and cooling again, the temperature at the top of the melting peak was defined as the melting point (Tm). When there are a plurality of endothermic peaks in the DSC curve, the apex temperature of the endothermic peak with the maximum area is adopted.

  Preferred examples of such a crystalline resin include polyolefin resins and polyester resins. Examples of the polyolefin resin include polyethylene resin, polypropylene resin, polybutene resin, ethylene / propylene copolymer resin, ethylene / propylene / butene copolymer resin, olefin thermoplastic elastomer, and the like. Examples of the polyester resin include polyethylene terephthalate, Preferable examples include polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, and ethylene-terephthalate-isophthalate copolymer.

  Polypropylene resin is preferable from the viewpoint of surface properties such as weather resistance and scratch resistance. Preferred examples of the polypropylene resin include homopolypropylene resins, random polypropylene resins, block polypropylene resins, and α-olefin copolymers having a polypropylene crystal part and having 2 to 20 carbon atoms other than propylene. In addition, a propylene-α-olefin copolymer containing 15 mol% or more of ethylene, 1-butene, 1-hexene, 1-octene, 3-methyl-1-butene, 4-methyl-1-pentene, etc., for example, ethylene / Propylene copolymers, ethylene / propylene / butene copolymers and the like are also preferred.

  The melting point of the polyolefin resin is preferably 130 to 220 ° C, more preferably 150 to 200 ° C. When the melting point of the polyolefin resin is within the above range, excellent specularity, surface characteristics and processing characteristics can be obtained, and it is effective in obtaining particularly excellent specularity and processing characteristics.

  Moreover, it is preferable to employ | adopt a polyester resin from a viewpoint which surface smoothness improves, the outstanding specularity is acquired, and obtaining the outstanding heat resistance. Preferred examples of the polyester resin include those described above. Among them, polyethylene terephthalate is preferable, and biaxially stretched polyethylene terephthalate is preferable. Since the resin layer using polyester resin itself has high surface smoothness, when it is provided on the base resin layer, excellent mirror surface properties of the mirror surface decorative sheet can be obtained even if the thickness of the surface protective layer is reduced. It is done.

The resin material for forming the support resin layer and the base resin layer may be the same or different. For example, a combination of polyethylene / polyethylene, polyethylene / polypropylene, polypropylene / polypropylene, or the like is preferable.
In addition, from the viewpoint of obtaining excellent specularity, a polyester resin (polyethylene terephthalate) is used as a resin for forming the base resin layer, such as polyethylene / polyethylene terephthalate, polyethylene / polyethylene terephthalate, polypropylene / polyethylene terephthalate, or polyethylene terephthalate / polyethylene terephthalate. The combination used is preferably mentioned.

  The base material layer is preferably colored with a colorant. By being colored, it is possible to conceal a base such as a substrate on which a decorative sheet is provided, and at the same time, excellent design properties are obtained. In this case, it is sufficient that at least one of the support resin layer and the base resin layer is colored, and both may be colored. From the viewpoint of obtaining better design properties, it is preferable that at least the base resin layer is colored. This is because the base resin layer is on the surface protective layer side (surface layer side), so that it is easy to visually recognize and more easily obtain a coloring effect.

Colorants that can be used for the base material layer include carbon black (black), iron black, titanium white, antimony white, yellow lead, titanium yellow, petal, cadmium red, ultramarine, cobalt blue and other inorganic pigments, quinacridone red, Organic pigments such as isoindolinone yellow and phthalocyanine blue, or pearly luster consisting of scaly foils such as dyes, metallic pigments made of scaly foils such as aluminum and brass, titanium dioxide-coated mica, and basic lead carbonate (pearl) ) Pigments are preferred.
The amount of the colorant used in the support resin layer and the base resin layer is not particularly limited as long as it does not decrease the film formability and mechanical strength when these layers are obtained by extrusion molding.

An additive may be blended in the resin material used for forming the base material layer, if necessary. Examples of the additive include a filler, a flame retardant, an antioxidant, a lubricant, a foaming agent, an ultraviolet absorber, and a light stabilizer.
Among the above additives, it is preferable to contain an inorganic filler such as calcium carbonate, barium sulfate, clay, and talc from the viewpoint of obtaining excellent processing characteristics. The content of these inorganic fillers is preferably in the range of 1 to 60% by mass with respect to the substrate 2.

Moreover, in this invention, if it is a range which does not affect the hardness of a base material layer, you may have a resin layer further. This resin layer may be present on the surface of the base material layer on the side of the support resin layer, may be present on the surface of the base resin layer side, or the support resin layer and the base resin layer May be present between
As the resin material constituting such a resin layer, the resin material for forming the support resin layer and the base resin layer can be preferably exemplified, and the resin layer includes the colored layer and the additive. May be.
Moreover, it is preferable that it is 3-50 micrometers from a viewpoint which sets the thickness of a resin layer as the range which does not affect the hardness of a base material layer, More preferably, it is 5-30 micrometers.

(Surface protective layer)
The surface protective layer 2 is a layer that imparts surface properties such as weather resistance, stain resistance, scratch resistance, water resistance, and chemical resistance to the decorative sheet of the present invention, and also provides excellent specularity. It is necessary that the ionizing radiation curable resin composition is provided by crosslinking and curing on the base resin layer side of the material layer, and the thickness thereof is 2 to 15 μm.

  The material constituting the surface protective layer is constituted by a cured product of an ionizing radiation curable resin composition containing an ionizing radiation curable resin. Here, the ionizing radiation curable resin composition is a resin composition that is cured by irradiating with ionizing radiation, and the ionizing radiation has an energy quantum capable of polymerizing or crosslinking molecules among electromagnetic waves or charged particle beams. In addition to ultraviolet rays (UV) or electron beams (EB), electromagnetic waves such as X-rays and γ-rays, and charged particle beams such as α-rays and ion rays are also used.

The ionizing radiation curable resin contained in the ionizing radiation curable resin composition is appropriately selected from polymerizable monomers and polymerizable oligomers (or prepolymers) conventionally used as ionizing radiation curable resins. be able to.
For example, polymerizable monomers such as monofunctional (meth) acrylate and polyfunctional (meth) acrylate, urethane (meth) acrylate oligomer, epoxy (meth) acrylate oligomer, polyester (meth) acrylate oligomer, polyether (meth) acrylate oligomer Polymerizable oligomers such as acrylic (meth) acrylate oligomers, or prepolymers can be used alone or in combination of two or more.

When an ultraviolet curable resin is used as the ionizing radiation curable resin, it is desirable to add about 0.1 to 5 parts by mass of the photopolymerization initiator with respect to 100 parts by mass of the resin. The initiator for photopolymerization can be appropriately selected from those conventionally used, and is not particularly limited. For example, the initiator for photopolymerization such as benzoin, acetophenone, phenylketone, benzophenone, and anthraquinone An agent is preferably mentioned.
Moreover, as a photosensitizer, p-dimethylbenzoic acid ester, tertiary amines, a thiol type sensitizer, etc. can be used, for example.

  The ionizing radiation curable resin used in the present invention is preferably electron beam curable. In the case of electron beam curable, solvent-free is possible, which is more preferable from the viewpoint of environment and health, and does not require a photopolymerization initiator, and stable curing characteristics can be obtained.

  In the ionizing radiation curable resin composition, various additives such as a filler (filler) such as an abrasion resistant filler, a mat forming filler, and a flaw resistant filler, or an ultraviolet absorber (UVA) or a hindered amine for improving weather resistance. A weathering agent such as a light stabilizer (HALS) can be contained. These weathering agents are reactive ultraviolet absorbers having reactive functional groups having ethylenic double bonds such as (meth) acryloyl groups, vinyl groups, and allyl groups, or reactive light stabilizers (HALS). It is preferable from the point that stable weather resistance can be obtained without causing bleeding out of the weathering agent.

  In addition, ionizing radiation curable resin compositions are used as various additive components for the purpose of improving the concealability of the surface protective layer in the resulting decorative sheet, preventing yellowing of the base material, and improving light resistance. Inorganic color pigments such as paste and carbon black can be appropriately added.

The thickness of the surface protective layer is required to be 2 to 15 μm. If the thickness of the surface protective layer is less than 2 μm, excellent specularity and surface characteristics cannot be obtained, and if it exceeds 15 μm, excellent processing characteristics cannot be obtained.
From the viewpoint of obtaining excellent specularity and excellent surface characteristics and processing characteristics, the thickness of the surface protective layer is preferably 4 to 12 μm.

(Primer layer)
The primer layer 3 is provided between the base material layer 1 and the surface protective layer 2 and is preferably provided in order to improve the adhesion of these layers and to improve the specularity.
The material for forming the primer layer 3 is not particularly limited, but is preferably formed from, for example, a two-component curable resin composition from the viewpoint of obtaining excellent adhesion and specularity. The two-component curable resin composition is not particularly limited as long as it is a resin that is cured by adding a curing agent to the main agent, the main agent is a polyol (polyhydric alcohol), and the curing agent is an isocyanate curing agent. A liquid curable urethane resin is preferred.

  Examples of the main agent include, for example, polyols such as polyethylene glycol, polypropylene glycol, butylene glycol, neopentyl glycol, and 1,6-hexanediol, (meth) acrylic acid esters such as methyl (meth) acrylate, and (meth) Acrylic polyols obtained by addition polymerization with monomers having a hydroxyl group such as 2-hydroxyethyl acrylate and 2-hydroxypropyl (meth) acrylate; known diols such as glycols such as ethylene glycol and propylene glycol and adipine Polyester polyols obtained by polycondensation reaction with at least one selected from dibasic acids such as acid, maleic acid, phthalic acid and terephthalic acid, and acid esters thereof; the above diols and ethylene oxide Id, propylene oxide, polyol having a hydroxyl group as a functional group, such as polyether polyols obtained by addition polymerization of such as tetrahydrofuran and the like preferably. These can be used individually or in mixture of multiple types.

  As the isocyanate curing agent, a conventionally known compound may be appropriately used. For example, aromatic compounds such as 2,4-tolylene diisocyanate (TDI), xylene diisocyanate (XDI), naphthalene diisocyanate, and 4,4′-diphenylmethane diisocyanate. Isocyanate or poly, such as 1,6-hexamethylene diisocyanate (HMDI), isophorone diisocyanate (IPDI), methylene diisocyanate (MDI), hydrogenated tolylene diisocyanate, hydrogenated diphenylmethane diisocyanate, etc. Isocyanates are used. Further, adducts or multimers of these various isocyanates, for example, adducts of tolylene diisocyanate, tolylene diisocyanate trimers and the like are also used.

  The thickness of a primer layer is about 0.5-20 micrometers normally, and 1-10 micrometers is preferable. When the thickness of the primer layer is within the above range, excellent adhesion and specularity can be obtained.

(Back primer layer)
The back surface primer layer 4 is a layer that is preferably provided for the purpose of improving the adhesion between the base material layer 1 and various adherends, that is, the substrate 21, and the surface of the base material layer 1 on which the surface protective layer 2 is provided. It is provided on the opposite surface.
The material used for forming the back primer layer is not particularly limited, and preferred examples include urethane resin, acrylic resin, polyester resin, vinyl chloride / vinyl acetate copolymer, chlorinated polypropylene resin, and chlorinated polyethylene resin. However, urethane resin is preferable. The material used for the back primer layer 7 is appropriately selected depending on the adherend.
Moreover, it is preferable that the thickness of a back surface primer layer is about 1-5 micrometers, More preferably, it is 1-3 micrometers. When the thickness is within the above range, excellent performance as a primer layer can be obtained efficiently.

(Masking film)
The masking film 5 is a film that is preferably provided on the surface protective layer of the mirror-finished decorative sheet in order to prevent scratches when carrying the decorative board and during construction, including when the mirror-finished decorative sheet is processed into a substrate. .

The masking film usually has a structure having a masking film substrate and an adhesive layer.
As a base material for masking films, polyester films, such as a polyethylene terephthalate (PET) film, polyolefin films, such as a polyethylene film and a polypropylene film, a polycarbonate film, etc. are mentioned preferably.
Although there is no restriction | limiting in particular about the thickness of this base material for masking films, It is preferable that it is 10-100 micrometers, and it is more preferable that it is 30-70 micrometers. When the thickness is within the above range, good scratch resistance can be obtained, turning and peeling are difficult to occur during processing, and cost can be reduced.

The pressure-sensitive adhesive that forms the pressure-sensitive adhesive layer is, for example, an acrylic-based polymer mainly composed of a (meth) acrylic acid ester-based polymer, from the viewpoint of being difficult to peel off during storage, easy to peel off during use, and difficult to leave a pressure-sensitive adhesive residue. In addition to the pressure-sensitive adhesive, rubber-based pressure-sensitive adhesives, silicone-based pressure-sensitive adhesives, and the like are preferable.
Moreover, 5-40 micrometers is preferable and, as for the thickness of an adhesive layer, 10-30 micrometers is more preferable. When the thickness is within the above range, it is difficult to peel off during storage, it is easy to peel off during use, and the adhesive remains difficult to leave.

(Decoration layer)
The decorative layer gives decorativeness to the mirror surface decorative sheet, and may be a uniformly colored concealing layer (solid printing layer), or by printing various patterns using ink and a printing machine. The pattern layer to be formed may be used, or a combination of a concealing layer and a pattern layer may be used. The decoration layer is usually provided between the support resin layer and the base resin layer, and is treated as one layer constituting the base material layer in the present invention. Therefore, the hardness of the base material layer having the decoration layer is the hardness of the base material layer including the decoration layer. However, like the above resin layer, this decorative layer does not affect the hardness of the base material layer, that is, the hardness of the base material layer is determined by the support resin layer and the base resin layer. It can be said.

By providing the concealing layer, it is possible to conceal the base such as the substrate on which the base material layer and the decorative sheet are provided, and when the base material layer is colored or uneven in color, the surface is given the intended color. Can arrange the color.
In addition, by providing a pattern layer, a grain pattern imitating the surface of a rock such as a wood grain pattern, marble pattern (for example, travertine marble pattern), a fabric pattern imitating a texture or cloth pattern, tiled pattern, brickwork A pattern such as a pattern or a combination of these, a parquet, a patchwork, or the like can be applied to the decorative sheet. These patterns are formed by multicolor printing with the usual yellow, red, blue and black process colors, as well as by multicolor printing with special colors prepared by preparing the individual color plates constituting the pattern. Is done.

As the ink composition used for the decorative layer, a binder resin in which a colorant such as a pigment or a dye, an extender pigment, a solvent, a stabilizer, a plasticizer, a catalyst, or a curing agent is appropriately mixed is used. The binder resin is not particularly limited. For example, urethane resin, vinyl chloride / vinyl acetate copolymer resin, vinyl chloride / vinyl acetate / acrylic copolymer resin, chlorinated polypropylene resin, acrylic resin, polyester resin, polyamide resin. , Butyral resin, polystyrene resin, nitrocellulose resin, cellulose acetate resin and the like are preferable, and polyurethane resin is more preferable. Any of these binder resins can be used alone or in admixture of two or more.
Moreover, as a coloring agent, what was illustrated as a coloring agent used for a base material layer is mentioned preferably.

  The thickness of the decoration layer is usually about 0.5 to 20 μm, and preferably 1 to 10 μm. If the thickness of the decoration layer 6 exists in the said range, the design property excellent in the decorative sheet can be provided, and concealment property can be provided.

(Production method)
The mirror surface decorative sheet of the present invention includes, for example, a step (1a) a step of obtaining a base material layer by laminating a support resin layer and a base resin layer, and a step (2a) the surface of the base material layer on the base base material layer side. Next, the ionizing radiation curable resin composition is applied and then cross-linked and cured to sequentially form a surface protective layer, or step (1b) the ionizing radiation curable resin composition is applied to one surface of the base resin layer. And a step of forming a surface protective layer by crosslinking and curing, step (2b) by sequentially laminating the base resin layer and the support resin layer to obtain a base material layer.

Step (1a) is a step of obtaining a base material layer by laminating a support resin layer and a base resin layer.
The base material layer is a resin composition obtained by adding a colorant or other additives to a resin material for forming a base resin layer, for example, a resin material for forming the base resin layer, for example, a calendar method. Then, a base resin layer is obtained by forming into a sheet by a method such as an inflation method or a T-die extrusion method. Here, biaxial stretching may be performed as necessary.
Next, if necessary, the surface of the obtained base resin layer is subjected to corona discharge treatment or the like to provide an easy-adhesion layer, and a decorative layer composed of a concealing layer and / or a pattern layer is formed on the base resin layer. After applying the adhesive, the support resin layer can be laminated by adhering and press-bonding by a method such as extrusion lamination, dry lamination, wet lamination, thermal lamination, or the like. In the case where a back primer layer is provided, a resin composition for forming a back primer layer on a surface opposite to a surface on which a decorative layer of the base resin layer is provided before or after the support resin layer is laminated is publicly known. What is necessary is just to apply and form by the application | coating method.

The step (2a) is a step of forming a surface protective layer by applying an ionizing radiation curable resin composition to the surface of the base material layer on the base base material layer side, followed by crosslinking and curing.
The surface protective layer is obtained by applying an ionizing radiation curable resin composition containing the above ionizing radiation curable resin on a base substrate layer or a primer layer provided as desired, followed by crosslinking and curing.

  Application of the ionizing radiation curable resin composition is a gravure printing method, a bar coating method, a roll coating method, a reverse coating on the surface of a primer layer provided as desired so that the thickness after curing is 2 to 15 μm. It is performed by a known method such as a roll coating method or a comma coating method, preferably a gravure printing method. The viscosity of the ionizing radiation curable resin composition is not particularly limited as long as it is a viscosity capable of forming an uncured resin layer on the surface of the base substrate layer or the primer layer.

Next, the uncured resin layer formed by applying the ionizing radiation curable resin composition is irradiated with ionizing radiation such as an electron beam and ultraviolet rays to cure the uncured resin layer, and the ionizing radiation curable resin composition A surface protective layer which is a cured product of is formed.
When an electron beam is used as the ionizing radiation, the accelerating voltage can be appropriately selected according to the resin used and the thickness of the layer, but it is preferable to cure the uncured resin layer usually at an accelerating voltage of about 70 to 300 kV.

In electron beam irradiation, transmission capability increases as the acceleration voltage increases. Therefore, when using a material that deteriorates due to electron beams as the base layer, the transmission depth of the electron beam and the thickness of the resin layer are substantially equal. By selecting the accelerating voltage so as to be equal, it is possible to suppress the irradiation of the extra electron beam to the base material 2 and to minimize the deterioration of the base material layer due to the excess electron beam.
The irradiation dose is preferably such that the crosslinking density of the resin layer is saturated, usually 5 to 300 kGy (0.5 to 30 Mrad), preferably 10 to 100 kGy (1 to 10 Mrad), more preferably 30 to 70 kGy (3 to 7 Mrad). It is selected in the range.
The electron beam source is not particularly limited. For example, various electron beam accelerators such as a cockroft Walton type, a bandegraft type, a resonant transformer type, an insulated core transformer type, a linear type, a dynamitron type, and a high frequency type. Can be used.

  When ultraviolet rays are used as the ionizing radiation, those containing ultraviolet rays having a wavelength of 190 to 380 nm are emitted. There is no restriction | limiting in particular as an ultraviolet-ray source, For example, a high pressure mercury lamp, a low pressure mercury lamp, a metal halide lamp, a carbon arc lamp, etc. are used.

  The primer layer is formed by applying a resin composition forming the primer layer by a known method such as a gravure printing method, a bar coating method, a roll coating method, a reverse roll coating method, or a comma coating method. be able to.

  Moreover, the mirror surface decorative sheet of the present invention is obtained by applying the ionizing radiation curable resin composition to one surface of the base substrate layer in the step (1b) in which the steps of the step (1a) and the step (2a) are reversed, A step of forming a surface protective layer by crosslinking and curing, a step (2b) by a production method in which the base base material layer and the support resin layer are laminated to obtain a base material layer in order, ie, surface protection first. It can also be manufactured by laminating the base resin layer and the support resin layer after forming the layer.

The specular decorative sheet of the present invention thus obtained is a sheet having a color difference (ΔE) of 0.7 or less. The mirror surface decorative sheet of the present invention has such a color difference, is excellent in concealment properties, and is not easily affected by the substrate, so that excellent mirror surface properties can be obtained. Here, the color difference (ΔE) is obtained by taking a test piece from the center part of the mirror surface decorative sheet and using the black background of the concealment rate test paper (JIS K5400 7.2 (2) (f)) as the background and the white background as the background. In two points, the CIE (International Commission on Illumination) L * a * b * color system defined in JIS Z 8729-1994 represents L *, a *, and b * as D65 light source and 10 degrees. ΔE measured using a spectrocolorimeter under visual field conditions, and the difference between L *, a *, and b * at the two points was ΔL *, Δa *, and Δb *, respectively, and calculated using the following formula: It is. In addition, it shows that concealment property is so high that the numerical value of (DELTA) E is low.
Color difference ΔE = ((ΔL *) ² + (Δa *) ² + (Δb *) ² ) ^1/2

  Moreover, the hardness of the mirror surface decorative sheet of the present invention thus obtained is preferably in the range of 800 to 2200 MPa, more preferably 1000 to 2150 MPa, and further preferably 1250 to 2100 MPa. The hardness of the mirror surface decorative sheet is substantially the same as the hardness of the base material layer described above, but tends to increase somewhat due to the presence of the surface protective layer and the like.

[Mirror face panel]
The mirror surface decorative sheet of the present invention has a substrate, an adhesive layer, and the mirror surface decorative sheet of the present invention in this order. The decorative board of the present invention will be described with reference to FIG.

FIG. 3 is a schematic view showing a cross section of a preferred embodiment of the mirror surface decorative board of the present invention. The mirror surface decorative plate 20 shown in FIG. 3 has a substrate 21, an adhesive layer 22, and a mirror surface decorative sheet 10 in this order.
The substrate used in the mirror surface decorative plate of the present invention is not particularly limited, and a wood-based board such as wood, a plastic film or a plastic sheet, a metal plate, a ceramic material, etc. can be appropriately selected according to the application. .

  Examples of wood-based boards include veneer of various materials such as cedar, firewood, firewood, pine, lawan, teak, and merapie, and wood materials such as wood veneer, wood plywood, particle board, and medium density fiberboard (MDF). It is done. These can be used alone or in a laminated manner. The wooden board includes not only a wooden board but also a plastic board containing paper powder and reinforced paper having strength.

As a plastic film and a plastic sheet, what consists of various synthetic resins is mentioned. Examples of the synthetic resin include polyolefin resin, vinyl resin, polyester resin, acrylic resin, polyamide resin, cellulose resin, polystyrene resin, polycarbonate resin, polyarylate resin, and polyimide resin.
Moreover, when using a plastic film or a plastic sheet as a substrate, in order to improve the adhesion with the decorative sheet, if desired, on one or both sides, corona discharge treatment, chromium oxidation treatment, flame treatment, hot air treatment, A physical or chemical surface treatment such as an oxidation method such as an ozone-ultraviolet treatment method or an unevenness method such as a sand blast method or a solvent treatment method can be performed.

  Examples of the metal plate include metal materials such as iron, aluminum, stainless steel, and copper, and these may be subjected to surface treatment such as hot dip galvanizing or electrogalvanizing. In addition, in order to impart concealability, the metal plate may be directly colored and provided with a coating layer.

  Examples of ceramic materials include ceramic building materials such as gypsum plates, calcium silicate plates, and wood cement plates, ceramics, glass, firewood, fired tiles, plates made mainly of volcanic ash, and the like. In addition to these, composites of various materials such as a fiber reinforced plastic (FRP) plate, an iron plate attached to both sides of a paper honeycomb, and a polyethylene resin sandwiched between two aluminum plates can also be used as a substrate.

It does not specifically limit as an adhesive agent used for the contact bonding layer for adhere | attaching a board | substrate and a mirror surface decorative sheet, A heat sensitive adhesive, a pressure sensitive adhesive, etc. are mentioned. Examples of the resin used for the adhesive constituting this adhesive layer include acrylic resins, vinyl chloride resins, vinyl acetate resins, vinyl chloride-vinyl acetate copolymer resins, styrene-acryl copolymer resins, At least one resin selected from polyester resins and polyamide resins is used. Further, a two-component curable polyurethane adhesive or polyester adhesive using isocyanate as a curing agent can also be applied. Among these, a thermoplastic resin adhesive is preferable because it functions as a cushion layer and has an effect of suppressing cracks in the surface protective layer during processing under severe conditions when a metal plate is used as a substrate.
An adhesive can also be used for the adhesive layer. As the pressure-sensitive adhesive, an acrylic, urethane, silicone, rubber or the like can be appropriately selected and used.

The adhesive layer is formed by applying and drying the above resin in a form that can be applied, such as a solution or emulsion, by means of gravure printing, screen printing, or reverse coating using a gravure plate. Can do.
Although there is no restriction | limiting in particular in the thickness of an contact bonding layer, Usually, it is the range of 1-100 micrometers. By setting it as this range, the outstanding adhesiveness and the suppression effect of the crack generation of a surface protective layer are acquired.

  EXAMPLES Next, although an Example demonstrates this invention further in detail, this invention is not limited at all by these examples.

(Evaluation method)
1. Evaluation of color tone About the specular decorative sheet obtained in the examples and comparative examples, the difference in color when the black background and the white background of the concealment rate test paper (JIS K5400 7.2 (2) (f)) are used as a base is visually observed. Confirmed and evaluated according to the following criteria.
◎: No difference is observed. ○: There is a slight difference, but there is no problem in actual use. △: There is a difference and there is a sense of incongruity. Evaluation of specularity About the specular decorative sheet and decorative plate obtained in the examples and comparative examples, visually confirm the image in which the fluorescent lamp is reflected on the surface of the decorative sheet under the fluorescent lamp (straight tube type), Evaluation was made according to the following criteria.
(Double-circle): The surface was smooth and the image of the fluorescent lamp looked straight.
○: The surface is smooth, and the fluorescent lamp image appears to be a straight line.
○ ^- : Slight undulation of the fluorescent lamp image occurred or the surface was smooth, but slight irregularities were confirmed in the appearance, but there was no problem in practical use.
Δ: Slight undulation of the fluorescent lamp image occurred, or the surface was smooth, but some irregularities were observed in the appearance.
X: The wave of the fluorescent lamp image was remarkable or the surface was smooth, but irregularities were confirmed in the appearance.
3. Evaluation of processing characteristics (evaluation of cracks)
A metal material bending test specified in JIS Z2248 was applied to a decorative metal plate in which the mirror-finished decorative sheet obtained in Examples and Comparative Examples was attached to an aluminum plate having a thickness of 0.8 mm and 40 × 40 mm. Performed at 0C. The test method is as follows.
The decorative metal plate for test was bent by 90 ° with an outer radius of 1 mm. In addition, although JIS Z2248 prescribes | regulates the bending test of a metal plate, the test was done according to JIS Z2248 about the metal plate in which the decorative sheet was affixed in the present Example.
At this time, cracks and whitening in the bent portion were visually observed and evaluated according to the following criteria.
A: No cracking or whitening was confirmed.
○: Fracture and whitening were hardly confirmed.
○ ^- : Slight cracking or whitening was confirmed, but there was no practical problem.
Δ: Cracking or whitening was confirmed.
X Significant cracking and whitening were confirmed.
4). Evaluation of processing characteristics (evaluation of springback)
3. above. The state of peeling (spring back) of the end face of the mirror-finished decorative sheet when evaluated in the same manner as the evaluation of processing characteristics (evaluation of cracks) was evaluated based on the following criteria.
A: Peeling was not confirmed at all.
○: Peeling was hardly confirmed.
○ ^- : Slight peeling was confirmed, but there was no practical problem.
Δ: Peeling was confirmed.
X Significant peeling was confirmed.
5. Evaluation of heat resistance (dry heat test)
The decorative sheet obtained in the example and the comparative example is placed on an aluminum jig heated to 75 ° C. (cylindrical shape with a diameter of 10 cm, weight: 700 g) for 20 minutes, and then the appearance of the place on which the jig is placed. Was visually evaluated and evaluated according to the following criteria.
○: Almost no change in appearance was confirmed.
Δ: Although slight change in appearance was confirmed, there was no practical problem.
X: A remarkable change in appearance was confirmed.
6). Evaluation of hardness (concaveness) About the mirror surface decorative sheets obtained in Examples and Comparative Examples, a “scratch hardness (pencil method) test” based on JIS K5600-5-4 was conducted at a load of 750 g, and the appearance after the test Was evaluated according to the following criteria.
A: A test was conducted at a hardness of 2B, and there was almost no change in appearance.
○: A test was conducted with a hardness of 3B, and there was almost no change in appearance.
○ ^- : A test was conducted at a hardness of 3B, and coating film scratches or dents were slightly generated.
Δ: A test was conducted with a hardness of 3B, and a coating film scratch or dent was generated.
X: The test was conducted at a hardness of 4B, and a coating film scratch or dent was generated.
7). Measurement of hardness Prepare a test piece obtained by punching the support resin layer, the base resin layer, and the mirror-finished decorative sheet obtained in the examples and comparative examples into a dumbbell shape conforming to JIS K7127, and in a temperature environment of 25 ° C. , Tensile stress obtained by using a tensile tester (“RTC-1250A (model number)”, manufactured by Orientec Co., Ltd.) under the conditions of a tensile speed of 50 mm / min, a distance between chucks of 80 mm, and a width of 10 mm. E (tensile modulus) calculated by the following formula from the first direct part of the strain curve was defined as hardness.
Tensile modulus = Δρ / Δε
Δρ: Stress difference due to the original average cross-sectional area between two points on a straight line Δε: Strain difference between the same two points Measurement of color difference (ΔE) A test piece was taken from the central part of the mirror-finished decorative sheet obtained in the examples and comparative examples, and the black background of the concealment rate test paper (JIS K5400 7.2 (2) (f)) was used as the base. The LIE, C * (L * a * b *) color system L *, a *, and b * defined in JIS Z 8729-1994 Measured using a spectrocolorimeter (“CM-3700d (model number)”, manufactured by Konica Minolta Co., Ltd.) with a D65 light source and a viewing angle of 10 degrees, and the difference between L *, a *, and b * at the two points Are ΔL *, Δa *, and Δb *, respectively, and a value calculated using the following equation is ΔE.
Color difference ΔE = ((ΔL *) ² + (Δa *) ² + (Δb *) ² ) ^1/2

Example 1
A colored polypropylene resin sheet (“Art Ply (trade name)”, manufactured by Mitsubishi Plastics, Inc., thickness: 150 μm) is prepared as a base resin layer, and a wood-patterned decorative layer (thickness: 5 μm) is provided on one side thereof. After applying a polyester resin composition (two-component thermosetting resin type) to the other surface to form a primer layer (thickness: 2 μm), a polypropylene resin sheet (thickness: 100 μm) is formed on the decorative layer side. Is laminated by a T-die extrusion method as a support resin layer to form a base material layer having a decoration layer and a primer layer, and a polyester-urethane resin composition is applied to the support resin layer side surface of the base material layer. Thus, a back primer layer (thickness: 2 μm) was formed.
Next, an ionizing radiation curable resin composition (a mixture of a urethane acrylate oligomer (functional group number: 3) and a monomer) was applied on the primer layer at a coating amount of 7 g / m ² by gravure printing to form a coating film. . Next, the coating film was crosslinked and cured by irradiation with an electron beam under the conditions of 175 keV and 5 Mrad (50 kGy) to form a surface protective layer (thickness: 7 μm) to obtain a mirror-finished decorative sheet. Further, a polyethylene film (thickness: 50 μm) having an adhesive layer (acrylic resin adhesive, thickness: 10 μm) on the surface protective layer side is masked so that the surface protective layer and the adhesive layer face each other. Films were laminated.
Then, an ethylene-vinyl acetate adhesive (water-based emulsion type, “BA-20 (trade name)”, manufactured by Chuo Rika Co., Ltd.) was applied to the surface of the mirror-finished decorative sheet on the back primer layer side, and the adhesive layer (Thickness: 7 μm) was formed and attached to a medium density wood fiber board (MDF, thickness: 2.7 mm) to obtain a mirror-finished decorative board.
Said evaluation was performed about the obtained mirror surface decorative sheet and mirror surface decorative board. The evaluation results are shown in Table 1.

Examples 2-12
Example 1 except that the thickness and hardness of the support resin layer and the base resin layer, the thickness of the base material layer, and the thickness of the surface protective layer in Example 1 were as shown in Table 1. In the same manner as above, a mirror surface decorative sheet and a mirror surface decorative plate were obtained. Said evaluation is performed about the obtained mirror surface decorative sheet and mirror surface decorative board, and the evaluation result is shown in Table 1.

* 1, This is the total thickness of the support resin layer and the base resin layer.

Example 13
A polyethylene terephthalate resin sheet (“E20 Lumirror”, manufactured by Toray Industries, Inc., thickness: 125 μm) is prepared as a base resin layer, and a wood grain decorative layer (thickness: 5 μm) is provided on one side thereof. After applying a polyester resin composition (two-component thermosetting resin type) to form a primer layer (thickness: 2 μm), an ionizing radiation curable resin composition (urethane acrylate oligomer (functional group number) is formed on the primer layer. : 3) and a monomer mixture) were applied by gravure printing at a coating amount of 3 g / m ² to form a coating film. Subsequently, the coating film was crosslinked and cured by irradiation with an electron beam under the conditions of 175 keV and 5 Mrad (50 kGy) to form a surface protective layer (thickness: 3 μm).
Next, a polypropylene resin sheet (thickness: 120 μm, manufactured by Diaplus Film Co., Ltd.) is prepared as a support resin layer, and a base resin layer provided with a surface protective layer and a support resin layer are bonded to an adhesive (two-component heat A curable resin type) layer (film thickness: 5 μm) is pasted, and a polyester-urethane resin composition is applied to the surface of the support resin layer, and a back primer layer (thickness: 2 μm) is applied. The mirror surface decorative sheet was obtained. Further, a polyethylene film (thickness: 50 μm) having an adhesive layer (acrylic resin adhesive, thickness: 10 μm) on the surface protective layer side is masked so that the surface protective layer and the adhesive layer face each other. Films were laminated.
Then, an ethylene-vinyl acetate adhesive (water-based emulsion type, “BA-20 (trade name)”, manufactured by Chuo Rika Co., Ltd.) was applied to the surface of the mirror-finished decorative sheet on the back primer layer side, and the adhesive layer (Thickness: 7 μm) was formed and attached to a medium density wood fiber board (MDF, thickness: 2.7 mm) to obtain a mirror-finished decorative board.
Said evaluation was performed about the obtained mirror surface decorative sheet and mirror surface decorative board. The evaluation results are shown in Table 2.

Example 14
In Example 13, the support resin layer was a polyethylene terephthalate resin sheet (“E20 Lumirror”, manufactured by Toray Industries, Inc., thickness: 75 μm), and the thickness of the surface protective layer was 7 μm. Thus, a mirror surface decorative sheet and a mirror surface decorative plate were produced. Said evaluation was performed about the obtained mirror surface decorative sheet and mirror surface decorative board. The evaluation results are shown in Table 2.

Example 15
In Example 13, the base resin layer was a polypropylene resin sheet (thickness: 150 μm, manufactured by Diaplus Film), and the support resin layer was a polyethylene terephthalate resin sheet (“E20 Lumirror”, manufactured by Toray Industries, Inc., thickness: 75 μm). In the same manner as in Example 13, except that the thickness of the surface protective layer was changed to 7 μm, a mirror surface decorative sheet and a mirror surface decorative plate were produced. Said evaluation was performed about the obtained mirror surface decorative sheet and mirror surface decorative board. The evaluation results are shown in Table 2.

* 1, This is the total thickness of the support resin layer and the base resin layer.
* 2, PET (polyethylene terephthalate resin sheet, “E20 Lumirror”, manufactured by Toray Industries, Inc.), PP (polypropylene resin sheet, manufactured by Diaplus Film)

Comparative Examples 1-9
In Example 1, except that the thickness and hardness of the support resin layer and the base resin layer, the thickness of the base material layer, and the thickness of the surface protective layer were as shown in Table 3, Example 1 In the same manner as above, a mirror surface decorative sheet and a mirror surface decorative plate were obtained. Said evaluation is performed about the obtained mirror surface decorative sheet and mirror surface decorative board, and the evaluation result is shown in Table 3.

Comparative Examples 10 and 11
In Example 1, a mirror surface decorative sheet and a mirror surface decorative plate were obtained in the same manner as in Example 1 except that the material and hardness of the support resin layer and the base resin layer were those shown in Table 4. Said evaluation is performed about the obtained mirror surface decorative sheet and mirror surface decorative board, and the evaluation result is shown in Table 4.

Comparative Examples 12-16
In Example 1, a mirror surface decorative sheet and a mirror surface makeup were prepared in the same manner as in Example 1 except that the support resin layer was not provided and the material, thickness and hardness of the base resin layer were as shown in Table 4. I got a plate. Said evaluation is performed about the obtained mirror surface decorative sheet and mirror surface decorative board, and the evaluation result is shown in Table 4.

* 1, This is the total thickness of the support resin layer and the base resin layer.
* 2, PET (polyethylene terephthalate resin sheet, “E20 Lumirror”, Toray Industries, Inc.), PET-G (amorphous polyethylene terephthalate resin sheet, “Easter PETG 6763 ™”, manufactured by Eastman Chemical Co.), PE ( (Polyethylene resin sheet, “Art Ply”, manufactured by Mitsubishi Plastics)

  The mirror surface decorative sheet obtained by bonding the mirror surface decorative sheet of the present invention to a substrate such as a metal plate, an inorganic plate (gypsum board, etc.), a wooden board (MDF, particle board, laminated plate, etc.) is used for interior and exterior of buildings, building materials. It is suitably used for various materials such as furniture, or for home appliances, especially interior materials such as kitchen doors of kitchen products.

1. Base material layer 1a. Support resin layer 1b. Base resin layer2. 2. Surface protective layer Primer layer 4. 4. Back primer layer Masking film10. Mirror surface decorative sheet 20. Mirror surface decorative board 21. Substrate 22. Adhesive layer

Claims (10)

It has a base material layer having a support resin layer and a base resin layer, and a surface protective layer, the thickness of the support resin layer is 60 to 160 μm, and the hardness measured by the following method is 300 to 300 1000 MPa, the thickness of the base resin layer is 100 to 300 μm, the hardness measured by the following method is 600 to 1900 MPa, and the total thickness of the support resin layer and the base resin layer is 200. ˜460 μm, the hardness of the base resin layer is harder than the hardness of the support resin layer, and the surface protective layer is obtained by crosslinking and curing the ionizing radiation curable resin composition on the base resin layer side of the base material layer. Mirror surface decorative sheet, which is a layer provided in a thickness of 2 to 15 μm.
(Measurement method of hardness)
Prepare a test piece punched into a dumbbell shape conforming to JIS K7127, and measure it under a temperature environment of 25 ° C. using a tensile tester under the conditions of a tensile speed of 50 mm / min, a distance between chucks of 80 mm, and a width of 10 mm. E (tensile modulus) calculated from the following formula from the initial direct portion of the obtained tensile stress-strain curve was defined as hardness.
Tensile modulus = Δρ / Δε
Δρ: Stress difference due to the original average cross-sectional area between two points on a straight line Δε: Strain difference between the same two points   The mirror surface decorative sheet according to claim 1, further comprising a masking film on the surface protective layer.   The mirror surface decorative sheet according to claim 1 or 2, wherein the support resin layer is composed of a polyolefin resin.   The mirror surface decorative sheet according to any one of claims 1 to 3, wherein the base resin layer is made of a polyolefin resin.   The mirror surface decorative sheet according to any one of claims 1 to 4, wherein a pigment is contained in at least one of the support resin layer and the base resin layer.   Hardness is 800-2200MPa, The mirror surface decorative sheet in any one of Claims 1-5.   The specular decorative sheet according to any one of claims 1 to 6, wherein the glossiness (incident angle 60 °) is 40 or more and the center line average roughness (Ra) is 1 µm or less. The specular decorative sheet according to any one of claims 1 to 7, wherein a color difference (ΔE) measured by the following method is 0.7 or less.
(Measurement of color difference (ΔE))
Take a test piece from the center part of the mirror surface decorative sheet, JIS K5400 7.2 (2) (f)) of JIS K5400 7.2 (2) (f) when using a black background and white background JIS CIE (International Commission on Illumination) specified in Z 8729-1994 L * a * b * L *, a *, and b * in the color system using a D65 light source and a spectrocolorimeter with a viewing condition of 10 degrees The difference between L *, a *, and b * at the two points was ΔL *, Δa *, and Δb *, respectively, and ΔE calculated using the following equation was the color difference.
Color difference ΔE = ((ΔL *) ² + (Δa *) ² + (Δb *) ² ) ^1/2 The mirror surface according to any one of claims 1 to 8, wherein the resin material forming the support resin layer and the base resin layer is a crystalline resin and is at least one selected from polyolefin resins and polyester resins. Makeup sheet. Substrate, adhesive layer, and specular decorative plate having a mirror surface decorative sheet according to order any of claims 1-9.