JP2013203060A - Decorative sheet and decorative metal panel using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a decorative sheet with improved bending workability, weather resistance and fire resistance, while obtaining favorable adhesion between a surface protection layer forming an outermost layer of the decorative sheet and a layer disposed under the surface protection layer, and to provide a decorative metal panel having the decorative sheet.SOLUTION: A decorative sheet 1 includes a base material 1, a coloring ink layer 3, a primer layer 4 and a surface protection layer 5 in this order. The base material is made of a polyester-based film. The thickness of the base material 2 is 20-95 μm. The surface protection layer 5 is made of a cured material of a resin composition containing an ionizing radiation curable resin and a thermosetting resin at a ratio of 95:5-50:50 in mass ratio. The elongation of the cured material measured in conformity to JIS K6732 is at least 1%, and the elongation of the decorative sheet measured in conformity to JIS K6732 is 30 to 180%.

Description

  The present invention relates to a decorative sheet having a base, a colored ink layer, a primer layer, and a surface protective layer in this order, and a decorative metal plate using the decorative sheet.

Conventionally, a decorative sheet has been used to impart a design such as a pattern or a pattern to a metal plate. Designs such as patterns and patterns are formed on the decorative sheet by printing or the like, and are used by being attached to a metal plate. A metal sheet with a decorative sheet attached is called a decorative metal sheet.
An example of a decorative sheet is a laminate obtained by thermally laminating a surface protective layer made of polyvinyl chloride resin on a substrate made of polyvinyl chloride resin through a pattern layer containing vinyl chloride / acrylic resin as a binder. It is done.
In addition to the polyvinyl chloride resin, a decorative sheet formed from a polyolefin resin containing no chloride has been proposed (see Patent Document 1). Polyvinyl chloride resin has the advantage of being inexpensive and highly versatile, but it has a high environmental impact and is susceptible to deterioration due to ultraviolet rays. The decorative sheets that have been used have come to come in handy.

  The decorative metal plate is usually subjected to a bending process or the like, and is used as an interior / exterior material for a building or a structure. When the decorative metal plate is bent, a load is applied to the base material, the surface protective layer, and the like constituting the decorative sheet at the bent portion, and the surface design may be cracked or whitened. This tendency was conspicuous in the decorative sheet mainly composed of polypropylene resin among the above-mentioned polyolefin resins. On the other hand, a decorative sheet using a polyester resin as a main material has been proposed (see Patent Document 2).

By the way, in recent years, with the expansion of the application field of the decorative sheet, the decorative sheet is required to further improve the designability, the processability according to the application field, and the characteristics according to the application field. For example, when a decorative metal plate is applied to an exterior material of a structure or a building, not only bending workability but also a particularly high level of weather resistance and fire resistance are required as compared with the case of being used as an interior material.
The decorative sheet mainly made of polypropylene resin has weather resistance compared to the decorative sheet mainly made of polyester resin. However, as described above, a decorative sheet made of polypropylene resin as a main material needs a certain thickness in order to prevent sagging during production and thermal shrinkage and hot fever due to drying. When the thickness of the decorative sheet is increased, the organic content increases, so that the fire resistance may be inferior.
In addition, the decorative sheet made of polyester resin as the main material has better bending workability even if it is thinner than the decorative sheet made of polypropylene resin as the main material. Therefore, from the viewpoint of fire resistance, polypropylene resin is the main material. Is superior to the decorative sheet. However, the decorative sheet made of polyester resin as the main material is inferior in weather resistance to the decorative sheet made of polypropylene resin as the main material, so in order to satisfy the desired weather resistance, it is necessary to provide a coating layer, It was also a factor causing an increase in manufacturing costs.
Thus, there is room for further improvement in order to satisfy the three conflicting performances of the decorative sheet, such as folding processability, weather resistance, and fire resistance, at the same time at a high level.
In addition, when the decorative sheet is applied to the exterior material, it is exposed to a harsher environment than when applied to the interior material in temperature change, humidity change, moisture contact, etc. It has also been a problem that the adhesion between the surface protective layer forming the outermost layer of the decorative sheet and the layer disposed below the surface protective layer is lowered.

JP 2000-326443 A JP 2007-290382 A

  The present invention can improve both folding workability, weather resistance, and fire resistance, and further, the surface protective layer forming the outermost layer of the decorative sheet and the layer disposed below the surface protective layer are excellent. It is an object of the present invention to provide a decorative sheet capable of obtaining adhesion and a decorative metal plate having the decorative sheet.

As a result of intensive studies to achieve the above object, the present inventor has determined the thickness of the base material, the composition of the resin composition constituting the surface protective layer, the elongation of the surface protective layer, and the elongation of the decorative sheet. It has been found that the above problem can be solved by setting a specific value.
That is, the present invention
[1] A decorative sheet having a substrate, a colored ink layer, a primer layer, and a surface protective layer in this order, wherein the substrate is made of a polyester film, and the thickness of the substrate is 20 μm or more and 95 μm or less, The surface protective layer comprises a cured product of a resin composition containing an ionizing radiation curable resin and a thermosetting resin in a mass ratio of 95: 5 to 50:50, and measured according to JIS K6732 of the cured product. A decorative sheet having an elongation of 1% or more and an elongation measured in accordance with JIS K6732 of 30% or more and 180% or less of the decorative sheet,
[2] The decorative sheet according to [1], wherein the thermosetting resin includes at least one selected from a resin having a hydroxy group and the same resin as that constituting the primer layer,
[3] The decorative sheet according to the above [1] or [2], wherein the base material is made of biaxially stretched polyethylene terephthalate,
[4] The decorative sheet according to [1] to [3], wherein the ionizing radiation curable resin contains urethane (meth) acrylate,
[5] The decorative sheet according to any one of [1] to [4], wherein the ionizing radiation curable resin includes at least one of a triazine-based ultraviolet absorber and a light stabilizer.
[6] The decorative sheet according to any one of [1] to [5], wherein the resin constituting the primer layer includes at least one of a triazine-based ultraviolet absorber and a light stabilizer.
[7] The decorative sheet according to any one of the above [1] to [6], wherein the resin constituting the primer layer includes a polycarbonate urethane acrylic copolymer,
[8] A decorative metal plate formed by adhering a metal plate and the base material of the decorative sheet of any one of [1] to [7] via an adhesive layer,
I will provide a.

  According to the present invention, it is possible to improve both the bending workability, the weather resistance, and the fire resistance, and the surface protective layer that forms the outermost layer of the decorative sheet and the layer disposed below the surface protective layer. A decorative sheet capable of obtaining good adhesion and a decorative metal plate having the decorative sheet can be provided.

It is sectional drawing explaining the decorative sheet shown as embodiment of this invention.

  The decorative sheet according to the present invention is a decorative sheet having a base material, a colored ink layer, a primer layer, and a surface protective layer in this order, the base material comprising a polyester film, and the thickness of the base material is 20 μm or more and 95 μm. The surface protective layer is made of a cured product of a resin composition containing an ionizing radiation curable resin and a thermosetting resin in a mass ratio of 95: 5 to 50:50, and JIS K6732 of the cured product. The elongation measured in accordance with JIS is 1% or more, and the elongation measured in accordance with JIS K6732 of the decorative sheet is from 30% to 180%.

[Decorative sheet]
A typical structure of the decorative sheet 1 shown as an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a cross-sectional view illustrating an example of a preferred embodiment of the decorative sheet 1.
As shown in FIG. 1, the decorative sheet 1 includes a base material 2, a colored ink layer 3, a primer layer 4, and a surface protective layer 5 in this order.
The elongation of the decorative sheet 1 measured in accordance with JIS K6732 is 30% or more and 180% or less, and preferably 40% or more and 170% or less.
If the elongation of the decorative sheet 1 is less than 30%, the rigidity is too high, and cracks and whitening occur in the base material 2 or the surface protective layer 5 at the bent portion of the decorative sheet 1. If the elongation of the decorative sheet 1 exceeds 180%, the base material 2 is easily stretched, but the colored ink layer 3, the primer layer 4, and the surface protective layer 5 cannot follow the deformation of the base material 2, and cracks and whitening occur. Occur.
The elongation includes both the elongation in the flow direction (referred to as the MD direction) during the production of the decorative sheet 1 and the elongation in the direction intersecting the flow direction (the MD direction) (referred to as the CD direction). The decorative sheet 1 of the present invention requires that at least one of the elongation in the MD direction and the elongation in the CD direction satisfies 30% to 180%, and both the elongation in the MD direction and the elongation in the CD direction are It is more preferable to satisfy 30% or more and 180% or less.

[Base material]
The base material 2 needs to consist of a polyester resin film in terms of weather resistance, fire resistance, bending workability, and versatility. As the polyester resin film, those usually used in the field of decorative sheets can be used.
The polyester resin used for the polyester resin film refers to a polymer containing an ester group obtained by polycondensation from a polyvalent carboxylic acid and a polyhydric alcohol. Examples of the polyvalent carboxylic acid include terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, adipic acid, sebacic acid, decanedicarboxylic acid, azelaic acid, dodecanedicarboxylic acid, and cyclohexanedicarboxylic acid.
Polyhydric alcohols include ethylene glycol, propanediol, butanediol, pentanediol, hexanediol, neopentylglycol, 1,4-cyclohexanedimethanol, decanediol, 2-ethyl-butyl-1-propanediol, and bisphenol. A etc. are mentioned. Furthermore, the polyester resin used in the present invention may be a copolymer of three or more types of polycarboxylic acid or polyhydric alcohol, and is a copolymer with a monomer or polymer such as diethylene glycol, triethylene glycol, or polyethylene glycol. There may be.

Preferable examples of the polyester resin used for the polyester resin film include polyethylene terephthalate (PET), polybutylene terephthalate (PBT), and polyethylene naphthalate (PEN). In consideration of production cost, polyethylene terephthalate (PET) is preferable.
The substrate 2 may be a single layer film formed from one type selected from the above polyester resins, or a multilayer film in which a plurality of single layer films formed from one type selected from the above polyester resins are stacked. It may be. Furthermore, it may be a multilayer film in which a single layer film formed from one type selected from the above polyester resins and a single layer film formed from another resin selected from the above resins are stacked. The polyester resin may be a homopolymer, a copolymer, or a copolymer obtained by copolymerizing a third component.

  As the polyester resin, in addition to various homopolymers, copolymerized polyester resins and polyester thermoplastic elastomers to which various copolymer components or modifying components are added for the purpose of softening the resin can be used. For example, in the case of PET, long chain aliphatic dicarboxylic acids such as sebacic acid, eicoic acid, dodecanedioic acid, dimer acid, and cyclohexanedicarboxylic acid are used as the dicarboxylic acid component in the condensation polymerization reaction of terephthalic acid and ethylene glycol. And / or alicyclic dicarboxylic acids can be introduced. In addition, polyether diols having hydroxy groups at both ends, such as polyethylene glycol and polytetramethylene glycol, can be introduced as the diol component.

In the present invention, the polyester resin film used as the substrate 2 can be formed into a film by, for example, a calendar method, an inflation method, a T-die extrusion method, or the like. The polyester resin film used as the substrate 2 is preferably a stretched film that is stretched in a uniaxial direction or a biaxial direction, and more preferably a biaxially stretched film. The stretching method may be sequential biaxial stretching or simultaneous biaxial stretching. Moreover, you may extend | stretch again in the vertical and / or horizontal direction as needed before or after performing heat setting.
The stretch ratio of the polyester resin film is preferably 10 times or less, more preferably 6 times or less as the area magnification. Furthermore, it is preferably 3 times or more and 4 times or less. If it is in this range, when the obtained polyester resin film is used as the base material 2, good bending workability and dimensional stability can be obtained.

The thickness of the base material 2 is 20 μm or more and 95 μm or less, preferably 25 to 80 μm, more preferably 30 to 50 μm. When the thickness of the base material is less than 20 μm, the base material 2 is broken, and when the thickness of the base material 2 exceeds 95 μm, predetermined fire resistance cannot be obtained.
The fire resistance in the present invention is CLASS A, CLASS B, CLASS C based on numerical values of flame diffusion index (FSI) and smoke generation index (SDI) obtained by a Steiner tunnel combustion test according to ASTM E-84. expressed. Specifically, CLASS A if FSI ≦ 25 and SDI ≦ 450. Further, CLASS B is satisfied when 26 ≦ FSI ≦ 75 and SDI ≦ 450. CLASS C if 76 ≦ FSI ≦ 200 and SDI ≦ 450. In the present invention, “having fire resistance” means corresponding to CLASS A.

  Particularly in the present invention, the substrate 2 is preferably made of biaxially stretched polyethylene terephthalate. By using biaxially stretched polyethylene terephthalate, the mechanical strength of the substrate 2 is improved.

  The polyester resin used for the substrate 2 may be blended with additives as 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. As the ultraviolet absorber and the light stabilizer, those similar to those that can be added to the resin constituting the surface protective layer 5 described in detail later can be used. The base material 2 may be colored. The colorant is not particularly limited, and known colorants such as pigments and dyes can be used.

  Examples of colorants include titanium white, zinc white, petal, vermilion, ultramarine, cobalt blue, titanium yellow, yellow lead, carbon black and other inorganic pigments; isoindolinone, Hansa yellow A, quinacridone, permanent red 4R, Organic pigments (including dyes) such as phthalocyanine blue, indanthrene blue RS, and aniline black; metal pigments such as aluminum and brass; pearlescent pigments made of titanium dioxide-coated mica and foil powder such as basic lead carbonate Is mentioned. The coloring of the substrate 2 includes transparent coloring and opaque coloring (hiding coloring), and these can be arbitrarily selected. For example, when the ground color of the adherend (metal plate to which the decorative sheet is bonded) is concealed, opaque coloring may be selected. On the other hand, in order to make the ground pattern of the adherend visible, transparent coloring may be selected.

The base material 2 can be subjected to a physical or chemical surface treatment such as an oxidation method or an unevenness method on one side or both sides as desired in order to improve the adhesion to other layers (hereinafter, easy adhesion). Called processing). In the embodiment of the present invention, at least one surface of the substrate 2 is preferably subjected to an easy adhesion treatment.
In the present invention, an easy adhesion coating treatment can be suitably used as the chemical surface treatment. The easy adhesion coating treatment is to improve the adhesion by coating a resin layer or the like on the substrate 2, and the resin used for this is selected from polyester resin, acrylic resin and urethane resin. Can be selected as appropriate by combining one or a plurality thereof.
Examples of the oxidation method include corona discharge treatment, chromium oxidation treatment, flame treatment, hot air treatment, ozone / ultraviolet treatment method, and the like. Examples of the concavo-convex method include a sand blast method and a solvent treatment method. These surface treatments are appropriately selected according to the type of the substrate 2.

[Colored ink layer]
The colored ink layer 3 is formed between the base material 2 and the primer layer 4. The colored ink layer 4 is composed of at least one of a picture layer and a colored masking layer.

<Pattern layer>
The pattern layer imparts design properties with a desired pattern to the decorative sheet and the decorative metal plate, and the type of the pattern is not particularly limited. Examples thereof include a wood grain pattern, a stone pattern, a grain pattern, a tiled pattern, a brickwork pattern, a cloth pattern, a leather pattern, a geometric figure, a character, a symbol, and an abstract pattern.
The pattern layer is formed by printing various patterns using ink and a printing machine. It is formed by multicolor printing using normal process colors of yellow, red, blue, and black, or by multicolor printing using special colors prepared by preparing individual color plates constituting the pattern. As the ink used for the picture layer, a binder and a colorant such as a pigment or dye, an extender pigment, a solvent, a stabilizer, a plasticizer, a catalyst, or a curing agent are appropriately mixed.
The binder is not particularly limited. For example, polyurethane resin, acrylic resin, polyester resin, polyamide resin, butyral resin, polystyrene resin, vinyl chloride-vinyl acetate copolymer resin, vinyl chloride-vinyl acetate-acrylic copolymer resin, Resins such as chlorinated polypropylene resin, nitrocellulose resin, and cellulose acetate resin are preferably exemplified, and these can be used alone or in admixture of two or more.
The colorant may be appropriately selected from the use of the decorative sheet and the color compatibility with the colored hiding layer. For example, carbon black (black), iron black, titanium white, antimony white, yellow lead, titanium yellow, Petal, inorganic pigments such as cadmium red, ultramarine, and cobalt blue, organic pigments or dyes such as quinacridone red, isoindolinone yellow, and phthalocyanine blue, metallic pigments made of scaly foils such as aluminum and brass, titanium dioxide-coated mica And pearlescent pigments made of scaly foils such as basic lead carbonate.

<Coloring hiding layer>
The coloring hiding layer is arbitrarily provided for the purpose of improving the design of the decorative sheet 1 and improving the interlayer adhesion between the base material 2 and the pattern layer.
The colored concealment layer is provided when the surface of the metal plate forming the decorative metal plate is colored or when there is a color spot on the surface of the metal plate, and the color of the surface of the metal plate is adjusted to display the intended color. Can be issued. The colored concealment layer is usually formed with an opaque color for the purpose of concealing the metal plate or the base, but it can be formed with a colored transparent color to make use of the pattern of the substrate or the base. As the ink used for forming the colored hiding layer, the same ink as the above-mentioned picture layer can be used. The thickness of the colored hiding layer is preferably 0.5 to 20 μm, more preferably 1 to 10 μm, and further preferably 1 to 6 μm. When the thickness is within the above range, the effect of providing the colored concealing layer is sufficiently obtained.

[Primer layer]
The primer layer 4 is arbitrarily provided. Usually, a resin material used as a primer layer of a decorative sheet can be used. Examples of the resin forming the primer layer 4 include thermosetting resins. As a specific example of the thermosetting resin, it is preferable to use a polycarbonate urethane acrylic copolymer, a polyester urethane acrylic copolymer, or a resin composed of a polycarbonate urethane acrylic copolymer and an acrylic polyol. An acrylic copolymer is more preferable.
By forming the primer layer 4 using these resins, stress relaxation properties are imparted, and those having excellent weather resistance are obtained.
The polycarbonate urethane acrylic copolymer is a resin obtained by radical polymerization of an acrylic monomer using a polycarbonate polyurethane polymer obtained by reacting polycarbonate diol and diisocyanate as a radical polymerization initiator.
Examples of the diisocyanate used as the curing agent include various aliphatic (or alicyclic) or aromatic diisocyanates conventionally known in the polyurethane field.
Here, preferred examples of the diisocyanate include aliphatic isocyanates such as hexamethylene diisocyanate, and alicyclic isocyanates such as isophorone diisocyanate and hydrogenated xylylene diisocyanate. Preferred examples of the acrylic monomer include (meth) acrylic acid and (meth) acrylic acid alkyl esters having about 1 to 6 carbon atoms in the alkyl group, and these can be used alone or in combination of two or more. .
It is preferable that 1-30 mass parts of diisocyanates used as a hardening | curing agent are contained with respect to 100 mass parts of thermosetting resins mentioned above.
Moreover, it is preferable that the mass ratio of the urethane component and acrylic component in a polycarbonate-type urethane acrylic copolymer is 90 / 10-50 / 50.

The primer layer 4 may contain a colorant. The colorant is not particularly limited, and examples thereof include the same ones that can be used for coloring the substrate 2 and carbon black. Of these colorants, inorganic pigments such as titanium white (titanium oxide) are preferred. These inorganic pigments have a high effect of concealing the base, and also have an effect of cutting off ultraviolet rays. Furthermore, there is an effect of preventing blocking in the production process of the decorative sheet.
Silica can be used as the inorganic pigment. When silica is used, spherical silica having a spherical particle shape is preferable. The particle size of the spherical silica is preferably about 1 to 10 μm, and in order to improve transparency, the particle size is more preferably about 1 to 4 μm. As the kind of the spherical silica, conventionally known ones can be used regardless of whether they are treated or untreated, and these can be used alone or in admixture of two or more.
Further, the blending amount of the spherical silica is preferably 5 to 25 parts by mass with respect to 100 parts by mass of the resin constituting the primer layer 4. By blending the spherical silica having such a particle size in the above-mentioned blending amount, it is possible to ensure specularity and transparency while maintaining the coating performance.

Although there is no restriction | limiting in the thickness of the primer layer 4, from a viewpoint of relieving the stress concerning the surface protective layer 5 at the time of a bending process, or suppressing a blocking in the production process of a decorative sheet, and obtaining sufficient adhesiveness, it is 0. The range of 5 to 10 μm is preferable. The thickness of the primer layer 4 is further preferably in the range of 1 to 5 μm. The coating amount of the resin for forming the primer layer is in the range of 0.5 to 10 g / m ^2, more preferably from 1 to 5 g / m ^2.

<Additives>
In the embodiment of the present invention, the primer layer 4 can contain various additives. Examples of additives include a weather resistance improver, an abrasion resistance improver, a polymerization inhibitor, a crosslinking agent, an infrared absorber, an antistatic agent, an adhesion improver, a leveling agent, a thixotropic (thixotropic) imparting agent, Examples include coupling agents, plasticizers, antifoaming agents, fillers, solvents, and coloring agents.

(Weather resistance improver)
As a weather resistance improver, the primer layer 4 preferably contains at least one of an ultraviolet absorber and a light stabilizer.
The weather resistance includes resistance to the primer layer 4 from being deteriorated and peeled off by ultraviolet rays or the like and resistance to the colored ink layer 3 and the substrate 2 from being deteriorated and discolored by ultraviolet rays or the like. The weather resistance improving agent is suitable in that both effects are improved.
The ultraviolet absorber may be either inorganic or organic, and as the inorganic ultraviolet absorber, titanium oxide, cerium oxide, zinc oxide or the like having an average particle size of about 5 to 120 nm can be preferably used. Moreover, as an organic type ultraviolet absorber, a benzotriazole type, a triazine type, a benzophenone type, a salicylate type, an acrylonitrile type etc. can be mentioned preferably, for example. Of these, triazines are preferred because they have a high ability to absorb ultraviolet rays and do not easily deteriorate even with high energy such as ultraviolet rays.
As the triazine-based ultraviolet absorber, 2- (2-hydroxy-4- [1-octyloxycarbonylethoxy] phenyl) -4,6-bis (4-phenylphenyl) -1 which is a hydroxyphenyl triazine-based ultraviolet absorber. , 3,5-triazine (trade name “TINUVIN 479” manufactured by BASF), 2- (4,6-bis (2,4-dimethylphenyl) -1,3,5-triazin-2-yl) -5 -Reaction product of hydroxyphenyl and oxirane {especially [(C10-C16, mainly C12-C13 alkyloxy) methyl] oxirane} (BASF, trade name “TINUVIN 400”), 2- (2,4 -Dihydroxyphenyl) -4,6-bis- (2,4-dimethylphenyl) -1,3,5-triazine and (2-ethylhexyl) -Reaction product of glycidic acid ester (manufactured by BASF, trade name “TINUVIN 405”), 2,4-bis [2-hydroxy-4-butoxyphenyl] -6- (2,4-dibutoxyphenyl) -1 , 3-5-triazine (trade name “TINUVIN 460” manufactured by BASF Corporation). Further, as the ultraviolet absorber, an ultraviolet absorber having an electron beam reactive group in the molecule can be used.
Specific examples of the triazole ultraviolet absorber include 2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- (2-hydroxy-3,5-di-tert-amylphenyl) benzotriazole, and polyethylene. Examples include 3- [3- (benzotriazol-2-yl) -5-tert-butyl-4-hydroxyphenyl] propionic acid ester of glycol.

  In particular, when a triazine-based ultraviolet absorber is used, the content thereof is preferably 0.1 to 50 parts by mass, more preferably 1 to 40 parts per 100 parts by mass of the resin component forming the primer layer 4. Part by mass, more preferably 10 to 35 parts by mass.

(Light stabilizer)
Preferred examples of the light stabilizer include hindered amine light stabilizers (HALS). Moreover, the light stabilizer which has the (meth) acryloyl group which is an electron beam reactive group in a molecule | numerator can also be used.
Specific examples of the hindered amine light stabilizer include bis (1,2,2,6,6-pentamethyl-4-piperidyl) sebacate (manufactured by BASF, trade name “TINUVIN 292”), bis (2,2) decanoic acid (2, 2,6,6-tetramethyl-1- (octyloxy) -4-piperidinyl) ester, reaction product of 1,1-dimethylethyl hydroperoxide and octane (trade name “TINUVIN 123” manufactured by BASF AG), bis (1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, methyl (1,2,2,6,6-pentamethyl-4-piperidinyl) sebacate, 2,4-bis [N-butyl-N -(1-cyclohexyloxy-2,2,6,6-tetramethylpiperidin-4-yl) amino] -6- (2-hydroxyethylamine) 1,3,5-triazine) hindered amine light stabilizers, and the like.
In addition, 1,2,2,6,6-pentamethyl-4-piperidinyl methacrylate (manufactured by BASF, trade name “Sanol LS-3410”), pentamethyl piperidyl methacrylate (manufactured by Hitachi Chemical Co., Ltd., trade name “ FA-71lMM ”), 2,2,6,6-tetramethyl-4-piperidiel methacrylate (manufactured by Hitachi Chemical Co., Ltd., trade name“ FA-712HMJ ”) and the like. Can be mentioned.
When the hindered amine light stabilizer is used, the content thereof is 0.05 to 15 parts by mass, more preferably 0.5 to 12 parts by mass with respect to 100 parts by mass of the resin component forming the primer layer 4. More preferably, it is 1-10 mass parts, Most preferably, it is 3-10 mass parts.

<Method for forming primer layer>
The primer layer 4 is applied to the surface of the colored ink layer 3 by a known printing method, coating method, or the like, with the composition containing the resin forming the primer layer 4 as it is or dissolved or dispersed in a solvent. Then, it can be formed by drying and curing.

[Surface protective layer]
The surface protective layer 5 is made of a cured product of a resin composition containing an ionizing radiation curable resin and a thermosetting resin in a mass ratio of 95: 5 to 50:50.
If the mass ratio of the thermosetting resin is less than 5%, adhesion after the environmental resistance test between the surface protective layer 5 and the primer layer is not preferable. On the other hand, if the mass ratio of the thermosetting resin exceeds 50%, the crosslink density of the ionizing radiation curable resin is lowered, so that scratch resistance and solvent resistance are lowered. When the mass ratio of the ionizing radiation curable resin exceeds 95%, the adhesion after the environmental resistance test is lowered, and when the mass ratio of the ionizing radiation curable resin is less than 50%, the contamination resistance is lowered.
<Ionizing radiation curable resin>
The ionizing radiation curable resin is a resin that is cured by being irradiated with ultraviolet rays or electron beams having an energy quantum capable of crosslinking and polymerizing molecules in electromagnetic waves or charged particle beams. Specifically, a polymerizable monomer, a polymerizable oligomer, or a prepolymer conventionally conventionally used as an ionizing radiation curable resin can be appropriately selected and used.
Typically, a (meth) acrylate monomer having a radical polymerizable unsaturated group in the molecule is suitable as the polymerizable monomer, and among them, a polyfunctional (meth) acrylate is preferable. Here, “(meth) acrylate” means “acrylate or methacrylate”. The polyfunctional (meth) acrylate is not particularly limited as long as it is a (meth) acrylate having two or more ethylenically unsaturated bonds in the molecule.

  In the present invention, a monofunctional (meth) acrylate can be used in combination with the polyfunctional (meth) acrylate as appropriate for the purpose of lowering the viscosity of the polyfunctional (meth) acrylate as long as the object of the present invention is not impaired. Examples of monofunctional (meth) acrylates include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl ( Examples include meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, and isobornyl (meth) acrylate. These monofunctional (meth) acrylates may be used alone or in combination of two or more.

  As the polymerizable oligomer, an oligomer having a radically polymerizable unsaturated group in the molecule, for example, epoxy (meth) acrylate, urethane (meth) acrylate, polyester (meth) acrylate, polyether (meth) acrylate, Examples include caprolactone-based urethane (meth) acrylate and polycaprolactone diol-based urethane (meth) acrylate. Among these, urethane (meth) acrylate and polycaprolactone diol-based urethane (meth) acrylate are preferably used from the viewpoint of enhancing the bending workability.

The epoxy (meth) acrylate oligomer can be obtained, for example, by reacting (meth) acrylic acid with an oxirane ring of a relatively low molecular weight bisphenol type epoxy resin or novolak type epoxy resin and esterifying it. Further, a carboxyl-modified epoxy (meth) acrylate oligomer obtained by partially modifying this epoxy (meth) acrylate oligomer with a dibasic carboxylic acid anhydride can also be used.
The urethane (meth) acrylate oligomer can be obtained, for example, by esterifying a polyurethane oligomer obtained by reaction of polyether polyol or polyester polyol and polyisocyanate with (meth) acrylic acid.
As a polyester (meth) acrylate oligomer, for example, by esterifying the hydroxy group of a polyester oligomer having a hydroxy group at both ends obtained by condensation of a polyvalent carboxylic acid and a polyhydric alcohol with (meth) acrylic acid, or It can be obtained by esterifying the terminal hydroxy group of an oligomer obtained by adding an alkylene oxide to a polyvalent carboxylic acid with (meth) acrylic acid. The polyether (meth) acrylate oligomer can be obtained by esterifying the hydroxy group of the polyether polyol with (meth) acrylic acid.

Caprolactone-based urethane (meth) acrylate can be obtained by reaction of caprolactone-based polyol, organic isocyanate, and hydroxy (meth) acrylate. A commercially available product can be used as the caprolactone-based polyol, preferably having two hydroxy groups, and having a number average molecular weight of preferably 500 to 3000, more preferably 750 to 2000. Moreover, polyols other than caprolactone, for example, polyols such as ethylene glycol, diethylene glycol, 1,4-butanediol, 1,6-hexanediol, etc., can be used by mixing one or more kinds in an arbitrary ratio.
As the organic polyisocyanate, a diisocyanate having two isocyanate groups is preferable, and from the viewpoint of suppressing yellowing, isophorone diisocyanate, hexamethylene diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, trimethylhexamethylene diisocyanate and the like are preferable. . Moreover, as hydroxy (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, caprolactone modified | denatured 2-hydroxyethyl (meth) acrylate, etc. are mentioned preferably.

The caprolactone-based urethane acrylate can be synthesized by a reaction of these polycaprolactone-based polyols, organic polyisocyanate, and hydroxy (meth) acrylate. As a synthesis method, a polycaprolactone-based polyol and an organic polyisocyanate are reacted to form a polyurethane prepolymer containing -NCO groups (isocyanate groups) at both ends, and then reacted with hydroxy (meth) acrylate. The method is preferred. Reaction conditions and the like may be in accordance with conventional methods.
As the caprolactone diol urethane acrylate, those obtained by using polycaprolactone and diethylene glycol in combination as a caprolactone polyol, isophorone diisocyanate as an organic polyisocyanate, and 2-hydroxyethyl (meth) acrylate as a hydroxy (meth) acrylate are particularly used. preferable.

  Furthermore, other polymerizable oligomers include polybutadiene (meth) acrylate oligomers with high hydrophobicity that have (meth) acrylate groups in the side chain of polybutadiene oligomers, and silicone (meth) acrylate oligomers that have polysiloxane bonds in the main chain. In a molecule such as an aminoplast resin (meth) acrylate oligomer modified with an aminoplast resin having many reactive groups in a small molecule, or a novolak epoxy resin, bisphenol epoxy resin, aliphatic vinyl ether, aromatic vinyl ether, etc. There are oligomers having a cationic polymerizable functional group.

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 a photopolymerization initiator with respect to 100 parts by mass of the resin composition. The photopolymerization initiator can be appropriately selected from those conventionally used and is not particularly limited. For example, a photopolymerization initiator such as benzoin, acetophenone, phenylketone, benzophenone, and anthraquinone Is preferred.
Further, as a photosensitizer, for example, p-dimethylbenzoic acid ester, tertiary amines, thiol sensitizers and the like may be used.

<Thermosetting resin>
The thermosetting resin is a resin that is crosslinked and cured by heating alone or in combination with a curing agent described later.
The thermosetting resin is preferably at least one selected from a resin having a hydroxy group and the same resin as that constituting the primer layer.
The resin having a hydroxy group is considered to react with the curing agent contained in the primer layer. For this reason, adhesiveness with the adjacent primer layer 4 can be improved because resin which forms the surface protective layer 5 contains resin which has a hydroxyl group as a thermosetting resin. Further, since the resin forming the surface protective layer 5 contains the same resin as the resin constituting the primer layer 4, the familiarity between the resin forming the surface protective layer 5 and the resin forming the primer layer 4 is improved. Adhesion between the surface protective layer 5 and the primer layer 4 is enhanced.
As the resin having a hydroxy group, a polyol compound is preferable. The polyol compound has two or more hydroxy groups in the molecule, and examples thereof include acrylic polyol, polyester polyol, polyether polyol, polycarbonate polyol, polycaprolactone polyol, polyethylene glycol, and polypropylene glycol. These may be used singly or in combination of two or more. Among these, acrylic polyol and polyester polyol are preferable, and acrylic polyol is more preferable.
A resin having a carboxy group can also be used. Examples of the resin having a carboxy group include polyester resins, styrene-acrylic copolymers, epoxy resins, polycarbonates, polyurethane resins and the like.
From the viewpoint of accelerating the curing of the thermosetting resin, a curing agent may be contained. The curing agent may be any compound that can cure the thermosetting resin by reaction with the thermosetting resin, and a known curing agent may be appropriately selected and used depending on the type of the thermosetting resin. Can do.
For example, when a polyol compound is used as the resin having a hydroxy group, it is preferable to use a polyisocyanate compound as a curing agent from the viewpoint of reactivity.
The polyisocyanate compound is a compound having two or more isocyanate groups in the molecule. Group polyisocyanate, and polyisocyanates having an aromatic ring such as tolylene diisocyanate, xylylene diisocyanate, and diphenylmethane diisocyanate. Of these, dicyclohexylmethane diisocyanate, hexamethylene diisocyanate, and xylylene diisocyanate are preferable from the viewpoint of stain resistance and weather resistance. These may be used individually by 1 type, and may be used in combination of 2 or more types.
Moreover, a polycarbonate urethane acrylic copolymer can be used as the same resin as that constituting the primer layer.
From such a viewpoint, it is preferable to use polycarbonate urethane acryl as the thermosetting resin.

<Additives>
Various additives can be blended in the ionizing radiation curable resin of the present invention depending on the physical properties desired for the surface protective layer to be formed. Examples of additives include a weather resistance improver, an abrasion resistance improver, a polymerization inhibitor, a crosslinking agent, an infrared absorber, an antistatic agent, an adhesion improver, a leveling agent, a thixotropic (thixotropic) imparting agent, Examples include coupling agents, plasticizers, antifoaming agents, fillers, solvents, and coloring agents.
As the weather resistance improving agent, it is preferable to include at least one of an ultraviolet absorber and a light stabilizer. The same ultraviolet absorber and light stabilizer as those described in the primer layer 4 can be used. The light stabilizer may be a reactive light stabilizer having reactivity.
The content of the ultraviolet absorber is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, and further preferably 1 to 5 parts per 100 parts by mass of the resin component forming the surface protective layer. Part by mass. The content of the light stabilizer is preferably 0.05 to 20 parts by mass, more preferably 0.1 to 10 parts by mass, and still more preferably 0 with respect to 100 parts by mass of the resin component forming the surface protective layer. .5 to 5 parts by mass.
By blending at least one of an ultraviolet absorber and a light stabilizer in the above blending amount as a weather resistance improver, the resistance to deterioration and discoloration of the colored ink layer 3 and the substrate 2 by ultraviolet rays or the like is improved. be able to.

<Method for forming surface protective layer>
When forming the surface protective layer, a resin composition in which an ionizing radiation curable resin and a thermosetting resin are mixed at a predetermined ratio is prepared, and a polymerizable monomer, a polymerizable oligomer that is an electron beam curable component, and Various additives are uniformly mixed in the resin composition at a predetermined ratio to prepare a coating agent. The viscosity of the coating agent is not particularly limited as long as it is a viscosity capable of forming an uncured resin layer on the surface of the substrate by a coating method described later.
The coating agent prepared in this way is a known system such as gravure coat, bar coat, roll coat, reverse roll coat, comma coat, etc., on the primer layer so that the thickness after curing is 1 to 20 μm, Preferably, it is applied by gravure coating to form an uncured resin layer.
The preferable film thickness after curing is appropriately determined in the range of 1 to 20 μm depending on the type of resin forming the surface protective layer.

The uncured resin layer formed as described above is irradiated with an electron beam to cure the uncured resin layer. The acceleration voltage can be appropriately selected according to the type or thickness of the resin forming the surface protective layer, but is preferably about 70 to 300 kV.
In the electron beam irradiation, the transmission capability increases as the acceleration voltage is higher, so when using a base material that deteriorates due to the electron beam, the transmission depth of the electron beam and the thickness of the resin layer are substantially equal. It is preferable to select an acceleration voltage. Thereby, it is possible to prevent the base material from being irradiated with an extra electron beam, and to minimize deterioration of the base material due to the excess electron beam. The amount of electron beam irradiation is preferably such that the crosslinking density of the uncured resin layer forming the surface protective layer is saturated, and is usually selected in the range of 5 to 300 kGy.

  There is no restriction | limiting in an electron beam source, For example, electron beam accelerators, such as a Cockloft Walton type, a bandegraft type, a resonance transformer type, an insulation core transformer type, a linear type, a dynamitron type, a high frequency type, can be used.

  Moreover, after irradiating an electron beam, it heats in order to harden a thermosetting resin. As heating conditions, it can set suitably according to the curing temperature of the thermosetting resin to be used. For example, it can be set to 60-80 degreeC.

  The surface protective layer thus formed has various functions by adding various additives, for example, high hardness and scratch resistance, so-called hard coat function, anti-fogging coat function, anti-fouling coating function. Further, an antiglare coating function, an antireflection coating function, an ultraviolet shielding coating function, an infrared shielding coating function, and the like can be provided.

In the present invention, the elongation measured in accordance with JIS K6732 of the cured product of the ionizing radiation curable resin forming the surface protective layer thus formed is required to be 1% or more. JIS K6732 normally defines the measurement test of agricultural polyvinyl chloride film. In this example, the elongation of the cured product of ionizing radiation curable resin forming the surface protective layer 5 is defined in JIS K6732. It is specified by the value measured according to the specified method.
If the elongation is less than 1%, the bending workability is lowered, and cracks and whitening occur in the bent portion. Moreover, when elongation exceeds 400%, the rigidity of a surface protective layer will fall.

[Decorated metal plate]
The decorative sheet can be used alone as a laminating material or a wrapping material, and is attached to a metal plate made of a metal material such as iron, aluminum, or copper to constitute a decorative metal plate. There is no limitation on the adhesive or pressure-sensitive adhesive for sticking the metal material and the decorative sheet, and any adhesive or pressure-sensitive adhesive known in the field of decorative sheets can be used.
That is, the decorative metal plate includes a metal plate, an adhesive layer disposed on the surface of the metal plate, and a decorative sheet attached to the metal plate via the adhesive layer in this order.
The metal material may be subjected to surface treatment such as hot dip galvanizing or electrogalvanizing. Further, the shape of the adherend is not particularly limited, and may be, for example, a flat plate, a curved plate, a polygonal column, or the like. Although there is no restriction | limiting in the thickness of a metal plate, It is preferable that it is 0.2-2 mm. In addition, in order to provide concealability to the metal plate which is an adherend, the metal plate may be directly colored or may be provided with a coating layer on which a color, a pattern, or the like is formed.
The above-mentioned decorative metal plate is made of, for example, building interior materials such as walls and ceilings, exterior materials for structures and buildings, surface materials for fittings such as doors, door frames, and window frames, fringes, baseboards, etc. It can be used as a surface material of a member, a surface material of furniture such as a bag or a cabinet.

Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to the examples.
[Evaluation method]
<Elongation of surface protective layer>
The elongation of the cured product of the ionizing radiation curable resin forming the surface protective layer of each decorative sheet of Examples 1 to 9 and Comparative Examples 1 to 10 was measured according to JIS K6732. That is, the cured product of the ionizing radiation curable resin forming the surface protective layer of each decorative sheet of Examples 1 to 9 and Comparative Examples 1 to 10 is punched into a dumbbell shape in accordance with JIS K6732, and a test sheet is obtained. Prepared. The elongation of this test sheet was measured using a tensile compression tester (Tensilon RTC-1250A manufactured by Orientec Co., Ltd.) under a temperature environment of 25 ° C. under conditions of a tensile speed of 50 mm / min and a distance between chucks of 100 mm. .

<Elongation of decorative sheet>
The elongation of each decorative sheet of Examples 1 to 9 and Comparative Examples 1 to 10 was measured as follows. That is, each decorative sheet of Examples 1 to 9 and Comparative Examples 1 to 10 was punched into a dumbbell shape in accordance with JIS K6732, and a test sheet was prepared. The elongation of this test sheet was measured under the same conditions using the above-described tensile and compression tester.

<Adhesion>
From each of the decorative sheets of Examples 1 to 9 and Comparative Examples 1 to 10, a peel test was further performed on the following three types of decorative sheets to evaluate the adhesion.
Before the weather resistance test and before the water resistance test: State A
After light deterioration treatment (“eye super UV tester”, irradiated with ultraviolet rays for 300 hours under irradiation conditions of 60 mW / cm ² ): State B
After moisture deterioration treatment (after placing in warm water at 80 ° C for 1 month): State C
Each of the decorative sheets of the states A to C obtained from the decorative sheets of Examples 1 to 9 and Comparative Examples 1 to 10 was cut into a grid of 1 mm × 1 mm with a cutter knife, and a 100 square grid Eyes were made. Adhesive tape was attached to the grid area, and the adhesive tape was peeled off at an angle of 45 °. The following criteria evaluated by the ratio of the peeled sheet piece. 1 and 2 were accepted.
0-5%: 1
6-10%: 2
11% or more: 3

<Processability>
A metal material defined in JIS Z2248 with respect to a decorative metal plate for testing in which each decorative sheet of Examples 1 to 9 and Comparative Examples 1 to 10 was attached to an aluminum plate having a thickness of 0.8 mm and 40 × 40 mm. The bending test was performed at a test temperature of 25 ± 5 ° C. The test method is as follows. The test decorative metal plate was bent 90 ° by the V-block method, and then a plate having the same thickness as that of the aluminum plate was interposed, and the plate was bent 180 ° by the push-bending method. 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 of the substrate, the colored ink layer, the primer layer, and the surface protective layer in the bent portion were visually observed and evaluated according to the following criteria. 1 and 2 were accepted.
Little cracking or whitening is observed: 1
Minor cracks and whitening were confirmed, but there were no practical problems: 2
Significant cracking and whitening were confirmed: 3

<Weather resistance>
Each of the decorative sheets of Examples 1 to 9 and Comparative Examples 1 to 10 was irradiated with ultraviolet rays under an irradiation condition of 60 mW / cm ² using a weather resistance test apparatus (“I-Super UV Tester” manufactured by Iwasaki Electric Co., Ltd.). Was measured, and the time until the appearance change such as cracking and whitening occurred on the surface of the decorative sheet was measured and evaluated according to the following criteria. 1 and 2 were accepted.
500 hours or more: 1
150 hours or more and less than 500 hours: 2
Less than 150 hours: 3

<Fire resistance>
A decorative metal plate for test in which each decorative sheet of Examples 1 to 9 and Comparative Examples 1 to 10 was attached to an aluminum plate was subjected to a Steiner tunnel combustion test based on ASTM E-84, and a flame diffusion index ( Based on the numerical values of FSI) and smoke generation index (SDI), it was classified into CLASS A, CLASS B, and others. 1 was accepted.
CLASS A (FSI ≦ 25, SDI ≦ 450): 1
CLASS B (26 ≦ FSI ≦ 75, SDI ≦ 450): 2
Other than that (FSI ≧ 76): 3

<Abrasion resistance>
The scratch resistance of each of the decorative sheets of Examples 1 to 9 and Comparative Examples 1 to 10 was brought into contact with steel wool (# 0000) and rubbed 10 times with a load of 1.5 kg. The surface was visually observed and evaluated according to the following criteria. 1 and 2 were accepted.
There was little change in appearance: 1
Appearance was slightly scratched or color changed: 2
Appearance was severely scratched or color changed: 3

<Solvent resistance>
The solvent resistance was evaluated as follows. After reciprocating 50 kg of weight of 1.5 kg weight gauze infused with methyl ethyl ketone with rubber bands on the surface of each decorative sheet of Examples 1-9 and Comparative Examples 1-10, the surface of the decorative sheet was Visual observation was made and the following criteria were evaluated. 1 and 2 were accepted.
There was almost no change in the appearance of the sheet surface: 1
A slight change in the appearance of the sheet surface was observed, but there was no practical problem: 2
The appearance change of the sheet surface was remarkable: 3

<Contamination resistance>
Contaminants based on NEMA LD3 were applied to the surfaces of the decorative sheets of Examples 1 to 9 and Comparative Examples 1 to 10, and wiped off by the following method after 24 hours. Contaminants include distilled water, ethanol water, acetone, ammonia, 10% citric acid aqueous solution, vegetarian bucking oil, coffee, tea, ketchup, mustard, 10% iodine aqueous solution, stamp ink (purple), # 2 pencil, crayon, and Shoe ink was selected. When it was able to wipe off with the following wiping method, the score was added and the total score was evaluated on the following reference | standard. The higher the total score, the worse the stain resistance. 1, 2, 3 (acceptance points were 0 to 50) were accepted.
(Wiping method)
Can be wiped off with water or dry wipe: 0 points Can be wiped off with water or dry wipe under a load (1 kg): 1 point Can be wiped off with a general cleaner: 2 points Wipe off with a remover Can be removed: 3 points Can be wiped off with hypochlorous acid bleach solution: 4 points The above cannot be removed: 5 points (contamination resistance evaluation)
Total points 0-15: 1
Total score 16-25 points: 2
Total score is 26-50: 3
The total score is 51 points or more: 4

<Color change after electron beam irradiation>
An electron beam was emitted to each of the decorative sheets of Examples 1 to 9 and Comparative Examples 1 to 10, and the presence or absence of a color change after the emission was visually determined based on the following criteria. 1 and 2 were accepted.
No discoloration: 1
There was slight discoloration, but there was no practical problem: 2
There is significant discoloration: 3

[Example]
<Example 1>
As the substrate 2, a film A1 having a thickness of 45 μm was used. After printing a colored ink layer having a colored concealing layer and a pattern layer on one side of the film A1, a resin composition to be described later is applied on the pattern layer so that the thickness after curing is 3 μm. A layer was formed. Subsequently, a resin composition containing an ionizing radiation curable resin and a thermosetting resin B1 was further applied on the primer layer by a gravure direct coater method so that the thickness after curing was 5 μm. After coating, the ionizing radiation curable resin was cured by irradiating an electron beam with an acceleration voltage of 90 kV and an irradiation dose of 50 kGy (5 Mrad). Thereafter, curing was performed at 70 ° C. for 24 hours to cure the thermosetting resin. Thereby, the surface protective layer 5 was formed.
(Base material)
The film A1 is a biaxially stretched polyethylene terephthalate film (trade name “Z210E45” manufactured by Mitsubishi Plastics, Inc.), and has been subjected to an easy adhesion coating treatment.
(Primer layer)
The resin that forms the primer layer is 100 parts by mass of a polycarbonate urethane acryl copolymer having a mass ratio of the urethane component to the acrylic component in the polycarbonate urethane acryl copolymer of 70/30, and hexanemethylene diisocyanate as a curing agent. 7 parts by mass. In addition to this, an appropriate amount of a triazine ultraviolet absorber as an ultraviolet absorber and a hindered amine light stabilizer as a light stabilizer were blended in the resin forming the primer layer.
Examples of triazine ultraviolet absorbers include 2- (4,6-bis (2,4-dimethylphenyl) -1,3,5-triazin-2-yl) -5-hydroxyphenyl and oxirane {[(C10- C16, mainly Cl2-C13 alkyloxy) methyl] oxirane} (BASF, trade name “TINUVIN 400”), and 2- (2-hydroxy-4- [1-octyloxycarbonylethoxy] phenyl ) -4,6-bis (4-phenylphenyl) -1,3,5-triazine (trade name “TINUVIN 479” manufactured by BASF AG) was used.
Examples of hindered amine light stabilizers include bis (2,2,6,6-tetramethyl-1- (octyloxyne) -4-piperidiel) decanoate, a reaction product of 1,1-dimethylethyl hydroperoxide and octane ( The product name “TINUVIN 123” manufactured by BASF Corporation) was used.
13 parts by mass of “TINUVIN 400”, 17 parts by mass of “TINUVIN 479”, and 8 parts by mass of “TINUVIN 123” were blended.
(Surface protective layer)
The resin composition forming the surface protective layer is an ionizing radiation curable resin, 90 parts by mass of trifunctional caprolactone urethane acrylate (solid resin content 65%, elongation 17%), and an acrylic polyol type as thermosetting resin B1. 10 parts by mass of resin and 1 part by mass of hexamethylene diisocyanate (HMDI) as a curing agent.
As a weathering agent, 3 parts by mass of a triazine-based ultraviolet absorber, 3 parts by mass of a hindered amine light stabilizer (HALS), and 1 part by mass of an antioxidant were added to 100 parts by mass of the resin composition described above. As the triazine ultraviolet absorber, “TINUVIN 479” is used as the triazine ultraviolet absorber, and 1,2,2,6,6-pentamethyl-4-piperidi is used as a hindered amine light stabilizer having an electron beam reactive functional group. Nyl methacrylate (manufactured by BASF, trade name “Sanol LS-3410”) was used.

<Examples 2 to 7>
A decorative sheet was produced in the same manner as in Example 1 except that the composition and the amount of the resin forming the surface protective layer were changed as shown in Table 1. The thermosetting resin B2 is a polyester polyol resin, and the thermosetting resin B3 is a polycarbonate urethane acrylic resin.
<Example 8>
A decorative sheet was produced in the same manner as in Example 7 except that a film A2 having a thickness of 25 μm was used as the substrate 2.
Film A2 is obtained by subjecting a biaxially stretched polyethylene terephthalate film (trade name “E5007”, manufactured by Toyobo Co., Ltd.) to a corona discharge treatment before printing a colored ink layer on the front and back surfaces.
<Example 9>
A decorative sheet was produced in the same manner as in Example 7 except that a film A3 having a thickness of 38 μm was used as the substrate 2.
Film A3 is a biaxially stretched polyethylene terephthalate film (trade name “G900E38” manufactured by Mitsubishi Plastics, Inc.), and has been subjected to an easy adhesion coating treatment.

[Comparative example]
<Comparative Example 1>
A decorative sheet was produced in the same manner as in Example 1 except that no thermosetting resin was used as the resin for forming the surface protective layer.
<Comparative Examples 2-7>
A decorative sheet was prepared in the same manner as in Example 1 except that the ionizing radiation curable resin was not used as the resin for forming the surface protective layer, and the type of the thermosetting resin was changed as shown in Table 2.
<Comparative Example 8>
A decorative sheet was produced in the same manner as in Example 7 except that a film A4 having a thickness of 12 μm was used as the substrate 2. Film A4 is obtained by subjecting a biaxially stretched polyethylene terephthalate film (trade name “E5100”, manufactured by Toyobo Co., Ltd.) to a corona discharge treatment before printing a colored ink layer on the front and back surfaces.
<Comparative Example 9>
A decorative sheet was produced in the same manner as in Example 7 except that a film A5 having a thickness of 80 μm was used as the substrate 2. The film A5 is a polypropylene resin film (trade name “Art Ply”, manufactured by Mitsubishi Plastics, Inc.) and has been subjected to an easy adhesion coating treatment.
<Comparative Example 10>
A decorative sheet was produced in the same manner as in Example 7 except that a film A6 having a thickness of 170 μm was used as the substrate 2. Film A6 is a polyvinyl chloride resin film (manufactured by Bando Chemical Co., Ltd., trade name “SHF BW-201”), and has been subjected to an easy adhesion coating treatment.

[Evaluation results]
The evaluation results based on the evaluation method described above are shown in Tables 1 and 2.

  As shown in Tables 1 and 2, while using a biaxially stretched polyethylene terephthalate film as the base material, the thickness of the base material was set to 25, 38, 45 μm, and the surface protective layer was made of ionizing radiation curable resin and heat. A cured product of a resin composition containing a curable resin in a mass ratio of 95: 5 to 50:50, and further, an elongation of the cured product measured in accordance with JIS K6732 is 1% or more, and a decorative sheet It was found that a decorative sheet satisfying an elongation measured in accordance with JIS K6732 of 30% or more and 180% or less is excellent in workability, weather resistance, and fire resistance and has good adhesion.

  DESCRIPTION OF SYMBOLS 1 ... Cosmetic sheet, 2 ... Base material, 3 ... Colored ink layer, 4 ... Primer layer, 5 ... Surface protective layer

Claims (8)

A decorative sheet having a base, a colored ink layer, a primer layer and a surface protective layer in this order,
The substrate is made of a polyester film,
The thickness of the substrate is 20 μm or more and 95 μm or less,
The surface protective layer comprises a cured product of a resin composition containing an ionizing radiation curable resin and a thermosetting resin in a mass ratio of 95: 5 to 50:50,
The elongation measured according to JIS K6732 of the cured product is 1% or more,
A decorative sheet having an elongation of 30% or more and 180% or less measured according to JIS K6732 of the decorative sheet.   The decorative sheet according to claim 1, wherein the thermosetting resin includes at least one selected from a resin having a hydroxy group and a resin that is the same as a resin constituting the primer layer.   The decorative sheet according to claim 1 or 2, wherein the base material is made of biaxially stretched polyethylene terephthalate.   The decorative sheet according to any one of claims 1 to 3, wherein the ionizing radiation curable resin contains urethane (meth) acrylate.   The decorative sheet according to any one of claims 1 to 4, wherein the ionizing radiation curable resin contains at least one of a triazine-based ultraviolet absorber and a light stabilizer.   The decorative sheet according to any one of claims 1 to 5, wherein the resin constituting the primer layer contains at least one of a triazine-based ultraviolet absorber and a light stabilizer.   The decorative sheet according to any one of claims 1 to 6, wherein the resin constituting the primer layer contains a polycarbonate-based urethane acrylic copolymer.   A decorative metal plate formed by adhering a metal plate and the base material of the decorative sheet according to any one of claims 1 to 7 via an adhesive layer.