JP2023079757A - makeup sheet - Google Patents

Abstract

A decorative sheet capable of reducing the occurrence of delamination is provided. The adhesive layer provided between the base material of the decorative sheet and the transparent resin layer containing polyolefin as a main component is composed of a polyether carbonate-based urethane resin, and the polyether carbonate-based urethane resin is The resin component contains at least one polyether polyol selected from polyethylene ether glycol (PEG), polypropylene ether glycol (PPG), and polytetramethylene ether glycol (PTMG), and contains at least one alkanediol having 8 or less carbon atoms. Contains seeds, contains at least one polyisocyanate selected from hexamethylene diisocyanate (HDI) and isophorone diisocyanate (IPDI), has a hydroxyl value in the range of 10 mgKOH/g or more and 150 mgKOH/g or less, and contains an isocyanate curing agent as a cross-linking component. include. [Selection drawing] Fig. 1

Description

The present disclosure relates to decorative sheets.

As interior or exterior materials for buildings such as walls, ceilings, floors, entrance doors, window frames, doors, handrails, baseboards, rims, malls, etc. A decorative sheet is attached to an adherend composed of a metal member, a resin member, a wooden member, or the like.
Many decorative sheets are laminates, and in particular, decorative sheets used for building exteriors and bathrooms are subject to deterioration due to sunlight, etc., and moisture intrusion from the edges of the decorative sheet toward the inside of the decorative sheet. , delamination may occur.

When manufacturing a decorative sheet, which is generally a laminate, an adhesive layer may be provided. Acrylic resin, polyurethane resin, epoxy resin, and polyester resin are generally used for this adhesive layer (for example, Patent Document 1). In particular, when polyurethane resin is used as the adhesive layer, polyether urethane resin is often used in consideration of wettability and flexibility.

Japanese Patent No. 4737722

However, polyether urethane resins are resistant to hydrolysis and are therefore resistant to water, but have low weather resistance. Therefore, delamination may occur between the adhesive layer formed using the polyether urethane resin and the transparent resin layer formed on the adhesive layer. As a urethane resin with high weather resistance, there is a polycarbonate urethane resin, but it is disadvantageous in terms of adhesion due to its poor flexibility.
An object of the present disclosure is to provide a decorative sheet that can reduce the occurrence of delamination (especially the occurrence of delamination between an adhesive layer and a transparent resin layer) in order to solve the above problems. .

As a result of intensive studies, the present inventors have found that a decorative sheet using a resin containing a specific element in an adhesive layer can achieve the above-described goals, and have arrived at the present disclosure.
In order to solve the above problems, a decorative sheet according to one aspect of the present disclosure includes a base material, a pattern layer, an adhesive layer, a transparent resin layer containing polyolefin as a main component, and a surface protective layer laminated in this order. The adhesive layer is composed of a polyether carbonate-based urethane resin, and the polyether carbonate-based urethane resin contains polyethylene ether glycol (PEG), polypropylene ether glycol (PPG), and polytetramethylene as resin components. Contains at least one polyether polyol of ether glycol (PTMG), contains at least one alkanediol having 8 or less carbon atoms, and contains at least one of hexamethylene diisocyanate (HDI) and isophorone diisocyanate (IPDI). It contains isocyanate, has a hydroxyl value in the range of 10 mgKOH/g or more and 150 mgKOH/g or less, and contains an isocyanate curing agent as a cross-linking component.

According to one aspect of the present disclosure, it is possible to obtain a decorative sheet capable of reducing the occurrence of delamination (in particular, the occurrence of delamination between the adhesive layer and the transparent resin layer).

1 is a schematic diagram showing a cross-sectional structure of a decorative sheet according to an embodiment of the present disclosure; FIG.

The present disclosure is described in detail below. Note that FIG. 1 is a schematic diagram, and the size, shape, etc. of each part are appropriately exaggerated for easy understanding. Further, the embodiments shown below are examples of configurations for embodying the technical idea of the present disclosure. is not limited to Various modifications can be made to the technical idea of the present disclosure within the technical scope defined by the claims.

A decorative sheet 10 according to an embodiment of the present disclosure will be described below with reference to FIG. FIG. 1 is a cross-sectional view showing one configuration example of the decorative sheet 10. As shown in FIG.

(1) Configuration of Decorative Sheet As shown in FIG. 1, the decorative sheet 10 includes a substrate 11, a pattern layer 12 formed on the substrate 11, an adhesive layer 13 formed on the pattern layer 12, A transparent resin layer 14 formed on the adhesive layer 13 and a surface protection layer 15 formed on the transparent resin layer 14 are provided. The decorative sheet 10 may also have a primer layer 16 provided on the surface of the substrate 11 opposite to the pattern layer 12 .
Each layer of the decorative sheet 10 will be described below with reference to FIG.

(adhesive layer)
The adhesive layer 13 is a layer provided to bond the pattern layer 12 and the transparent resin layer 14 together. Further, when the pattern layer 12 is provided only on a part of the base material 11, the adhesive layer 13 is used to bond the pattern layer 12 forming side surface of the base material 11 and the pattern layer 12 to the transparent resin layer 14. provided in
The adhesive layer 13 is composed of a polyether carbonate-based urethane resin, and is formed using a normal coating method such as gravure coating, micro gravure coating, comma coating, knife coating, and die coating.

The polyether carbonate-based urethane resin that constitutes the adhesive layer 13 contains, as a resin component, at least one polyether polyol selected from polyethylene ether glycol (PEG), polypropylene ether glycol (PPG), and polytetramethylene ether glycol (PTMG). containing at least one alkanediol having 8 or less carbon atoms, and at least one polyisocyanate selected from hexamethylene diisocyanate (HDI) and isophorone diisocyanate (IPDI).

At least one of polytetramethylene ether glycol (PTMEG), polytetramethylene glycol (PTMG), and pentamethylene glycol (PMG) is used as the polyether polyol constituting the polyether carbonate-based urethane resin of the present embodiment. can be done. By using these polyether polyols as the resin component of the polyether carbonate-based urethane resin, the flexibility of the adhesive layer 13 is increased, and excellent flexibility can be imparted to the adhesive layer 13 as a whole.

Alalkanediols having 8 or less carbon atoms that constitute the polyether carbonate-based urethane resin of the present embodiment include, for example, 1,2-ethanediol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexane. diol, 2-methyl-1,4-butanediol, 2-methyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 2-methyl-1,3-pentanediol, 2-ethyl- At least one of 1,3-hexanediol can be used. By using these alalkanediols as the resin component of the polyether carbonate-based urethane resin, the weather resistance of the adhesive layer 13 is improved, and the adhesive layer 13 and the transparent resin layer can be maintained even after a long period of time after the decorative sheet 10 is manufactured. 14 is less likely to cause delamination.

At least one of hexamethylene diisocyanate (HDI) and isophorone diisocyanate (IPDI) can be used as the polyisocyanate constituting the polyether carbonate-based urethane resin of the present embodiment. By using these polyisocyanates as the resin component of the polyether carbonate-based urethane resin, the polyether carbonate-based urethane resin constituting the adhesive layer 13 can be imparted with the necessary yellowing resistance.
The amount of polyisocyanate used is designed according to the molar ratio (isocyanate group/hydroxyl group (mol)) of the isocyanate group of the polyisocyanate and the total hydroxyl group of the polyol (polyether carbonate polyol or chain extender polyol) used. preferably the molar ratio is between 0.75 and 1.8, more preferably between 0.85 and 1.6.

The polyether carbonate-based urethane resin of the present embodiment preferably has a hydroxyl value within the range of 10 mgKOH/g or more and 150 mgKOH/g or less. When the hydroxyl value is in the range of 10 mgKOH/g or more and 150 mgKOH/g or less, the weather resistance of the adhesive layer 13 is improved, and the adhesion between the adhesive layer 13 and the transparent resin layer 14 is maintained for a long time after the decorative sheet 10 is manufactured. Delamination between layers is less likely to occur.

The polyether carbonate-based urethane resin of this embodiment contains an isocyanate curing agent as a cross-linking component. The isocyanate curing agent is not particularly limited, and can be appropriately selected from commercially available curing agents including, for example, hexamethylene diisocyanate, isophorone diisocyanate, tolylene diisocyanate, xylylene diisocyanate, diphenylmethane diisocyanate, and the like. By including these isocyanate curing agents, the cross-linking density of the polyether carbonate-based urethane resin is improved, and delamination between the adhesive layer 13 and the transparent resin layer 14 is less likely to occur.

The adhesive layer 13 may contain, for example, a weather resistant agent such as an ultraviolet absorber and a light stabilizer, if necessary.
As the ultraviolet absorber, for example, benzotriazole-based, benzoate-based, benzophenone-based, and triazine-based ultraviolet absorbers can be used. As the light stabilizer, for example, a hindered amine system or the like can be used. In particular, it is preferable to use an ultraviolet absorber having a triazine skeleton or a light stabilizer having a NOR-type skeleton as a weather resistant agent for the adhesive layer 13 . The various additives described above are generally added in any combination, but the adhesive layer 13 contains at least both an ultraviolet absorber having a triazine skeleton and a light stabilizer having a NOR-type skeleton. preferably. By including the weather resistant agent in the adhesive layer 13, the weather resistance of the adhesive layer 13 is improved, and delamination occurs between the adhesive layer 13 and the transparent resin layer 14 even after a long period of time after the decorative sheet 10 is manufactured. become difficult.

The molecular weight of the polyether carbonate-based urethane resin of the present embodiment is not particularly limited. It is desirable that the molecular weight (Mw) is in the range of 5,000 to 100,000. If the mass average molecular weight (Mw) is within this numerical range, the printability can be easily improved.

Although the method for producing the polyether carbonate-based urethane resin according to the present embodiment is not particularly limited, it preferably includes, for example, a step of transesterifying an alkanediol and a polyether polyol in the presence of an ester exchange catalyst. The adhesive layer 13 can be cured by adding a proper amount of a curing agent such as isocyanate to the terminal of the polyether carbonate-based urethane resin having hydroxyl groups.

The method of joining the transparent resin layer 14 to the base material 11 provided with the pattern layer 12 may be via the adhesive layer 13, for example, using various lamination methods such as heat lamination, extrusion lamination, dry lamination, and sand lamination. be able to.

(Base material)
As the resin constituting the base material 11, that is, the resin component, polyolefin or polyester is preferably used, and polyolefin is most preferable from the viewpoint of versatility. The resin constituting the base material 11 can be arbitrarily selected from existing materials such as polyethylene, polypropylene, polybutylene, polyethylene terephthalate, polybutylene terephthalate, and polyethylene naphthalate. Materials other than the polyolefin-based resins described above include, for example, α-olefins (eg, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1- Undecene, 1-dodecene, tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1-nonadecene, 1-eicosene, 3-methyl-1-butene, 3-methyl-1- Pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4-dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1- hexene, 9-methyl-1-decene, 11-methyl-1-dodecene, 12-ethyl-1-tetradecene, etc.), ethylene-vinyl acetate copolymer, ethylene・Vinyl alcohol copolymer, ethylene-methyl methacrylate copolymer, ethylene-ethyl methacrylate copolymer, ethylene-butyl methacrylate copolymer, ethylene-methyl acrylate copolymer, ethylene-ethyl acrylate copolymer, ethylene-butyl Examples thereof include copolymers of ethylene or α-olefins with other monomers, such as acrylate copolymers.

The base material 11 may be subjected to surface treatment such as corona treatment, plasma treatment, ozone treatment, electron beam treatment, ultraviolet treatment, dichromic acid treatment, etc., in order to enhance adhesion with adjacent layers. Furthermore, a primer layer (not shown) may be provided between the substrate 11 and the pattern layer 12 to ensure close contact.
If the base material 11 is made of polyolefin or polyester, the adhesiveness with the pattern layer 12 to be described later is ensured. .

When it is desired to impart concealability to the decorative sheet 10, a concealable colored sheet may be used as the base material 11, or a concealing layer (not shown) may be used as the upper layer of the base material 11 and the lower layer of the pattern layer 12. ) may be provided. When a colored sheet is used as the base material 11, a coloring agent can be added to the resin material forming the base material 11 for coloring. Examples of the coloring agent include inorganic pigments (titanium oxide, carbon black, etc.), organic pigments (phthalocyanine blue, etc.), and dyes. One or two or more of known or commercially available colorants can be selected and used as the colorant of the present embodiment, and the amount added can be adjusted so as to obtain the desired concealing properties and design properties. .
In addition, if necessary, the base material 11 may contain, for example, a filler, a foaming agent, a flame retardant, a lubricant, an antistatic agent, an antioxidant, a crystal nucleating agent, an ultraviolet absorber, a light stabilizer, a heat stabilizer, Various additives such as coloring agents and matting agents may be added.

(picture layer)
The pattern layer 12 is, for example, a layer including a pattern printed on the base material 11 using ink. The ink used to form the pattern layer 12 may contain, for example, a binder resin. The binder resin contained in the ink used to form the pattern layer 12 is, for example, nitrocellulose, cellulose, vinyl chloride-vinyl acetate copolymer, polyvinyl butyral, polyurethane, acrylic, polyester, etc. alone or in each modified product. can be appropriately selected and used from. The ink may be water-based, solvent-based, or emulsion type, and may be one-liquid type or two-liquid type using a curing agent. In this embodiment, as the ink used for forming the pattern layer 12, a water-based colored ink is suitable from the viewpoint of coatability.
As a method for curing the ink used for forming the pattern layer 12, for example, there is a method for curing the ink by irradiation with ultraviolet rays, electron beams, or the like. Among them, the most common method is to use urethane-based ink and to cure it with polyisocyanate.

The ink used to form the pattern layer 12 includes, in addition to the binder resin described above, various additives such as pigments, dyes, and other coloring agents, extender pigments, solvents, light stabilizers, and the like, which are contained in ordinary inks. may be added. Examples of highly versatile pigments include condensed azo, insoluble azo, quinacridone, isoindoline, anthraquinone, imidazolone, cobalt, phthalocyanine, carbon, titanium oxide, iron oxide, and pearl pigments such as mica.
The method of providing the pattern layer 12 is not particularly limited, and ordinary printing methods such as gravure printing, offset printing, screen printing, flexographic printing, and ink jet printing can be used.

(Transparent resin layer)
The transparent resin layer 14 is made of a transparent resin containing polyolefin as a main component. Polyolefins such as polypropylene, polyethylene, polybutene, and various α-olefin copolymers (copolymers of propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, etc.) are used as the material of the transparent resin layer 14. . Among these resins, polypropylene is the most preferable material for the transparent resin layer 14 .
The transparent resin layer 14 of the present embodiment may be a sheet formed by film formation, or may be a laminate of already formed sheets. The transparent resin layer 14 may be made of, for example, a highly crystalline polypropylene resin.

The polyolefin preferably accounts for 80% by mass or more of the entire mass of the transparent resin layer 14, and more preferably 90% by mass or more. The term “transparent resin layer containing polyolefin as a main component” means a state in which polyolefin accounts for 80 mass % or more of the mass of the entire transparent resin layer 14 .

The transparent resin layer 14 may optionally contain, for example, an ultraviolet absorber, a weather resistant agent such as a light stabilizer, a heat stabilizer, a flame retardant, an antiblocking agent, a catalyst scavenger, and a Various additives such as colorants, light scattering agents, and luster modifiers can also be added within the range not included.
As the heat stabilizer, for example, phenol-based, sulfur-based, phosphorus-based, hydrazine-based, and the like can be used. Aluminum hydroxide, magnesium hydroxide, etc. can be used as a flame retardant. As the ultraviolet absorber, for example, benzotriazole-based, benzoate-based, benzophenone-based, and triazine-based ultraviolet absorbers can be used. As the light stabilizer, for example, a hindered amine system or the like can be used. These additives are generally added in any combination.

A method for producing the transparent resin layer 14 is not particularly limited, and for example, a normal method such as calendar film formation or extrusion film formation can be used.
The transparent resin layer 14 may be provided with surface unevenness, so-called embossing, in order to impart designability. Examples of the method of providing unevenness include a method of subjecting the transparent resin layer 14 to heat embossing after extrusion molding, and a method of performing embossing simultaneously with extrusion molding using a cooling roll provided with unevenness during extrusion. More specifically, the uneven pattern (embossed pattern) is directly imparted to the transparent resin layer 14, for example, a highly crystalline polypropylene sheet, and the method is an embossing plate having an uneven pattern by heat and pressure on the polypropylene sheet formed into a film. and a method of providing embossing at the same time as cooling using a cooling roll having an uneven pattern when forming a film using an extruder. In this case, it is also possible to fill the recesses of the uneven pattern with colored ink to further improve the design.
The uneven pattern may be provided if necessary, and may not be provided if unnecessary.
Also, one side or both sides of the transparent resin layer 14 may be activated by, for example, corona treatment, plasma treatment, electron beam treatment, ultraviolet treatment, dichromic acid treatment, or the like, if necessary.

(Surface protective layer)
The surface protective layer 15 according to the present embodiment is a layer provided to the decorative sheet 10 to provide functions such as weather resistance, scratch resistance, stain resistance, and design. The material forming the surface protective layer 15 is not particularly limited, and can be appropriately selected from, for example, resin materials such as urethane, acrylic, acrylic silicon, fluorine, and epoxy resins.
From the viewpoint of coatability, the material of the surface protective layer 15 is preferably a resin containing urethane polymer as a main component, more preferably a resin containing polycarbonate urethane as a main component. Here, "a resin containing a urethane polymer as a main component" means a state in which the urethane polymer accounts for 80% by mass or more of the total mass of the resin.
In the present embodiment, the urethane-based surface protective layer 15 using an isocyanate reaction is desirable from the viewpoints of workability, cost, cohesive strength of the resin itself, and the like.

Examples of isocyanates constituting the surface protective layer 15 include tolylene diisocyanate (TDI), xylylene diisocyanate (XDI), hexamethylene diisocyanate (HMDI), diphenylmethane diisocyanate (MDI), lysine diisocyanate (LDI), and isophorone diisocyanate (IPDI). , bis(isocyanatomethyl)cyclohexane (HXDI), and trimethylhexamethylene diisocyanate (TMDI), which are derivatives of adducts, burettes, isocyanurates, and various prepolymers.
The surface protective layer 15 may optionally contain various additives such as ultraviolet absorbers, heat stabilizers, light stabilizers, antiblocking agents, catalyst scavengers, colorants, light scattering agents, and gloss modifiers. may be blended.

As with the transparent resin layer 14, the surface protective layer 15 may optionally contain, for example, weather resistance agents such as ultraviolet absorbers, light stabilizers, heat stabilizers, flame retardants, antiblocking agents, catalyst scavengers, Various additives such as colorants, light scattering agents, and luster modifiers can be added within the range that does not impair the features of the present embodiment. As various additives, materials similar to those of the transparent resin layer 14 can be used.
In particular, it is preferable to use an ultraviolet absorber having a triazine skeleton or a light stabilizer having a NOR-type skeleton as a weather resistant agent for the surface protective layer 15 . Although the various additives described above are generally added in any combination, the surface protective layer 15 contains at least both an ultraviolet absorber having a triazine skeleton and a light stabilizer having a NOR-type skeleton. preferably.

The method of forming the surface protective layer 15 is not particularly limited, and the above-mentioned material is made into a coating liquid and applied by a conventional method such as gravure coating, micro gravure coating, comma coating, knife coating, and die coating. Alternatively, it may be formed by curing by a method suitable for the material, such as heat curing or ultraviolet curing.
Also, the surface protective layer 15 may be provided after the pattern layer 12 formed on the base material 11 and the transparent resin layer 14 are bonded via the adhesive layer 13 .

(primer layer)
The decorative sheet 10 according to this embodiment may further include a primer layer 16 on the back surface of the substrate 11 opposite to the pattern layer 12 side.
The primer layer 16 may be made of the same component as the binder resin contained in the colored ink for forming the pattern layer 12 .

The method of forming the primer layer 16 is not particularly limited. It may be formed by curing by a method suitable for the material, such as heat curing or ultraviolet curing.
Further, the primer layer 16 may be provided after forming a laminate including the substrate 11, the pattern layer 12, the adhesive layer 13, the transparent resin layer 14, and the surface protective layer 15 in this order, or may be provided in advance. After providing the primer layer 16 on the back surface of the base material 11, the base material 11 provided with the primer layer 16, the pattern layer 12, the adhesive layer 13, the transparent resin layer 14, and the surface protective layer 15 are arranged in this order. A laminate may be formed comprising:

Considering that the back surface of the decorative sheet 10 is to be wound in a web form, the primer layer 16 should be made of silica, alumina, or the like to avoid blocking and enhance adhesion to the adhesive. Inorganic fillers such as magnesia, titanium oxide and barium sulfate may be added.

The thickness of the base material 11 constituting the decorative sheet 10 according to this embodiment is desirably in the range of 50 μm or more and 100 μm or less in consideration of printing workability, cost, and the like. Also, the thickness of the pattern layer 12 is desirably in the range of 1 μm or more and 5 μm or less. The thickness of the adhesive layer 13 is preferably in the range of 1 μm to 3 μm, and is preferably in the range of 1 μm to 2.5 μm in consideration of hydrolysis resistance, printing workability, and cost. More preferably, it is in the range of 1.5 μm or more and 2 μm or less. Moreover, it is desirable that the thickness of the transparent resin layer 14 is in the range of 70 μm to 100 μm. Moreover, it is desirable that the thickness of the surface protective layer 15 is in the range of 3 μm or more and 15 μm or less.
In addition, when the thickness of each layer is less than each lower limit mentioned above, the function (performance) of each layer may not be sufficiently obtained. In addition, when the thickness of each layer exceeds the upper limit value described above, the function (performance) of each layer does not improve so much, so it is preferable to set the thickness of each layer to the upper limit value or less from the viewpoint of manufacturing cost.

Moreover, when the primer layer 16 is provided, the thickness of the primer layer 16 is preferably in the range of 1 μm or more and 5 μm or less. If the thickness of the primer layer 16 is within the range of 1 μm or more and 5 μm or less, the function (performance) of the primer layer 16 can be reliably exhibited.
Also, the total thickness of the decorative sheet 10 is preferably within the range of 125 μm or more and 240 μm or less. If the total thickness of the decorative sheet 10 is within the range of 125 μm or more and 240 μm or less, the printing workability can be easily improved, and the manufacturing cost can be reduced.

The peel strength between the adhesive layer 13 and the transparent resin layer 14 in the decorative sheet 10 according to this embodiment is preferably 15 N/inch or more. If the peel strength between the adhesive layer 13 and the transparent resin layer 14 is 15 N/inch or more, it is possible to reliably prevent roll misalignment when the decorative sheet 10 is produced in a roll form.

Further, when the peel strength between the adhesive layer 13 and the transparent resin layer 14 after the weather resistance test is performed on the decorative sheet 10 is 10 N/inch or more, the decorative sheet is imparted with excellent weather resistance. Therefore, it is possible to deploy the decorative sheet 10 outdoors. At this time, the peel strength after the weather resistance test was performed with a super xenon tester (Atlas Weatherometer Ci4000 manufactured by Toyo Seiki Co., Ltd.) under the test conditions of 180 W light irradiation, 12 minutes rain / 120 minutes cycle, 24 hours. of peel strength.
In addition, the peel strength in this embodiment can be determined, for example, by the delamination test described below.

<Delamination test>
In the decorative sheet 10 with the adhesive layer 13 having a thickness of 10 μm, a test (interlaminar delamination test) is conducted to determine whether or not the adhesive layer 13 and the transparent resin layer 14 are peeled off.

After the cellophane tape made by Nichiban was crimped onto the surface of the decorative sheet 10, it was strongly peeled off with a certain force (for example, 5 N/inch, 10 N/inch, 15 N/inch, 20 N/inch) to form the adhesive layer 13 and the transparent resin layer 14. The presence or absence of peeling between and is evaluated with a microscope. In the present embodiment, the maximum force at which peeling does not occur between the adhesive layer 13 and the transparent resin layer 14 is defined as "peel strength".
The measurement of the peel strength in the present embodiment is not limited to the method described above. A test may be performed to measure (determine) the peel strength between the adhesive layer 13 and the transparent resin layer 14 .

(2) Manufacturing method of decorative sheet Hereinafter, an example of a manufacturing method of the decorative sheet 10 according to one embodiment of the present disclosure will be described.
First, a pattern layer 12 is formed with a thickness of 1 μm or more and 5 μm or less on a substrate 11 which is a polyolefin substrate having a thickness of 50 μm or more and 100 μm or less with a water-based colored ink.
Next, at least one polyether polyol selected from polyethylene ether glycol (PEG), polypropylene ether glycol (PPG), and polytetramethylene ether glycol (PTMG) is placed on the formed pattern layer 12 as a resin component. , containing at least one alkanediol having 8 or less carbon atoms, containing at least one polyisocyanate selected from hexamethylene diisocyanate (HDI) and isophorone diisocyanate (IPDI), and having a hydroxyl value of 10 mgKOH/g or more and 150 mgKOH/g or less The adhesive layer 13 is formed with a thickness of 1 μm or more and 3 μm or less, which is within the range and made of a polyether-based urethane resin containing an isocyanate curing agent as a cross-linking component.
Next, a transparent resin layer 14 mainly composed of polyolefin is formed on the adhesive layer 13 by extrusion molding with a thickness of 70 μm or more and 100 μm or less.
Finally, on the transparent resin layer 14, a surface protection layer 15 is formed with a film thickness of 3 μm or more and 15 μm or less using water-based ink containing urethane polymer as a main component.
Thus, the decorative sheet 10 according to this embodiment is manufactured.

After forming the pattern layer 12 and before forming the adhesive layer 13, the surface of the pattern layer 12 on the adhesive layer 13 side may be surface-treated so that the wetting index is 60 dyne or more. .
In addition, the colored ink used in the step of forming the pattern layer 12 may contain a binder resin. A primer layer 16 having a thickness of 1 μm or more and 5 μm or less may be formed using the same material as the binder resin.

EXAMPLES Hereinafter, the invention according to this embodiment will be described in detail by showing examples and comparative examples, but the invention according to this embodiment is not limited to the following examples.

<Example 1>
124 g of polyethylene ether glycol (PEG) having a number average molecular weight of 130 as a polyether polyol, 118.2 g of 1,6-hexanediol (6 carbon atoms) as an alkanediol, 189.2 g of dimethyl carbonate, and lithium hydroxide as a catalyst. The mixture was mixed and reacted at 150° C. for 12 hours under normal pressure while distilling off low boiling point components. Furthermore, under reduced pressure (0.1 to 6.7 kPa), the reaction was carried out at 150 to 170° C. for 6 hours while distilling off residual polyol to obtain a polyether polycarbonate diol (molecular weight: 1966) as an intermediate product.
20 g of the synthesized polyether polycarbonate diol, 4.6 g of 1,4-butanediol as a chain extender, and 12.8 g of isophorone diisocyanate (IPDI) as a polyisocyanate were mixed, and methyl ethyl ketone (MEK) was added so that the solid content was 30%. and reacted at 80° C. for 4 hours to obtain a methyl ethyl ketone solution (polyurethane emulsion) of polyether carbonate urethane resin.
The hydroxyl value of the polyether carbonate urethane resin thus obtained was 62.2 mgKOH/g.

A wood grain pattern is gravure-printed to a thickness of 3 μm using a two-component urethane ink (V180 manufactured by Toyo Ink Co., Ltd.) on a base material composed of a polyethylene raw fabric (thickness of 70 μm) with concealing properties, and a pattern layer is formed. formed.
An adhesive layer having a thickness of 10 μm was formed by applying the above-mentioned polyurethane emulsion and an isocyanate curing agent to the base material provided with the pattern layer. Through this adhesive layer, the pattern layer formation side surface of the substrate and the transparent polyolefin resin serving as the transparent resin layer were dry-laminated.
Finally, as a surface protective layer, an acrylic polyol (copolymer of methyl methacrylate and 2-hydroxy methacrylate) and a curing agent (hexamethylene diisocyanate nurate) were coated on the transparent polyolefin resin to form a layer having a thickness of 8 μm. A decorative sheet of Example 1 was obtained by forming a two-liquid curing polyurethane resin layer.

<Example 2>
In the same manner as in Example 1, except that the resin layer was formed using a polyether carbonate resin having a hydroxyl value of 12.2 mgKOH/g formed by changing the amount of isophorone diisocyanate (IPDI) mixed to 13.5 g. A decorative sheet of Example 2 was obtained.

<Example 3>
In the same manner as in Example 1, except that the resin layer was formed using a polyether carbonate resin having a hydroxyl value of 146.9 mgKOH/g formed by changing the amount of isophorone diisocyanate (IPDI) mixed to 11.7 g. A decorative sheet of Example 3 was obtained.

<Example 4>
The same as in Example 1 except that a resin layer was formed by adding a triazine-based ultraviolet absorber (BASF Tinuvin 479) and a NOR type light stabilizer (BASF Tinuvin 123) as a weather resistant agent to the polyether carbonate resin. A decorative sheet of Example 4 was obtained by the method of .

<Comparative Example 1>
202.3 g of 1,12-dodecanediol (8 carbon atoms) was used as the alkanediol instead of 1,6-hexanediol, and 12.1 g of isophorone diisocyanate (IPDI) was mixed with 1,4-butanediol. A decorative sheet of Comparative Example 1 was obtained in the same manner as in Example 1, except that the resin layer was formed using a polyether carbonate resin having a hydroxyl value of 71.4 mgKOH/g, which was formed by changing the amount to 4.4 g. rice field.

<Comparative Example 2>
A comparison was made in the same manner as in Example 1 except that the resin layer was formed using a polyether carbonate resin having a hydroxyl value of 4.5 mgKOH/g formed by changing the amount of isophorone diisocyanate (IPDI) mixed to 13.6 g. A decorative sheet of Example 2 was obtained.

<Comparative Example 3>
In the same manner as in Example 1 except that a resin layer was formed using a polyether carbonate resin having a hydroxyl value of 177.7 mgKOH/g formed by changing the amount of isophorone diisocyanate (IPDI) mixed to 11.3 g, comparison was performed. A decorative sheet of Example 3 was obtained.

<Comparative Example 4>
A decorative sheet of Comparative Example 4 was obtained in the same manner as in Example 1, except that an epoxy crosslinking agent was used as the crosslinking agent instead of the isocyanate curing agent.

[evaluation]
The decorative sheets obtained in each of the examples and comparative examples described above were evaluated by measuring the initial peel strength and the peel strength after the weather resistance test by the following methods.

(Initial peeling test)
In the decorative sheets of each example and each comparative example having an adhesive layer with a thickness of 10 μm, a test (delamination test) was conducted to determine whether or not the adhesive layer and the transparent resin layer were peeled off.

After the cellophane tape made by Nichiban was pressure-bonded to the surface of the decorative sheet, the cellophane tape was strongly peeled off with a force increased by 1 N/inch from 1 N/inch to 20 N/inch, and the adhesive layer and the transparent resin layer were separated. The presence or absence of peeling was evaluated under a microscope.
In this evaluation, the maximum force at which peeling did not occur between the adhesive layer and the transparent resin layer was defined as "initial peel strength (N/inch)".

(Peel test after weather resistance test)
The decorative sheets of each example and each comparative example were subjected to a 24-hour weather resistance test using a super xenon tester (Atlas Weatherometer Ci4000 manufactured by Toyo Seiki Co., Ltd.) under test conditions of 180 W light irradiation, 12-minute rain/120-minute cycle, The test was conducted under the same conditions as the initial peel test described above, and the peel strength after the weather resistance test was evaluated.

[Evaluation criteria]
Initial peel test ○: Peel strength is 15 N / inch or more △: Peel strength is 10 N / inch or more and less than 15 N / inch ×: Peel strength is less than 10 N / inch Peel test after weathering test ◎: Peel strength is 0 from the initial peel strength % to 10% ○: Peel strength decreased from 10% to 20% from the initial peel strength △: Peel strength decreased from 20% to 40% from the initial peel strength ×: Peel strength decreased from the initial peel strength by 40% or more In this example, if both the "initial peel strength" and the "peeling strength after the weather resistance test" were evaluated to be "O" or higher, they were considered to be acceptable.
Table 1 below shows the evaluation results.

As shown in Table 1, it contains polyethylene ether glycol (PEG), 1,6-hexanediol, which is an alkanediol having 8 or less carbon atoms, and isophorone diisocyanate (IPDI), and has a hydroxyl value of 10 mgKOH/g or more and 150 mgKOH. / g or less, and the decorative sheets of Examples 1 to 4, which had an adhesive layer made of a polyether carbonate-based urethane resin containing an isocyanate curing agent as a cross-linking component, both before and after the weather resistance test. The peel strength between the transparent resin layer was high.

On the other hand, the decorative sheet of Comparative Example 1, which has an adhesive layer composed of a polyether carbonate-based urethane resin containing 1,12-dodecanediol, which is an alkanediol having 8 or less carbon atoms, has a peel strength after the weather resistance test. It was lower than the decorative sheet of each example.
Further, the decorative sheets of Comparative Examples 2 and 3, which have an adhesive layer composed of a polyether carbonate-based urethane resin having a hydroxyl value outside the range of 10 mgKOH/g or more and 150 mgKOH/g or less, had a peel strength after the weather resistance test of It was lower than the decorative sheets of each example and comparative example 1.
Furthermore, the decorative sheet of Comparative Example 4 having an adhesive layer containing an epoxy cross-linking agent as a cross-linking agent also had lower peel strength after the weather resistance test than the decorative sheets of each of Examples and Comparative Example 1.

From the above, the adhesive layer contains a predetermined polyether polyol, an alkanediol having 8 or less carbon atoms, and a predetermined polyisocyanate, the hydroxyl value is in the range of 10 mgKOH / g or more and 150 mgKOH / g or less, and the cross-linking component It was confirmed that the decorative sheet having an adhesive layer composed of a polyether carbonate-based urethane resin containing an isocyanate curing agent as the adhesive layer is less likely to cause delamination.

Although the embodiments of the present disclosure have been exemplified above, it goes without saying that the present disclosure is not limited to the above-described embodiments. Also, it is optional to use a combination of the above-described embodiments.

INDUSTRIAL APPLICABILITY The present disclosure can be used as a decorative sheet that requires durability against high temperature and high humidity, such as building exteriors and bathrooms, and can also be used as an indoor sheet such as a surface material for fittings and a floor material.

REFERENCE SIGNS LIST 10 Decorative sheet 11 Base material 12 Pattern layer 13 Adhesive layer 14 Transparent resin layer 15 Surface protective layer 16 Primer layer

Claims (6)

A base material, a pattern layer, an adhesive layer, a transparent resin layer containing polyolefin as a main component, and a surface protective layer are laminated in this order,
The adhesive layer is composed of a polyether carbonate-based urethane resin,
The polyether carbonate-based urethane resin is
At least one polyether polyol selected from polyethylene ether glycol (PEG), polypropylene ether glycol (PPG), and polytetramethylene ether glycol (PTMG) as a resin component,
containing at least one alkanediol having 8 or less carbon atoms,
At least one polyisocyanate selected from hexamethylene diisocyanate (HDI) and isophorone diisocyanate (IPDI),
The hydroxyl value is within the range of 10 mgKOH/g or more and 150 mgKOH/g or less,
A decorative sheet containing an isocyanate curing agent as a cross-linking component. 2. The decorative sheet according to claim 1, wherein the adhesive layer contains, as weather resistance agents, an ultraviolet absorber having a triazine skeleton and a light stabilizer having a NOR type skeleton. The film thickness of the base material is in the range of 50 μm or more and 100 μm or less,
The film thickness of the pattern layer is in the range of 1 μm or more and 5 μm or less,
The film thickness of the adhesive layer is in the range of 1 μm or more and 3 μm or less,
The film thickness of the transparent resin layer is in the range of 70 μm or more and 100 μm or less,
3. The decorative sheet according to claim 1, wherein the thickness of the surface protective layer is in the range of 3 [mu]m to 15 [mu]m. 4. The decorative sheet according to any one of claims 1 to 3, wherein the surface protective layer is formed of a resin containing urethane polymer as a main component. 5. The decorative sheet according to any one of claims 1 to 4, wherein the surface protective layer contains, as weather resistance agents, an ultraviolet absorber having a triazine skeleton and a light stabilizer having a NOR-type skeleton. further comprising a primer layer formed on the back surface of the base material, which is the surface opposite to the pattern layer side surface;
The pattern layer is formed of colored ink containing a binder resin,
The decorative sheet according to any one of claims 1 to 5, wherein the primer layer is made of the same component as the binder resin contained in the colored ink for forming the pattern layer.

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