WO2018008719A1

WO2018008719A1 - Decorative sheet base material and decorative sheet

Info

Publication number: WO2018008719A1
Application number: PCT/JP2017/024786
Authority: WO
Inventors: 真志服部; 恵柏女; 達彦古田; 宮本　慎一
Original assignee: 凸版印刷株式会社
Priority date: 2016-07-07
Filing date: 2017-07-06
Publication date: 2018-01-11
Also published as: JP6950690B2; JPWO2018008719A1

Abstract

High incombustibility and durability are realized in this decorative sheet base material and this decorative sheet. The decorative sheet is formed from: a decorative sheet base material comprising a layered stretch film provided with a surface layer that contains a non-crystalline thermoplastic resin having a degree of crystallization equal to or lower than 10%, and a layer that is different from the surface layer and that contains a crystalline thermoplastic resin having a degree of crystallization of 40%-80%; and one or more transparent resin layers containing a polyolefin-based resin and being formed on the surface of the surface layer side of the decorative sheet base material. At least one of the surface layer and the layer different from the surface layer preferably includes a polyolefin-based resin, and particularly the polyolefin-based resin is preferably polypropylene. The surface layer preferably contains, as the polyolefin-based resin, a polypropylene in which the meso pentad fraction is not lower than 30% but lower than 50%.

Description

Base material for decorative sheet and decorative sheet

The present invention relates to a base material for a decorative sheet and a decorative sheet used for building interior materials, surface materials for fittings, surface materials for home appliances, and the like.

For decorative sheets used on the surface of building interior materials and fittings, especially for decorative sheets used for public use, the non-combustible materials described in Building Standard Law Enforcement Ordinance Article 108-2 No. 1 and No. 2 It is required to meet technical standards. Conventionally, as a decorative sheet satisfying the technical standard of such a noncombustible material, one using a soft polyvinyl chloride resin has been used. However, a decorative sheet using a soft polyvinyl chloride resin has a problem in that toxic gas is generated during incineration after disposal.

For this reason, a decorative sheet using a polyolefin resin instead of the polyvinyl chloride resin has been proposed. However, when polyolefin resin is used, the generation of toxic gases during combustion is suppressed, but because polyolefin resin has excellent flammability, technical standards for nonflammable materials It was difficult to satisfy.
A decorative sheet using a polyolefin resin that satisfies the technical standards of non-combustible materials described in the above-mentioned laws and regulations is disclosed in

Patent Documents

1 and 2 shown below.

Patent Documents

1 and 2 disclose structures using a polyolefin-based resin layer containing an inorganic filler such as calcium carbonate.

JP 2013-010931 A JP 2011-122293 A

As a method for obtaining a decorative sheet made of a polyolefin-based resin that satisfies the technical standards for non-combustible materials as described above, for example, there is a method of thinning the base material of the decorative sheet. Moreover, in order to give design properties to the decorative sheet, it is essential to provide a printing layer on the surface of the base material. Here, when the substrate is put into the printing machine, the substrate is required to have a sufficient mechanical strength in order to suppress the occurrence of displacement of the printing position.

From the above, by subjecting the base material for the decorative sheet to uniaxial stretching or biaxial stretching, the base material can be thinned to increase nonflammability, and at the same time, the base material can be mechanically strengthened. Has been done.
However, by stretching the base material, crystallization of the resin constituting the base material proceeds, and the generation of voids, crazes, and cracks is promoted by the difference in density between the crystal part and the amorphous part. In particular, if there are cracks in the substrate, the substrate is easily damaged. This is a problem in obtaining a highly durable decorative sheet.
The present invention has been made paying attention to the above points, and an object thereof is to obtain a decorative sheet base material and decorative sheet having high incombustibility and durability.

In order to solve the above-described problems, a decorative sheet base material according to an embodiment of the present invention includes a surface layer that includes an amorphous thermoplastic resin and the degree of crystallinity of the thermoplastic resin is 10% or less; And a layer different from the surface layer in which the degree of crystallinity of the thermoplastic resin is 40% or more and less than 80%.
Further, another decorative sheet base material according to one embodiment of the present invention includes a non-crystalline thermoplastic resin, a surface layer having a crystallization temperature of 40 ° C. or more and 90 ° C. or less, a crystal A laminated stretched film comprising a layer different from the surface layer, wherein the thermoplastic resin has a crystallization temperature of 100 ° C. or more and 170 ° C. or less.
Moreover, the decorative sheet according to one embodiment of the present invention is a single-layer or multiple-layer transparent resin layer including the above-described decorative sheet base material and a polyolefin-based resin formed on the surface layer side surface of the decorative sheet base material. And.

According to one embodiment of the present invention, a decorative sheet base material and decorative sheet having high incombustibility and durability can be obtained.

It is sectional drawing which shows one structural example of the decorative sheet which concerns on embodiment of this invention.

Next, embodiments according to the present invention will be described with reference to the drawings.
Here, the configuration shown in FIG. 1 below is schematic, and the relationship between the thickness and the planar dimensions, the ratio of the thickness of each layer, and the like are different from the actual ones. Further, the embodiment described below exemplifies a configuration for embodying the technical idea of the present invention, and the technical idea of the present invention is that the material, shape, structure, etc. of the component parts are as follows. It is not something specific. The technical idea of the present invention can be variously modified within the technical scope defined by the claims described in the claims.

“First Embodiment”
First, a first embodiment based on the present invention will be described.
(Constitution)
FIG. 1 is a cross-sectional view illustrating a configuration of a decorative sheet 1 according to the present embodiment. The decorative sheet 1 includes a decorative sheet base material 6 (hereinafter also referred to as a base material 6) containing a thermoplastic resin, a printed layer 5, an adhesive layer 4, and a transparent layer provided on one surface of the base material 6. The resin layer 3 and the surface protective layer 2 are provided. Further, the decorative sheet 1 includes a concealing layer 7 and a primer layer 8 provided on the other surface of the substrate 6.
Here, the substrate 6 includes at least a first substrate layer (hereinafter referred to as a surface layer) 6-1 and second substrate layers 6-2 to n-th different from the surface layer 6-1. And at least one of the base material layers 6-n. That is, the substrate 6 is formed of a surface layer 6-1 and n layers from the second substrate layer 6-2 to the n-th substrate layer 6-n (n is an arbitrary number). Yes.

The printing layer 5, the adhesive layer 4, the transparent resin layer 3, and the surface protective layer 2 described above are provided in this order on the surface layer 6-1 that is one surface of the substrate 6. Further, the concealing layer 7 and the primer layer 8 described above are provided in this order on the other surface of the substrate 6 (the surface of the substrate 6 opposite to the surface layer 6-1). That is, when the substrate 6 includes the surface layer 6-1 and the second substrate layer 6-2, the second substrate layer 6-2 becomes the other surface of the substrate 6.
The concealing layer 7 may be formed between the base material 6 and the printing layer 5 or may be omitted. In particular, in this embodiment, since an inorganic pigment is mixed in the base material 6 as will be described later, there is no problem in design even if the masking layer 7 is omitted. When suppressing the pigment mixed with the base material 6, it is preferable to provide the concealing layer 7 as needed.

The thickness of the decorative sheet 1 is preferably in the range of 49 μm to 360 μm, for example. When the thickness of the decorative sheet 1 is within this range, the printing workability at the time of manufacturing the decorative sheet 1 is improved and the manufacturing cost can be suppressed.
Such a decorative sheet 1 constitutes a decorative board by affixing the surface on the primer layer 8 side to a base plate (not shown) such as a wood base.
Hereinafter, each part of the decorative sheet 1 will be described in detail.

<Base material>
The base material 6 is a laminated stretched film that has been thinned by uniaxial stretching or biaxial stretching from the viewpoint of nonflammability. The thickness of the substrate 6 is preferably 20 μm or more and 60 μm or less, and more preferably 20 μm or more and 40 μm or less. When the thickness of the base material 6 is in the range of 20 μm or more and 60 μm or less, both the nonflammability and the mechanical properties (strength) of the decorative sheet 1 can be achieved. Moreover, since the nonflammability improves further when the thickness of the base material 6 is the range of 20 micrometers or more and 40 micrometers or less, it is more preferable.
The base material 6 is formed of a resin material, and includes a thermoplastic resin as a main component of the resin material. The main component means, for example, a resin material contained in 70 parts by mass or more and 100 parts by mass or less, preferably 90 parts by mass or more and 100 parts by mass or less, with 100 parts by mass of the resin material constituting the substrate 6.

(Crystallinity of substrate)
The surface layer 6-1 of the substrate 6 contains an amorphous thermoplastic resin. The crystallinity of the amorphous thermoplastic resin contained in the surface layer 6-1 is 10% or less, and preferably 5% or less. When the crystallinity of the thermoplastic resin contained in the surface layer 6-1 is 10% or less, the oriented crystallization of the thermoplastic resin by the stretching of the resin film that is the precursor of the surface layer 6-1 has not progressed too much. Therefore, the interlayer adhesion between the surface layer 6-1 and the second base material layer 6-2 or the transparent resin layer 3 is suitable.

On the other hand, if the crystallinity of the thermoplastic resin contained in the surface layer 6-1 exceeds 10%, the surface layer 6-1 is likely to crack due to orientation crystallization of the thermoplastic resin. Interlayer adhesion between 1 and the second base material layer or the transparent resin layer 3 is lowered.
The second base layer 6-2 to n-th base layer 6-n, which are different from the surface layer 6-1, contain a crystalline thermoplastic resin. The crystallinity of the crystalline thermoplastic resin contained in the second base layer 6-2 to the n-th base layer 6-n is 40% or more and less than 80%. When the crystallization degree of the thermoplastic resin contained in the second base material layer 6-2 to the n-th base material layer 6-n is 40% or more and less than 80%, oriented crystallization is in progress. The strength of the substrate 6 is improved.

On the other hand, when the crystallinity of the thermoplastic resin contained in the second base material layer 6-2 to the n-th base material layer 6-n is less than 40%, the strength of the base material 6 cannot be sufficiently obtained. Further, when the crystallinity of the thermoplastic resin contained in the second base material layer 6-2 to the n-th base material layer 6-n is 80% or more, the base material 6 becomes brittle and sufficiently torn. Strength cannot be obtained. Alternatively, when the crystallinity of the thermoplastic resin included in the second base material layer 6-2 to the nth base material layer 6-n exceeds 80%, the crystallinity is saturated in many resins. Therefore, it becomes difficult to form the second base material layer 6-2 to the nth base material layer 6-n.

(Resin materials and soft materials)
At least one layer constituting the substrate 6, that is, at least one of the surface layer 6-1 and a layer different from the surface layer 6-1 (second substrate layer 6-2 to n-th substrate layer 6-n). The two layers preferably include a polyolefin resin. Examples of the polyolefin resin include polyethylene, polypropylene, polybutene and the like, as well as α-olefins (for example, propylene, 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 Or the like, or ethylene / vinyl acetate copolymer, ethylene / vinyl alcohol copolymer, ethylene / methyl methacrylate copolymer, ethylene / ethyl methacrylate copolymer, ethylene / vinyl methacrylate copolymer, Copolymerized ethylene or α-olefin with other monomers such as butyl methacrylate copolymer, ethylene / methyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / butyl acrylate copolymer Is mentioned. In particular, from the viewpoint of price and processability, it is preferable to select and use at least one of polyethylene and polypropylene as the polyolefin resin. Moreover, when aiming at the improvement of the tensile elasticity modulus of the base material 6, it is preferable to use a highly crystalline polypropylene.

Further, the surface layer 6-1 may contain a resin material having low crystallinity as a soft material. For the surface layer 6-1, for example, a polyolefin resin having a mesopentad fraction of 30% or more and less than 50% is preferably used as a soft material. Specifically, it is particularly preferable to use a low crystalline polypropylene resin having a mesopentad fraction of 30% or more and less than 50% as the soft material.

When the surface layer 6-1 includes a soft material, the surface layer 6-1 includes 5 parts by mass or more and 30 parts by mass of the soft material with respect to 100 parts by mass of the main component resin (base resin) constituting the surface layer 6-1. Preferably, it is formed of a mixed resin mixed with less than a part. When the mixing amount of the soft material is less than 5 parts by mass, the soft effect due to the mixing of the soft material hardly appears. Further, when the mixing amount of the soft material is 30 parts by mass or more, the soft effect due to the mixing of the soft material appears, but the sticking of the surface layer 6-1 becomes a problem due to the heat treatment at the time of stretching the base material 6. There is.
Further, from the viewpoint of uniformity of the resin material forming the surface layer 6-1, the soft material is preferably a material having high compatibility with the resin material forming the surface layer 6-1. From such a viewpoint, for example, when the surface layer 6-1 is made of polypropylene resin, it is desirable that the soft material to be mixed is also polypropylene resin.

(Inorganic pigment)
At least one layer constituting the substrate 6, that is, at least one of the surface layer 6-1 and a layer different from the surface layer 6-1 (second substrate layer 6-2 to n-th substrate layer 6-n). The two layers preferably contain an inorganic pigment. By containing an inorganic pigment, the light transmittance of the base material 6 can be lowered so that the pattern of the base material plate cannot be transmitted.
The mixing amount of the inorganic pigment is 5 vol% or more and 50 vol% or less with respect to the resin material in each of the surface layer 6-1 and the second base layer 6-2 to the n-th base layer 6-n. It is preferable. When the mixing amount of the inorganic pigment is 5 vol% or more and 50 vol% or less, the effect of improving the incombustibility due to the addition of the inorganic pigment is exhibited, and the embrittlement of the base material 6 due to the excessive addition of the inorganic pigment is suppressed. This is because it can.

Although it does not specifically limit as an inorganic pigment contained in the at least 1 layer which comprises the base material 6, For example, a natural inorganic pigment and a synthetic inorganic pigment are mentioned.
Examples of natural inorganic pigments include earth-based pigments, calcined soils, and mineral pigments. Examples of the synthetic inorganic pigment include oxide pigments, hydroxide pigments, sulfide pigments, silicate pigments, phosphate pigments, carbonate pigments, metal powder pigments, and carbon pigments. Moreover, you may use the mixed pigment which mixed the 1 type (s) or 2 or more types from the natural inorganic pigment and the synthetic inorganic pigment.
In addition, it is not preferable to use an organic pigment as the pigment. This is because the incombustibility of the substrate 6 is impaired.

The substrate 6 preferably has a light transmittance of 40% or less in order to obtain the concealability required from the viewpoint of the design properties of the decorative sheet 1. When the light transmittance exceeds 40%, sufficient concealing property for obtaining the design of the decorative sheet 1 cannot be obtained. If sufficient concealability is not obtained, for example, in a decorative board in which the surface of the decorative sheet 1 on the side of the primer layer 8 is attached to a base plate such as a wooden base, the primer layer 8 such as a wooden base is opposed. It means that the surface pattern is visible from the surface protective layer 2 side through the decorative sheet 1. In this case, the pattern of the printing layer 5 and the pattern of the base plate such as the wood base may overlap and be visually recognized.

<Print layer>
The print layer 5 is a layer in which a pattern for imparting design properties is formed. The printing layer 5 can be provided using a known printing method. When the substrate 6 can be prepared in a wound state, printing for forming the printing layer 5 can be performed by a roll-to-roll printing apparatus. The printing method is not particularly limited, but for example, a gravure printing method can be used in consideration of productivity and picture quality.

An arbitrary pattern may be adopted as the design pattern in consideration of the design properties according to the place of use such as flooring or wall material. For example, when obtaining the decorative sheet 1 having a wooden pattern, various types of grain patterns are often used for the pattern, and a cork pattern may be used in addition to the grain pattern. In addition, when obtaining the decorative sheet 1 in the image of a stone floor such as marble, marble stones or the like are used for the pattern. In addition to the pattern patterns of natural materials, an artificial pattern such as an artificial pattern or a geometric pattern using them as a motif is used as the pattern pattern of the printing layer 5.
The printing ink used for forming the printing layer 5 is not particularly limited, but an ink corresponding to the printing method is appropriately selected. In particular, it is preferable to select a printing ink in consideration of adhesion to the substrate 6 and printability, weather resistance of the decorative sheet 1, and the like.

To the printing ink, a colorant such as a pigment or a dye, an extender pigment, a solvent, and a binder, which are contained in a normal ink, are appropriately added. Examples of the pigment include pearl pigments such as condensed azo, insoluble azo, quinacridone, isoindoline, anthraquinone, imidazolone, cobalt, phthalocyanine, carbon, titanium oxide, iron oxide, and mica. The binder may be water-based, solvent-based, or emulsion type, and the curing method is particularly limited, such as a one-component type, a two-component type consisting of a main agent and a curing agent, or a type that is cured by ultraviolet rays or electron beams. Not what you want. Among them, the most common method is a two-component type, which uses a urethane-based main agent and a curing agent made of isocyanate. In addition, the design may be applied by vapor deposition or sputtering of various metals.
The thickness of the printing layer 5 is preferably 3 μm or more and 20 μm or less. When the thickness of the printing layer 5 is within this range, the printing can be clarified, the printing workability at the time of manufacturing the decorative sheet 1 can be improved, and the manufacturing cost can be suppressed.

<Adhesive layer>
The adhesive layer 4 is provided for the purpose of strengthening the adhesion between the substrate 6 and the printed layer 5 and the transparent resin layer 3. By virtue of the strong adhesion between the substrate 6 and the printed layer 5 and the transparent resin layer 3, the decorative sheet 1 can be given bending workability that follows a curved surface or a right angle surface. The adhesive layer 4 is preferably transparent.

The adhesive layer 4 is formed of, for example, an acrylic adhesive, a polyester adhesive, a polyurethane adhesive, an epoxy adhesive, or the like. As the adhesive constituting the adhesive layer 4, it is usually preferable to use a urethane-based material obtained by a reaction with a polyol using an isocyanate as a two-component curing type because of its cohesive strength. Note that the adhesive layer 4 may be omitted when the adhesive strength between the transparent resin layer 3 and the printed layer 5 is sufficiently obtained.
An arbitrary method can be selected as a method for bonding the base material 6 and the printed layer 5 through the adhesive layer 4 and the transparent resin layer 3. For example, a lamination method such as heat lamination, extrusion lamination, dry lamination, or the like can be used. Can be mentioned.
The thickness of the adhesive layer 4 is preferably 1 μm or more and 20 μm or less. When the thickness of the adhesive layer 4 is within this range, the adhesive strength between the base material 6 and the printing layer 5 and the transparent resin layer 3 is improved, and the printing workability during the production of the decorative sheet 1 is improved, And manufacturing cost can be controlled.

<Transparent resin layer>
The transparent resin layer 3 is made of, for example, a transparent resin sheet, and is bonded to the base material 6 and the printing layer 5 with an adhesive layer 4. In the decorative sheet 1 shown in FIG. 1, the case where the transparent resin layer 3 is a single layer is illustrated, but a plurality of transparent resin layers 3 may be laminated. The transparent resin layer 3 of the present embodiment is preferably configured with a polyolefin resin as a main component. The main component means, for example, a resin material included in 70 parts by mass or more and 100 parts by mass or less, preferably 90 parts by mass or more and 100 parts by mass or less, with 100 parts by mass of the resin material constituting the transparent resin layer 3.

Examples of polyolefin resins constituting the transparent resin layer 3 include α-olefins (eg, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, in addition to polypropylene, polyethylene, polybutene, and the like. 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.) or a copolymer of two or more types, ethylene / vinyl acetate copolymer, ethylene / vinyl alcohol copolymer, ethylene / methyl methacrylate copolymer, ethylene / ethyl methacrylate copolymer Polymers, ethylene / butyl methacrylate copolymer, ethylene / methyl acrylate copolymer, ethylene / ethyl acrylate copolymer, ethylene / butyl acrylate copolymer, etc. Copolymerized one is mentioned. Moreover, when improving the surface strength of the decorative sheet 1, it is preferable to use highly crystalline polypropylene.
The thickness of the transparent resin layer 3 is preferably 20 μm or more and 200 μm or less. When the thickness of the transparent resin layer 3 is within this range, the strength of the decorative sheet 1 is improved, the printing workability at the time of manufacturing the decorative sheet 1 is improved, and the manufacturing cost can be suppressed.

<Surface protective layer>
The surface protective layer 2 is provided on the outermost surface of the decorative sheet 1 and has a function of protecting the surface and adjusting gloss. Examples of the material constituting the surface protective layer 2 include polyurethane resins, acrylic silicon resins, fluorine resins, epoxy resins, vinyl resins, polyester resins, melamine resins, aminoalkyd resins, urea resins, and the like. Can be mentioned. The form of the resin material is not particularly limited, such as aqueous, emulsion, solvent type. The curing method can be appropriately selected from a one-component type, a two-component type, an ultraviolet curing method, and the like.

In particular, as a resin material that is a main component of the surface protective layer 2, urethane resins using isocyanate are suitable from the viewpoints of workability, cost, cohesive strength of the resin itself, and the like. Isocyanates include tolylene diisocyanate (TDI), xylylene diisocyanate (XDI), hexamethylene diisocyanate (HMDI), diphenylmethane diisocyanate (MDI), lysine diisocyanate (LDI), isophorone diisocyanate (IPDI), methylhexane diisocyanate (HTDI), It can be appropriately selected from methylcyclohexanone diisocyanate (HXDI), trimethylhexamethylene diisocyanate (TMDI), and the like. Among these, from the viewpoint of weather resistance, hexamethylene diisocyanate (HMDI) having a linear molecular structure is suitable as the isocyanate. In addition to this, in order to improve the surface hardness, it is preferable to use a resin curable with active energy rays such as ultraviolet rays and electron beams. These resins can be used in combination with each other. For example, by using a hybrid type of a thermosetting type and a photocurable type, it is possible to improve surface hardness, suppress curing shrinkage, and improve adhesion. You can plan.
The thickness of the surface protective layer 2 is preferably 3 μm or more and 20 μm or less. When the thickness of the surface protective layer 2 is within this range, it is possible to protect the surface of the decorative sheet 1 and to provide sufficient gloss, to improve the printing workability when manufacturing the decorative sheet 1, and to reduce the manufacturing cost. Can be suppressed.

<Concealment layer>
The concealing layer 7 is formed for the purpose of maintaining concealment with respect to the base plate in the decorative plate in which the surface on the primer layer 8 side of the decorative sheet 1 is attached to a base plate such as a wooden base. The concealing layer 7 is formed, for example, by ink printing in the same manner as the printing layer 5. As the pigment to be included in the ink, it is preferable to use an opaque pigment, titanium oxide, iron oxide or the like. In addition, in order to improve the concealment of the pattern of the base plate such as the wood base to which the decorative sheet 1 is attached in the concealing layer 7, a metal such as gold, silver, copper, and aluminum can be added to the ink. In general, it is preferable to add flaky aluminum. As described above, the masking layer 7 is used when any layer of the substrate 6 (for example, the surface layer 6-1 or the second substrate layer 6-2) is opaque and has a masking property. Can be omitted.
The thickness of the masking layer 7 is preferably 2 μm or more and 20 μm or less. When the thickness of the concealment layer 7 is within this range, the concealability with respect to the base plate can be maintained, the printing workability during the production of the decorative sheet 1 can be improved, and the production cost can be suppressed.

<Primer layer>
The primer layer 8 is provided to improve the adhesion between the decorative sheet 1 and the base plate in the decorative plate in which the surface on the primer layer 8 side of the decorative sheet 1 is attached to the base plate.
The primer layer 8 can basically use the same material (printing ink) as the printing layer 5. Among these, in consideration of performing winding in a web shape for being applied to the back surface of the decorative sheet 1, an inorganic filler such as silica, alumina, magnesia, titanium oxide, barium sulfate or the like is added to the printing ink. It is preferable. Thereby, generation | occurrence | production of the blocking at the time of winding 1 decorative sheet can be avoided, and adhesion | attachment with an adhesive agent can be improved.

When the base plate is a wood base, the primer layer 8 is, for example, an ester resin, a urethane resin, an acrylic resin, a polycarbonate resin, a vinyl chloride-vinyl acetate copolymer, a polyvinyl butyral resin, a nitro resin, It is preferably formed of a resin material such as a cellulose resin. These resin materials can be used alone or mixed to form an adhesive composition, which can be formed using an appropriate application means such as a roll coating method or a gravure printing method. In this case, it is preferable to use a urethane-acrylate resin as the resin material constituting the primer layer 8. That is, it is particularly preferable to form the resin made of a copolymer of an acrylic resin and a urethane resin and an isocyanate.
The thickness of the primer layer 8 is preferably 0.1 μm or more and 20 μm or less. When the thickness of the primer layer 8 is within this range, the adhesion between the decorative sheet 1 and the base plate is improved, the printing workability when manufacturing the decorative sheet 1 is improved, and the manufacturing cost is reduced. Can be suppressed.

(Action and others)
By applying uniaxial stretching or biaxial stretching to the base material for the decorative sheet, it is possible to make the base material into a thin film and enhance nonflammability. And the decorative sheet 1 which concerns on this embodiment is improving the nonflammability by using the base material 6 formed by extending | stretching and thinning a resin film. This incombustibility is preferably configured so as to satisfy the provisions of Article 108-2 No. 1 and No. 2 of the Building Standard Law Enforcement Ordinance. In the present embodiment, it is possible to configure so as to satisfy the provisions of No. 108-2, No. 1 and No. 2 of the Building Standards Law Enforcement Ordinance as will be described later.

Conventionally, by stretching the base material, crystallization of the resin constituting the base material progresses, and voids, crazes, and cracks are generated due to the difference in density between the crystal part and the amorphous part. Could be promoted. In particular, if there is a crack in the base material, the base material is easily damaged in an interlayer adhesion test between the transparent resin layer formed on the base material via a printing layer and the base material. Such improvement of the interlaminar adhesion test force has been a problem in obtaining a highly durable decorative sheet.

On the other hand, the decorative sheet 1 according to the present embodiment suppresses the orientation crystallization of the surface layer of the base material when the resin film is stretched, so that the generation of the density difference between the crystal part and the amorphous part and The occurrence of voids, crazes and cracks associated therewith is suppressed. For this reason, the interlayer adhesiveness of a base material and a transparent resin layer improves, and the mechanical strength of a decorative sheet can be improved.
Thus, in this embodiment, the base material 6 and the decorative sheet 1 for a decorative sheet having durability can be provided while the base material can be thinned to increase nonflammability.

“Second Embodiment”
Next, a second embodiment will be described with reference to the drawings.
In the second embodiment, the same components as those in the first embodiment will be described with the same reference numerals.
(Constitution)
The laminated structure of the decorative sheet of the second embodiment will be described in the case of the same laminated structure as that of the first embodiment as shown in FIG. A decorative sheet 1 according to this embodiment includes a base material for a decorative sheet (hereinafter referred to as a base material) 6 containing a thermoplastic resin, a printed layer 5 provided on one surface of the base material 6, and an adhesive layer. 4, and a transparent resin layer 3 and a surface protective layer 2. Further, the decorative sheet 1 includes a concealing layer 7 and a primer layer 8 provided on the other surface of the substrate 6.
The substrate 6 includes at least a first substrate layer (hereinafter referred to as a surface layer) 6-1 and second substrate layers 6-2 to n-th substrate layers different from the surface layer 6-1. 6-n. That is, the substrate 6 is formed of a surface layer 6-1 and n layers from the second substrate layer 6-2 to the n-th substrate layer 6-n (n is an arbitrary number). Yes.

The basic configuration of the second embodiment is the same as that of the first embodiment. However, the configuration of the surface layer 6-1 and a layer different from the surface layer 6-1 (second substrate layer 6-2 to n-th substrate layer 6-n), that is, the configuration of the substrate 6, Different from the first embodiment.
For this reason, in the following description, the structure of the base material 6 different from that of the first embodiment, that is, the surface layer 6-1 and the layer different from the surface layer 6-1 (from the second base material layer 6-2 to the n-th material). The configuration of the base material layer 6-n) will be described, and description of other configurations that are the same as those of the first embodiment will be omitted.

<Base material>
The base material 6 is a laminated stretched film that has been thinned by uniaxial stretching or biaxial stretching from the viewpoint of nonflammability. The thickness of the substrate 6 is preferably 20 μm or more and 60 μm or less, and more preferably 20 μm or more and 40 μm or less. When the thickness of the base material 6 is in the range of 20 μm or more and 60 μm or less, both the nonflammability and the mechanical properties (strength) of the decorative sheet 1 can be achieved. Moreover, since the nonflammability improves further when the thickness of the base material 6 is the range of 20 micrometers or more and 40 micrometers or less, it is more preferable.
The thicknesses of the surface layer 6-1 and the second base material layer 6-2 to the n-th base material layer 6-n constituting the base material 6 are 25 μm or less.
The base material 6 is formed of a resin material, and includes a thermoplastic resin as a main component of the resin material. The main component means, for example, a resin material contained in 70 parts by mass or more and 100 parts by mass or less, preferably 90 parts by mass or more and 100 parts by mass or less, with 100 parts by mass of the resin material constituting the substrate 6.

(Base material crystallization temperature)
The surface layer 6-1 of the substrate 6 contains an amorphous thermoplastic resin. The crystallization temperature of the amorphous thermoplastic resin contained in the surface layer 6-1 is 40 ° C. or higher and 90 ° C. or lower. The crystallization temperature of the non-crystalline thermoplastic resin constituting the surface layer 6-1 is the crystalline thermoplasticity contained in the second base material layer 6-2 to the n-th base material layer 6-n. It is preferably different from the crystallization temperature of the resin, and more preferably has a temperature difference of 20 ° C. or more. This suppresses the progress of the orientation crystallization of the surface layer 6-1 when the second base layer 6-2 is stretched at a temperature that promotes the orientation crystallization of the nth substrate layer 6-n. can do. For this reason, generation | occurrence | production of the crack in the base material 6 and the fall of tearing strength can be suppressed.

The second base layer 6-2 to the n-th base layer 6-n different from the surface layer 6-1 contain a crystalline thermoplastic resin. The crystallization temperature of the crystalline thermoplastic resin contained in the second base material layer 6-2 to the n-th base material layer 6-n is 100 ° C. or higher and 170 ° C. or lower. As described above, the crystallization temperature of the crystalline thermoplastic resin contained in the second base material layer 6-2 to the n-th base material layer 6-n is the non-crystallinity constituting the surface layer 6-1. It is preferably different from the crystallization temperature of the thermoplastic resin, and more preferably has a temperature difference of 20 ° C. or more.

Here, “crystallization temperature” refers to the temperature at which oriented crystallization proceeds most in the resin layer stretching step. When the temperature at the time of stretching the resin layer is different from the orientation crystallization temperature, orientation crystallization is suppressed. The crystallization temperature can be confirmed by evaluating the orientation and crystallinity of the stretched film processed while changing the temperature during stretching by means of X-ray diffraction (XRD) or Raman spectroscopy. it can. The crystallization temperature is the same value as the crystal dispersion temperature.

Further, a layer different from the surface layer 6-1 (second base material layer 6-2 to n-th base material layer 6-n) may contain a resin material having low crystallinity as a soft material. The layer different from the surface layer 6-1 is preferably made of, for example, a polyolefin resin having a mesopentad fraction of 30% or more and less than 50% as a soft material. Specifically, it is particularly preferable to use a low crystalline polypropylene resin having a mesopentad fraction of 30% or more and less than 50% as the soft material.

For example, when the second base material layer 6-2 includes a soft material, the second base material layer 6-2 includes 100 masses of the main component resin (base resin) constituting the second base material layer 6-2. Preferably, the soft material is formed of a mixed resin in which 5 parts by mass or more and less than 30 parts by mass are mixed with respect to the part. When the mixing amount of the soft material is less than 5 parts by mass, the soft effect due to the mixing of the soft material hardly appears. Further, when the mixing amount of the soft material is 30 parts by mass or more, the soft effect due to the mixing of the soft material appears, but the sticking of the surface layer 6-1 becomes a problem due to the heat treatment at the time of stretching the base material 6. There is. The same applies to a layer different from the other surface layer 6-1.
Further, from the viewpoint of uniformity of the resin material forming the second base material layer 6-2, the soft material is a material having high compatibility with the resin material forming the second base material layer 6-2. Is preferred. From such a viewpoint, for example, when the second base material layer 6-2 is made of polypropylene resin, it is desirable that the soft material to be mixed is also polypropylene resin. The same applies to a layer different from the other surface layer 6-1.

(Action and others)
By applying uniaxial stretching or biaxial stretching to the base material for the decorative sheet, it is possible to make the base material into a thin film and enhance nonflammability. And the decorative sheet 1 which concerns on this embodiment has improved the nonflammability by using the base material formed by extending | stretching and thinning a resin film. This incombustibility is preferably configured so as to satisfy the provisions of Article 108-2 No. 1 and No. 2 of the Building Standard Law Enforcement Ordinance. In the present embodiment, it is possible to configure so as to satisfy the provisions of No. 108-2, No. 1 and No. 2 of the Building Standards Law Enforcement Ordinance as will be described later.

Further, conventionally, by subjecting a base material made of polyolefin resin to uniaxial stretching, oriented crystallization proceeds, and the strength of the stretched base material is improved. Due to the difference in density, the occurrence of voids, crazes and cracks may be promoted. In particular, if there is a crack in the base material, the base material tends to tear along the stretching direction. For this reason, improvement of tear strength has been a problem in obtaining a highly durable decorative sheet.

On the other hand, the decorative sheet 1 according to the present embodiment suppresses the orientation crystallization of the surface layer of the base material when the resin film is stretched, so that the generation of the density difference between the crystal part and the amorphous part and The occurrence of voids, crazes and cracks associated therewith is suppressed. For this reason, the interlayer adhesiveness of the base material 6 and the transparent resin layer 3 is improved, and the mechanical strength of the decorative sheet can be improved by improving the tear strength.
Thus, in this embodiment, the base material 6 and the decorative sheet 1 for a decorative sheet having durability can be provided while the base material can be thinned to increase nonflammability.

Hereinafter, the decorative sheet based on this invention is demonstrated concretely by an Example.
“First Example”
First, the first embodiment will be described.
<Sample 1-1>
A decorative sheet of Sample 1-1 was formed by the following steps.
(Process for forming resin sheet for transparent resin layer)
First, a resin material is prepared by adding a hindered phenol-based antioxidant, a benzotriazole-based ultraviolet absorber, and a hindered amine-based light stabilizer to a highly crystalline homopolypropylene resin. Here, as the highly crystalline homopolypropylene resin, the mesopentad fraction is 97.8%, the MFR (melt flow rate) is 15 g / 10 min (230 ° C.), and the molecular weight distribution MWD (Mw / Mn) is 2.3. Material used. Further, a hindered phenol-based antioxidant (Irganox 1010: manufactured by BASF) was added at 500 PPM to the highly crystalline homopolypropylene resin. A benzotriazole-based ultraviolet absorber (Tinuvin 328: manufactured by BASF) was added at 2000 PPM to a highly crystalline homopolypropylene resin. A hindered amine light stabilizer (Kimasorb 944: manufactured by BASF) was added at 2000 PPM to the highly crystalline homopolypropylene resin. Such a resin material was extruded using a melt extruder to form a transparent resin sheet made of a highly crystalline polypropylene having a thickness of 80 μm and used as a transparent resin layer.
Subsequently, both sides of the obtained transparent resin sheet were subjected to corona treatment, and the wet tension on the surface of the transparent resin sheet was set to 40 dyn / cm or more.

(Base material forming process)
A base material on which two layers of a surface layer and a second base material layer were laminated was formed by forming a film by an extrusion method and stretching.
A layer serving as a precursor of the first surface layer was formed with a thickness of 60 μm using a resin material A (low density polyethylene) to which an inorganic pigment was added. Subsequently, a resin material E (homopolypropylene) to which an inorganic pigment is added is used as a second base material layer precursor on the first surface layer precursor layer. And a thickness of 60 μm. As a result, a laminated resin precursor having a total thickness of two layers of 120 μm was formed.
Subsequently, the laminated resin precursor was stretched 4 times by a uniaxial stretching method to form a base material having a thickness of 30 μm (a surface layer thickness of 15 μm and a second base material layer thickness of 15 μm).

The crystallinity of the surface layer and the second substrate layer at this time was measured using XRD (X-Ray Diffraction). In XRD, the crystal part volume, the crystal part area, and the amorphous part volume were measured, and the crystallinity was calculated based on the following formula (1). The metastable state portion of polypropylene was treated as an amorphous part.
Crystallinity [%] = Crystal part volume / (Crystal part area + Amorphous part volume) × 100 (1)
The crystallinity in the surface layer of the decorative sheet of Sample 1-1 was 2%, and the crystallinity in the second base material layer was 58%.

(Printing layer and primer layer forming step)
On the surface layer of the substrate, pattern printing was performed by a gravure printing method to form a printed layer. The printing layer is a two-component urethane ink (V180; manufactured by Toyo Ink Manufacturing Co., Ltd.), and 0.5% by mass of a hindered amine light stabilizer (Kimasorb 944; manufactured by BASF) based on the binder resin content of the ink. Formed with added ink.
Moreover, the primer layer was formed in the back surface of the 2nd base material layer of a base material. The primer layer was formed by printing the same two-component urethane ink as the printing layer by a gravure printing method.

(Transparent resin layer forming process)
Subsequently, an adhesive for dry lamination (Takelac A540; manufactured by Mitsui Chemicals, Inc .; application amount 2 g / m ² ) was applied as an adhesive layer to the front surface (printing layer forming surface) of the substrate. Then, the transparent resin layer was formed by bonding a transparent resin sheet to the front surface of a base material through the adhesive layer by the dry lamination method. The surface of the transparent resin layer was embossed.
(Surface protection layer forming process)
A two-component curable urethane topcoat (W184; manufactured by DIC Graphics Co., Ltd.) was applied to the surface of the transparent resin layer having an embossed pattern at a coating thickness of 6 g / m ² and dried to form a surface protective layer. .
Thereby, a decorative sheet having a total thickness of 120 μm was obtained.

<Sample 1-2>
A decorative sheet was formed in the same manner as Sample 1-1, except that the surface layer was formed of resin material B (random polypropylene). Note that the degree of crystallinity in the surface layer of the decorative sheet of Sample 1-2 was 7%, and the degree of crystallinity in the second base material layer was 64%.
<Sample 1-3>
A decorative sheet is formed in the same manner as in Sample 1-1, except that the surface layer is formed of resin material C (mixed resin of 100 parts by weight of random polypropylene and 100 parts by weight of low crystalline polypropylene (mesopentad fraction: 30%)). did. The crystallinity in the surface layer of the decorative sheet of Sample 1-3 was 5%, and the crystallinity in the second base material layer was 63%.
<Sample 1-4>
A decorative sheet was formed in the same manner as Sample 1-1, except that the surface layer was formed of resin material D (mixed resin of 100 parts by weight of random polypropylene and 20 parts by weight of low crystalline polypropylene (mesopentad fraction 30%)). did. The crystallinity in the surface layer of the decorative sheet of Sample 1-4 was 3%, and the crystallinity in the second base material layer was 59%.

<Sample 1-5>
A decorative sheet was formed in the same manner as in Sample 1-1, except that the surface layer and the second base material layer were formed without including a pigment. Note that the crystallinity of the surface layer of the decorative sheet of Sample 1-5 was 2%, and the crystallinity of the second base material layer was 58%.
<Sample 1-6>
A decorative sheet was formed in the same manner as in Sample 1-1 except that the thickness of the surface layer after stretching was set to 30 μm and a base material without a second base material layer was used. The crystallinity of the surface layer of the decorative sheet of Sample 1-6 was 4%.
<Sample 1-7>
Sample 1-1, except that the surface layer was formed using resin material B (random polypropylene) so that the thickness after stretching was 30 μm, and a base material without a second base material layer was used. A decorative sheet was formed in the same manner. The crystallinity in the surface layer of the decorative sheet of Sample 1-7 was 9%.

<Sample 1-8>
A decorative sheet was formed in the same manner as in Sample 1-1 except that the thickness of the second base material layer after stretching was 30 μm and a base material without a surface layer was used. The crystallinity of the second base material layer of the decorative sheet of Sample 1-8 was 57%.
<Sample 1-9>
A decorative sheet was formed in the same manner as Sample 1-1 except that the second base material layer was formed to a thickness of 30 μm without stretching and a base material without a surface layer was used. The crystallinity of the second base material layer of the decorative sheet of Sample 1-9 was 61%.
<Sample 1-10>
A decorative sheet was formed in the same manner as in Sample 1-1 except that the second base material layer was formed to a thickness of 70 μm without stretching and a base material without a surface layer was used. Note that the degree of crystallinity in the second base material layer of the decorative sheet of Sample 1-10 was 63%.

<Performance evaluation of decorative sheet>
The performance of each sample decorative sheet was evaluated.
[Tensile modulus]
The elastic sheet was measured by pulling the decorative sheet of each sample with a Tensilon universal material testing machine at 50 mm / min.
The evaluation of the elastic modulus is as follows.
A: Very good (elastic modulus 800 MPa or more)
○: Good (elastic modulus 500 MPa or more and less than 800 MPa)
X: Defect (elastic modulus less than 500 MPa)

[Nonflammability test]
Using the decorative sheet of each sample, a heat generation test was conducted using a cone calorimeter tester in accordance with ISO5660-1. Nonflammability was judged by whether or not the provisions of Article 108-2 No. 1 and No. 2 of the Building Standards Law Enforcement Ordinance were satisfied.
The evaluation is as follows.
○: Good (within standard)
×: Defect (non-standard)
[Interlayer adhesion test]
The interlayer adhesion test is a test for evaluating the adhesion between the transparent resin layer and the substrate. The interlayer adhesion test was performed according to JIS K 6854-2 using the decorative sheet of each sample.
[Transparency test]
The transparency test is a test for evaluating the design of the decorative sheet. In the transparency test, the transmittance of the decorative sheet of each sample was measured by a spectrophotometer and evaluated.
Table 1 below shows the results of each evaluation.

As shown in Table 1, a surface layer containing an amorphous thermoplastic resin having a crystallinity of 10% or less, and a second group containing a crystalline thermoplastic resin having a crystallinity of 40% or more and less than 80% The decorative sheets of Sample 1-1 to Sample 1-5 having the material layer were excellent in elastic modulus, nonflammability, and interlayer adhesion.
In addition, the decorative sheets of Sample 1-1 to Sample 1-4 containing the pigment in the surface layer and the second base material layer are decorative sheets of Sample 1-5 that do not contain the pigment in the surface layer and the second base material layer. Compared with, the light transmittance was low and the hiding property was excellent.

In contrast, the decorative sheets of Sample 1-6 and Sample 1-7, in which the base material does not have the second base material layer, did not have sufficient elastic modulus. From this result, in order to improve the intensity | strength of a decorative sheet, it turned out that it has to have the base material provided with the 2nd base material layer which consists of resin material with high crystallinity. In addition, the decorative sheet of Sample 1-8 in which the base material did not have a surface layer did not have sufficient interlayer adhesion. From this result, in order to improve the interlayer adhesion of the decorative sheet, it was found that it was necessary to have a substrate provided with a surface layer made of a thermoplastic resin in which orientation crystallization did not progress too much.

In addition, the decorative sheets of Sample 1-9 and Sample 1-10, in which the base material does not have a surface layer and the second base material layer is not stretched, do not stretch, so the interlayer adhesion is not It was enough. However, the decorative sheet of Sample 1-9 in which the film thickness of the second base material layer was 30 μm did not have sufficient elastic modulus. In addition, the decorative sheet of Sample 1-10 in which the film thickness of the second base material layer is 70 μm has a sufficient elastic modulus because the film thickness of the second base material layer is thicker than the decorative sheet of Sample 1-9. Although there was, the nonflammability decreased. From this result, it was found that, when stretching (thinning) was not performed in order to compensate for a decrease in interlayer adhesion due to stretching, it was difficult to achieve both the strength and nonflammability of the decorative sheet.

From the above results, a surface layer containing an amorphous thermoplastic resin having a crystallinity of 10% or less and a second base material layer containing a crystalline thermoplastic resin having a crystallinity of 40% or more and less than 80% The decorative sheet having the above was excellent in elastic modulus, nonflammability and interlayer adhesion. Moreover, it turned out that a low light transmittance (high concealment property) is further acquired by the surface layer and the 2nd base material layer containing an inorganic pigment.

"Second Example"
Next, a second embodiment will be described.
<Sample 2-1>
A decorative sheet of Sample 2-1 was formed by the following steps.
(Process for forming resin sheet for transparent resin layer)
First, a resin material is prepared by adding a hindered phenol-based antioxidant, a benzotriazole-based ultraviolet absorber, and a hindered amine-based light stabilizer to a highly crystalline homopolypropylene resin. Here, as the highly crystalline homopolypropylene resin, the mesopentad fraction is 97.8%, the MFR (melt flow rate) is 15 g / 10 min (230 ° C.), and the molecular weight distribution MWD (Mw / Mn) is 2.3. Material used. Further, a hindered phenol-based antioxidant (Irganox 1010: manufactured by BASF) was added at 500 PPM to the highly crystalline homopolypropylene resin. A benzotriazole-based ultraviolet absorber (Tinuvin 328: manufactured by BASF) was added at 2000 PPM to a highly crystalline homopolypropylene resin. A hindered amine light stabilizer (Kimasorb 944: manufactured by BASF) was added at 2000 PPM to the highly crystalline homopolypropylene resin. Such a resin material was extruded using a melt extruder to form a transparent resin sheet made of a highly crystalline polypropylene having a thickness of 80 μm and used as a transparent resin layer.
Subsequently, both sides of the obtained transparent resin sheet were subjected to corona treatment, and the wet tension on the surface of the transparent resin sheet was set to 40 dyn / cm or more.

(Base material forming process)
A base material on which three layers of a surface layer, a second base material layer, and a third base material layer were laminated was formed by forming and stretching by an extrusion method.
A layer serving as a precursor of the first surface layer was formed with a thickness of 40 μm from resin material A (low density polypropylene, crystallization temperature 70 ° C.) to which an inorganic pigment was added. Subsequently, on the layer that becomes the precursor of the first surface layer, the layer that becomes the precursor of the second base layer of the second layer is resin material D (homopolypropylene, crystallized) to which an inorganic pigment is added. And a thickness of 40 μm. Furthermore, a resin material D (homopolypropylene) in which an inorganic pigment is added to a layer that is a precursor of the third base material layer on the layer that is a precursor of the second base material layer of the second layer. And a crystallization temperature of 120 ° C.). As a result, a laminated resin precursor having a total thickness of three layers of 120 μm was formed. The difference between the crystallization temperature of the surface layer of the decorative sheet of Sample 2-1 and the crystallization temperature of the second and third base material layers was 50 ° C.
Subsequently, the laminated resin precursor is stretched 4 times by a uniaxial stretching method, whereby a 30 μm-thick base material (the surface layer, the second base material layer, and the third base material layer each have a thickness of 10 μm). ) Was formed. The stretching temperature was 120 ° C. and uniaxial stretching was performed.

(Printing layer and primer layer forming step)
On the surface layer of the substrate, pattern printing was performed by a gravure printing method to form a printed layer. The printing layer is a two-component urethane ink (V180; manufactured by Toyo Ink Manufacturing Co., Ltd.), and 0.5% by mass of a hindered amine light stabilizer (Kimasorb 944; manufactured by BASF) based on the binder resin content of the ink. Formed with added ink.
Moreover, the primer layer was formed in the back surface of the 3rd base material layer of a base material. The primer layer was formed by printing the same two-component urethane ink as the printing layer by a gravure printing method.

<Sample 2-2>
A decorative sheet was formed in the same manner as in Sample 2-1, except that the surface layer was formed of resin material B (random polypropylene, crystallization temperature 80 ° C.). The difference between the crystallization temperature of the surface layer of the decorative sheet of Sample 2-2 and the crystallization temperature of the second and third base material layers was 40 ° C.
<Sample 2-3>
Same as Sample 2-1, except that the surface layer was formed of resin material C (mixed resin of 100 parts by weight of random polypropylene and 20 parts by weight of low crystalline polypropylene (mesopentad fraction 30%), crystallization temperature 90 ° C.) Thus, a decorative sheet was formed. The difference between the crystallization temperature of the surface layer of the decorative sheet of Sample 2-3 and the crystallization temperature of the second and third base material layers was 30 ° C.

<Sample 2-4>
A decorative sheet was formed in the same manner as in Sample 2-1, except that the surface layer, the second substrate layer, and the third substrate layer were formed without including a pigment. The difference between the crystallization temperature of the surface layer of the decorative sheet of Sample 2-4 and the crystallization temperature of the second and third base material layers was 50 ° C.
<Sample 2-5>
A decorative sheet was formed in the same manner as in Sample 2-1, except that the thickness of each of the stretched second base material layer and third base material layer was 30 μm and a base material without a surface layer was used. .
<Sample 2-6>
A decorative sheet was formed in the same manner as in Sample 2-1, except that the thickness of the surface layer after stretching was 30 μm and a base material without the second base material layer and the third base material layer was used.

<Sample 2-7>
The surface layer was formed using the resin material B (random polypropylene) so that the thickness after stretching was 30 μm, and a base material on which the second base material layer and the third base material layer were not provided was used. Except for this, a decorative sheet was formed in the same manner as in Sample 2-1.
<Sample 2-8>
A decorative sheet in the same manner as in Sample 2-1, except that the second base material layer and the third base material layer were formed with a thickness of 30 μm without stretching and a base material without a surface layer was used. Formed.
<Sample 2-9>
The surface layer is formed with a thickness of 70 μm without stretching using the resin material B (random polypropylene), and a substrate that does not provide the second substrate layer and the third substrate layer is used. A decorative sheet was formed in the same manner as Sample 2-1.

[Nonflammability test]
Using the decorative sheet of each sample, a heat generation test was conducted using a cone calorimeter tester in accordance with ISO5660-1. Nonflammability was judged by whether or not the provisions of Article 108-2 No. 1 and No. 2 of the Building Standards Law Enforcement Ordinance were satisfied.
The evaluation is as follows.
○: Good (within standard)
×: Defect (non-standard)

[Tear strength test]
The tear strength test is a test for evaluating the tear strength of a substrate by the Elmendorf method. The tear strength test was performed according to JIS K 7128-2 using the decorative sheet of each sample.
The evaluation is as follows.
○: Good ×: Bad [Transparency test]
The transparency test is a test for evaluating the design of the decorative sheet. In the transparency test, the transmittance of the decorative sheet of each sample was measured by a spectrophotometer and evaluated.
Table 2 below shows the results of each evaluation.

As shown in Table 2, a surface layer containing an amorphous thermoplastic resin and having a crystallization temperature of 40 ° C. or more and 90 ° C. or less, and crystallization of the thermoplastic resin containing a crystalline thermoplastic resin The decorative sheets of Sample 2-1 to Sample 2-4 having a layer different from the surface layer having a temperature of 100 ° C. or higher and 170 ° C. or lower were excellent in elastic modulus, nonflammability, and tear strength.
In addition, the decorative sheets of Sample 2-1 to Sample 2-3 containing pigments in the surface layer, the second base material layer, and the third base material layer are the surface layer, the second base material layer, and the third base material layer. Compared with the decorative sheet of Sample 2-4 in which no pigment was contained in the material layer, the light transmittance was low and the hiding property was excellent.

On the other hand, the decorative sheet of Sample 2-5 in which the base material did not have a surface layer had a poor tear strength, although it had a sufficient elastic modulus. From this result, in order to improve the tear strength of the decorative sheet, a base material provided with a surface layer containing a non-crystalline thermoplastic resin and having a crystallization temperature of the thermoplastic resin of 40 ° C. or higher and 90 ° C. or lower is provided. I found it necessary to have. In addition, the decorative sheets of Sample 2-6 and Sample 2-7 in which the base material does not have the second base material layer and the third base material layer do not have sufficient elastic modulus even if the resin material is changed. It was. From this result, in order to improve the elastic modulus of the decorative sheet, a layer different from the surface layer containing a crystalline thermoplastic resin and having a crystallization temperature of the thermoplastic resin of 100 ° C. or more and 170 ° C. or less was provided. It has been found necessary to have a substrate.

In addition, the decorative sheet of Sample 2-8, in which the base material does not have a surface layer and the second base material layer and the third base material layer are not stretched, has an elastic modulus because it is not stretched. Was not enough. From this result, in order to improve the elastic modulus of the decorative sheet, it was found that it was necessary to have a stretched substrate. Furthermore, the decorative sheet of Sample 2-9, in which the base material does not have the second base material layer and the third base material layer, and the surface layer is not stretched, has a surface layer thickness of 70 μm. As a result, a sufficient elastic modulus was obtained, but the nonflammability decreased. From this result, in order to improve the elastic modulus of the decorative sheet, it was found that it was necessary to have a stretched substrate. From this result, it was found that when stretching (thinning) was not performed, it was difficult to achieve both the strength and nonflammability of the decorative sheet.

From the above results, a surface layer containing an amorphous thermoplastic resin having a crystallization temperature of 40 ° C. or more and 90 ° C. or less, and a surface containing a crystalline thermoplastic resin having a crystallization temperature of 100 ° C. or more and 170 ° C. or less. The decorative sheet having a layer different from the layer was excellent in elastic modulus, nonflammability and tear strength. Moreover, it turned out that a low light transmittance (high concealment property) is further obtained by the surface layer, the 2nd base material layer, and the 3rd base material layer containing an inorganic pigment.

Although the present invention has been described above by the embodiments, the scope of the present invention is not limited to the illustrated and described exemplary embodiments, and brings about effects equivalent to those intended by the present invention. All embodiments are also included. Furthermore, the scope of the invention is not limited to the combinations of features of the invention defined by the claims, but can be defined by any desired combination of specific features among all the disclosed features.
In addition, the entire contents of Japanese Patent Application No. 2016-135084 (filed on July 7, 2016) and Japanese Patent Application No. 2016-135085 (filed on July 7, 2016), to which the present application claims priority, Part of this disclosure by reference.

DESCRIPTION OF SYMBOLS 1 Decorative sheet 2 Surface protective layer 3 Transparent resin layer 4 Adhesive layer 5 Print layer 6 Base material 7 Hiding layer 8 Primer layer

Claims

A surface layer containing a non-crystalline thermoplastic resin, the crystallinity of the thermoplastic resin being 10% or less,
A layer different from the surface layer containing a crystalline thermoplastic resin, the crystallinity of the thermoplastic resin being 40% or more and less than 80%,
A decorative sheet base material comprising a laminated stretched film.
A surface layer containing a non-crystalline thermoplastic resin, wherein the crystallization temperature of the thermoplastic resin is 40 ° C. or higher and 90 ° C. or lower;
A layer different from the surface layer, comprising a crystalline thermoplastic resin, wherein the crystallization temperature of the thermoplastic resin is 100 ° C. or higher and 170 ° C. or lower;
A decorative sheet base material comprising a laminated stretched film.
3. The decorative sheet base material according to claim 1, wherein at least one of the surface layer and the layer different from the surface layer contains a polyolefin-based resin.
The base material for decorative sheets according to claim 3, wherein the polyolefin resin is polypropylene.
The decorative sheet base material according to claim 1, wherein the surface layer includes a polyolefin resin, and the polyolefin resin includes polypropylene having a mesopentad fraction of 30% or more and less than 50%.
The surface layer is formed of a mixed resin in which the polypropylene having a mesopentad fraction of 30% or more and less than 50% is mixed with 5 parts by mass or more and less than 30 parts by mass with respect to 100 parts by mass of the base resin. The base material for decorative sheets as described in 2.
The crystallization temperature of the non-crystalline thermoplastic resin constituting the surface layer has a temperature difference of 20 ° C. or more with the crystallization temperature of the crystalline thermoplastic resin constituting the layer different from the surface layer. The base material for decorative sheets of Claim 2 characterized by the above-mentioned.
The decorative sheet base material according to claim 7, wherein the layer different from the surface layer includes a polyolefin resin, and the polyolefin resin includes polypropylene having a mesopentad fraction of 30% or more and less than 50%.
At least one of the surface layer and the layer different from the surface layer contains an inorganic pigment, and the inorganic pigment is contained in the layer containing the inorganic pigment in an amount of 5 vol% to 50 vol% with respect to the thermoplastic resin. The base material for a decorative sheet according to any one of claims 1 to 8.
In the exothermic test with a cone calorimeter tester conforming to ISO5660-1 in a state where the decorative sheet using the base material for decorative sheet is bonded to a non-combustible base material, Article 108-2 of the Building Standards Act Enforcement Ordinance The decorative sheet base material according to any one of claims 1 to 9, wherein the decorative sheet base material is a non-combustible material satisfying the requirements described in the first and second items.
A decorative sheet base material according to any one of claims 1 to 10, and a single layer or a plurality of layers containing a polyolefin-based resin formed on a surface layer side surface of the decorative sheet base material. A decorative sheet comprising a transparent resin layer.