JP2005212384A - Decorative sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a decorative sheet excellent in fire retardancy or spread-of-fire preventing properties, enhanced in mechanical strength and stability, having high surface strength and capable of achieving the enhancement of a design effect without requiring a primer or the like at the time of lap bonding. <P>SOLUTION: The decorative sheet is composed of a sheetlike formed product having a multilayered structure and the pressure-sensitive adhesive layer laminated thereon. The sheetlike formed product has a layer comprising a polyolefin resin having transparency comprising an ethylene/vinyl alcohol copolymer and a layer comprising a thermoplastic resin composition. A transparent layer is provided on the surface on the side opposite to the side on which the pressure-sensitive adhesive layer is provided and the thermoplastic resin composition contains 0.1-100 pts.wt. of a laminar silicate and 0.1-70 pts.wt. of a metal hydroxide with respect to 100 pts.wt. of a thermoplastic resin. Two decorative sheets are used and, when the pressure-sensitive adhesive layer is applied to the surface of the layer comprising a polyolefinic resin having transparency of the decorative sheet to which one of them is laminated, peel strength is 1.5 kg/25 mm or more. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

The present invention is excellent in flame retardancy and fire spread prevention, expresses excellent flame retardancy and fire spread prevention effect due to shape retention effect during combustion, and has the same design as a decorative sheet made of a conventional vinyl chloride resin. Further, the present invention relates to a decorative sheet that is excellent in overlayability.

In general, the decorative sheet is required to have flame retardancy for the purpose of preventing the spread of fire through the decorative sheet in a fire in addition to the concealability and workability of the base material. For this reason, conventionally, a decorative sheet made of a soft polyvinyl chloride resin has been used.

However, polyvinyl chloride resin tends to be avoided as a raw material due to waste disposal such as incineration and problems of environmental hormones, etc., and so-called environmentally adaptable materials such as polyolefin resin that does not contain halogen atoms can be converted. It is being considered. In the field of decorative sheets as well, for example, Patent Document 1 and Patent Document 2 disclose decorative sheets made of polyolefin resin in order to switch to an environment-adaptive material with a low environmental load during combustion. However, the polyolefin resin is one of the most flammable resins, and it has been difficult to achieve high flame retardancy.

As a method for making a polyolefin resin flame-retardant, a method of kneading a large amount of a flame retardant into the resin is known. Among flame retardants, if a flame retardant comprising a halogen-containing compound is used, the effect of flame retardancy is high, and the deterioration of moldability and the mechanical strength of the resulting sheet-like molded product are relatively small. When a flame retardant comprising the above is used, a large amount of halogen-based gas may be generated during molding or combustion, and the generated halogen-based gas may corrode equipment or may have an undesirable effect on the human body. Therefore, so-called non-halogen flame retardant technology that does not use a halogen-containing compound is strongly desired from the viewpoint of safety.

Non-halogen flame retardant technologies for polyolefin resins include, for example, Patent Document 3 and Patent Document 4, which are metal compounds such as aluminum hydroxide, magnesium hydroxide, and basic magnesium carbonate that do not generate toxic gas during combustion. A method of adding is disclosed. However, in order to impart sufficient flame retardancy to the flammable polyolefin resin, it is necessary to add a large amount of a metal compound. As a result, the mechanical strength (particularly stretchability, tearing) of the obtained molded body is required. There is a problem that it is difficult to put it into practical use, for example, it is difficult to form into a film or sheet. In addition, even if metal hydroxide is added to the polyolefin-based resin, a coating layer is not formed during combustion, brittle ash is exposed, and the residue falls off. The fire spread due to deformation of the material cannot be stopped.

Other non-halogen flame retardant technologies for polyolefin resins include, for example, adding phosphorus flame retardants to polyolefin resins, forming a coating on the surface during combustion, and utilizing the oxygen barrier effect of this combustion coating A method for developing flame retardancy has been proposed. In this case as well, there are problems similar to the addition of the metal compound, and it is difficult to form a strong coating layer as a continuous layer although it forms a coating locally, and the mechanical strength of the coating is very weak. There was a problem that the function as a heat insulating layer was lost early.

Further, for example, Patent Document 5 discloses a resin composition in which red phosphorus or a phosphorus compound and expandable graphite are added to a polyolefin resin. However, although this resin composition has sufficient flame retardancy when viewed from the oxygen index, it can actually form a film only locally and the mechanical strength of the film is very weak. It cannot be expected to function as a heat insulating layer. Furthermore, since graphite is added, it cannot be used as a decorative sheet.

As a flame retardant method using non-halogen or non-phosphorus, for example, Patent Document 6 discloses a method of blending flat talc. However, this method also requires that a large amount of flat talc of 80 to 130 parts by weight is added to 100 parts by weight of the polyolefin resin in order to impart sufficient flame retardancy to the polyolefin resin. However, there is a problem that it is difficult to ensure flexibility and elongation, which are important physical properties.

In addition, the decorative sheet needs to be provided with a transparent layer on the printed layer for the purpose of protecting the printed layer or improving the glossiness of the entire decorative sheet. It is required to have flammability. However, when a transparent layer is formed by using a conventional flame retardant method, the transparency of the transparent layer is impaired, causing problems such as the printed layer pattern appearing blurred, and the decorative sheet. Since the overall designability deteriorated, it could not be put to practical use.

In addition, when constructing a decorative sheet using the above-mentioned environmentally friendly resin composition, it has been difficult to impart flexibility as in the conventional soft polyvinyl chloride resin-based decorative sheet. When using a polyolefin-based resin that does not contain halogen, which is a representative example of an environmentally-friendly resin composition, whitening due to necking is noticeable when the decorative sheet is folded during construction on curved surfaces and sharp edges. There was a drawback that it was not put to practical use. Furthermore, in the flame retarding technique including a metal hydroxide mentioned as a conventional flame retarding technique for a decorative sheet using these resin compositions, whitening due to necking (a phenomenon in which the stretched portion becomes white) Practical problems such as being conspicuous, limiting the construction site and site, and excessive construction load (cautious construction is required, which increases the number of construction steps) were considered.

  On the other hand, regarding the workability of the decorative sheet, when two or more decorative sheets are continuously applied in parallel, the appearance of the decorative sheet changes due to changes in the dimensions of the decorative sheet over time (especially two decorative sheets). There is a case where it is applied by overlapping several 10 millimeters in fear of occurrence of an appearance defect called “opening” or “open space” in which the base is exposed from between the sheets. In addition to the primer for base treatment, the primer for the lip is usually applied to the surface of the decorative sheet on the base side, and then the upper decorative sheet is applied (attached) to the part where the decorative sheets overlap. The construction method which prevents that a base | substrate is exposed by peeling of the unexpected sheet | seat is performed.

However, after applying the base treatment and applying the decorative sheet on one side, applying the primer for the mouth again and then applying the decorative sheet after drying it is time consuming to dry the primer. In addition, there are many constructions that do not take the overlapped part because the element that becomes a problem in appearance due to the primer sticking out of the overlapping part and drying, and the finished appearance may be damaged.
JP-A-8-3380 JP-A-8-1897 JP-A-57-165437 JP-A-61-36343 JP-A-6-25476 JP-A-6-41371

In view of the above situation, the present invention is excellent in flame retardancy and fire spread prevention, expresses excellent flame retardancy and fire spread prevention effect due to shape retention effect during combustion, mechanical strength and stability, necking and sink marks Furthermore, the present invention has an object to provide a decorative sheet that has high designability as well as a decorative sheet made of a conventional vinyl chloride resin and that is excellent in overlayability.

The present invention includes a transparent polyolefin-based resin layer composed of an ethylene-vinyl alcohol copolymer having a vinyl alcohol copolymer ratio of 50 to 90 mol%, 0.1 to 100 parts by weight of layered silicate with respect to 100 parts by weight of a thermoplastic resin, and A decorative sheet in which a pressure-sensitive adhesive layer is laminated on the decorative substrate layer side of a decorative sheet substrate comprising a decorative substrate layer containing 0.1 to 70 parts by weight of a metal hydroxide, The present invention relates to a decorative sheet characterized in that the 180-degree peel strength according to JIS Z 0237 on the back surface is 15 N / 25 mm or more, whereby the above-mentioned problems are solved.
The present invention is described in detail below.

The decorative sheet of the present invention comprises a decorative sheet base material and a pressure-sensitive adhesive layer laminated thereon, and the decorative sheet base material has at least a transparent polyolefin resin layer and a decorative base material layer. A system resin layer exists in the surface on the opposite side to the side by which the said adhesive layer was laminated | stacked.

The transparent polyolefin resin layer in the decorative sheet of the present invention is made of an ethylene-vinyl alcohol copolymer. An ethylene-vinyl alcohol copolymer is preferable because it exhibits excellent flame retardancy, transparency, flexibility, and the like. The ethylene-vinyl alcohol copolymer is only required to have excellent transparency and relatively high flame retardancy, but the composition ratio between the ethylene component and the vinyl alcohol component is good in terms of workability and texture. In view of this, the copolymerization ratio of vinyl alcohol is 50 to 90 mol%. When the vinyl alcohol copolymerization ratio is less than 50 mol%, it becomes difficult to obtain sufficient adhesive properties at the time of overlapping and sheet molding becomes difficult. On the contrary, when it exceeds 90 mol%, it becomes difficult to obtain strength and elongation. A more preferable vinyl alcohol copolymerization ratio is 55 mol% or more, and a preferable upper limit is 80 mol%. Sufficient elongation is necessary to flexibly cope with dimensional changes of the base material and curved surface construction.

The thickness of the transparent polyolefin resin layer is preferably 15 to 70 μm. If it is less than 15 μm, the function of protecting the surface of the decorative substrate layer and the printed layer that may be applied to the surface may be insufficient, and if it exceeds 70 μm, the curved surface workability is insufficient. Sometimes. A more preferable lower limit is 20 μm, and a more preferable upper limit is 50 μm.

The tensile strength at 2% elongation of the transparent polyolefin resin layer is preferably 3 to 40 N / 10 mm. If it is less than 3 N / 10 mm, the resulting decorative sheet of the present invention will be low, causing problems such as air biting, resulting in insufficient curved surface workability. If it exceeds 40 N / 10 mm, makeup This is because the physical properties of the sheet are lowered, and the texture as a decorative sheet may be impaired.

In consideration of practicality as a decorative sheet, it is preferable that a layer made of a polyolefin-based resin having transparency is blended with an ultraviolet absorber in order to impart weather resistance. As a compounding quantity of a ultraviolet absorber, 0.1-5 weight part is preferable with respect to 100 weight part of ethylene-vinyl alcohol copolymers. If it is less than 0.1 part by weight, practical weather resistance cannot be obtained, and even if it exceeds 5 parts by weight, the effect is saturated and there is a risk of bleeding out, further increasing the cost. Although the said ultraviolet absorber will not be specifically limited if it can be obtained for polyolefin resin, A triazine type ultraviolet absorber is especially suitable.

The transparent polyolefin-based resin layer has a nucleating agent that can be a crystal nucleus for refining crystals as an auxiliary means for homogenizing physical properties and an antioxidant, as necessary, as long as the achievement of the object of the present invention is not hindered. One type or two or more types of various additives such as (anti-aging agent), heat stabilizer, light stabilizer, ultraviolet absorber, lubricant, flame retardant, antistatic agent, and antifogging agent may be blended.

The decorative base material layer in the decorative sheet of the present invention contains a thermoplastic resin as a main component.
Examples of the thermoplastic resin include polyolefin resins, polystyrene resins, polyester resins, polyamide resins, polyvinyl acetal resins, polyvinyl alcohol resins, polyvinyl acetate resins, poly (meth) acrylic ester resins, Examples include norbornene resins, polyphenylene ether resins, polyoxymethylene resins, and the like. Among these, polyolefin resins are preferably used. These thermoplastic resins may be used alone or in combination of two or more. In the present specification, (meth) acryl means acryl and methacryl.

By using a polyolefin resin as the thermoplastic resin, the mechanical strength, oil resistance, etc. of the decorative sheet of the present invention can be improved, and the burden on the environment can be reduced.

The polyolefin resin is obtained by homopolymerizing or copolymerizing an olefin monomer having a polymerizable double bond in the molecule. Examples of the olefin monomer include α- such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 4-methyl-1-pentene, vinyl acetate and the like. Olefins; conjugated dienes such as butadiene and isoprene are listed. These olefinic monomers may be used alone or in combination of two or more.

The polyolefin resin is not particularly limited. For example, a homopolymer of ethylene; a copolymer of ethylene and an α-olefin other than ethylene copolymerizable with ethylene; ethylene- (meth) acrylic acid and / or For example, (meth) acrylic ester copolymer such as ethyl (meth) acrylate; ethylene-vinyl acetate copolymer; polyethylene resin such as ethylene-styrene copolymer; homopolymer of propylene; propylene and the propylene Copolymers with copolymerizable α-olefins other than propylene; propylene-ethylene random copolymers or block copolymers; polypropylene resins such as polypropylene alloy resins; butene homopolymers; butadiene, isoprene, etc. Examples thereof include homopolymers or copolymers of conjugated dienes.

Among them, ethylene homopolymer, copolymer of ethylene and α-olefin other than ethylene copolymerizable with ethylene, ethylene-ethyl acrylate copolymer, ethylene-vinyl acetate copolymer, propylene homopolymer Preferably, at least one polyolefin resin selected from the group consisting of a polymer, a copolymer of propylene and an α-olefin other than propylene copolymerizable with the propylene, and a polypropylene alloy resin is preferably used. These polyolefin resin may be used independently and 2 or more types may be used together.

When a polyolefin resin having excellent flexibility is required, a copolymer of ethylene and an α-olefin other than ethylene is generally used. In particular, the flexibility is improved by increasing the content of α-olefin, and it is suitably used as a decorative sheet requiring flexibility. Although it does not specifically limit as alpha olefins other than the said ethylene, For example, propylene, 1-butene, 1-hexene, 4-methyl-1- pentene, 1-octene etc. are used suitably. These α-olefins other than ethylene may be used alone or in combination of two or more.

Further, when a polyolefin resin having excellent flexibility is required, a polyolefin alloy resin having a polyolefin resin as a main component and an elastomer component (rubber component) finely dispersed therein is used.

The method for finely dispersing the elastomer component, which is a rubber component, in the polyolefin resin as the main component is not particularly limited. For example, a method in which the elastomer component is added to the heated and melted polyolefin resin and uniformly co-kneaded. In addition, there is a method in which an elastomer component is added to the polymerization system of the polyolefin resin, and polymerization of the polyolefin resin and fine dispersion of the elastomer component are performed at the same time. The latter method is preferably employed because a polyolefin alloy resin finely dispersed in the resin can be obtained.

By using a polyolefin alloy resin in which the elastomer component, which is a rubber component, is highly finely dispersed, the resulting thermoplastic resin composition exhibits excellent flexibility and elongation without impairing other physical properties. It becomes.

Among the above-mentioned polyolefin alloy resins, a thermoplastic resin composition exhibiting more excellent flexibility and elongation can be obtained. For example, other than propylene homopolymer and propylene copolymerizable with propylene A polypropylene alloy resin comprising, as a main component, a polypropylene resin such as a copolymer of α-olefin, a propylene-ethylene random copolymer or a block copolymer, in which an elastomer component is finely dispersed is preferably used. It is done.

Among the polypropylene alloy resins, the elution amount at 10 ° C. or less is 30 to 80% by weight, and the elution amount at 10 ° C. or more and 70 ° C. or less is 5 to 5%. A polypropylene alloy resin mainly composed of 35% by weight of a polypropylene resin is more preferably used.

When the elution amount at 10 ° C. or less is less than 30% by weight among the total elution amounts by the cross fractionation chromatograph, the flexibility of the polypropylene resin becomes insufficient, so this polypropylene resin is the main component. Polypropylene-based resin may be difficult to be highly filled with layered silicate and flame retardant, and when the elution amount at 10 ° C. or less exceeds 80% by weight, the polypropylene-based resin becomes too flexible. The decorative base material layer using a polypropylene-based alloy resin containing a resin as a main component may have insufficient mechanical strength.

Moreover, since the heat resistance of polypropylene resin becomes inadequate when the elution amount in excess of 10 degreeC and below 70 degreeC is less than 5 weight% among the total elution quantities by a cross fractionation chromatograph, this polypropylene resin The heat resistance of the decorative base layer using a polypropylene alloy resin containing as a main component may be insufficient, and if it exceeds 35% by weight, the flexibility of the polypropylene resin becomes insufficient. A polypropylene alloy resin containing a polypropylene resin as a main component may be difficult to highly fill with a layered silicate or a flame retardant.

The molecular weight and molecular weight distribution of the thermoplastic resin are not particularly limited, but the preferred lower limit of the weight average molecular weight is 5000, the preferred upper limit is 5,000,000, the more preferred lower limit is 20,000, and the more preferred upper limit is 300,000. Moreover, the preferable minimum of molecular weight distribution calculated | required by a weight average molecular weight / number average molecular weight is 1.1, a preferable upper limit is 80, a more preferable minimum is 1.5, and a more preferable upper limit is 40.

The thermoplastic resin may be blended with thermoplastic elastomers and oligomers for resin modification as needed within a range that does not impede achievement of the object of the present invention.

The decorative base fat layer contains a layered silicate. In the present specification, the layered silicate means a silicate mineral having an exchangeable metal cation between layers. The layered silicate is not particularly limited, and examples thereof include smectite clay minerals such as montmorillonite, saponite, hectorite, beidellite, stevensite, and nontronite, vermiculite, halloysite, and swelling mica. Among these, montmorillonite and / or swellable mica is preferably used. The layered silicate may be a natural product or a synthetic product. Moreover, these layered silicates may be used independently and 2 or more types may be used together.

As the layered silicate, smectites having high shape anisotropy and swelling mica defined by the following formula are preferably used. By using a layered silicate having a large shape anisotropy, the mechanical strength of the decorative base material layer becomes more excellent.

Shape anisotropy = Area of crystal surface (A) / Area of crystal surface (B) (In the formula, crystal surface (A) means the layer surface, and crystal surface (B) means the side surface of the layer. )

The shape of the layered silicate is not particularly limited, but the preferable lower limit of the average length is 0.01 μm, the preferable upper limit is 3 μm, the preferable lower limit of the thickness is 0.001 μm, and the preferable upper limit is 1 μm. The preferred lower limit is 20, and the preferred upper limit is 500. The more preferable lower limit of the average length is 0.05 μm, the more preferable upper limit is 2 μm, the more preferable lower limit of the thickness is 0.01 μm, the more preferable upper limit is 0.5 μm, and the more preferable lower limit of the aspect ratio is 50, more A preferred upper limit is 200.

The exchangeable cation existing between the crystal layers of the layered silicate is a metal ion such as sodium or calcium existing on the crystal surface, and these metal ions have a cation exchange property with a cationic substance. Various substances having cationic properties can be trapped (intercalated) between the crystal layers of the layered silicate.

Although it does not specifically limit as a cation exchange capacity | capacitance of the said layered silicate, A preferable minimum is 50 meq / 100g and an upper limit is 200 meq / 100g. When the amount is less than 50 meq / 100 g, the amount of the cationic substance that can be trapped between the crystal layers by cation exchange decreases, so the crystal layer may not be sufficiently nonpolarized. When the amount exceeds 200 meq / 100 g, The bonding strength between the crystal layers of the layered silicate becomes strong, and the crystal flakes may be difficult to peel off.

When a low-polarity resin such as a polyolefin resin is used as the thermoplastic resin, it is preferable that the layered silicate layer is previously cation-exchanged with a cationic surfactant to be hydrophobized. By making the layers of the layered silicate hydrophobic in advance, the affinity between the layered silicate and the thermoplastic resin is increased, and the layered silicate can be finely dispersed more uniformly in the thermoplastic resin.

The cationic surfactant is not particularly limited, and examples thereof include quaternary ammonium salts and quaternary phosphonium salts. Among them, a quaternary ammonium salt having an alkyl chain having 6 or more carbon atoms, that is, an alkyl ammonium salt having 6 or more carbon atoms is preferably used since the crystal layer of the layered silicate can be sufficiently nonpolarized.

The layered silicate used in the present invention can be improved in dispersibility in the thermoplastic resin by chemical treatment as described above. The chemical treatment is not limited to a cation exchange method using a cationic surfactant (hereinafter, also referred to as a chemical modification (1) method). For example, chemical modification (2) to chemical modification (6) shown below. It can also be carried out by various chemical treatment methods. These chemical modification methods may be used alone or in combination of two or more. In addition, the layered silicate whose dispersibility in the thermoplastic resin is improved by the following various chemical treatment methods including the chemical modification (1) method is hereinafter also referred to as “organized layered silicate”.

In the chemical modification (2) method, a hydroxyl group present on the crystal surface of the organically modified layered silicate chemically treated by the chemical modification (1) method can be combined with a functional group or a chemical bond. In this method, chemical treatment is performed with a compound having at least one functional group having high chemical affinity at the molecular end. Such a functional group that can be chemically bonded to a hydroxyl group, or a functional group that does not have a chemical bond but has high chemical affinity is not particularly limited. For example, an alkoxy group, a glycidyl group, a carboxyl group (dibasic acid (Including anhydrides), functional groups such as hydroxyl groups, isocyanate groups, and aldehyde groups, and other functional groups having high chemical affinity with hydroxyl groups. In addition, the functional group that can be chemically bonded to the hydroxyl group, or a compound having a functional group with high chemical affinity without chemical bonding is not particularly limited. Examples thereof include silane compounds having a group, titanate compounds, glycidyl compounds, carboxylic acids, alcohols and the like. These compounds may be used alone or in combination of two or more.

In the chemical modification (3) method, a hydroxyl group present on the crystal surface of the organically modified layered silicate chemically treated by the chemical modification (1) method can be chemically bonded to a functional group or a chemical bond. In this method, chemical treatment is performed with a compound having one or more functional groups and reactive functional groups having high chemical affinity at the molecular ends.

The chemical modification (4) method is a method in which the crystallized surface of the organically modified layered silicate chemically treated by the chemical modification (1) method is chemically treated with a compound having an anionic surface activity.

The chemical modification (5) method is a chemical treatment (4) method in which a chemical treatment is performed with a compound having one or more reactive functional groups in addition to the anion site in the molecular chain of the compound having anionic surface activity.

In the chemical modification (6) method, the organically modified layered silicate chemically treated by any one of the chemical modification (1) method to the chemical modification (5) method is further used, for example, maleic anhydride-modified polyphenylene ether type. In this method, a composition containing a resin having a functional group capable of reacting with a layered silicate such as a resin is used as a dispersant. This improves the compatibility of both by mixing a dispersant that has a high affinity with the layered silicate and a high affinity with the thermoplastic resin, and reduces the energy required to disperse the layered silicate. It is a method to make it. As such a dispersant, maleic anhydride-modified polyolefin oligomers and the like are preferably used, and among them, AB type diblock polymers or diblock oligomers having different properties at both ends are preferably used. Both ends have both ends with different properties, a property having a high affinity for the layered silicate and a property having a high affinity for the thermoplastic resin, and A (layered silicate affinity site) -B (thermoplastic affinity site) Since it is a type | mold, a suitable dispersion | distribution effect is acquired from being easy to exhibit affinity to each efficiently. A method for obtaining a highly dispersed state using such an AB type dispersant is not particularly limited, and examples thereof include melt kneading a thermoplastic resin and a layered silicate together with a dispersant in an extruder.

The layered silicate preferably has an average interlayer distance of (001) plane measured by wide angle X-ray diffraction method of 3 nm or more, and part or all are dispersed in 5 layers or less. More preferably, the average interlayer distance is 6 nm or more, and a part or all of the average interlayer distance is dispersed in 5 layers or less. In this specification, the average interlayer distance of the layered silicate means an average interlayer distance when the layered silicate fine flaky crystals are used as a layer, and a wide-angle X-ray diffraction method using an X-ray diffraction peak. Can be calculated. Further, the dispersion state of the layered silicate is observed by using a transmission electron microscope at 50,000 to 100,000 times, and five layers out of the number (X) of layered silicate laminates that can be observed in a certain area. The number (Y) of the laminated assemblies dispersed below can be counted and calculated by the following formula.

    Ratio of layered silicate dispersed in 5 layers or less (%) = (Y / X) × 100

When layered molecules of layered silicate, which is essentially a laminate of several tens of layers, peel and disperse, the interaction between the layered silicate crystal flakes becomes so negligible that crystal flakes are thermoplastic. It becomes a finely dispersed state at a certain distance and stabilizes. As a result, the layered silicate increases the average interlayer distance between the crystal flake layers and stabilizes dispersion, and at the time of combustion, it becomes easy to form a sintered body by the movement of the crystal flakes of the layered silicate. That is, a thermoplastic resin in which a lamellar silicate crystal flake layer is dispersed with an average interlayer distance of 3 nm or more, more preferably 6 nm or more, easily forms a sintered body that can be a flame retardant coating. Since this sintered body is formed at an early stage during combustion, not only the supply of oxygen from the outside world can be blocked, but also the flammable gas generated by the combustion can be blocked, and the heat generation of the thermoplastic resin composition Speed can be suppressed. That is, it becomes possible to exhibit excellent fire spread prevention properties. Therefore, the decorative sheet of the present invention obtained by blending and dispersing such a layered silicate in a thermoplastic resin exhibits various properties such as extremely excellent flame retardancy, mechanical strength, and heat resistance. . In addition, when the average interlayer distance between the layered silicate crystal flake layers is 3 nm or more, preferably 6 nm or more, the layered silicate crystal flake layers are separated into layers, and the interaction between the layered silicate crystal flake layers is Since it weakens so that it can be almost ignored, there is an advantage that the dispersed state of the crystal flakes constituting the layered silicate in the thermoplastic resin progresses in the direction of crushing stabilization.

In addition, the fact that part or all of the layered silicate is dispersed in 5 layers or less means that part or all of the layered molecules of the layered silicate which is essentially a laminate of several tens of layers is peeled off. This means that it is widely dispersed, and this also means that the interaction between the crystal flake layers of the layered silicate is weakened, so that the same effect as described above can be obtained. Specifically, it is preferable that 10% or more of the layered silicate is dispersed in 5 layers or less, in which part or all of the layered silicate is dispersed in 5 layers or less. More preferably, 20% or more is dispersed in 5 layers or less. The above-mentioned effect can be obtained by dividing the number of layered silicate layers into 5 layers or less, but it is more preferably divided into 3 layers or less, and particularly preferably in a single layer shape. It is thinning.

In the decorative base material layer, the average interlayer distance between crystal flake layers of the layered silicate is 3 nm or more, and a part or all of the layered silicate is dispersed in 5 layers or less, that is, the decorative base material If the layered silicate is highly dispersed in the layer, the interface area between the thermoplastic resin and the layered silicate increases. When the interface area between the thermoplastic resin and the layered silicate increases, the degree of restraint of the thermoplastic resin on the surface of the layered silicate increases, and mechanical strength such as elastic modulus improves. Moreover, when the degree of restraint of the thermoplastic resin on the surface of the layered silicate increases, the melt viscosity increases and the moldability also improves. Moreover, the gas barrier property can be expressed by the baffle effect of the layered silicate. Further, the fact that the layered silicate is present in the number of laminated layers of 5 layers or less is advantageous also from the viewpoint of maintaining the strength of the layered silicate itself, and is particularly advantageous for expressing the mechanical strength, particularly the elastic modulus. .

The more the layered silicate peels and the crystal flakes are dispersed in the thermoplastic resin, the smaller the average adjacent distance between the crystal flakes, and the formation of a sintered body by movement of the layered silicate crystal flakes during combustion occurs. It becomes easy to break. Further, the more the layered silicate crystal flakes are dispersed in the decorative base layer, the more the elastic modulus and gas barrier properties of the decorative base layer are significantly improved.

Any of the above phenomena is due to the fact that the interface area between the layered silicate and the thermoplastic resin increases as the dispersion of crystal flakes increases. That is, the mechanical strength such as the elastic modulus of the decorative resin layer is increased by restraining the molecular motion of the thermoplastic resin at the adhesive surface between the thermoplastic resin and the layered silicate. The better, the greater the effect of increasing the mechanical strength of the decorative substrate layer.

In general, gas molecules in a polymer are much more easily diffused than inorganic substances. Therefore, when gas molecules diffuse in a thermoplastic resin, they diffuse while bypassing the inorganic substance. Therefore, also in this case, the higher the dispersion ratio of the lamellar silicate crystal flakes, the more efficiently the gas barrier property of the decorative base layer can be increased.

The lower limit of the amount of the layered silicate in the decorative base layer is preferably 0.1 parts by weight and the upper limit is 100 parts by weight with respect to 100 parts by weight of the thermoplastic resin. If it is less than 0.1 part by weight, it becomes difficult to form a continuous sintered body at the time of combustion, so the flame retardant effect is small. If it exceeds 100 parts by weight, mechanical strength and formability are impaired. Since it is too much, practicality becomes poor. The preferred lower limit is 1 part by weight, the preferred upper limit is 40 parts by weight, the more preferred lower limit is 4 parts by weight, the more preferred upper limit is 30 parts by weight, the still more preferred lower limit is 7 parts by weight, and the still more preferred upper limit is 20 parts by weight. is there. A continuous film having a high mechanical strength is formed when the amount is 4 to 30 parts by weight, and a continuous film having a higher mechanical strength is formed when the amount is 7 to 20 parts by weight. The same applies to the organic layered silicate.

The method for dispersing the layered silicate in the thermoplastic resin is not particularly limited, for example, a method using the above-mentioned organic layered silicate; a method of foaming after kneading the thermoplastic resin and the layered silicate by a conventional method A method using a dispersant, and the like. By using these dispersion methods, the layered silicate can be more uniformly and finely dispersed in the thermoplastic resin.

The decorative base layer contains a metal hydroxide.
The metal hydroxide has a role as a flame retardant and can make the flame retardant effect of the layered silicate more effective. Although it does not specifically limit as said metal hydroxide, For example, magnesium hydroxide, aluminum hydroxide, calcium hydroxide etc. are used suitably. These metal hydroxides may be used alone or in combination of two or more. The shape of the metal hydroxide is not particularly limited. The metal hydroxide may be surface treated.

The metal hydroxide preferably has a calendering aid treated on its surface. Thereby, the calendering aid can be uniformly dispersed in the resin, and the decorative base material can be produced by a calendering method. Further, if a calendering aid having a function as a lubricant is used, the compatibility between the thermoplastic resin and the metal hydroxide can be improved. Although it does not specifically limit as said calender shaping | molding adjuvant, For example, a fatty-acid type metal soap is used suitably.

The lower limit of the blending amount of the metal hydroxide in the decorative base layer is preferably 0.1 parts by weight and the upper limit is 70 parts by weight with respect to 100 parts by weight of the thermoplastic resin. If the amount is less than 0.1 parts by weight, a sufficient effect of improving flame retardancy cannot be obtained. If the amount exceeds 70 parts by weight, the flexibility and elongation of the decorative base layer are extremely lowered. The preferred lower limit is 1 part by weight, the preferred upper limit is 65 parts by weight, the more preferred lower limit is 10 parts by weight, and the still more preferred upper limit is 60 parts by weight. Conventionally, in order to impart sufficient flame retardancy to a thermoplastic resin such as an olefin resin, it has been necessary to add a large amount of metal hydroxide to the thermoplastic resin. However, in the decorative sheet of the present invention, by using the layered silicate and the metal hydroxide in combination, sufficient flame retardancy is imparted without adding a large amount of metal hydroxide, and by adding a large amount of flame retardant. It will not cause any harmful effects.

The decorative base material layer is within a range that does not impair the object of the present invention, and, for example, a filler, a softening agent, a plasticizer, a lubricant, an antistatic agent, an antifogging agent, a coloring agent, an antioxidant ( One type or two or more types of various additives such as an anti-aging agent), a heat stabilizer, a light stabilizer, and an ultraviolet absorber may be blended.

The method for preparing the resin composition constituting the decorative base layer is not particularly limited. For example, a predetermined amount of thermoplastic resin, layered silicate and metal hydroxide, and various additions blended as necessary. A method of directly blending and kneading one or two or more predetermined amounts of the agent at normal temperature or under heating (direct kneading method); a predetermined amount of layered silicate in advance in a part of the predetermined amount of the thermoplastic resin A master batch prepared by mixing and kneading is prepared, and the master batch and the remainder of a predetermined amount of the thermoplastic resin and metal hydroxide, and one or more kinds of various additives added as necessary. Examples include a method (master batch method) of kneading each predetermined amount at room temperature or under heating, and any method may be adopted.

The specific production method of the composition by the direct kneading method or the master batch method is not particularly limited. For example, the decorative base material layer is configured using a kneading machine such as an extruder, a two-roll machine, or a Banbury mixer. Thermoplastic resin, layered silicate, metal hydroxide and various additives blended as necessary uniformly melt and kneaded at room temperature or under heating; thermoplastic resin, layered silicate, metal hydroxide and A method of uniformly kneading various additives blended as necessary in a solvent in which they can be dissolved or dispersed can be mentioned, and any method may be adopted.

When a polyolefin resin is used as the thermoplastic resin, for example, a layered silicate containing a polymerization catalyst (polymerization initiator) such as a transition metal complex is used to form the olefin single resin constituting the polyolefin resin. A method for simultaneously producing a polyolefin resin and a decorative resin simultaneously by kneading a monomer and a layered silicate containing a polymerization catalyst (polymerization initiator) and polymerizing the olefin monomer. May be taken.

The minimum with the preferable thickness of the said decoration base material layer is 50 micrometers, and a preferable upper limit is 150 micrometers. When the thickness is less than 50 μm, practical concealing property may not be obtained, or the unevenness of the adherend may be easily affected, and the smoothness of the finished appearance may be poor. The organic mass may increase and flame retardancy may decrease. A more preferable lower limit is 60 μm, and a more preferable upper limit is 100 μm.

A preferred lower limit of the tensile modulus of the decor substrate layer 190 N / mm ^2, the upper limit is preferably 1500 N / mm ^2. If it is less than 190 N / mm ² , the resulting decorative sheet of the present invention has a low waist, and it may be difficult to construct in the practical stage or may be easily affected by the unevenness of the adherend. ^When it exceeds ² , it may be difficult to construct a curved surface and may be impractical. The lower limit is more preferably 300N / mm ^2, and more preferable upper limit is 880N / mm ^2.

  The decorative sheet of the present invention preferably has a printing layer between the transparent polyolefin resin layer and the decorative resin layer. By providing the printed layer, the design of the decorative sheet of the present invention can be remarkably enhanced.

The decorative sheet of the present invention has an adhesive layer laminated on the decorative sheet. It does not specifically limit as an adhesive which comprises the said adhesive layer, For example, an elastomer type (rubber type) adhesive, an acrylic resin type adhesive, a polyvinyl ether resin type adhesive, a silicone resin type adhesive etc. are mentioned.

The form of the pressure-sensitive adhesive is not particularly limited. For example, a solvent-type pressure-sensitive adhesive, a non-water emulsion-type pressure-sensitive adhesive, an emulsion-type pressure-sensitive adhesive, a dispersion-type pressure-sensitive adhesive, a hot-melt-type pressure-sensitive adhesive, for example, active energy such as ultraviolet rays A monomer type or oligomer type pressure-sensitive adhesive that can be cured (polymerized) with a wire. The pressure-sensitive adhesive may be a cross-linked pressure-sensitive adhesive, a non-cross-linked pressure-sensitive adhesive, a one-component pressure-sensitive adhesive, or a multi-component pressure-sensitive adhesive having two or more liquids. It may be. Moreover, as said adhesive, what has a flame retardance is more preferable. Thereby, the flame retardance of the decorative sheet of the present invention becomes more excellent. The pressure-sensitive adhesive layer contains inorganic substances such as pigments, UV absorbers, hindered amine light stabilizers (HALS), etc. for the purpose of improving weather resistance, as long as flame retardancy is not affected. It is also possible to make it.

Although it does not specifically limit as thickness of the said adhesive layer, A preferable minimum is 10 micrometers in thickness of a solid content, and a preferable upper limit is 60 micrometers. If it is less than 10 μm, the adhesive strength may be insufficient, and if it exceeds 60 μm, the thickness of the decorative sheet of the present invention increases, which is disadvantageous for flame retardancy.

The decorative sheet of the present invention is laminated in the order of, for example, a colored film layer / a printed layer / a colored film layer / an adhesive layer, by adding a coloring material to the transparent polyolefin resin layer or the decorative substrate layer and using it as a colored film layer. It may be a thing. As described above, the decorative sheet of the present invention can obtain various physical properties and properties depending on the type and application. In addition, a coating layer having a thickness of about several μm may be laminated on the surface of the decorative sheet of the present invention in order to impart functions such as stain resistance, weather resistance, scratch resistance, and slip resistance.

In the present invention, in order to satisfy the overlayability when the decorative sheet is carried out, it is necessary that the 180-degree peeling strength with respect to the back surface is 15 N / 25 mm or more. In general, since this type of decorative sheet is manufactured as a long roll-shaped product having a certain width, the joint between the decorative sheets is always generated particularly when the decorative sheet is applied in the width direction. Therefore, assuming that the sheet shrinks due to dimensional changes over time, it is pre-applied by applying about 10 mm in advance, so-called overlap bonding is performed, but if the adhesiveness to the back surface is low, the sheet at the time of construction work Under the influence of applied stress strain or slight environmental change, peeling or floating occurs at the joints, causing poor construction. For this reason, in the construction of the conventional decorative sheet, primer treatment was performed on the end portion of the sheet to be overlaid, but not only did it take time to apply and dry it, but also protruded from the applied construction part. In some cases, the finished appearance may be significantly impaired.
In the decorative sheet of the present invention, the above-mentioned peeling strength can be achieved without requiring primer application by using an ethylene-vinyl alcohol resin layer having a specific amount of vinyl alcohol component on its back surface.

  The thickness of the decorative sheet of the present invention is not particularly limited as long as it is set as appropriate according to the type and application, but the preferred lower limit is 65 μm and the upper limit is 300 μm. If it is less than 65 μm, the concealability of the underlying wall material pattern, etc. may be insufficient and may not be suitable for practical use as a decorative sheet, and it is difficult to maintain mechanical strength. If it exceeds 300 μm, combustible components per unit area The increase in the amount makes it difficult to suppress the flammability, and the load on the installer increases because the weight per unit area increases. A more preferable lower limit is 100 μm, and a more preferable upper limit is 150 μm.

The decorative sheet of the present invention is obtained by compressing a combustion residue burned by heating for 30 minutes under a radiant heating condition of 50 kW / m ² at a compression rate of 1 mm / second in a combustion test in accordance with ASTM E 1354. The yield point stress is preferably 4.9 kPa or more. If it is less than 4.9 kPa, the combustion residue tends to collapse with a slight force, and the flame retardancy and fire spread prevention property may be insufficient. That is, in order for the decorative sheet of the present invention to fully exhibit the function as a flame retardant coating, it is preferable that the sintered body keeps its shape until the end of combustion. More preferably, it is 15 kPa or more.

When the decorative sheet of the present invention is bonded to a non-combustible material and burned under a radiation heating condition of 50 kW / m ² in accordance with ISO 1182, the maximum heat generation rate is continuously 200 kW in 20 minutes after the start of heating. / M ² or more is preferably less than 10 seconds, and the total calorific value is preferably 8 MJ / m ² or less. In 20 minutes after the start of heating, if the time for which the maximum heat generation rate is continuously 200 kW / m ² or more is 10 seconds or more, or if the total heat generation exceeds 8 MJ / m ² , the flame retardancy and fire spread of the decorative sheet Insufficient prevention. In addition, when the thickness of the decorative sheet excluding the adhesive layer is less than 65 μm, the total calorific value and the maximum heat generation rate are naturally reduced because the amount of combustible material is small. The decorative sheet is not suitable for practical use because basic mechanical properties are impaired, the finish is not flat due to the condition of the base, the concealability is low, and the base putty color can be easily picked up.

As a method for producing the decorative sheet of the present invention, for example, a corona treatment is applied to the side of the transparent polyolefin resin film on which the decorative substrate layer is laminated, an adhesive for dry laminating is applied and dried, and a decorative group is used. Examples include a method of laminating the corona-treated surface of the material layer to form a decorative sheet base material, and forming an adhesive layer on this. When the decorative sheet of the present invention has a printed layer, the decorative base material may be printed and the surface subjected to corona treatment may be laminated on the adhesive-coated surface of the transparent polyolefin resin film.

The method for producing the sheet constituting the decorative base material layer is not particularly limited. For example, the composition prepared in advance is melt-kneaded with an extruder and extruded, and a sheet shape is obtained using a T-die or a circular die. A method in which the composition is dissolved or dispersed in a solvent such as an organic solvent, and then molded into a sheet by a cast method; after the composition is melt-kneaded, it is roll-molded by a calendering method using a roll molding machine. Examples thereof include a calendar molding method. Especially, it is preferable to manufacture by the calendar molding method. Calender molding, in which molten resin is kneaded and stretched on a roll molding machine, has a low loss of raw materials when changing the type / resin when producing many types of products. Excellent. Conventionally, olefin-based resins have a low melt viscosity at a high temperature, and therefore, in the calender molding method, the molding adaptation temperature range is narrow and is not suitable for calendering. However, a calendar molding method can be performed by adding molding aids such as the above-described calender molding aids.

Moreover, it can produce also about the sheet | seat which comprises the said polyolefin resin layer by using the method similar to the said decoration base material sheet.

  Since the decorative sheet of the present invention has the above configuration, it has excellent dimensional stability, excellent flame retardancy and workability, and exhibits various performances such as heat resistance. That is, by using an ethylene-vinyl alcohol copolymer for the transparent polyolefin resin layer, it is possible to express sufficient adhesiveness without applying primer treatment when overlaying and applying decorative sheets, and has high follow-up and protection. The property is also high. In addition, when layered silicates and metal hydroxides are blended, it can provide a decorative sheet with very little dimensional change even when exposed to high-temperature environments, and is excellent in flame retardancy and fire spread prevention. An excellent flame retardant effect and fire spread preventing effect can be exhibited by the holding effect. Accordingly, it is possible to provide a decorative sheet that is inferior to conventional vinyl chloride resin decorative sheets.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

(Example 1)
As a sheet made of a polyolefin-based resin having transparency, an ethylene-vinyl alcohol copolymer (manufactured by Kuraray Co., Ltd., trade name “EVAL”, vinyl alcohol copolymerization ratio 56 mol%) and a predetermined amount of additive dry-blended in advance. Then, it was put into a small sheet molding die mounting extrusion test machine, and a transparent polyolefin resin sheet was molded to a predetermined thickness shown in Table 1.

As a resin composition for the decorative base layer, ratios of thermoplastic resin, layered silicate, magnesium hydroxide and other additives as shown in Table 1 in a small extruder (trade name “PCM30”, manufactured by Ikegai Co., Ltd.) The mixture was melt kneaded at a set temperature of 190 ° C., extruded into a strand, and the extruded strand was pelletized with a pelletizer.

The obtained pellets were rolled up and down at 180 ° C. by compression molding to produce a decorative base layer sheet having a predetermined thickness shown in Table 1. Next, after applying corona discharge treatment to one surface of the transparent polyolefin resin sheet and both surfaces of the decorative base material layer sheet to make the surface wetness index 4.2 × 10 ⁻⁴ N / cm, the decorative base material One layer of the layer sheet was coated with an acrylic paint (trade name “POS”, manufactured by Teikoku Ink Co., Ltd.) with a Mayer bar and dried to a thickness of 1 μm to provide a printed layer.

  Further, the treated surface of the transparent polyolefin-based resin sheet was bonded to the printing layer, and was again pressure-bonded and laminated by a hot press whose temperature was adjusted to 150 ° C. up and down to obtain a decorative sheet base material. On the other hand, a two-component cross-linked acrylic resin-based adhesive is applied to a release paper that has been subjected to silicone release treatment with a comma coater so that the thickness after drying is 40 μm, and dried to form an adhesive layer. Then, the adhesive layer and the decorative sheet base material were laminated from the decorative base material layer side to obtain a decorative sheet.

Similarly, for Examples 2 and 3 and Comparative Examples 1 to 3, test specimens were prepared according to the formulation shown in Table 1. In Comparative Example 2, the transparent polyolefin resin layer was not formed.

  For decorative sheets prepared as examples and comparative examples, the average interlayer distance of layered silicate, yield stress of combustion residue, exothermic test, tensile strength at 2% elongation, elongation at break, and curved surface workability test by the following methods And the dimensional change rate was measured. These results are also shown in Table 1.

(1) Using a layered silicate average interlayer distance X-ray diffractometer (RINT1100, manufactured by Rigaku Corporation), 2θ of a diffraction peak obtained from diffraction of a layered surface of a layered silicate in a decorative base material layer is measured. The (001) plane distance d (nm) of the layered silicate was calculated by the Bragg diffraction formula below, and was used as the average interlayer distance.
λ = 2 dsin θ
In the formula, λ is 0.154 nm, d represents the interplanar spacing of the layered silicate, and θ represents the diffraction angle.

(2) Yield point stress of combustion residue 100 mm × 100 in accordance with ASTM E 1354 “Building Material Flammability Test Method”
The decorative sheet cut to mm (thickness 3 mm) was burned by irradiating it with 50 kW / m ² of heat rays using a cone calorimeter, and then the combustion residue was compressed at a compression rate of 1 mm / second using an intensity measuring device. The yield point stress (kPa) of the combustion residue was measured.

(3) in compliance with pyrogenic test ISO 1182, the decorative sheet non-combustible material (100 mm × 100 mm × 12.5 mm thick plasterboard) the bonding with 50 kW / m heating starts after 20 minutes combustion under the conditions of ² I let you. The time during which the maximum heat generation rate at this time was continuously 200 kW / m ² or more and the total heat generation amount were measured.

(4) Elongation at break Using a dumbbell-shaped No. 3 test piece cut out from a sheet-shaped molded article in accordance with JIS K-6301 “Vulcanized Rubber Physical Test Method”, in an atmosphere of 20 ° C. to 50% RH Then, a tensile test was conducted at a tensile speed of 50 mm / min, and the elongation at break (%) was measured.

(5) Tensile strength at 2% elongation The tensile strength at 2% elongation of the decorative sheet was measured in accordance with JIS K 6734 “Test method for rigid vinyl chloride sheet and film”.

(6) Curved surface workability As shown in FIG. 1, a decorative sheet is flattened on the convex apex 2 of the curved surface workability evaluation jig 1 made of rolled steel for building structure (equal mountain steel) according to JIS G 3136. The sheet was placed and pasted together along the groove part 3 (the slope part 4 and the bottom part 5) while pushing the sheet with a squeegee. The curved surface workability at this time was evaluated by appearance. The evaluation criteria are as follows.
◯: Compared with a polyvinyl chloride resin sheet (trade name “Palois”, manufactured by Sekisui Chemical Co., Ltd.), the surface workability was inferior.
Δ: Compared with a polyvinyl chloride resin sheet (manufactured by Sekisui Chemical Co., Ltd., trade name “Palois”), the sheet had low waist and curved surface workability was slightly inferior.
X: The softness | flexibility of a decorative sheet was scarce, it was difficult to make it fit along the bending part of the jig | tool for curved surface workability evaluation, and it could not be provided as a product practically.

(7) (Overlap peel strength)
After applying a decorative sheet to a base material base in accordance with JIS Z 0237 “Adhesive tape / adhesive tape test method”, another decorative sheet is further applied to the surface of the decorative sheet, and 180 ° of the decorative sheet applied from above. The peel strength was measured.

(8) Weather resistance test test A sample with a decorative sheet attached to the ground (aluminum steel plate) was exposed for 300 hours with a sunshine weatherometer, and then the fading was visually confirmed.
◯: There was no discoloration after the test.
Δ: Precipitates were confirmed on the surface after the test.
X: Discoloration was observed after the test.

It is a side view which shows the jig | tool for curved surface workability evaluation.

Explanation of symbols

1: Curved workability evaluation jig 2: Convex top part 3: Groove part 4: Slope part 5: Bottom part

Claims (7)

A transparent polyolefin resin layer made of an ethylene-vinyl alcohol copolymer having a vinyl alcohol copolymer ratio of 50 to 90 mol%, a layered silicate of 0.1 to 100 parts by weight and a metal hydroxide with respect to 100 parts by weight of a thermoplastic resin A decorative sheet in which a pressure-sensitive adhesive layer is laminated on the decorative substrate layer side of a decorative sheet substrate comprising 0.1 to 70 parts by weight of a decorative substrate layer, wherein the decorative sheet has a JIS for the back surface of the decorative sheet. A decorative sheet having a 180 degree peel strength in accordance with Z0237 of 15 N / 25 mm or more. The thermoplastic resin is a homopolymer of ethylene, a copolymer of ethylene and an α-olefin other than ethylene, an ethylene-ethyl acrylate copolymer, an ethylene-vinyl acetate copolymer, a homopolymer of propylene, and propylene. The decorative sheet according to claim 1, wherein the decorative sheet is at least one selected from the group consisting of a copolymer with an α-olefin other than propylene and a polypropylene-based alloy resin. The decorative sheet according to any one of claims 1 and 2, wherein the layered silicate is montmorillonite and / or swellable mica. 2. The layered silicate has an average interlayer distance of (001) plane measured by wide-angle X-ray diffraction method of 3 nm or more, and part or all of them are dispersed in 5 layers or less. The decorative sheet according to any one of -3. In a combustion test in accordance with ASTM E 1354, a combustion residue burned by heating the decorative sheet according to any one of claims 1 to 4 under a radiation heating condition of 50 kW / m ² for 30 minutes is 1 mm. A decorative sheet characterized by having a yield point stress of 4.9 kPa or more when compressed at a compression rate of / sec. In accordance with ISO 1182, when the decorative sheet according to any one of claims 1 to 4 is bonded to a non-combustible material and burned under a radiation heating condition of 50 kW / m ² , in 20 minutes after the start of heating, A decorative sheet characterized in that the time during which the maximum heat generation rate is continuously 200 kW / m ² or more is less than 10 seconds and the total heat generation amount is 8 MJ / m ² or less. The decorative sheet according to any one of claims 1 to 6, wherein an organic component amount in the entire decorative sheet layer is 200 g / m ² or less.

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