JP7322381B2 - Decorative sheet and its manufacturing method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a decorative sheet used for surface decoration of interiors and exteriors of buildings, fittings, furniture, fitting materials, flooring materials, etc., and a method for producing the same.

In recent years, as shown in Patent Document 1, many decorative sheets using olefin resins (for example, polypropylene sheets) have been proposed as decorative sheets to replace polyvinyl chloride decorative sheets, which are of concern for environmental protection. ing. Since these decorative sheets do not use vinyl chloride resin, generation of toxic gas and the like during incineration is suppressed. However, polypropylene sheets generally have problems such as poor scratch resistance due to their low modulus of elasticity, and that they tend to stretch when tension is applied to the sheets during sheet preparation for printing or the like.

By the way, the decorative sheet is attached to the surface of a substrate such as a wooden substrate, a metal substrate, or a noncombustible substrate to form a decorative sheet, and the decorative sheet imparts a desired design to the decorative sheet. Therefore, the decorative sheet must cover the surface of the substrate so that it cannot be seen completely, if necessary. In this case, it is necessary to use a decorative sheet that is at least colored with a pigment and imparted with concealability. The simplest configuration of the decorative sheet can be said to be a configuration of only a substrate layer composed of a single colored sheet (single layer). In the case of a decorative sheet consisting only of such a base material layer, the design that can be imparted is usually limited to a single color without a pattern. Since it is possible to impart a sense of feeling, necessary and sufficient design expression is possible. Moreover, when it is desired to impart a more sophisticated design, it is also effective to apply decoration such as printing to the surface of the base material layer.

On the other hand, as described above, since the colored polypropylene film has a low elastic modulus, when it is used as a single-layer decorative sheet, it needs to be scratch resistant and not to stretch even when tension is applied during processing such as printing. The elongation under tension can be improved in conventional colored polypropylene films by increasing the layer thickness to about 60 μm or more. Regarding scratch resistance, conventional colored polypropylene films use a transparent resin layer made of polypropylene resin or a urethane-based thermosetting resin made of polyol and isocyanate, as in Patent Documents 2 and 3. Improvement is possible by providing a topcoat layer.

In addition, as in Patent Documents 2 and 3, by optimally selecting the polypropylene resin used for the colored polypropylene film, it is possible to improve scratch resistance and elongation during printing. However, while increasing the crystallinity improves the elastic modulus, the breaking stress does not increase correspondingly to the elastic modulus, so the film itself tends to break, and problems such as breakage tend to occur during printing. Furthermore, in post-processing as a decorative sheet, particularly during bending such as V-cutting, defects such as cracking and whitening at the bent portion are likely to occur.

As described above, the decorative sheet is attached to the surface of a substrate such as a wooden substrate and used as a decorative board. When attached, the decorative sheet is attached not only to the surface of the wooden board, but also to the edge of the board. Since the edges of the wooden substrate are rougher than the surface, and there are also steps in the bonding portion, the decorative sheet is required to have a uniform surface without following these irregularities.

Japanese Patent No. 3271022 Japanese Patent No. 3861472 Japanese Patent No. 3772634

Conventionally, for decorative sheets that use colored polypropylene film alone and decorative sheets that use colored polypropylene film as a base layer, printing processing suitability (difficulty in stretching, etc.), scratch resistance, bending workability, wrapping, etc. It is required to achieve both surface uniformity during processing.

In response to the above requirements, it is necessary to increase the thickness of the decorative sheet and increase the elastic modulus in order to improve printability, scratch resistance, and surface uniformity during wrapping. It makes it worse, and there is a trade-off relationship.
The present invention has been made by paying attention to the above-mentioned points, and a decorative sheet using a colored polypropylene film alone, which is compatible with printing processing suitability, scratch resistance, surface uniformity during wrapping processing, and bending workability. , a decorative sheet having a colored polypropylene film as a base layer, or a method for producing such a decorative sheet.

The present inventors have found that a nucleating agent that improves the crystallinity of polypropylene is encapsulated in a vesicle having a single-layer outer membrane to form a vesicle, which is added to the polypropylene resin as a nucleating agent vesicle. After various investigations and experiments on the process, the inventors have found that by adjusting the Martens hardness to an optimum range, it is possible to provide a decorative sheet and a method for producing the same that solves the above problems.
In order to achieve the object, a decorative sheet according to one aspect of the present invention has a base layer made of a colored polypropylene film obtained by mixing an inorganic pigment with a polypropylene resin, and the base layer contains the inorganic pigment. A nucleating agent vesicle containing a nano-sized nucleating agent is added to a vesicle having a single-layer outer film to the polypropylene resin, and the Martens hardness of the base layer is 50 N / mm. ² or more and 120 N/mm ² or less, and the thickness of the base material layer is 50 μm or more and 150 μm or less.

When at least one of the transparent resin layer and the topcoat layer is laminated on one side of the base material layer, the total thickness of the decorative sheet is preferably 100 μm or more and 250 μm or less.
Here, the nucleating agent vesicle has a configuration in which a nucleating agent is encapsulated in a capsule-like vesicle having a single-layer outer membrane, and can be prepared, for example, by a supercritical reverse phase evaporation method. . A nucleating agent is a substance that serves as a starting point for crystallization in a crystalline polypropylene resin.

According to one aspect of the present invention, a nucleating agent that improves the crystallinity of polypropylene is vesicled and added as a nucleating agent vesicle to optimize the Martens hardness and film thickness, thereby improving printability (elongation (hardness, etc.), scratch resistance, surface uniformity during lapping, and bending workability.

1 is a cross-sectional view showing a decorative sheet according to an embodiment of the present invention; FIG. FIG. 4 is a cross-sectional view showing another decorative sheet according to an embodiment based on the present invention;

An embodiment of the present invention will be described below with reference to the drawings.
Here, the drawings are schematic, and the relationship between the thickness and the planar dimension, the ratio of the thickness of each layer, and the like are different from the actual ones. Further, the embodiments shown below are examples of configurations for embodying the technical idea of the present invention. It does not specify anything. Various modifications can be made to the technical idea of the present invention within the technical scope defined by the claims.

"composition"
The decorative sheet 10 of the embodiment shown in FIG. 1 is an example in the case of a single-layer structure of only the base material layer 1 (original fabric layer).
The substrate layer 1 of this embodiment is composed of a colored polypropylene film. The substrate layer 1 made of a colored polypropylene film contains a polypropylene resin mixed with an inorganic pigment for coloring and contains a nano-sized nucleating agent. In this embodiment, the nucleating agent is added to the polypropylene resin in the form of nucleating agent vesicles that are encapsulated by the outer membrane and formed into vesicles.
The base material layer 1 has a Martens hardness of 50 N/mm ² or more and 120 N/mm ² or less, and a thickness of the base material layer 1 of 50 μm or more and 150 μm or less.
50% by mass or more and 100% by mass or less of the polypropylene resin constituting the base material layer 1 is preferably a highly crystalline homopolypropylene resin having an isotactic pentad fraction (mmmm fraction) of 95% or more. .

The amount of the nucleating agent vesicle added is preferably 0.05 parts by mass or more and 0.5 parts by mass or less in terms of the nucleating agent in the nucleating agent vesicle with respect to 100 parts by mass of the polypropylene resin. The nucleating agent vesicle is preferably a nucleating agent liposome having an outer membrane composed of phospholipids.
If necessary, the pattern layer 2 may be formed (laminated) on one surface of the substrate layer 1 to improve the design.
In addition, the decorative sheet 10 may have at least one layer of the transparent resin layer 3 and the topcoat layer 4 laminated on one surface side of the base material layer 1. The decorative sheet 10 illustrated in FIG. In this example, a pattern layer 2, a transparent resin layer 3 and a top coat layer 4 are laminated in this order on one side of a decorative sheet 10. FIG. Either the transparent resin layer 3 or the topcoat layer 4 may be omitted. Also, the pattern layer 2 may be omitted.

However, when the decorative sheet 10 of the present embodiment is provided with the transparent resin layer 3 and the topcoat layer 4, it is preferable to design the total thickness to be 100 μm or more and 250 μm or less. If the total thickness of the decorative sheet 10 is less than 100 μm, the strength of the decorative sheet 10 as a whole is insufficient, which may cause problems with smoothness during wrapping. If the total thickness of the decorative sheet 10 exceeds 250 μm, the overall strength of the decorative sheet 10 is too high, which may cause problems during bending.

When the transparent resin layer 3 and the top coat layer 4 are provided, for example, the base layer 1: 120 μm, the transparent resin layer 3: 115 μm, and the top coat layer 4: 15 μm. Among the substrate layer 1, the pattern layer 2, the transparent resin layer 3, and the topcoat layer 4, the pattern layer 2 has a thin layer thickness. The total thickness may be designed to be 100 μm or more and 250 μm or less.
Here, at least one layer of the transparent resin layer 3 and the top coat layer 4 may be provided with an uneven shape by embossing depending on the design requirements. Furthermore, in consideration of scratch resistance requirements, at least one of the transparent resin layer 3 and the top coat layer 4 may be laminated in multiple layers, and other known layers may be arranged.

In FIGS. 1 and 2, symbol B represents a substrate. The substrate B is a substrate to which the decorative sheet 10 is attached. The substrate B is not particularly limited, but examples thereof include wood boards, inorganic boards, metal plates, composite plates made of a plurality of materials, and the like. A primer layer, a masking layer, or the like may be provided between the decorative sheet 10 and the substrate B as appropriate.
The tensile modulus of the decorative sheet 10 of the present embodiment, particularly the tensile modulus of the substrate layer 1 alone, preferably ranges from 700 MPa to 2000 MPa. If the tensile modulus is less than 700 MPa, there is a risk that problems during printing cannot be suppressed, or surface smoothness cannot be maintained during wrapping. If the tensile modulus exceeds 2000 MPa, the crystallinity is too high, and even if the nucleating agent vesicle is used, problems such as whitening and cracking may occur during bending. A preferable range of tensile modulus is 1000 MPa or more and 1800 MPa or less. Within this range, problems during printing, scratch resistance, surface smoothness during wrapping, and bending can all be satisfactorily achieved.

Next, each layer constituting the decorative sheet 10 will be described.
<Base material layer 1>
The base material layer 1 consists of a colored polypropylene film. The colored polypropylene film is mainly made of polypropylene resin, and is colored by mixing the polypropylene resin with an inorganic pigment.
Furthermore, a nano-sized nucleating agent is added to the substrate layer 1 in order to increase the crystallinity. In this embodiment, nano-sized nucleating agents are added in the form of nucleating agent vesicles.

(polypropylene resin)
The polypropylene resin is preferably a highly crystalline homopolypropylene, which will be described later, but is not limited to a highly crystalline homopolypropylene. In applications where workability such as bending is more important, the highly crystalline homopolypropylene can be mixed with, for example, a random polypropylene resin having an ethylene content within a predetermined range or a known amorphous polypropylene resin. .
The Martens hardness of the substrate layer 1 made of the colored polypropylene film is adjusted to 50 N/mm ² or more and 120 N/mm ^{2 or} less.

If the Martens hardness is less than 50 N/mm ² , the surface may not be smooth during lapping, or defects during printing may not be suppressed, and it may be difficult to ensure the practically necessary scratch resistance. is high. On the other hand, when the Martens hardness exceeds 120 N/mm ² , the crystallinity is too high, and even when the nucleating agent vesicle is used, problems such as whitening and cracking may occur during bending.
A suitable range of the Martens hardness of the substrate layer 1 is 80 N/mm ² or more and 100 N/mm ² or less. Within this range, problems during printing, surface smoothness, scratch resistance, and bending during wrapping can all be satisfactorily satisfied.

Here, Martens hardness is a kind of index that indicates the hardness of a substance. depth) and is defined as the quotient of the indentation force calculated from the load and the surface area of the depression calculated from the indentation depth. The measurement is performed by the method specified in ISO14577.
Moreover, it is important that the thickness of the substrate layer 1 made of the colored polypropylene film is 50 μm or more and 150 μm or less.

If the thickness of the substrate layer 1 is less than 50 μm, the film strength will be insufficient even if the Martens hardness is within the optimum range, making it difficult to suppress problems during printing and deterioration of scratch resistance. It is also difficult to maintain surface smoothness during lapping. On the other hand, if the thickness of the base material layer 1 exceeds 150 μm, there is a high possibility that problems such as whitening and cracking will occur during bending, and the followability to the end face and laminated portion of the wooden substrate during lapping will be remarkable. As the adhesive strength becomes insufficient, problems such as peeling over time may occur.
A more preferable range for the thickness of the base material layer 1 is 60 μm or more and 120 μm or less. Within this range, problems during printing, surface smoothness during wrapping, scratch resistance, and bending can be achieved with sufficient leeway.

In the present embodiment, it is preferable to use a highly crystalline polypropylene resin as the polypropylene resin. In particular, a highly crystalline homopolypropylene resin, which is a propylene homopolymer having an isotactic pentad fraction (mmmm fraction) of 95% or more, is contained in an amount of 50% by mass or more and 100% by mass or less based on the mass of the total polypropylene resin. It is preferable to use in
The crystallization temperature of polypropylene resin is generally within the range of 100 to 130°C, and is within the range of 110 to 140°C when a nucleating agent is added. In the colored polypropylene film in the decorative sheet 10 of the present embodiment, the cooling time from the crystallization temperature to the curing completion temperature within this range is controlled by a known cooling process, thereby reducing the Martens hardness to 50 N/mm. It is adjusted to ² or more and 120 N/mm ² or less. In addition, when a polypropylene resin having an isotactic pentad fraction (mmmm fraction) of less than 95% is used, the crystallinity is insufficient, so even if the cooling process is controlled, the Martens hardness becomes lower than the preferable range. Sometimes I end up Similarly, when the highly crystalline homopolypropylene resin is less than 50% by mass, the crystallinity is insufficient, so that even if the cooling process is controlled, the Martens hardness may be lower than the preferred range.

Here, the isotactic pentad fraction (mmmm fraction) is a resin material with a predetermined resonance frequency by 13C-NMR measurement (nuclear magnetic resonance measurement) using carbon C (nuclide) with a mass of 13. It is calculated from the numerical value (electromagnetic wave absorption rate) obtained by resonating at , and defines the atomic arrangement, electronic structure, and molecular fine structure in the resin material. The pentad fraction of a crystalline polypropylene resin is the ratio of five propylene units arranged in a row as determined by 13C-NMR, and is used as a measure of crystallinity or stereoregularity. The pentad fraction is one of the important factors that mainly determines the scratch resistance of the surface. Basically, the higher the pentad fraction, the higher the crystallinity.

(Inorganic pigment)
As the inorganic pigment, a known inorganic pigment typified by titanium oxide for imparting concealability can be used. Examples of inorganic pigments for coloring include composite oxides such as iron-zinc, chromium-antimony, and iron-aluminum, and iron oxides. be. Inorganic pigments such as aluminum flakes and pearl pigments can also be added. Also, for example, an organic pigment such as carbon black may be used in combination.
Furthermore, additives such as fatty acid metal salts may be added in order to improve dispersibility and extrusion suitability.

(Nucleating agent vesicle)
Moreover, the base material layer 1 contains a nano-sized nucleating agent. The nano-sized nucleating agent is used by being added to the polypropylene resin in the form of nucleating agent vesicles enclosed in vesicles having a single-layer outer membrane. Since the substrate layer 1 contains a nucleating agent, the degree of crystallinity can be improved, and the abrasion resistance (scratch resistance) of the substrate layer 1 can be improved. In this embodiment, the nucleating agent in the resin constituting the substrate layer 1 may be encapsulated in a vesicle with a portion of the nucleating agent exposed.
The nano-sized nucleating agent preferably has an average particle size of 1/2 or less of the wavelength range of visible light. Specifically, since the wavelength range of visible light is 400 nm or more and 750 nm or less, is preferably 375 nm or less.

Since nano-sized nucleating agents have extremely small particle sizes, the number of nucleating agents present per unit volume and the surface area increase in inverse proportion to the cube of the particle diameter. As a result, since the distance between each nucleating agent particle becomes short, when crystal growth occurs from the surface of one nucleating agent particle added to the polypropylene resin, the edge where the crystal is growing immediately One nucleating agent particle comes into contact with the edges of crystals growing from the surface of other nucleating agent particles adjacent to each other, and the edges of each crystal inhibit the growth of each crystal, stopping the growth of each crystal. The average particle size of the spherulites in the crystal part of the crystalline polypropylene resin can be reduced, for example, the spherulite size can be reduced to 1 μm or less. As a result, a colored polypropylene film with a high degree of crystallinity and high hardness can be obtained, and stress concentration between spherulites generated during bending is efficiently dispersed, so cracking and whitening during bending are suppressed. Colored polypropylene films can be realized.

Here, when the nucleating agent is simply added, the particle size increases due to secondary aggregation of the nucleating agent in the polypropylene resin, and the number of crystal nuclei with respect to the amount of the added nucleating agent increases. It may be significantly less than when added as drug vesicles. As a result, the average grain size of the spherulites in the crystal part of the polypropylene resin becomes large, and cracking and whitening during bending may not be suppressed. Therefore, it may not be possible to achieve both improvement in elastic modulus and workability by increasing the degree of crystallinity.
The base material layer 1 made of a colored polypropylene film, which constitutes the decorative sheet 10 of the present embodiment, is 0.05 parts by mass or more in terms of the addition amount of the nucleating agent with respect to 100 parts by mass of the polypropylene resin as the main component. .5 parts by mass or less, preferably 0.1 to 0.3 parts by mass of the nucleating agent vesicle is added. If the amount of the nucleating agent vesicle added is less than 0.05 parts by mass, the degree of crystallinity may not be sufficiently improved, and the required elastic modulus (hardness) may not be achieved. On the other hand, if the amount added exceeds 0.5 parts by mass, the spherulite growth is conversely inhibited due to excessive crystal nuclei, and as a result, the crystallinity is not sufficiently improved, and the required elastic modulus (hardness) is not achieved. may not be reached.

In addition, as a method to nanoize the nucleating agent, for example, the nucleating agent is mainly mechanically pulverized to obtain nano-sized particles, a solid-phase method, a nucleating agent, and a method of dissolving the nucleating agent. The liquid-phase method, which synthesizes and crystallizes nano-sized particles in a solution, and the vapor-phase method, which synthesizes and crystallizes nano-sized particles from a nucleating agent or a gas or vapor containing a nucleating agent. It can be used as appropriate. Examples of solid-phase methods include ball mills, bead mills, rod mills, colloid mills, conical mills, disk mills, hammer mills, jet mills, and the like. Examples of the liquid phase method include a crystallization method, a coprecipitation method, a sol-gel method, a liquid phase reduction method, and a hydrothermal synthesis method. Furthermore, the gas phase method includes, for example, an electric furnace method, a chemical flame method, a laser method, a thermal plasma method, and the like.

A supercritical reversed-phase evaporation method is preferable as a method for nano-izing the nucleating agent. The supercritical reversed-phase evaporation method is a method of producing capsules (nano-sized vesicles) encapsulating a target substance using carbon dioxide in a supercritical state or under temperature or pressure conditions equal to or higher than the critical point. Carbon dioxide in a supercritical state means carbon dioxide in a supercritical state with a critical temperature (30.98 ° C.) and a critical pressure (7.3773 ± 0.0030 MPa) or higher, under conditions of temperature above the critical point or Carbon dioxide under pressure conditions means carbon dioxide under conditions where only temperature or only pressure exceeds critical conditions.

In addition, as a specific nano-processing by the supercritical reverse phase evaporation method, first, the water phase is injected into a mixed fluid of supercritical carbon dioxide, phospholipids as outer membrane forming substances, and nucleating agents as inclusion substances. and stirring to generate an emulsion of supercritical carbon dioxide and an aqueous phase. Next, when the pressure is reduced, the carbon dioxide expands and evaporates, causing a phase inversion and forming nanocapsules (nanovesicles) in which the surface of the nucleating agent particles is covered with a monolayer film of the phospholipid. By using this supercritical reverse phase evaporation method, unlike the conventional encapsulation method in which the outer film is a multi-layered film on the surface of the nucleating agent particle, it is possible to easily produce a single-layer film capsule. Small diameter capsules can be prepared.
Nucleating agent vesicles can be prepared by, for example, the Bangham method, extrusion method, hydration method, surfactant dialysis method, reverse phase evaporation method, freeze-thaw method, supercritical reverse phase evaporation method, and the like. Among them, the supercritical reverse phase evaporation method is particularly preferred.

The outer membrane constituting the nucleating agent vesicle is composed of, for example, a monolayer membrane. In addition, the outer membrane is composed of, for example, a substance containing biological lipids such as phospholipids.
Nucleogenic vesicles whose outer membrane is composed of a substance containing biological lipids such as phospholipids are referred to herein as nucleogenic liposomes.
Phospholipids constituting the outer membrane include, for example, phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidic acid, phosphatidylglycerol, phosphatidylinositol, cardiopine, egg yolk lecithin, hydrogenated egg yolk lecithin, soybean lecithin, hydrogenated soybean lecithin, and the like. and sphingolipids such as sphingomyelin, ceramide phosphorylethanolamine and ceramide phosphorylglycerol.

Other substances that form the outer membrane of vesicles include, for example, nonionic surfactants and dispersing agents such as mixtures of these with cholesterols or triacylglycerols. Among these, nonionic surfactants include, for example, polyglycerin ether, dialkylglycerin, polyoxyethylene hydrogenated castor oil, polyoxyethylene alkyl ether, polyoxyethylene sorbitan fatty acid ester, sorbitan fatty acid ester, polyoxyethylene polyoxypropylene copolymer. , polybutadiene-polyoxyethylene copolymer, polybutadiene-poly2-vinylpyridine, polystyrene-polyacrylic acid copolymer, polyethylene oxide-polyethylethylene copolymer, polyoxyethylene-polycaprolactam copolymer, etc. Or 2 or more types can be used. Examples of cholesterols that can be used include cholesterol, α-cholestanol, β-cholestanol, cholestan, desmosterol (5,24-cholestadien-3β-ol), sodium cholate and cholecalciferol.

Alternatively, the liposome outer membrane may be formed from a mixture of a phospholipid and a dispersing agent. In the decorative sheet 10 of the present embodiment, the nucleating agent vesicle is preferably a radical scavenger liposome having an outer membrane made of phospholipids. The compatibility between the resin material, which is the main component of the vesicle, and the vesicle can be improved.
The nucleating agent is not particularly limited as long as it is a substance that serves as a starting point for crystallization when the resin crystallizes. Nucleating agents include, for example, phosphate metal salts, benzoate metal salts, pimelic acid metal salts, rosin metal salts, benzylidene sorbitol, quinacridone, cyanine blue and talc. In particular, in order to maximize the effect of the nano-processing, it is preferable to use phosphate ester metal salts, benzoate metal salts, pimelic acid metal salts, and rosin metal salts that are non-melting and can be expected to have good transparency. Colored quinacridone, cyanine blue, talc, etc. can also be used when the material itself can be made transparent by nano-processing. Further, a melting type benzylidene sorbitol may be appropriately mixed with a non-melting type nucleating agent.

As described above, one of the features (invention specifying matter) of the decorative sheet 10 of the present embodiment is that "the base material layer 1 contains a nucleating agent encapsulated in vesicles". By adding the nucleating agent to the resin composition in a state where the nucleating agent is encapsulated in the vesicles, the effect of dramatically improving the dispersibility of the nucleating agent in the resin material, that is, in the substrate layer 1 is exhibited. However, it may be difficult, depending on the situation, to directly specify the characteristics of the finished decorative sheet 10 based on its structure and characteristics, and it can be said to be impractical. The reason is as follows. The nucleating agent added in the form of vesicles is in a dispersed state with high dispersibility, and even in the state of the produced decorative sheet 10, the nucleating agent is highly dispersed in the base material layer 1. ing. However, in the process of producing the decorative sheet 10 after the base layer 1 is produced by adding a nucleating agent in the form of vesicles to the resin composition constituting the base layer 1, compression into a laminate is usually performed. Various treatments such as treatment and hardening treatment are performed, and by such treatment, the outer membrane of the vesicle encapsulating the nucleating agent is crushed or chemically reacted, and the nucleating agent is enclosed in the outer membrane (foreskin). This is because the state in which the outer film is crushed or undergoes a chemical reaction varies depending on the processing steps of the decorative sheet 10 . In situations where the nucleating agent is not included in the outer membrane, it is difficult to specify the physical properties themselves in terms of numerical values. It may be difficult to determine whether the material is added separately from the nucleating agent. As described above, the present invention differs from the conventional one in that the nucleating agent is highly dispersed in the base material layer 1, but is added in the form of vesicles containing the nucleating agent. In some cases, it may be impractical to specify the structure and characteristics of the decorative sheet 10 in terms of numerical ranges analyzed based on measurements.
Here, the nucleating agent vesicle having the above structure may also be contained in the transparent resin layer 3 and the topcoat layer 4 .

(Picture layer 2)
A pattern layer 2 for adding a pattern to the decorative sheet 10 can be provided on the surface of the colored polypropylene film (base layer 1). As the pattern, for example, a wood grain pattern, a stone grain pattern, a grain pattern, a tiled pattern, a brickwork pattern, a cloth pattern, a leather tie pattern, a geometric figure, or the like can be used.
Further, between the base material layer 1 and the pattern layer 2, a base solid ink layer (not shown) may be provided according to the desired degree of design. The underlying solid ink layer is provided so as to cover the entire surface of the substrate layer 1 . Further, the underlying solid ink layer may be a multi-layer of two or more layers, if necessary, such as for concealing properties. Further, the pattern layer 2 may be formed by laminating the number of separation plates required to express the desired design. As described above, the pattern layer 2 and the underlying solid ink layer can be combined in various ways depending on the desired design, that is, the design to be expressed, but the combinations are not particularly limited.

The constituent materials of the underlying solid ink layer and the pattern layer 2 are not particularly limited. For example, printing inks and coating agents obtained by dissolving and dispersing a matrix and a coloring agent such as a dye or pigment in a solvent can be used. As the matrix, for example, oily nitrocellulose resin, two-part urethane resin, acrylic resin, styrene resin, polyester resin, urethane resin, polyvinyl resin, alkyd resin, epoxy resin, melamine resin, fluorine Various synthetic resins such as silicone resins, silicone resins, and rubber resins, or mixtures and copolymers thereof can be used. Examples of colorants include inorganic pigments such as carbon black, titanium white, zinc oxide, red iron oxide, chrome, iron blue, cadmium red, azo pigments, lake pigments, anthraquinone pigments, phthalocyanine pigments, and isoindolinone pigments. , organic pigments such as dioxazine pigments, or mixtures thereof can be used. Examples of solvents that can be used include toluene, xylene, ethyl acetate, butyl acetate, methyl alcohol, ethyl alcohol, isopropyl alcohol, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, water, or mixtures thereof. .

In order to impart various functions to the base solid ink layer and the pattern layer 2, for example, an extender pigment, a plasticizer, a dispersant, a surfactant, a tackifier, an adhesion aid, a desiccant, a curing agent, and a curing agent are added. Functional additives such as accelerators and set retarders may be added.
Here, the underlying solid ink layer and the pattern layer 2 can be formed by various printing methods such as gravure printing, offset printing, screen printing, electrostatic printing, and inkjet printing. Further, since the underlying solid ink layer covers the entire surface of the substrate layer 1, it can be formed by various coating methods such as roll coating, knife coating, micro gravure coating, and die coating. These printing method and coating method may be selected separately depending on the layer to be formed, but it is efficient to select the same method and perform collective processing.

(Transparent resin layer 3)
The resin material used as the main component of the transparent resin layer 3 is preferably made of an olefin-based resin such as polypropylene, polyethylene, polybutene, α-olefin (eg, propylene, -hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1 -nonadecene, 1-eicosene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4, 4 -dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 9-methyl-1-decene, 11-methyl-1-dodecene, 12-ethyl-1-tetradecene, etc.) alone Polymerization or copolymerization of two or more types, ethylene/vinyl acetate copolymer, ethylene/vinyl alcohol copolymer, ethylene/methyl methacrylate copolymer, ethylene/ethyl methacrylate copolymer, ethylene/butyl methacrylate copolymer polymers, ethylene/methyl acrylate copolymers, ethylene/ethyl acrylate copolymers, ethylene/butyl acrylate copolymers, and copolymers of ethylene or α-olefins with other monomers. . Moreover, in order to improve the surface strength of the decorative sheet 10, it is preferable to use a highly crystalline polypropylene resin as in the case of the base material layer 1.

Here, the term "main component" as used in this specification refers to 90% by mass or more of the target material, unless otherwise specified.
When the transparent resin layer 3 is provided, the layer thickness of the transparent resin layer 3 is preferably 50 μm or more and 100 μm or less. If the thickness is less than 50 μm, the effect of improving the scratch resistance of the surface of the transparent resin layer 3 is low, and the significance of providing the transparent resin layer 3 may be reduced. If it exceeds 100 μm, problems such as whitening and cracking may occur during bending.
However, when the top coat layer 4 is provided on the transparent resin layer 3, the layer thickness of the transparent resin layer 3 may be less than 50 μm.
The resin composition constituting the transparent resin layer 3 may have various functions such as a heat stabilizer, a light stabilizer, an antiblocking agent, a catalyst scavenger, a coloring agent, a light scattering agent, and a luster adjusting agent, if necessary. may contain a sexual additive. These various functional additives can be appropriately selected from well-known ones and used.

(Top coat layer 4)
A top coat layer 4 can be provided on the surface of the transparent resin layer 3 when further improvement in scratch resistance and adjustment of gloss are required.
The resin material that is the main component of the top coat layer 4 is appropriately selected from, for example, polyurethane-based, acrylic silicon-based, fluorine-based, epoxy-based, vinyl-based, polyester-based, melamine-based, aminoalkyd-based, and urea-based resin materials. can be used as The form of the resin material is not particularly limited, and may be water-based, emulsion, solvent-based, or the like. As for the curing method, a one-liquid type, a two-liquid type, an ultraviolet curing method, or the like can be selected as appropriate.

As the resin material used as the main component of the top coat layer 4, a urethane-based material using isocyanate is suitable from the viewpoints of workability, cost, cohesion of the resin itself, and the like. Isocyanates include, for example, tolylene diisocyanate (TDI), xylylene diisocyanate (XDI), hexamethylene diisocyanate (HMDI), diphenylmethane diisocyanate (MDI), lysine diisocyanate (LDI), isophorone diisocyanate (IPDI), bis(isocyanatomethyl) Curing agents such as adducts, burettes, and isocyanurates, which are derivatives of cyclohexane (HXDI) and trimethylhexamethylene diisocyanate (TMDI), can be appropriately selected for use. Curing agents based on hexamethylene diisocyanate (HMDI) or isophorone diisocyanate (IPDI) having the molecular structure of are preferred. In addition, in order to improve the surface hardness, it is preferable to use a resin that is cured by 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 thermosetting type and photosetting type, it is possible to improve surface hardness, suppress curing shrinkage, and improve adhesion. can be planned.

A gloss adjusting agent can be added to the top coat layer 4 for gloss adjustment. As the luster adjusting agent, a commercially available known one may be used. For example, fine particles made of inorganic materials such as silica, glass, alumina, calcium carbonate, and barium sulfate may be used. Alternatively, fine particles made of an organic material such as acryl can also be used. However, when high transparency is required, it is desirable to use highly transparent fine particles of silica, glass, acryl, or the like. In particular, among fine particles such as silica and glass, gloss modifiers having a low bulk density formed by secondary agglomeration of fine primary particles rather than solid spherical particles have a high matting effect with respect to the amount added. Therefore, by using such a luster modifier, the amount of the luster modifier to be added can be reduced.

Moreover, in order to impart various functions to the topcoat layer 4, functional additives such as an antibacterial agent and an antifungal agent may be added. Moreover, you may add an ultraviolet absorber and a light stabilizer as needed. As the UV absorber, for example, benzotriazole-based, benzoate-based, benzophenone-based, triazine-based, and cyanoacrylate-based agents can be used. Moreover, a hindered amine system can be used as a light stabilizer.
The layer thickness of the topcoat layer 4 is preferably 3 μm or more and 15 μm or less. If the thickness is less than 3 μm, the effect of improving the scratch resistance is low, and the significance of providing the topcoat layer 4 may be reduced. If the thickness exceeds 15 μm, cracks and splits may occur during bending, which may cause design problems and deterioration of weather resistance.

<Manufacturing method>
A manufacturing example of the decorative sheet 10 will be described.
A nucleating agent vesicle is prepared by encapsulating a nucleating agent in a vesicle and converting the nucleating agent into a vesicle, and the prepared nucleating agent vesicle is added to a polypropylene resin together with an inorganic pigment to obtain a resin material for a base material layer. to make.
Nucleating agent vesicles are prepared by, for example, encapsulating the nucleating agent in vesicles having a monolayer membrane by supercritical reversed-phase evaporation to form vesicles.
As for the polypropylene resin to be used, it is preferable to use a highly crystalline homopolypropylene resin having an isotactic pentad fraction (mmmm fraction) of 95% or more in 50% or more and 100% or less by mass.

The base material layer 1 is obtained by heating and melting the above resin material for the base material layer and molding it into a sheet having a thickness of 50 μm or more and 150 μm or less by extrusion molding or the like.
At this time, the Martens hardness of the substrate layer 1 is controlled to 50 N/mm ² or more and 120 N/mm ² or less by adjusting the cooling time from the crystallization temperature to the curing completion temperature by a known adjustment method.
Further, if necessary, a pattern layer 2 is formed on the upper surface of the base material layer 1 by printing, and at least one of a transparent resin layer 3 and a top coat layer 4 is formed thereon by printing.
At this time, the thickness of the transparent resin layer 3 may be in the range of 50 μm to 100 μm, the thickness of the top coat layer 4 may be in the range of 3 μm to 15 μm, and the total thickness of the decorative sheet 10 may be in the range of 100 μm to 250 μm. preferable.

<Other effects>
(1) The decorative sheet 10 of the present embodiment has a base layer 1 made of a colored polypropylene film obtained by mixing an inorganic pigment with a polypropylene resin, and the base layer 1 contains a nano-sized nucleating agent, The nucleating agent is added in the form of nucleating agent vesicles that are encapsulated in the outer membrane and vesicled, and the substrate layer 1 has a Martens hardness of 50 N/mm ² or more and 120 N/mm ² or less, and Layer 1 has a thickness of 50 μm or more and 150 μm or less.
According to this configuration, a nucleating agent that improves the crystallinity of polypropylene is vesicled and added as a nucleating agent vesicle, and the Martens hardness and film thickness are optimized to improve printing processability (difficult to stretch). etc.), it is possible to provide the decorative sheet 10 capable of achieving both surface smoothness, scratch resistance and bending workability during lapping.

(2) In the decorative sheet 10 of the present embodiment, 50% by mass or more and 100% by mass or less of the polypropylene resin constituting the base material layer 1 has a high isotactic pentad fraction (mmmm fraction) of 95% or more. It is preferably made of crystalline homopolypropylene resin.
According to this configuration, it is possible to more reliably adjust the Martens hardness to 50 N/mm ² or more and 120 N/mm ^{2 or} less.
(3) In the decorative sheet 10 of the present embodiment, the amount of the nucleating agent vesicle added to the base material layer 1 is 0.00 in terms of the nucleating agent in the nucleating agent vesicle with respect to 100 parts by mass of the polypropylene resin. 05 parts by mass or more and 0.5 parts by mass or less.
According to this configuration, the degree of crystallinity of the colored polypropylene forming the base material layer 1 is sufficiently improved, and the necessary elastic modulus (hardness) can be ensured.

(4) In the decorative sheet 10 of the present embodiment, the nucleating agent vesicle is preferably a nucleating agent liposome having an outer membrane made of a phospholipid.
According to this configuration, the compatibility between the resin material, which is the main component of the substrate layer 1, and the vesicles can be improved.
(5) The decorative sheet 10 of the present embodiment preferably has the pattern layer 2 laminated on one surface of the base material layer 1 .
With this configuration, the design of the decorative sheet 10 can be improved.
(6) In the decorative sheet 10 of the present embodiment, at least one of the transparent resin layer 3 and the topcoat layer 4 is laminated on one side of the base material layer 1, and the total thickness of the decorative sheet 10 is 100 μm or more. It is preferably 250 μm or less.
According to this configuration, it is possible to suppress the occurrence of defects such as peeling over time due to the fact that the followability to the end surface of the wooden substrate and the laminated portion is significantly deteriorated during the lapping process, and the adhesive strength becomes insufficient. .

[Example]
Specific examples of the decorative sheet 10 of the present embodiment will be described below.
(Method for producing nucleating agent vesicle)
First, the method for producing the nucleating agent liposome used in this example will be described.
The nucleating agent liposome was prepared by using the above-described supercritical reverse phase evaporation method, using 100 parts by mass of methanol and 70 parts by mass of a phosphate ester metal salt-based nucleating agent (ADEKA STAB NA-21; manufactured by ADEKA) as a nucleating agent. , 5 parts by mass of phosphatidylcholine as a phospholipid constituting the outer membrane of the vesicle is put in a high-pressure stainless steel container kept at 60 ° C. and sealed, and carbon dioxide is injected into the container so that the pressure becomes 20 MPa. Critical state. After that, while vigorously stirring the inside of the container, 100 parts by mass of ion-exchanged water is injected. After stirring and mixing for an additional 15 minutes while maintaining the temperature and pressure in a supercritical state, the carbon dioxide is discharged from the container and the pressure is returned to atmospheric pressure, so that the nucleating agent is added to the vesicles having a monolayer outer membrane composed of phospholipids. A vesicle containing a nucleating agent was obtained.

(Example 1)
A highly crystalline homopolypropylene resin with a pentad fraction of 97.8%, a melt flow rate (MFR) of 15 g/10 min (230°C), and a molecular weight distribution MWD (Mw/Mn) of 2.3 as a raw material for colored polypropylene films. To 78 parts by mass, 6 parts by mass of a titanium oxide pigment as an inorganic pigment, 16 parts by mass of a chromium-antimony composite oxide pigment, and the above-described nucleating agent vesicle are added as a nucleating agent so as to be 0.05 part by mass. A substrate layer 1 made of a colored polypropylene film having a thickness of 50 μm was formed by extrusion molding using a melt extruder.
(Example 2)
A base layer 1 having a thickness of 50 μm was formed by extrusion molding using a melt extruder in the same manner as in Example 1 except that the above-mentioned nucleating agent vesicle was added as a nucleating agent so as to be 0.5 parts by mass. A film was formed.

(Example 3)
A highly crystalline homopolypropylene resin with a pentad fraction of 97.8%, a melt flow rate (MFR) of 15 g/10 min (230°C), and a molecular weight distribution MWD (Mw/Mn) of 2.3 as a raw material for colored polypropylene films. 39 parts by mass of random polypropylene resin with a melt flow rate (MFR) of 12 g/10 min (230 ° C.) containing 4% of ethylene component, 6 parts by mass of titanium oxide pigment as inorganic pigment, chromium-antimony composite oxide 16 parts by mass of a pigment and the above-described nucleating agent vesicle are added as a nucleating agent so as to be 0.05 part by mass, and are extruded using a melt extruder to form a substrate comprising a colored polypropylene film having a thickness of 50 μm. Layer 1 was deposited.

(Example 4)
A base layer 1 having a thickness of 50 μm was formed by extrusion molding using a melt extruder in the same manner as in Example 3 except that the above-mentioned nucleating agent vesicle was added as a nucleating agent so as to be 0.5 parts by mass. A film was formed.
(Example 5)
A base layer 1 having a thickness of 100 μm was formed by extrusion molding using a melt extruder in the same manner as in Example 1, except that the above-mentioned nucleating agent vesicle was added as a nucleating agent so as to be 0.1 part by mass. A film was formed.
(Example 6)
In the same manner as in Example 1, a base layer 1 having a thickness of 150 μm was formed by extrusion molding using a melt extruder.
(Example 7)
In the same manner as in Example 2, a base material layer 1 having a thickness of 150 μm was formed by extrusion molding using a melt extruder.
(Example 8)
In the same manner as in Example 3, a base layer 1 having a thickness of 150 μm was formed by extrusion molding using a melt extruder.
(Example 9)
In the same manner as in Example 4, a base layer 1 having a thickness of 150 μm was formed by extrusion molding using a melt extruder.

(Example 10)
Both sides of the base layer 1 having a thickness of 50 μm prepared in the same manner as in Example 1 were subjected to corona treatment, and one of them was coated with a two-liquid curable urethane ink (V180; manufactured by Toyo Ink Mfg. Co., Ltd.). A pattern layer 2 was formed by performing pattern printing. Further, a two-liquid curable urethane topcoat (W184; manufactured by DIC Graphics, coating amount 10 g/m2) was applied to the surface of the pattern layer 2 to form a topcoat layer 4 to obtain a decorative sheet 10. .

(Example 11)
A topcoat layer 4 was formed in the same manner as in Example 10 on a base layer 1 having a thickness of 50 μm, which was prepared in the same manner as in Example 2, to obtain a decorative sheet 10 .
(Example 12)
A topcoat layer 4 was formed in the same manner as in Example 10 on a base layer 1 having a thickness of 50 μm, which was prepared in the same manner as in Example 3, to obtain a decorative sheet 10 .
(Example 13)
A topcoat layer 4 was formed in the same manner as in Example 10 on a base layer 1 having a thickness of 50 μm, which was prepared in the same manner as in Example 4, to obtain a decorative sheet 10 .
(Example 14)
A topcoat layer 4 was formed in the same manner as in Example 10 on a substrate layer 1 having a thickness of 100 μm, which was prepared in the same manner as in Example 5, to obtain a decorative sheet 10 .

(Example 15)
A topcoat layer 4 was formed in the same manner as in Example 10 on a base layer 1 having a thickness of 150 μm, which was prepared in the same manner as in Example 6, to obtain a decorative sheet 10 .
(Example 16)
A topcoat layer 4 was formed in the same manner as in Example 10 on a base layer 1 having a thickness of 150 μm, which was prepared in the same manner as in Example 7, to obtain a decorative sheet 10 .
(Example 17)
A topcoat layer 4 was formed in the same manner as in Example 10 on a substrate layer 1 having a thickness of 150 μm, which was prepared in the same manner as in Example 8, to obtain a decorative sheet 10 .
(Example 18)
A topcoat layer 4 was formed in the same manner as in Example 10 on a substrate layer 1 having a thickness of 150 μm, which was prepared in the same manner as in Example 9, to obtain a decorative sheet 10 .

(Example 19)
One surface of the substrate layer 1 having a thickness of 50 μm, which was prepared in the same manner as in Example 1, was subjected to corona treatment to set the wetting tension of the surface to 40 dyn/cm or more. Subsequently, a highly crystalline homopolypropylene resin having a pentad fraction of 97.8%, a melt flow rate (MFR) of 15 g/10 min (230°C), and a molecular weight distribution MWD (Mw/Mn) of 2.3 was melt extruded. A transparent resin layer 3 having a thickness of 90 μm was formed by extrusion using a machine, and both surfaces thereof were subjected to corona treatment so that the wetting tension of the surface was 40 dyn/cm or more.
Subsequently, a design layer 2 was formed by printing a pattern on the corona-treated surface of the substrate layer 1 with a two-liquid curable urethane ink (V180; manufactured by Toyo Ink Mfg. Co., Ltd.). Further, the transparent resin layer 3 is attached to the surface of the pattern layer 2 by a dry lamination method via an adhesive layer made of an adhesive for dry lamination (Takelac A540; manufactured by Mitsui Chemicals, coating amount 2 g/m ² ). Matched. Next, after forming an embossed pattern on the surface of the transparent resin layer 3 using an embossing mold roll, a two-component curable urethane top coat (W184; manufactured by DIC Graphics Co., Ltd.) is applied so as to cover the embossed pattern. , a coating amount of 10 g/m ² ) to form a topcoat layer 4 and obtain a decorative sheet 10 .

(Example 20)
A transparent resin layer 3 and a topcoat layer 4 were formed in the same manner as in Example 19 on a base layer 1 having a thickness of 50 μm, which was prepared in the same manner as in Example 2, to obtain a decorative sheet 10 .
(Example 21)
A transparent resin layer 3 and a topcoat layer 4 were formed in the same manner as in Example 19 on a substrate layer 1 having a thickness of 50 μm, which was prepared in the same manner as in Example 3, to obtain a decorative sheet 10 .
(Example 22)
A transparent resin layer 3 and a topcoat layer 4 were formed in the same manner as in Example 19 on a base layer 1 having a thickness of 50 μm, which was prepared in the same manner as in Example 4, to obtain a decorative sheet 10 .
(Example 23)
A transparent resin layer 3 and a topcoat layer 4 were formed in the same manner as in Example 19 on a substrate layer 1 having a thickness of 100 μm, which was prepared in the same manner as in Example 5, to obtain a decorative sheet 10 .

(Example 24)
A transparent resin layer 3 and a top coat layer 4 were formed in the same manner as in Example 19 on a substrate layer 1 having a thickness of 150 μm, which was prepared in the same manner as in Example 6, to obtain a decorative sheet 10 .
(Example 25)
A transparent resin layer 3 and a topcoat layer 4 were formed in the same manner as in Example 19 on a substrate layer 1 having a thickness of 150 μm, which was prepared in the same manner as in Example 7, to obtain a decorative sheet 10 .
(Example 26)
A transparent resin layer 3 and a topcoat layer 4 were formed in the same manner as in Example 19 on a substrate layer 1 having a thickness of 150 μm, which was prepared in the same manner as in Example 8, to obtain a decorative sheet 10 .
(Example 27)
A transparent resin layer 3 and a topcoat layer 4 were formed in the same manner as in Example 19 on a substrate layer 1 having a thickness of 150 μm, which was prepared in the same manner as in Example 9, to obtain a decorative sheet 10 .

(Example 28)
A highly crystalline homopolypropylene resin with a pentad fraction of 97.8%, a melt flow rate (MFR) of 15 g/10 min (230°C), and a molecular weight distribution MWD (Mw/Mn) of 2.3 as a raw material for colored polypropylene films. For 31.2 parts by mass, 46.8 parts of random polypropylene resin with a melt flow rate (MFR) of 12 g / 10 min (230 ° C.) containing 4% of ethylene component, 6 parts by mass of titanium oxide pigment as inorganic pigment, chromium- 16 parts by mass of the antimony composite oxide pigment and the above-described nucleating agent vesicle are added as a nucleating agent so as to be 1.0 part by mass, and are extruded using a melt extruder to form a colored polypropylene film having a thickness of 50 μm. A substrate layer 1 consisting of was formed.

(Example 29)
A highly crystalline homopolypropylene resin with a pentad fraction of 97.8%, a melt flow rate (MFR) of 15 g/10 min (230°C), and a molecular weight distribution MWD (Mw/Mn) of 2.3 as a raw material for colored polypropylene films. To 78 parts by mass, 6 parts by mass of a titanium oxide pigment as an inorganic pigment, 16 parts by mass of a chromium-antimony composite oxide pigment, and the above-mentioned nucleating agent vesicle were added as a nucleating agent so as to be 1.0 part by mass. A substrate layer 1 made of a colored polypropylene film having a thickness of 50 μm was formed by extrusion molding using a melt extruder.

(Comparative example 1)
A base layer 1 having a thickness of 50 μm was formed by extrusion molding using a melt extruder in the same manner as in Example 1 except that an untreated nucleating agent was used instead of the nucleating agent vesicles described above. .
(Comparative example 2)
A base layer 1 having a thickness of 50 μm was formed by extrusion molding using a melt extruder in the same manner as in Example 2 except that an untreated nucleating agent was used instead of the above-mentioned nucleating agent vesicles. .
(Comparative Example 3)
A substrate layer 1 having a thickness of 50 μm was formed by extrusion molding using a melt extruder in the same manner as in Example 3 except that an untreated nucleating agent was used instead of the above-mentioned nucleating agent vesicles. .
(Comparative Example 4)
A base layer 1 having a thickness of 50 μm was formed by extrusion molding using a melt extruder in the same manner as in Example 4 except that an untreated nucleating agent was used instead of the above-mentioned nucleating agent vesicles. .

(Comparative Example 5)
A substrate layer 1 having a thickness of 150 μm was formed by extrusion molding using a melt extruder in the same manner as in Example 6 except that an untreated nucleating agent was used instead of the above-mentioned nucleating agent vesicles. .
(Comparative Example 6)
A substrate layer 1 having a thickness of 150 μm was formed by extrusion molding using a melt extruder in the same manner as in Example 7 except that an untreated nucleating agent was used instead of the above-mentioned nucleating agent vesicles. .
(Comparative Example 7)
A substrate layer 1 having a thickness of 150 μm was formed by extrusion molding using a melt extruder in the same manner as in Example 8 except that an untreated nucleating agent was used instead of the above-mentioned nucleating agent vesicles. .
(Comparative Example 8)
A substrate layer 1 having a thickness of 150 μm was formed by extrusion molding using a melt extruder in the same manner as in Example 9 except that an untreated nucleating agent was used instead of the nucleating agent vesicles described above. .

(Comparative Example 9)
In the same manner as in Comparative Example 2, a base layer 1 having a thickness of 180 μm was formed by extrusion molding using a melt extruder. After that, a transparent resin layer 3 and a top coat layer 4 were formed in the same manner as in Example 19 to obtain a decorative sheet 10 .
(Comparative Example 10)
In the same manner as in Example 2, a base material layer 1 having a thickness of 180 μm was formed by extrusion molding using a melt extruder. After that, a transparent resin layer 3 and a top coat layer 4 were formed in the same manner as in Example 19 to obtain a decorative sheet 10 .
(Comparative Example 11)
In the same manner as in Example 2, a base layer 1 having a thickness of 40 μm was formed by extrusion molding using a melt extruder.

(Comparative Example 12)
A highly crystalline homopolypropylene resin with a pentad fraction of 97.8%, a melt flow rate (MFR) of 15 g/10 min (230°C), and a molecular weight distribution MWD (Mw/Mn) of 2.3 as a raw material for colored polypropylene films. For 31.2 parts by mass, 46.8 parts of random polypropylene resin with a melt flow rate (MFR) of 12 g / 10 min (230 ° C.) containing 4% of ethylene component, 6 parts by mass of titanium oxide pigment as inorganic pigment, chromium- 16 parts by mass of the antimony composite oxide pigment and the above-described nucleating agent vesicle are added as a nucleating agent so as to be 0.5 parts by mass, and extruded using a melt extruder to form a colored polypropylene film having a thickness of 50 μm. A substrate layer 1 consisting of was formed.

(Comparative Example 13)
A highly crystalline homopolypropylene resin with a pentad fraction of 97.8%, a melt flow rate (MFR) of 15 g/10 min (230°C), and a molecular weight distribution MWD (Mw/Mn) of 2.3 as a raw material for colored polypropylene films. 39 parts by mass of random polypropylene resin with a melt flow rate (MFR) of 12 g/10 min (230 ° C.) containing 4% of ethylene component, 6 parts by mass of titanium oxide pigment as inorganic pigment, chromium-antimony composite oxide 16 parts by mass of a pigment and the above-described nucleating agent vesicle are added as a nucleating agent so as to be 1.0 part by mass, and are extruded using a melt extruder to form a substrate comprising a colored polypropylene film having a thickness of 50 μm. Layer 1 was deposited.

(evaluation)
For the above Examples 1 to 29 and Comparative Examples 1 to 13, Martens hardness measurement, tensile modulus measurement, defects during printing processing (printing processing suitability), scratch resistance, smoothness during wrapping processing (wrapping processing Surface uniformity at time) and evaluation of bending suitability were performed.
<Martens hardness>
The measurement was performed using a Martens hardness measuring device (Fischerscope HM2000; Fisher Instruments Co., Ltd.) conforming to ISO14577. A sample was taken from the cross section of the decorative sheet 10 in order to avoid the influence of the laminated resin layers other than the base material layer 1 at the time of measurement. Specifically, the decorative sheet 10 is embedded in a resin such as a cold-curing type epoxy resin or a UV-curing resin, which is sufficiently cured, and then cut so that the cross section of the decorative sheet 10 appears, followed by mechanical polishing. A measurement surface was obtained by applying. A specific measuring method is to press an indenter into the substrate layer 1 on the measurement surface of each sample, and calculate the Martens hardness from the depth of the indentation and the load. The measurement was performed under the conditions of a test force of 10 mN, a required test force load time of 10 seconds, and a test force retention time of 5 seconds. Table 1 shows the calculated Martens hardness of each sample.

<Tensile modulus>
The tensile modulus was measured using an autograph (AGS-500NX) manufactured by Shimadzu Corporation, a tensile test was performed at a tensile speed of 50 mm/min, and the tensile modulus was calculated.
<Problems during printing (printing suitability)>
The pattern layer 2 was formed by gravure printing using a gravure printing machine, and at that time, the substrate layer 1 was stretched by tension, and the misregistration during lamination of each color was evaluated as a printing defect.
"◎" indicates that registration adjustment is not required at all, "○" indicates that it can be easily adjusted by automatic registration adjustment, "△" indicates that registration adjustment requires attention, and printing cannot be continued because register adjustment is not possible. The case was marked with "x". In addition, when the film during printing was frequently broken and there was a problem in mass production, it was also evaluated as "x". In addition, if the evaluation is "△" or higher, there is no problem as a printing process.

<Scratch resistance>
The scratch resistance was evaluated by conducting a pencil hardness test. In the pencil hardness test, a 3B pencil was used, the angle of the pencil was fixed at 45±1° with respect to the decorative sheet 10, and the pencil was slid while a load of 750 kg was applied to the surface of the decorative sheet 10. The state was observed (according to old JIS standard JISK5400). The test was conducted 5 times, and the scratches and marks of the pencil were evaluated.
"◎" indicates no scratches or marks, "○" indicates slight pencil marks, "△" indicates pencil marks, and pencil marks or torn colored polypropylene film are visible. was set to "x".
In addition, if the evaluation is "○" or higher, there is no practical problem. Also, if the evaluation is "Δ" or higher, the application is limited to, for example, furniture or a vertical surface at a high position that is not touched by people, but no problem occurs. An evaluation of "○" or higher is preferable.

<Bending suitability>
In the bending process suitability test, each decorative sheet 10 of Examples 1 to 29 and Comparative Examples 1 to 13 obtained by the above method was applied to one side of a medium density fiberboard (MDF) as the base material layer 1. is attached using a urethane-based adhesive, and a V-shaped groove is formed between the base layer 1 and the decorative sheet 10 so that the decorative sheet 10 on the opposite side of the base layer 1 is not scratched. Insert up to the boundary where the and are pasted together. Next, the base material layer 1 is bent up to 90 degrees along the V-shaped grooves so that the surface of the decorative sheet 10 forms a mountain fold, and whitening or cracking occurs in the bent portion of the surface of the decorative sheet 10. The state of bending workability was evaluated by observing with an optical microscope.
"◎" when no whitening or cracks are seen, "○" when slightly whitening is visible in some areas, "△" when whitening is partially visible, and whitening is visible on the entire surface or partially The case where cracks were visible was rated as "x". In addition, if it is evaluation more than "(triangle|delta)", there will be no practical problem.

<Surface uniformity during lapping>
In the surface uniformity test at the time of lapping, a rectangular material obtained by bonding 3 to 5 plates or particle boards between two medium density fiberboards (MDF) was used as the base material layer 1, and obtained by the above method. The obtained decorative sheets 10 of Examples 1 to 29 and Comparative Examples 1 to 13 were attached by wrapping using a hot-melt adhesive to obtain a decorative board. Subsequently, the surface where the decorative sheet 10 was bonded to the edge of the plate was observed, and whether there was surface unevenness caused by the unevenness of the plate or the step of the bonded portion of the plate was visually observed. Further, the resulting decorative sheet was left for 1000 hours in an environment of 80° C. temperature and 85% humidity, and surface unevenness and peeling of the decorative sheet 10 at the same locations were checked.
“◎” indicates that the surface is smooth with no visible unevenness or steps even after 1000 hours, “○” indicates that the surface is slightly rough, and “△” indicates that unevenness or steps are visible in some areas. A case where unevenness or a step was observed on the surface, or peeling of the decorative sheet 10 was observed after 1000 hours was evaluated as "X". An evaluation of "Δ" or higher is practically acceptable, but an evaluation of "◯" or higher is preferable.
These evaluation results are shown in Table 1.

As can be seen from Table 1, in the decorative sheets 10 of Examples 1 to 9, 28, and 29, smoothness and bending during wrapping are ensured while securing a situation that can withstand practical use in terms of defects and strength during printing. It can be seen that both are compatible. Furthermore, it can be seen that the decorative sheets 10 of Examples 10 to 18 are improved in scratch resistance by laminating the pattern layer 2 and the top coat layer 4 on Examples 1 to 9. In addition, in the decorative sheets 10 of Examples 19 to 27, the pattern layer 2, the transparent resin layer 3 and the top coat layer 4 are laminated on Examples 1 to 9, and while achieving both high design and high scratch resistance, It can be seen that both smoothness and bending work are compatible.

On the other hand, in the decorative sheets 10 of Comparative Examples 1 to 9, since a nucleating agent that was not vesicled was used, the strength was not sufficiently improved by improving the degree of crystallinity, and the film thickness was thin and a highly crystalline homopolypropylene resin was added. When the ratio is low, problems occur during printing. Moreover, even when there is no problem during printing, there are cases where problems occur during bending or problems occur in smoothness during wrapping. These are considered to be caused by the lower ability to improve the degree of crystallinity compared to vesicled nucleating agents and the relatively large spherulite size.

Further, in the decorative sheets 10 of Comparative Examples 10 to 13, any of the added amount as the nucleating agent, the blending ratio of the highly crystalline homopolypropylene resin, the film thickness of the base material layer 1, and the Martens hardness is the numerical value of the present application. Although it is beyond the range, it can be seen that one of the evaluation results has a problem.
Here, in Comparative Example 11, although automatic register adjustment was possible, the film during printing frequently broke, and the product could not be manufactured. This is probably because although the Martens hardness and tensile modulus were sufficient, the thickness was too small, so the film could not withstand tension fluctuations during printing, and the frequency of breakage increased. In Comparative Example 10, peeling of the decorative sheet 10 was observed after 1000 hours in the evaluation of the lapping process. This is probably because the decorative sheet 10 was too thick with high crystallinity, and as a result, the conformability to the wooden substrate was remarkably deteriorated, and the adhesion to the wooden substrate was insufficient.

From the above, the decorative sheets 10 of Examples 1 to 29 have all of the problems during printing (printing process suitability), scratch resistance, smoothness during wrapping process (surface uniformity during wrapping process), and bending process suitability. It became clear that it is the decorative sheet 10 which compatible.
It should be noted that the decorative sheet of the present invention is not limited to the above embodiments and examples, and various modifications are possible without impairing the features of the present invention.

10 decorative sheet 1 base material layer 2 pattern layer 3 transparent resin layer 4 top coat layer B substrate

Claims (17)

It has a substrate layer made of a colored polypropylene film obtained by mixing an inorganic pigment with a polypropylene resin, and the substrate layer is a vesicle having a single-layer outer film for the polypropylene resin containing the inorganic pigment. The substrate layer is formed by adding a nucleating agent vesicle containing a nano-sized nucleating agent, the Martens hardness of the substrate layer is 80 N/mm ² or more and 120 N/mm ² or less, and the thickness of the substrate layer is is 50 μm or more and 150 μm or less,
The amount of the nucleating agent vesicle added is 0.5 parts by mass or more and 1.0 part by mass or less in terms of the nucleating agent in the nucleating agent vesicle with respect to 100 parts by mass of the polypropylene resin. Make-up sheet. It has a substrate layer made of a colored polypropylene film obtained by mixing an inorganic pigment with a polypropylene resin, and the substrate layer is a vesicle having a single-layer outer film for the polypropylene resin containing the inorganic pigment. The substrate layer is formed by adding a nucleating agent vesicle containing a nano-sized nucleating agent, the Martens hardness of the substrate layer is 80 N/mm ² or more and 120 N/mm ² or less, and the thickness of the substrate layer is is 50 μm or more and 150 μm or less,
The decorative sheet , wherein the base material layer further contains a fatty acid metal salt as an additive . It has a substrate layer made of a colored polypropylene film obtained by mixing an inorganic pigment with a polypropylene resin, and the substrate layer is a vesicle having a single-layer outer film for the polypropylene resin containing the inorganic pigment. The substrate layer is formed by adding a nucleating agent vesicle containing a nano-sized nucleating agent, the Martens hardness of the substrate layer is 80 N/mm ² or more and 120 N/mm ² or less, and the thickness of the substrate layer is is 50 μm or more and 150 μm or less,
The decorative sheet , wherein the inorganic pigment contains a composite oxide containing two kinds of metal elements . It has a substrate layer made of a colored polypropylene film obtained by mixing an inorganic pigment with a polypropylene resin, and the substrate layer is a vesicle having a single-layer outer film for the polypropylene resin containing the inorganic pigment. The substrate layer is formed by adding a nucleating agent vesicle containing a nano-sized nucleating agent, the Martens hardness of the substrate layer is 80 N/mm ² or more and 120 N/mm ² or less, and the thickness of the substrate layer is is 50 μm or more and 150 μm or less,
The decorative sheet , wherein the inorganic pigment contains titanium oxide and a chromium-antimony composite oxide . 50% by mass or more and 100% by mass or less of the polypropylene resin is a highly crystalline homopolypropylene resin having an isotactic pentad fraction (mmmm fraction) of 95% or more. 5. The decorative sheet according to any one of 4 . The amount of the nucleating agent vesicle added is 0.05 parts by mass or more and 0.5 parts by mass or less in terms of the nucleating agent in the nucleating agent vesicle with respect to 100 parts by mass of the polypropylene resin. The decorative sheet according to any one of claims 2 to 4 . The decorative sheet according to any one of claims 1 to 6 , wherein the nucleating agent vesicle is a nucleating agent liposome having an outer membrane made of phospholipid. 8. The decorative sheet according to any one of claims 1 to 7, wherein a pattern layer is laminated on one surface of the base material layer. At least one layer of a transparent resin layer and a top coat layer is laminated on one surface side of the base material layer,
The decorative sheet according to any one of claims 1 to 8 , characterized in that the total thickness of the decorative sheet is 100 µm or more and 250 µm or less. The nucleating agent vesicle is obtained by encapsulating the nucleating agent in a vesicle having a monolayer membrane by a supercritical reverse phase evaporation method to form a vesicle. 1. The cosmetic sheet described in 1. 4. The decorative sheet according to claim 3 , wherein the inorganic pigment further contains titanium oxide. 12. The decorative sheet according to claim 3 , wherein the composite oxide is an oxide composed of iron-zinc, chromium-antimony, or iron-aluminum. 5. The decorative sheet according to claim 4 , wherein the content of said titanium oxide is less than the content of said chromium-antimony composite oxide. The decorative sheet according to any one of claims 1 to 13 , wherein the base layer has a tensile modulus of 700 MPa or more and 2000 MPa or less. A method for manufacturing a decorative sheet according to any one of claims 1 to 14 ,
Producing a nucleating agent vesicle obtained by encapsulating a nucleating agent in a vesicle to vesicleize the nucleating agent,
The base layer having a Martens hardness of 80 N/mm ² or more and 120 N/mm ^{2 or} less and a thickness of 50 μm or more and 150 μm or less is formed from a resin material obtained by adding an inorganic pigment and the nucleating agent vesicle prepared above to a polypropylene resin. A method for manufacturing a decorative sheet, comprising: 6. The method for producing a decorative sheet according to claim 15 , wherein the Martens hardness of the base material layer is controlled to 80 N/mm ² or more and 120 N/mm ^{2 or} less when manufacturing the base material layer. Laminating at least one layer of a transparent resin layer and a top coat layer on one surface side of the base material layer,
When the transparent resin layer and the top coat layer are provided, the thickness of the transparent resin layer is 50 μm or more and 100 μm or less, the thickness of the top coat layer is 3 μm or more and 15 μm or less, and the total thickness of the decorative sheet is 100 μm or more and 250 μm. 17. The method for producing a decorative sheet according to claim 15 or 16 , characterized by the following.

Images