JP2023126797A - Decorative sheet and manufacturing method thereof - Google Patents

Abstract

To provide a decorative sheet excellent in scratch resistance while capable of preventing an elongation at print processing and of reducing occurrence of flexural whitening or a crack, and a manufacturing method of the decorative sheet.SOLUTION: A decorative sheet 1 includes a substrate layer 2 composed of a pigmented polypropylene film formed by mixing an inorganic pigment in a polypropylene resin. Furthermore, the substrate layer 2 contains a nano-sized nucleating agent. Furthermore, the substrate layer 2 has a value 0.7-0.9 of peak intensity ratio x calculated from an absorption spectrum obtained at Fourier-type infrared spectroscopy. Furthermore, the substrate layer 2 is 50-150 μm thick.SELECTED DRAWING: Figure 1

Description

The present invention relates to a decorative sheet used for the exterior and interior of buildings, the surface of fittings, the surface material of home appliances, etc., and a method for manufacturing 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 decorative sheets made of polyvinyl chloride, which are concerned about environmental protection issues. ing. Since these decorative sheets do not use vinyl chloride resin, the generation of toxic gases and the like during incineration is suppressed. However, polypropylene sheets generally have problems such as poor scratch resistance due to their low elastic modulus, and the tendency to stretch when tension is applied to the sheet during printing or other sheet production.

By the way, a decorative sheet can be attached to the surface of a substrate such as a wooden substrate, a metal substrate, a noncombustible substrate, etc. to form a decorative board, and the decorative sheet imparts a design to the decorative board according to the purpose. Therefore, the decorative sheet needs to cover the surface of the substrate so that it is completely hidden from view, if necessary. In this case, it is necessary to use a decorative sheet that is colored with at least a pigment and has concealing properties. The simplest structure of a decorative sheet is a structure consisting of only a base material layer consisting of a single colored sheet (single layer). In the case of such a decorative sheet consisting only of a base material layer, the designs that can be applied are usually limited to single colors without patterns, but for example, by adding glittering materials such as aluminum flakes or pearl pigments as pigments, it is possible to create glittering designs. Since it is possible to give a sense of feeling, necessary and sufficient design expression is possible. Furthermore, if it is desired to provide a more sophisticated design, it is also effective to decorate the surface of the base material layer by printing or the like.

On the other hand, as mentioned above, a colored polypropylene film has a low elastic modulus, so when used as a single-layer decorative sheet, it needs to be scratch resistant and not stretch even when tension is applied during processing such as printing. Regarding elongation when tension is applied, conventional colored polypropylene films can be improved by increasing the layer thickness to about 50 μm or more. Regarding scratch resistance, conventional colored polypropylene films use a transparent resin layer made of polypropylene resin or a urethane thermosetting resin made of polyol and isocyanate, as in Patent Document 2 and Patent Document 3. This can be improved by providing a top coat layer.

Further, as in Patent Document 2 and Patent Document 3, by optimally selecting the polypropylene resin used for the colored polypropylene film, it is possible to improve scratch resistance and elongation during printing processing. However, although the modulus of elasticity improves by increasing the crystallinity, the stress at break does not increase commensurately with the modulus of elasticity, making the film itself more likely to tear, making it more likely to cause problems such as breakage during printing. Furthermore, during post-processing as a decorative sheet, particularly during bending such as V-cutting, problems such as cracking and whitening at the bent portions are likely to occur.

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

Conventionally, decorative sheets using colored polypropylene film alone or decorative sheets using colored polypropylene film as a base layer have been designed to have both print processing suitability (difficulty in stretching, etc.), scratch resistance, and bending workability. is required.
The present invention was made with attention to the above-mentioned points, and is a colored polypropylene film that can improve scratch resistance, suppress elongation during printing processing, and reduce the occurrence of whitening and cracking when bent. It is an object of the present invention to provide a decorative sheet using polypropylene alone, a decorative sheet using a colored polypropylene film as a base layer, and a method for producing these decorative sheets.

The present inventors added a nucleating agent that improves the crystallinity of polypropylene as a nucleating agent vesicle by encapsulating it in, for example, a vesicle having a single-layered outer membrane, and then adding it as a nucleating agent vesicle. After conducting various studies and experiments, it was discovered that by adjusting the degree of crystallinity to an optimal range, it is possible to provide a decorative sheet that improves the above problems and a method for producing the same.
In order to achieve the object, a decorative sheet according to one embodiment of the present invention has a base layer made of a colored polypropylene film made by mixing an inorganic pigment with a polypropylene resin, and the base layer contains a nano-sized nucleating agent. , the thickness of the base layer is 50 μm or more and 150 μm or less, and the value of the peak intensity ratio x calculated from the absorption spectrum obtained in Fourier infrared spectroscopy is 0.7 or more and 0.9. The gist is as follows. Note that in the decorative sheet according to one aspect of the present invention, the nucleating agent may be contained in the form of nucleating agent vesicles that are enclosed in the outer membrane and formed into vesicles.
Here, the nucleating agent vesicle has a structure in which a nucleating agent is encapsulated in a capsule-like vesicle having a single-layer outer membrane, and can be prepared by, for example, supercritical reverse phase evaporation. . Further, the nucleating agent is a substance that becomes the starting point of crystallization in the crystalline polypropylene resin.

According to one aspect of the present invention, a nucleating agent that improves the crystallinity of polypropylene is added as a nucleating agent vesicle by forming it into a vesicle, and the value of the peak intensity ratio and the value of the peak intensity ratio obtained in Fourier infrared spectroscopy are By optimizing the film thickness, it is possible to provide a decorative sheet that is suitable for printing processing (resistance to stretching, etc.), scratch resistance, and bending processability.

FIG. 1 is a sectional view showing a decorative sheet according to an embodiment of the present invention. It is a sectional view showing another decorative sheet concerning an embodiment based on the present invention.

Embodiments of the present invention will be described below with reference to the drawings.
Here, the drawings are schematic, and the relationship between thickness and planar dimension, the ratio of the thickness of each layer, etc. differ from the actual one. In addition, the embodiments shown below illustrate configurations for embodying the technical idea of the present invention, and the technical idea of the present invention is to It is not something specific. The technical idea of the present invention can be modified in various ways within the technical scope defined by the claims.

"composition"
The decorative sheet 1 according to the embodiment shown in FIG. 1 is an example of a single-layer structure including only the base material layer 2 (original fabric layer). The base material layer 2 of this embodiment is composed of a colored polypropylene film. The base material layer 2 made of a colored polypropylene film is a polypropylene resin mixed with an inorganic pigment for coloring, and also contains a nano-sized nucleating agent. In this embodiment, the nucleating agent may be contained, for example, in the form of nucleating agent vesicles, which are enclosed in the outer membrane and formed into vesicles.

The thickness of the base material layer 2 is 50 μm or more and 150 μm or less, and the peak intensity ratio x calculated from the absorption spectrum obtained in Fourier infrared spectroscopy is 0.7 or more and 0.9 or less. . Preferably, 50% by mass or more and 100% by mass or less of the polypropylene resin constituting the base layer 2 is a highly crystalline homopolypropylene resin having an isotactic pentad fraction (mmmm fraction) of 95% or more. .

The amount of the nano-sized nucleating agent added is preferably 0.01 parts by mass or more and 0.5 parts by mass or less with respect to 100 parts by mass of the polypropylene resin.
In addition, when using nucleating agent vesicles, the amount of the nucleating agent vesicles added is 0.01 parts by mass or more, calculated as the nucleating agent in the nucleating agent vesicles, per 100 parts by mass of the polypropylene resin. It is preferably 5 parts by mass or less. The nucleating agent vesicle is preferably a nucleating agent liposome having an outer membrane made of phospholipid.

If necessary, a pattern layer 3 may be formed (laminated) on one surface of the base layer 2 to improve the design. Further, the decorative sheet 1 may have at least one layer of the transparent resin layer 4 and the top coat layer 5 laminated on one side of the base layer 2. The decorative sheet 1 illustrated in FIG. This is an example in which a pattern layer 3, a transparent resin layer 4, and a top coat layer 5 are laminated in this order on one side of the decorative sheet 1. Either the transparent resin layer 4 or the top coat layer 5 may be omitted. Moreover, the pattern layer 3 may be omitted.

Here, at least one of the transparent resin layer 4 and the top coat layer 5 may be provided with an embossed uneven pattern (embossed pattern 4a) depending on design requirements. It is also possible to embed ink in the embossed pattern 4a to further improve the design. Further, if there is a problem in the adhesion between the pattern layer 3 and the transparent resin layer 4, an adhesive resin layer 4b may be provided as appropriate. When the adhesive resin layer 4b is provided, it is formed by co-extrusion of the transparent resin layer 4 and the adhesive resin layer 4b. The adhesive resin layer 4b is made of, for example, acid-modified resin such as polypropylene, polyethylene, or acrylic resin. The thickness of the adhesive resin layer 4b is desirably 2 μm or more for the purpose of improving adhesive strength. Furthermore, in view of requirements such as scratch resistance, it is possible to laminate a plurality of layers of at least one of the transparent resin layer 4 and the top coat layer 5, and it is also possible to arrange other known layers.

In FIGS. 1 and 2, the symbol B represents a substrate. The substrate B is a substrate to which the decorative sheet 1 is bonded. Although there is no particular limitation on the substrate B, examples thereof include wooden boards, inorganic boards, metal plates, and composite boards made of a plurality of materials. A primer layer 6, a concealing layer (not shown), etc. may be provided between the decorative sheet 1 and the substrate B as appropriate.
It is preferable that the tensile modulus of the decorative sheet 1 of this embodiment, particularly the tensile modulus of the base layer 2 alone, ranges from 850 MPa to 1600 MPa. If the tensile modulus is less than 850 MPa, there is a possibility that problems during printing cannot be suppressed. If the tensile modulus exceeds 1600 MPa, the crystallinity is too high, and even when a nucleating agent (for example, nucleating agent vesicles) is used, problems such as whitening and cracking may occur during bending.

Next, each layer constituting the decorative sheet 1 will be explained.
<Base material layer 2>
The base layer 2 is made of a colored polypropylene film. Colored polypropylene films are made from polypropylene resin as a main raw material, and are colored by mixing inorganic pigments with the polypropylene resin. Furthermore, a nano-sized nucleating agent is added to the base material layer 2 in order to improve crystallinity. In this embodiment, the nano-sized nucleating agent may be added in the form of nucleating agent vesicles.

(Polypropylene resin)
As the polypropylene resin, it is preferable to use highly crystalline homopolypropylene, which will be described later, but it is not limited to highly crystalline homopolypropylene. In applications where more emphasis is placed on workability such as bending, it is possible to mix highly crystalline homopolypropylene with, for example, a random polypropylene resin having an ethylene content within a predetermined range or a known amorphous polypropylene resin. .

The value of the peak intensity ratio x calculated from the absorption spectrum obtained in Fourier infrared spectroscopy of the base layer 2 made of a colored polypropylene film is adjusted to 0.7 or more and 0.9 or less. When the peak intensity ratio x is less than 0.7, it is highly likely that defects during printing cannot be suppressed and it becomes difficult to ensure scratch resistance required for practical use. On the other hand, when the peak intensity ratio x exceeds 0.9, the crystallinity is too high, and even when nucleating agent vesicles are used, problems such as whitening and cracking may occur during bending.

Here, Fourier type infrared spectrometry will be explained. First, infrared spectroscopy is based on the principle that the amount of infrared light, which is light with a wavelength of 2.5 μm to 25 μm, absorbed by a substance changes based on the vibration and rotational movement of the molecules of the substance. This is a measurement method that obtains information about the chemical structure and state of a substance by measuring the infrared light absorbed by the substance. The specific measurement method is to irradiate a material with infrared light from a light source, generate interference waves by combining the divided transmitted light and reflected light, and calculate each wave number from the signal strength of the interference waves. The infrared spectrum is measured by calculating the intensity of the component light. In particular, in this embodiment, the interference wave was calculated using the Fourier transform method, and the measurement was performed using Fourier infrared spectroscopy, which is a method of measuring an infrared spectrum. A graph in which the wavenumber obtained by the above method is plotted on the horizontal axis and the measured absorbance (or transmittance) is plotted on the vertical axis is called an infrared absorption spectrum (or infrared transmission spectrum), and a unique pattern is recognized for each substance. It will be done. At this time, the absorbance on the vertical axis changes in proportion to the concentration and thickness of the substance, and in the case of crystalline substances, the amount of crystalline or amorphous parts, so the value of the peak intensity at a given wavenumber changes. It is also possible to perform quantitative analysis based on peak height and area.

In this embodiment, by utilizing the above-mentioned characteristics of the infrared absorption spectrum, the peak intensity at a wave number of 997 cm ^-1 , which corresponds to the absorbance of the crystalline part of the colored polypropylene film, in the absorption spectrum obtained by the above-mentioned measurement. and the peak intensity at a wave number of 973 cm ^-1 corresponding to the absorbance of the amorphous part of the film, that is, the peak intensity ratio x representing the crystallinity of polypropylene is calculated using the following formula, and the peak intensity ratio is The purpose of the present invention is to clarify the relationship between x and the rigidity of a colored polypropylene film, and to provide a decorative sheet with excellent rigidity in which a colored polypropylene film having a peak intensity ratio x within a predetermined range is used as a base layer. Note that the peak intensity at wave number 997 cm ^-1 and the peak intensity at wave number 973 cm ^-1 are subjected to background correction using the peak intensity at wave number 938 cm ^-1 , respectively.

Moreover, it is important that the thickness of the base material layer 2 made of a colored polypropylene film is 50 μm or more and 150 μm or less.
If the thickness of the base material layer 2 is less than 50 μm, the film strength will be insufficient even if the peak intensity ratio be. On the other hand, if the thickness of the base layer 2 exceeds 150 μm, problems such as whitening and cracking may occur during bending.
In this embodiment, it is preferable to use a highly crystalline polypropylene resin as the polypropylene resin. In particular, highly crystalline homopolypropylene resin, which is a propylene monopolymer with an isotactic pentad fraction (mmmm fraction) of 95% or more, is contained in a range 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 it in

The crystallization temperature of polypropylene resin is generally within the range of 100 to 130°C, and when a nucleating agent is added, it is within the range of 110 to 140°C. In the colored polypropylene film of the decorative sheet 1 of this embodiment, the value of the peak intensity ratio It is adjusted to 0.7 or more and 0.9 or less. In addition, when polypropylene resin with an isotactic pentad fraction (mmmm fraction) of less than 95% is used, crystallinity is insufficient, so even if the cooling process is controlled, the peak intensity ratio x is lower than the preferred range. It may become low. Similarly, when the content of highly crystalline homopolypropylene resin is less than 50% by mass, crystallinity is insufficient, so even if the cooling process is controlled, the peak intensity ratio x may fall below the preferred range. .

Here, the isotactic pentad fraction (mmmm fraction) refers to the isotactic pentad fraction (mmmm fraction) when a resin material is measured at 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 resonance in the resin material, and defines the atomic arrangement, electronic structure, and fine structure of molecules in the resin material. The pentad fraction of a crystalline polypropylene resin is the ratio of five propylene units arranged 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, and basically the higher the pentad fraction, the higher the degree of crystallinity.

(Inorganic pigment)
As the inorganic pigment, a known inorganic pigment typified by titanium oxide for imparting concealing properties can be used. Inorganic pigments for coloring include, for example, complex oxides such as iron-zinc, chromium-antimony, iron-aluminum, iron oxide, etc., but the composition of these can be adjusted freely depending on the desired color. be. Further, as an inorganic pigment, for example, a glittering material such as aluminum flakes or pearl pigment can be added. Further, 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 to improve dispersibility and extrusion suitability.

(Nucleating agent vesicle)
Moreover, the base material layer 2 contains a nano-sized nucleating agent. The nano-sized nucleating agent may be used, for example, by being added to the polypropylene resin in the form of a nucleating agent vesicle encapsulated in a vesicle having a monolayer outer membrane. Since the base material layer 2 contains a nucleating agent, the degree of crystallinity can be improved, and the scratch resistance (scratch resistance) of the base material layer 2 can be improved. In this embodiment, the nucleating agent in the resin constituting the base layer 2 may be encapsulated in a vesicle with a portion of the nucleating agent exposed.
The average particle size of the nano-sized nucleating agent is preferably 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, the average particle size 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, the distance between each nucleating agent particle becomes shorter, so that when crystal growth occurs from the surface of one nucleating agent particle added to the polypropylene resin, the end where the crystal is growing immediately One nucleating agent particle comes into contact with the edge of a crystal growing from the surface of another nucleating agent particle adjacent to it, and the edges of each crystal inhibit growth and stop the growth of each crystal. The average particle size of spherulites in the crystalline portion 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 high crystallinity and high hardness can be obtained, and the stress concentration between the spherulites that occurs during bending is efficiently dispersed, which suppresses cracking and whitening during bending. Colored polypropylene films can be realized.

If the nucleating agent is simply added, the nucleating agent in the polypropylene resin will undergo secondary agglomeration, increasing the particle size and increasing the number of crystal nuclei relative to the amount of the nucleating agent added. The amount may be lower than when added as agent vesicles. For this reason, the average particle size of spherulites in the crystalline part of the polypropylene resin becomes large, and cracking and whitening during bending tend to be more difficult to suppress than when added as nucleating agent vesicles. Therefore, when a nucleating agent is simply added, compared to when it is added as a nucleating agent vesicle, it tends to be difficult to simultaneously improve the elastic modulus by increasing the degree of crystallinity and processability.

The base material layer 2 made of a colored polypropylene film constituting the decorative sheet 1 of the present embodiment is 0.01 parts by mass or more in terms of the amount of nucleating agent added per 100 parts by mass of the polypropylene resin as the main component. It is preferable that 0.5 parts by mass or less, preferably 0.05 parts by mass or more and 0.3 parts by mass or less of a nucleating agent (nucleating agent vesicles) be added. If the amount of the nucleating agent (nucleating agent vesicle) added is less than 0.01 parts by mass, the degree of crystallinity may not be sufficiently improved and the required elastic modulus (hardness) may not be achieved. In addition, if the amount added exceeds 0.5 part by mass, the growth of spherulites is inhibited due to excessive crystal nuclei, resulting in insufficient improvement of crystallinity and the required elastic modulus (hardness). There is a possibility that it will not be reached.

In addition, methods for nano-forming nucleating agents include, for example, the solid phase method, which mainly involves mechanically crushing the nucleating agent to obtain nano-sized particles, and the solid phase method, which involves dissolving the nucleating agent or the nucleating agent. methods such as the liquid phase method, which synthesizes and crystallizes nano-sized particles in a nucleating solution, and the gas-phase method, which synthesizes and crystallizes nano-sized particles from a nucleating agent or gas/steam containing the 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. Further, 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, examples of the gas phase method include an electric furnace method, a chemical flame method, a laser method, and a thermal plasma method.

As a method for nano-forming the nucleating agent, a supercritical reverse phase evaporation method is preferable. The supercritical reverse phase evaporation method is a method of producing capsules (nano-sized vesicles) containing a target substance using carbon dioxide under supercritical state, temperature conditions or pressure conditions above the critical point. Carbon dioxide in a supercritical state means carbon dioxide in a supercritical state at a critical temperature (30.98°C) and a critical pressure (7.3773 ± 0.0030 MPa) or above, and under a temperature condition above the critical point or Carbon dioxide under pressure means carbon dioxide under conditions where only the temperature or only the pressure exceeds the critical condition.

In addition, as a specific nano-forming process using supercritical reversed-phase evaporation method, first, an aqueous phase is injected into a mixed fluid of supercritical carbon dioxide, phospholipids as an outer membrane forming substance, and a nucleating agent as an encapsulating substance. Then, by stirring, an emulsion of supercritical carbon dioxide and an aqueous phase is generated. Next, by reducing the pressure, the carbon dioxide expands and evaporates, causing phase inversion, and the phospholipid generates nanocapsules (nanovesicles) in which the surface of the nucleating agent particles is covered with a monolayer film. By using this supercritical reversed-phase evaporation method, unlike the conventional encapsulation method in which the outer film forms a multilayer film on the surface of the nucleating agent particles, it is possible to easily produce capsules with a single layer film. Small diameter capsules can be prepared.
The nucleating agent vesicle 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, or the like. Among these, supercritical reverse phase evaporation is particularly preferred.
The outer membrane constituting the nucleating agent vesicle is composed of, for example, a single layer membrane. Further, the outer membrane is composed of a substance containing biological lipids such as phospholipids.

In this specification, a nucleating agent vesicle whose outer membrane is composed of a substance containing a biological lipid such as a phospholipid is referred to as a nucleating agent liposome.
Examples of the phospholipids constituting the outer membrane include phosphatidylcholine, phosphatidylethanolamine, phosphatidylserine, phosphatidic acid, phosphatidylglycerol, phosphatidylinositol, cardiopine, egg yolk lecithin, hydrogenated egg yolk lecithin, soybean lecithin, hydrogenated soybean lecithin, etc. Examples include sphingophospholipids such as glycerophospholipids, sphingomyelin, ceramide phosphorylethanolamine, and ceramide phosphorylglycerol.

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

Furthermore, the outer membrane of the liposome may be formed from a mixture of a phospholipid and a dispersant. In the decorative sheet 1 of this embodiment, the nucleating agent vesicle is preferably a radical scavenger liposome having an outer membrane made of phospholipid. It is possible to improve the compatibility between the resin material which is the main component of the vesicles and the vesicles.

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. Examples of the nucleating agent include phosphate metal salts, benzoic acid 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 treatment, it is preferable to use phosphate ester metal salts, benzoate metal salts, pimelic acid metal salts, and rosin metal salts, which are non-melting and can be expected to have good transparency. If the material itself can be made transparent by nano-processing, colored quinacridone, cyanine blue, talc, etc. can also be used. Furthermore, molten benzylidene sorbitol may be appropriately mixed with the non-melted nucleating agent.

As described above, one of the features (matters specifying the invention) of the decorative sheet 1 of this embodiment is that "the base layer 2 contains a nucleating agent encapsulated in vesicles." By adding the nucleating agent to the resin composition in a state in which it is encapsulated in vesicles, the dispersibility of the nucleating agent in the resin material, that is, in the base material layer 2, is dramatically improved. However, it may be difficult to directly specify the characteristics of the finished decorative sheet 1 based on its structure or characteristics, depending on the situation, and it may be impractical. The reason is as follows. The nucleating agent added in the form of vesicles has high dispersibility and is in a dispersed state, and even in the state of the prepared decorative sheet 1, the nucleating agent is highly dispersed in the base material layer 2. ing. However, in the process of manufacturing the decorative sheet 1 after adding a nucleating agent in the form of vesicles to the resin composition constituting the base layer 2, the process of manufacturing the decorative sheet 1 usually involves compression into a laminate. Various treatments such as treatment and hardening treatment are performed, but these treatments cause the outer membrane of the vesicle containing the nucleating agent to fracture or undergo a chemical reaction, causing the nucleating agent to be enclosed in the outer membrane (foreskin). This is because the state in which the outer film is crushed or chemically reacted varies depending on the processing process of the decorative sheet 1. In situations such as when this nucleating agent is not included in the outer membrane, it is difficult to specify the physical properties in a numerical range, and it is difficult to determine whether the constituent material of the fractured outer membrane is the outer membrane of the vesicle. It may be difficult to determine whether the material was added separately from the nucleating agent. As described above, although the present invention is different from the conventional method in that the nucleating agent is blended in a highly dispersed manner in the base material layer 2, it is added in the form of vesicles containing the nucleating agent. It is conceivable that it may be impractical to determine whether this is due to the fact that the structure and characteristics of the decorative sheet 1 are in a numerical range analyzed based on measurements.
Here, the nucleating agent vesicles having the above structure may also be contained in the transparent resin layer 4 and the top coat layer 5.

(Picture layer 3)
A pattern layer 3 for adding a pattern to the decorative sheet 1 can be provided on the surface of the colored polypropylene film (base layer 2). As the pattern, for example, a wood grain pattern, a stone grain pattern, a sand grain pattern, a tiling pattern, a brickwork pattern, a cloth grain pattern, a leather drawing pattern, a geometric figure, etc. can be used.
Furthermore, a base solid ink layer (not shown) may be provided between the base material layer 2 and the pattern layer 3 depending on the degree of the desired design. The base solid ink layer is provided so as to cover the entire surface of the base layer 2. Further, the base solid ink layer may be formed into a multilayer of two or more layers as necessary, such as for concealment properties. Furthermore, the pattern layer 3 may be formed by laminating as many layers as the number of separations necessary to express the desired design. In this way, the pattern layer 3 and the base solid ink layer can be combined in various ways depending on the desired design, that is, the design desired to be expressed, but are not particularly limited.

The constituent materials of the base solid ink layer and the pattern layer 3 are not particularly limited. For example, a printing ink or a coating agent formed by dissolving and dispersing a matrix and a coloring agent such as a dye or a pigment in a solvent can be used. Examples of the matrix include oil-based nitrified cotton resin, two-component urethane resin, acrylic resin, styrene resin, polyester resin, urethane resin, polyvinyl resin, alkyd resin, epoxy resin, melamine resin, and fluorine resin. Various synthetic resins such as resins, silicone resins, and rubber resins, or mixtures and copolymers thereof can be used. Examples of coloring agents include inorganic pigments such as carbon black, titanium white, zinc white, Bengara, yellow lead, navy blue, and 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. Further, as the solvent, for example, toluene, xylene, ethyl acetate, butyl acetate, methyl alcohol, ethyl alcohol, isopropyl alcohol, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, water, etc., or a mixture thereof, etc. can be used. .

In addition, in order to impart various functions to the base solid ink layer and the pattern layer 3, for example, extender pigments, plasticizers, dispersants, surfactants, tackifiers, adhesion aids, desiccants, curing agents, curing agents, etc. Functional additives such as accelerators and cure retarders may also be added.
Here, the base solid ink layer and the pattern layer 3 can be formed by various printing methods such as a gravure printing method, an offset printing method, a screen printing method, an electrostatic printing method, and an inkjet printing method. Further, since the base solid ink layer covers the entire surface of the base material layer 2, it can also be formed by various coating methods such as a roll coating method, a knife coating method, a microgravure coating method, and a die coating method. Although these printing methods and coating methods may be selected separately depending on the layer to be formed, it is efficient to select the same method and perform batch processing.

(Transparent resin layer 4)
The resin material used as the main component of the transparent resin layer 4 is preferably made of olefin resin, and in addition to polypropylene, polyethylene, polybutene, etc., α-olefin (for example, propylene, 1-butene, 1-pentene, 1 -Hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 1-undecene, 1-dodecene, tridecene, 1-tetradecene, 1-pentadecene, 1-hexadecene, 1-heptadecene, 1-octadecene, 1 -nonadecene, 1-eicosene, 3-methyl-1-butene, 3-methyl-1-pentene, 3-ethyl-1-pentene, 4-methyl-1-pentene, 4-methyl-1-hexene, 4,4 -dimethyl-1-pentene, 4-ethyl-1-hexene, 3-ethyl-1-hexene, 9-methyl-1-decene, 11-methyl-1-dodecene, 12-ethyl-1-tetradecene, 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, such as ethylene/methyl acrylate copolymer, ethylene/ethyl acrylate copolymer, ethylene/butyl acrylate copolymer, etc., include copolymers of ethylene or α-olefin and other monomers. . Moreover, when aiming at improving the surface strength of the decorative sheet 1, it is preferable to use a highly crystalline polypropylene resin similarly to the base material layer 2.
Here, in this specification, the main component refers to 90% by mass or more of the target material, unless otherwise specified.

When providing the transparent resin layer 4, the layer thickness of the transparent resin layer 4 is preferably 50 μm or more and 100 μm or less. If it is less than 50 μm, the effect of improving the scratch resistance of the surface of the transparent resin layer 4 may be low, and the significance of providing the transparent resin layer 4 may be reduced. If it exceeds 100 μm, the rigidity of the decorative sheet 1 will be too high, and problems such as whitening and cracking may occur during bending.
However, when the top coat layer 5 is provided on the transparent resin layer 4, the layer thickness of the transparent resin layer 4 may be less than 50 μm.
Note that the resin composition constituting the transparent resin layer 4 may contain 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 gloss control agent as necessary. It may also contain a sex additive. These various functional additives can be appropriately selected from well-known ones and used.

(Top coat layer 5)
If further improvement in scratch resistance or adjustment of gloss is required, a top coat layer 5 can be provided on the surface of the transparent resin layer 4.
The resin material as the main component of the top coat layer 5 is appropriately selected from, for example, polyurethane-based, acrylic silicon-based, fluorine-based, epoxy-based, vinyl-based, polyester-based, melamine-based, aminoalkyd-based, urea-based, and other resin materials. It 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. The curing method can be appropriately selected from one-liquid type, two-liquid type, ultraviolet curing method, etc.

As the resin material used as the main component of the top coat layer 5, a urethane-based resin material using isocyanate is preferable from the viewpoints of workability, price, cohesive force 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), and bis(methyl isocyanate). The curing agent can be appropriately selected from adducts, burettes, and isocyanurates of derivatives such as cyclohexane (HXDI) and trimethylhexamethylene diisocyanate (TMDI), but in consideration of weather resistance, linear Curing agents based on hexamethylene diisocyanate (HMDI) or isophorone diisocyanate (IPDI) having the molecular structure are suitable. 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. Note that these resins can be used in combination with each other. For example, by using a hybrid type of thermosetting type and photocuring type, it is possible to improve surface hardness, suppress curing shrinkage, and improve adhesion. can be achieved.

A gloss adjuster can be added to the top coat layer 5 for gloss adjustment. As the gloss adjuster, a known commercially available one may be used. For example, fine particles made of inorganic materials such as silica, glass, alumina, calcium carbonate, barium sulfate, etc. may be used. Alternatively, fine particles made of an organic material such as acrylic may also be used. However, if high transparency is required, it is desirable to use fine particles of highly transparent silica, glass, acrylic, or the like. In particular, among fine particles of silica, glass, etc., gloss modifiers with low bulk density, which are formed by secondary agglomeration of fine primary particles rather than solid spherical particles, have a high matting effect depending on the amount added. Therefore, by using such a gloss adjusting agent, the amount of the gloss adjusting agent added can be reduced.

Further, in order to impart various functions to the top coat layer 5, functional additives such as antibacterial agents and antifungal agents may be added. Further, an ultraviolet absorber and a light stabilizer may be added as necessary. As the ultraviolet absorber, for example, a benzotriazole type, a benzoate type, a benzophenone type, a triazine type, or a cyanoacrylate type can be used. Further, as the light stabilizer, a hindered amine type can be used.
The thickness of the top coat layer 5 is preferably 3 μm or more and 15 μm or less. When the thickness is less than 3 μm, the effect of improving scratch resistance is low, and the significance of providing the top coat layer 5 may be reduced. If the thickness exceeds 15 μm, cracks or fractures may occur during bending, which may cause design problems or deterioration of weather resistance.

<Manufacturing method>
An example of manufacturing the decorative sheet 1 will be described.
A nucleating agent vesicle is prepared by encapsulating a nucleating agent in a vesicle and turning the nucleating agent into a vesicle, and the prepared nucleating agent vesicle is added to a polypropylene resin together with an inorganic pigment to form a resin material for the base layer. Create.
The nucleating agent vesicle is produced, for example, by encapsulating the above-mentioned nucleating agent in a vesicle provided with a monolayer film and forming the vesicle by supercritical reverse phase evaporation.
The polypropylene resin used is preferably a highly crystalline homopolypropylene resin having an isotactic pentad fraction (mmmm fraction) of 95% or more for 50% by mass or more and 100% by mass or less.

The base layer 2 is formed by heating and melting the resin material for the base 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, by adjusting the cooling time from the crystallization temperature to the curing completion temperature using a known adjustment method, the peak intensity ratio The value of is controlled to be 0.7 or more and 0.9 or less.
Furthermore, if necessary, a pattern layer 3 is formed on the upper surface of the base material layer 2 by printing, and at least one of the transparent resin layer 4 and the top coat layer 5 is formed thereon by printing.
In addition, although the said manufacturing method demonstrated the case where the base material layer 2 was manufactured using a nucleating agent vesicle, this invention is not limited to this. For example, the base material layer 2 may be manufactured by replacing the nucleating agent vesicles with nano-sized nucleating agents that are not encapsulated in vesicles.

<Other effects>
(1) The decorative sheet 1 of this embodiment has a base layer 2 made of a colored polypropylene film made by mixing an inorganic pigment with a polypropylene resin, and the base layer 2 contains a nano-sized nucleating agent, The thickness of the base material layer 2 is 50 μm or more and 150 μm or less, and the value of the peak intensity ratio x calculated from the absorption spectrum obtained in Fourier infrared spectroscopy is 0.7 or more and 0.9 or less. Moreover, the tensile modulus of the base material layer 2 is 850 MPa or more and 1600 MPa or less.
According to this configuration, a nucleating agent that improves the crystallinity of polypropylene is added, and the value of the peak intensity ratio x calculated from the absorption spectrum obtained in Fourier infrared spectroscopy and the film thickness are optimized. By doing so, it is possible to provide a decorative sheet 1 that is compatible with print processability (difficulty in stretching, etc.), scratch resistance, and bending processability.

(2) In the decorative sheet 1 of this embodiment, 50% by mass or more and 100% by mass or less of the polypropylene resin constituting the base layer 2 has a high isotactic pentad fraction (mmmm fraction) of 95% or more. It is preferably made of crystalline homopolypropylene resin.
According to this configuration, the value of the peak intensity ratio x calculated from the absorption spectrum obtained in Fourier infrared spectroscopy can be more reliably adjusted to 0.7 or more and 0.9 or less.

(3) In the decorative sheet 1 of the present embodiment, the amount of the nucleating agent added to the base layer 2 is preferably 0.05 parts by mass or more and 0.5 parts by mass or less based on 100 parts by mass of the polypropylene resin. .
According to this configuration, the degree of crystallinity of the colored polypropylene constituting the base material layer 2 is sufficiently improved, and the necessary tensile modulus of 850 MPa or more and 1600 MPa or less can be reliably secured.

(4) In the decorative sheet 1 of the present embodiment, it is preferable that the nucleating agent is a nucleating agent vesicle in which the nucleating agent is encapsulated in a vesicle having a single-layer outer membrane.
According to this configuration, a nucleating agent that improves the crystallinity of polypropylene is vesicleized and added as a nucleating agent vesicle, and the peak intensity ratio x calculated from the absorption spectrum obtained in Fourier infrared spectroscopy is By optimizing the value of and the film thickness, it is possible to provide a decorative sheet 1 that is compatible with print processability (difficulty in stretching, etc.), scratch resistance, and bending processability.

(5) The decorative sheet 1 of the present embodiment contains nucleating agent vesicles of 0.05 parts by mass or more and 0.5 parts by mass in terms of the nucleating agent in the nucleating agent vesicles, based on 100 parts by mass of the polypropylene resin. It is preferable to add and form it so that it falls within the following range.
According to this configuration, a nucleating agent that improves the crystallinity of polypropylene is vesicleized and added as a nucleating agent vesicle, and the peak intensity ratio x calculated from the absorption spectrum obtained in Fourier infrared spectroscopy is By optimizing the value of and the film thickness, it is possible to provide a decorative sheet 1 that is compatible with print processability (difficulty in stretching, etc.), scratch resistance, and bending processability.

(6) In the decorative sheet 1 of the present embodiment, the amount of nucleating agent vesicles added to the base layer 2 is 0.0000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000001121, 1000,000. The content is preferably 0.05 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 constituting the base material layer 2 is sufficiently improved, and the necessary tensile modulus of 850 MPa or more and 1600 MPa or less can be reliably secured.

(7) In the decorative sheet 1 of this embodiment, the nucleating agent vesicle is preferably a nucleating agent liposome having an outer membrane made of phospholipid.
According to this configuration, the compatibility between the resin material, which is the main component of the base material layer 2, and the vesicles can be made good.
(8) In the decorative sheet 1 of this embodiment, it is preferable that the pattern layer 3 is laminated on one side of the base layer 2.
According to this configuration, the design of the decorative sheet 1 can be improved.
(9) In the decorative sheet 1 of this embodiment, it is preferable that at least one of the transparent resin layer 4 and the top coat layer 5 is laminated on one side of the base layer 2.

[Example]
Below, specific examples of the decorative sheet 1 of this embodiment will be described.
(Method for producing nucleating agent vesicles)
First, a method for producing the nucleating agent liposome used in this example will be explained.
The nucleating agent liposome was prepared using the above-mentioned 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 was placed in a high-pressure stainless steel container kept at 60°C, sealed, and carbon dioxide was injected into the container so that the pressure became 20 MPa. Set to critical state. Thereafter, the inside of the container is vigorously stirred, and 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 returned to atmospheric pressure to inject the nucleating agent into the vesicles, which have a monolayer outer membrane made of phospholipids. Nucleating agent vesicles containing the nucleating agent were obtained.

(Example 1)
As a raw material for colored polypropylene film, 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. To 78 parts by mass, 6 parts by mass of titanium oxide pigment as inorganic pigment, 16 parts by mass of chromium-antimony composite oxide pigment, and the above-mentioned nucleating agent vesicles were added as 0.01 part by mass as nucleating agent. A base material layer 2 made of a colored polypropylene film having a thickness of 55 μm was formed by extrusion molding using a melt extruder.
(Example 2)
A base material layer 2 with a thickness of 55 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)
As a raw material for colored polypropylene film, 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. To 39 parts by mass, 39 parts of random polypropylene resin with a melt flow rate (MFR) of 12 g/10 min (230°C) containing 4% ethylene component, 6 parts by mass of titanium oxide pigment as an inorganic pigment, and chromium-antimony composite oxide 16 parts by mass of the pigment and the above-mentioned nucleating agent vesicles were added as a nucleating agent so that the amount was 0.01 parts by mass, and extrusion molded using a melt extruder to obtain a base material made of a colored polypropylene film having a thickness of 55 μm. Layer 2 was formed.

(Example 4)
A base material layer 2 with a thickness of 55 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 in an amount of 0.5 parts by mass. A film was formed.
(Example 5)
As in Example 1, extrusion molding was performed using a melt extruder to form a base material layer 2 having a thickness of 145 μm.
(Example 6)
In the same manner as in Example 2, extrusion molding was performed using a melt extruder to form a base material layer 2 having a thickness of 145 μm.
(Example 7)
In the same manner as in Example 3, extrusion molding was performed using a melt extruder to form a base material layer 2 having a thickness of 145 μm.
(Example 8)
In the same manner as in Example 4, extrusion molding was performed using a melt extruder to form a base material layer 2 having a thickness of 145 μm.

(Example 9)
A pattern was printed on the surface of a base layer 2 having a thickness of 55 μm, which was prepared in the same manner as in Example 1, to form a pattern layer 3. The pattern layer 3 is made by adding 0.5 parts by mass of a hindered amine light stabilizer (Kimasorb 944; manufactured by BASF) to a two-component urethane ink (V180; manufactured by Toyo Ink Co., Ltd.) based on the binder resin content of the ink. It was formed using the added ink. Further, a primer layer 6 was formed on the back surface of the base layer 2. The primer layer 6 was formed by printing the same two-component urethane ink as the pattern layer 3.
Subsequently, 0 parts of a hindered amine light stabilizer ("Kimasorb 944" manufactured by BASF) was added to 100 parts by mass of crystalline polypropylene resin (pentad fraction 97.8%, molecular weight distribution 2.3, MFR 18 g/10 min). A mixture of 0.5 parts by mass and 0.5 parts by mass of a benzotriazole-based ultraviolet absorber ("Tinuvin 328" manufactured by BASF) and a polyethylene-based easily adhesive resin were coextruded using a melt extruder. A transparent resin layer 4 with a thickness of 60 μm and an adhesive resin layer 4b with a thickness of 10 μm were formed. Next, a dry laminating adhesive (Takelac A540; manufactured by Mitsui Chemicals, Inc.; coating amount: 2 g/m ² ) was applied to the surface of the base material on which the pattern layer 3 was formed. Subsequently, the three surfaces of the pattern layer of the base material coated with the adhesive and the transparent resin layer 4 were bonded together by extrusion lamination via the formed adhesive resin layer 4b. Furthermore, the embossed pattern 4a is applied to the surface of the transparent resin layer 4 side of the sheets bonded together using a mold roll for embossing formation, and then the two-liquid hardening is performed on the surface of the embossed pattern 4a. A top coat layer 5 was formed by applying a molded urethane top coat ("W184" manufactured by DIC Graphics) at a coating amount of 3 g/ ^m2 . In this way, the decorative sheet 1 shown in FIG. 2 was obtained.

(Example 10)
A transparent resin layer 4 and a top coat layer 5 were formed in the same manner as in Example 9 on a base material layer 2 having a thickness of 55 μm, which was prepared in the same manner as in Example 2, to obtain a decorative sheet 1.
(Example 11)
A transparent resin layer 4 and a top coat layer 5 were formed in the same manner as in Example 9 on a base layer 2 having a thickness of 55 μm, which was prepared in the same manner as in Example 3, to obtain a decorative sheet 1.
(Example 12)
A transparent resin layer 4 and a top coat layer 5 were formed in the same manner as in Example 9 on a base layer 2 having a thickness of 55 μm, which was prepared in the same manner as in Example 4, to obtain a decorative sheet 1.

(Example 13)
A transparent resin layer 4 and a top coat layer 5 were formed in the same manner as in Example 9 on a base layer 2 having a thickness of 145 μm, which was prepared in the same manner as in Example 5, to obtain a decorative sheet 1.
(Example 14)
A transparent resin layer 4 and a top coat layer 5 were formed in the same manner as in Example 9 on a base material layer 2 having a thickness of 145 μm, which was prepared in the same manner as in Example 6, to obtain a decorative sheet 1.
(Example 15)
A transparent resin layer 4 and a top coat layer 5 were formed in the same manner as in Example 9 on a base material layer 2 having a thickness of 145 μm, which was prepared in the same manner as in Example 7, to obtain a decorative sheet 1.
(Example 16)
A transparent resin layer 4 and a top coat layer 5 were formed in the same manner as in Example 9 to a base material layer 2 having a thickness of 145 μm, which was prepared in the same manner as in Example 8, to obtain a decorative sheet 1.

(Example 17)
A base material layer 2 having a thickness of 145 μm was formed by extrusion molding using a melt extruder in the same manner as in Example 7 except that a nucleating agent without an outer membrane was used instead of the above-mentioned nucleating agent vesicle. did.
(Example 18)
A base material layer 2 having a thickness of 145 μm was formed by extrusion molding using a melt extruder in the same manner as in Example 8 except that a nucleating agent without an outer membrane was used instead of the above-mentioned nucleating agent vesicle. did.
(Example 19)
A base material layer 2 having a thickness of 145 μm was formed by extrusion molding using a melt extruder in the same manner as in Example 5 except that a nucleating agent without an outer membrane was used instead of the above-mentioned nucleating agent vesicle. did.
(Example 20)
A base material layer 2 having a thickness of 145 μm was formed by extrusion molding using a melt extruder in the same manner as in Example 6 except that a nucleating agent without an outer membrane was used instead of the above-mentioned nucleating agent vesicle. did.

(Comparative example 1)
A base material layer 2 having a thickness of 55 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 above-mentioned nucleating agent vesicles. .
(Comparative example 2)
A base material layer 2 having a thickness of 55 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 base material layer 2 having a thickness of 55 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 material layer 2 having a thickness of 55 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 base material layer 2 having a thickness of 145 μm was formed by extrusion molding using a melt extruder in the same manner as in Example 5 except that an untreated nucleating agent was used instead of the above-mentioned nucleating agent vesicles. .
(Comparative example 6)
A base material layer 2 having a thickness of 145 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 7)
A base material layer 2 having a thickness of 145 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 8)
A base material layer 2 having a thickness of 145 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 9)
Similarly to Comparative Example 2, a base material layer 2 having a thickness of 155 μm was formed by extrusion molding using a melt extruder. Thereafter, a transparent resin layer 4 and a top coat layer 5 were formed in the same manner as in Example 9 to obtain a decorative sheet 1.
(Comparative example 10)
In the same manner as in Example 2, extrusion molding was performed using a melt extruder to form a base material layer 2 having a thickness of 155 μm. Thereafter, a transparent resin layer 4 and a top coat layer 5 were formed in the same manner as in Example 9 to obtain a decorative sheet 1.
(Comparative Example 11)
In the same manner as in Example 2, the base material layer 2 having a thickness of 45 μm was formed by extrusion molding using a melt extruder.

(Comparative example 12)
As a raw material for colored polypropylene film, 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. 31.2 parts by mass, 46.8 parts of a random polypropylene resin with a melt flow rate (MFR) of 12 g/10 min (230°C) containing 4% ethylene component, 6 parts by mass of titanium oxide pigment as an inorganic pigment, and chromium- 16 parts by mass of the antimony complex oxide pigment and the above-mentioned nucleating agent vesicles were added as a nucleating agent so that the amount was 0.5 parts by mass, and the mixture was extruded using a melt extruder to produce a colored polypropylene film with a thickness of 55 μm. A base material layer 2 consisting of the following was formed.

(Comparative example 13)
As a raw material for colored polypropylene film, 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. To 39 parts by mass, 39 parts of random polypropylene resin with a melt flow rate (MFR) of 12 g/10 min (230°C) containing 4% ethylene component, 6 parts by mass of titanium oxide pigment as an inorganic pigment, and chromium-antimony composite oxide 16 parts by mass of the pigment and the above-mentioned nucleating agent vesicles were added as a nucleating agent so that the amount was 1.0 parts by mass, and extrusion molded using a melt extruder to obtain a base material made of a colored polypropylene film having a thickness of 55 μm. Layer 2 was formed.

(evaluation)
Regarding the above Examples 1 to 20 and Comparative Examples 1 to 13, Fourier infrared spectroscopy measurement, measurement of tensile modulus, defects during printing processing (printing processing suitability), scratch resistance, bending processing suitability, and wrapping processing smoothness. (Surface uniformity during lapping processing) was evaluated.
<Fourier type infrared spectroscopy measurement>
Fourier type infrared spectroscopy was performed using a PerkinElmer Fourier type infrared spectrometer (Spectrum Spotlight 400) to obtain an absorption spectrum from 4000 cm ^-1 to 700 cm ^-1 . The peak intensity ratios of wave numbers 997 cm ⁻¹ , 973 cm ⁻¹ , and 938 cm ⁻¹ were extracted from the obtained absorption spectrum, and the peak intensity ratio x was calculated using the following formula.

<Tensile modulus>
To measure the tensile modulus, a tensile test was performed using an Autograph (AGS-500NX) manufactured by Shimadzu Corporation at a tensile speed of 50 mm/min, and the tensile modulus was calculated.
<Problems during printing processing (print processing suitability)>
The pattern layer 3 was formed by gravure printing using a gravure printing machine, and at that time, the base material layer 2 was stretched due to tension, and the malfunction of misregistration when laminating each color was evaluated as a printing malfunction.
``◎'' indicates that register adjustment is not necessary at all, ``○'' indicates that adjustment can be easily performed using automatic register adjustment, ``△'' indicates that care is required in register adjustment, and ``△'' indicates that register adjustment is not possible and printing cannot be continued. The case was marked as “×”. In addition, cases where the film broke frequently during printing and there was a problem with mass production were also marked as "x". Note that if the evaluation is "△" or higher, there is no problem in printing processing.

<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 with a load of 750 kg applied to the surface of the decorative sheet 10. The condition was observed (based on the old JIS standard JISK5400). The test was conducted five times, and scratches and marks caused by the pencil were evaluated.
``◎'' if there are no scratches or marks at all, ``○'' if there are slight pencil marks, ``△'' if pencil marks are visible, and ``△'' if pencil scratches or tears in the colored polypropylene film are visible. was marked as "x".
Note that if the evaluation is "○" or higher, there is no practical problem. Further, if the evaluation is "△" or higher, no problems will occur, although the application is limited to, for example, furniture or vertical surfaces at high positions that cannot be touched by people. It is preferable that the evaluation be "○" or higher.

<Bending suitability>
In the bending suitability test, each decorative sheet 1 of Examples 1 to 20 and Comparative Examples 1 to 13 obtained by the above method was applied to one side of medium density fiberboard (MDF) as the base material layer 2. using a urethane adhesive, and then cut a V-shaped groove between the base layer 2 and the decorative sheet 1 on the other side of the base layer 2 to avoid scratching the decorative sheet 1 on the opposite side. Insert up to the border where the and are pasted together. Next, the base material layer 2 is bent to 90 degrees along the V-shaped groove so that the surface of the decorative sheet 1 is mountain-folded, and the bent portions of the surface of the decorative sheet 1 are checked to avoid any whitening or cracks. The condition of bendability was evaluated by observing using an optical microscope.
``◎'' if no whitening or cracks are visible; ``○'' if slight whitening is visible in some areas; ``△'' if whitening is visible in some areas; whitening is visible on the entire surface or in some areas. The case where cracks were visible was marked as "×". Note that if the evaluation is "△" or higher, there is no problem in practical use.

<Surface uniformity during lapping process>
In the surface uniformity test during lapping processing, a square material made by laminating 3 to 5 sheets of plate material or particle board between two sheets of medium-density fiberboard (MDF) was used as the base material layer 2. Each of the decorative sheets 1 of Examples 1 to 20 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 1 was attached to the end of the plate material was observed, and visually observed whether there were any surface irregularities caused by unevenness of the plate material or steps at the bonded part of the plate material. Further, the obtained decorative board was left for 1000 hours in an environment with a temperature of 80° C. and a humidity of 85%, and surface irregularities at the same locations and peeling of the decorative sheet 1 were checked.
``◎'' indicates that the surface is smooth with no visible irregularities or steps even after 1000 hours, ``○'' indicates that the surface is slightly rough, and ``△'' indicates that unevenness or steps are visible in some areas. The case where irregularities or steps were visible or peeling of the decorative sheet 10 was observed after 1000 hours was rated as "x". It should be noted that although there is no practical problem if the evaluation is "△" or higher, it is preferable that the evaluation is "○" or higher.
Table 1 shows these evaluation results.

As can be seen from Table 1, the decorative sheets 1 of Examples 1 to 8 and 17 to 20 were able to maintain a practically usable condition in terms of defects and strength during printing processing, and were also able to be compatible with bending processing. I understand. Furthermore, the decorative sheets 1 of Examples 9 to 16 have a pattern layer 3, a transparent resin layer 4, and a top coat layer 5 laminated on Examples 1 to 9, and have a high design and high scratch resistance while also being resistant to bending. I can see that I am able to balance both.

On the other hand, in the decorative sheets 1 of Comparative Examples 1 to 9, since micro-sized nucleating agents that were not formed into vesicles were used, the strength improvement due to the improvement of the degree of crystallinity was not sufficient, especially when the film thickness was thin and when the crystallinity was high. Problems occur during printing when the blending ratio of homopolypropylene resin is low. Further, even if there are no problems during printing, the decorative sheet 1 may lack the required strength or may have problems during bending. This is thought to be due to a lower ability to improve crystallinity and a larger spherulite size compared to a vesicle-formed nucleating agent.

Furthermore, in the decorative sheets 1 of Comparative Examples 10 to 13, at least one of the film thickness of the base layer 2 and the peak intensity x exceeds the numerical range of the present application, but there are problems with either of the evaluation results. It can be seen that this is the result.
In Comparative Example 11, although automatic register adjustment was possible, the film broke frequently during printing, making it impossible to produce a product. This is considered to be because although the peak strength x and tensile modulus were sufficient, the film was too thin and could not withstand tension fluctuations during printing, resulting in an increased frequency of breakage.

From the above, it is clear that the decorative sheets 1 of Examples 1 to 20 are decorative sheets 1 that are compatible with all of the problems during printing processing (printing processing suitability), scratch resistance, and bending processing suitability. Furthermore, it was revealed that the decorative sheets 1 of Examples 1 to 20 also had wrapping smoothness.
Note that the decorative sheet of the present invention is not limited to the above-described embodiments and examples, and various changes can be made without impairing the characteristics of the invention.

DESCRIPTION OF SYMBOLS 1... Decorative sheet, 2... Base material layer, 3... Pattern layer, 4... Transparent resin layer, 4a... Embossed pattern, 4b... Adhesive resin layer, 5... Top coat layer, 6... Primer layer, B... Substrate

Claims (14)

It has a base layer made of a colored polypropylene film made by mixing an inorganic pigment with a polypropylene resin, the base layer contains a nano-sized nucleating agent, and the thickness of the base layer is 50 μm or more and 150 μm or less. A decorative sheet characterized in that the value of the peak intensity ratio x calculated from the absorption spectrum obtained in Fourier infrared spectroscopy using the following formula 1 is 0.7 or more and 0.9 or less. .
Here, in the following formula, I ₉₉₇ represents a peak intensity value at a wave number of 997 cm ⁻¹ , I ₉₃₈ represents a peak intensity value at a wave number of 938 cm ⁻¹ , and I ₉₇₃ represents a peak intensity value at a wave number of 973 cm ⁻¹ .

The decorative sheet according to claim 1, having a tensile modulus of 850 MPa or more and 1600 MPa or less. 50% by mass or more and 100% by mass or less of the polypropylene resin is comprised of a highly crystalline homopolypropylene resin having an isotactic pentad fraction (mmmm fraction) of 95% or more. The decorative sheet described in 2. Any one of claims 1 to 3, wherein the amount of the nano-sized nucleating agent added is 0.01 parts by mass or more and 0.5 parts by mass or less, based on 100 parts by mass of the polypropylene resin. Decorative sheet described in Section 1. 5. The nucleating agent according to any one of claims 1 to 4, wherein the nucleating agent is a nucleating agent vesicle in which the nucleating agent is encapsulated in a vesicle having a monolayer outer membrane. A decorative sheet. The nucleating agent vesicle is added to 100 parts by mass of the polypropylene resin in an amount of 0.01 part by mass or more and 0.5 part by mass or less, calculated as the nucleating agent in the nucleating agent vesicle. The decorative sheet according to claim 5. 7. The decorative sheet according to claim 5, wherein the nucleating agent vesicle is a nucleating agent liposome having an outer membrane made of phospholipid. 8. The decorative sheet according to claim 5, wherein the nucleating agent is encapsulated in the vesicles using a supercritical reverse phase evaporation method. The amount of the nucleating agent vesicle added is 0.01 part by mass or more and 0.5 part by mass or less, calculated as the nucleating agent in the nucleating agent vesicle, per 100 parts by mass of the polypropylene resin. The decorative sheet according to any one of claims 5 to 8. 10. The decorative sheet according to claim 1, wherein a pattern layer is laminated on one surface of the base layer. A method for manufacturing a decorative sheet according to any one of claims 1 to 10, comprising:
The above-mentioned base material layer having a tensile modulus of 850 MPa or more and 1600 MPa or less and a thickness of 50 μm or more and 150 μm or less is produced from a resin material in which a nano-sized nucleating agent is added to a polypropylene resin mixed with an inorganic pigment. A method for manufacturing a decorative sheet. When manufacturing the base material layer, the value of the peak intensity ratio x calculated from the absorption spectrum obtained in Fourier infrared spectroscopy is controlled to 0.7 or more and 0.9 or less. The method for manufacturing a decorative sheet according to claim 11. 13. The method for manufacturing a decorative sheet according to claim 11 or 12, wherein when manufacturing the base layer, the tensile modulus of the base layer is controlled to 850 MPa or more and 1600 MPa or less. The method for producing a decorative sheet according to any one of claims 11 to 13, wherein the nucleating agent is encapsulated in vesicles by a supercritical reverse phase evaporation method.

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