JP7035846B2 - Decorative sheet and its manufacturing method - Google Patents

Description

The present invention is a technique relating to a decorative sheet used for surface cosmetics such as interior / exterior of buildings, fittings, furniture, lumbers, and flooring materials.

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 concerned about environmental protection problems. ing. By not using vinyl chloride resin in these decorative sheets, the generation of toxic gas and the like during incineration is suppressed. However, in general, polypropylene sheets have problems such as inferior scratch resistance due to their low elastic modulus and easy elongation when tension is applied to the sheets during printing or the like.

By the way, the decorative sheet is attached to the surface of a substrate such as a wood substrate, a metal substrate, or a non-combustible substrate to form a decorative board, and the decorative sheet imparts a design property to the decorative board according to the purpose. Therefore, the decorative sheet needs to be covered so that the surface of the substrate is completely invisible, if necessary. In this case, it is necessary to use a decorative sheet that is at least colored with a pigment and has concealing properties. And, as the simplest structure of the decorative sheet, it can be said that the structure is only the base material layer composed of the colored sheet alone (single layer). In the case of a decorative sheet consisting of only such a base material layer, the design that can be applied is usually limited to a single color without a pattern, but for example, by adding a bright material such as aluminum flake or pearl pigment as a pigment, it shines. Since it is possible to give a feeling, it is possible to express the necessary and sufficient design. Further, when it is desired to give a higher design, it is also effective to decorate the surface of the base material layer by printing or the like.

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 is necessary to have scratch resistance and prevent it from stretching even when tension is applied during processing such as printing. The elongation at the time of applying tension can be improved by increasing the layer thickness to about 60 μm or more in the conventional colored polypropylene film. Regarding the scratch resistance, in the conventional colored polypropylene film, a transparent resin layer made of polypropylene resin or a urethane-based thermosetting resin made of polyol and isocyanate was used as in Patent Documents 2 and 3. Improvement is possible 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 the scratch resistance and the elongation during printing processing. However, while the elastic modulus is improved by increasing the crystallinity, the breaking stress does not increase correspondingly to the elastic modulus, so that the film itself is easily torn, and defects such as breaking are likely to occur during the printing process. Further, in the post-processing as a decorative sheet, particularly in the bending process such as V-cut, defects such as cracking and whitening of the bent portion are likely to occur.

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

Conventionally, for a decorative sheet using a colored polypropylene film alone or a decorative sheet using a colored polypropylene film as a base material, printing processability (difficulty in elongation, etc.) and both scratch resistance and bending processability are compatible. Is required.

In addition, in special buildings, etc. described in Article 35-2 of the Building Standards Act (Article 128-3-2 of the Building Standards Act Enforcement Ordinance, Article 128-4 of the same Ordinance, Article 129 of the same Ordinance and Article 112 of the same Ordinance). Is subject to interior restrictions that require the use of non-combustible (quasi-non-combustible, flame-retardant) materials on ceiling and wall surfaces. When a decorative sheet is used as such a non-combustible material, a combustion test is conducted on the non-combustible decorative plate in which the decorative sheet is attached to the non-combustible base material, and the Building Standard Law Enforcement Ordinance Article 108-2 No. 1 and No. 2 are conducted. It is necessary to reduce the thickness of the decorative sheet because polypropylene resin has a higher burning calorie than polyvinyl chloride resin, although it will be judged to be compatible with non-combustible materials that meet the technical standards of non-combustible materials described in No. It is difficult to comply with the standard. There is no problem if the decorative sheet is a single colored polypropylene film, but in the case of a decorative sheet provided with a transparent resin layer and a top coat layer that can impart higher functionality, the transparent resin layer and the top coat layer mainly have reduced scratch resistance. Since it is difficult to reduce the layer thickness, it is required to reduce the thickness of the colored polypropylene film as the base material layer.

That is, nonflammability may be required for a decorative sheet using a colored polypropylene film alone or a decorative sheet using a colored polypropylene film as a base layer. In this case, nonflammability and print processing aptitude ( There is a trade-off relationship between (difficulty in elongation, etc.) and scratch resistance. That is, in the past, it was necessary to reduce the layer thickness from the viewpoint of nonflammability, but if the layer thickness is reduced, it becomes easy to stretch or break when tension is applied, and scratch resistance cannot be ensured. A problem has occurred.
The present invention has been made by paying attention to the above points, and is a single colored polypropylene film having both scratch resistance, elongation suppression during printing, bending whitening and cracking, and compatibility with non-combustible materials. It is an object of the present invention to provide a decorative sheet used in the above and a decorative sheet using a colored polypropylene film as a base material.

The present inventors enclose a nucleating agent for improving the crystallinity of polypropylene in a vesicle having an outer film of a single-layer film to form a vesicle, and add the nucleating agent vesicle to the polypropylene resin to further produce the product. Through various studies and experiments on the process, it was found that it is possible to provide a decorative sheet in which the above-mentioned problems are improved by setting the Martens hardness within the optimum range.
In order to achieve the object, the decorative sheet according to one aspect of the present invention has a base material layer made of a colored polypropylene film made by mixing an inorganic pigment with a polypropylene resin, and the base material layer is polypropylene containing an inorganic pigment. The resin is formed by adding a nucleating agent vesicle containing a nano-sized nucleating agent to a vesicle having an outer film of a single-layer film, and the Martens hardness of the base material layer is 30 N / mm ² or more. The gist is that the thickness is 100 N / mm ² or less and the thickness of the base material layer is 20 μm or more and 55 μm or less.

When at least one layer of the transparent resin layer and the top coat layer is laminated on one surface side of the base material layer, the total thickness of the decorative sheet is preferably 140 μm or less.
Here, the nucleating agent vesicle has a structure in which the nucleating agent is encapsulated in a capsule-shaped vesicle provided with an outer membrane of a single-layer film, and can be prepared by, for example, a supercritical reverse-phase evaporation method. .. The nucleating agent is a substance that is 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 vesicled and added as a nucleating agent vesicle to optimize the maltens hardness and film thickness, thereby achieving printability (elongation). It is possible to provide a decorative sheet capable of achieving both resistance to scratches and bending workability, as well as nonflammability, printability (difficulty to stretch, etc.) and scratch resistance.
Here, the non-combustibility of the decorative sheet of the present invention is determined by conducting a combustion test on a non-combustible decorative board in which a decorative sheet to be evaluated is attached to a non-combustible substrate, and the Building Standards Act Enforcement Ordinance, Article 108-2, No. 1. It is preferable to meet the technical standards for non-combustible materials described in No. and No. 2. Specifically, the nonflammability of the decorative sheet of the present invention is based on the cone calorie combustion test based on ISO5660-1, and when the total calorific value with respect to time and the heat generation rate with respect to time of the decorative board are determined, (i). ) The total calorific value for 20 minutes after the start of heating is 8 MJ / m ² or less, and (ii) the maximum heat generation rate does not exceed 200 kW / m ² continuously for 10 seconds or more for 20 minutes after the start of heating, and (iii). For 20 minutes after the start of heating, it is preferable to have nonflammability that satisfies the absence of cracks and holes penetrating from the outside to the inside, which are harmful to fire protection.

It is sectional drawing which shows the decorative sheet of embodiment which concerns on this invention. It is sectional drawing which shows the other decorative sheet which concerns on embodiment based on this invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
Here, the drawings are schematic, and the relationship between the thickness and the plane dimensions, the ratio of the thickness of each layer, and the like are different from the actual ones. Further, the embodiments shown below exemplify a configuration for embodying the technical idea of the present invention, and the technical idea of the present invention describes the material, shape, structure, etc. of the constituent parts as follows. It is not specific to things. The technical idea of the present invention may be modified in various ways within the technical scope specified by the claims described in the claims.

"Constitution"
The decorative sheet 10 of the embodiment shown in FIG. 1 is an example in the case of a single-layer structure having only the base material layer 1 (raw fabric layer).
The base material layer 1 of the present embodiment is composed of a colored polypropylene film. The base material layer 1 made of a colored polypropylene film contains a nano-sized nucleating agent as well as a polypropylene resin mixed with an inorganic pigment for coloring. In the present embodiment, the nucleating agent is added to the polypropylene resin in the form of a vesicle of the nucleating agent contained in the outer membrane and vesicled.
The base material layer 1 has a maltens hardness of 30 N / mm ² or more and 100 N / mm ² or less, and the base material layer 1 has a thickness of 20 μm or more and 55 μm or less.
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 in an amount of 50% by mass or more and 100% by mass or less. ..

It is preferable that 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 nucleating agent vesicle is preferably a nucleating agent liposome having an outer membrane made of a phospholipid.
If necessary, the design layer 2 may be formed (laminated) on one surface of the base material layer 1 to improve the design.
Further, the decorative sheet 10 may have at least one layer of the transparent resin layer 3 and the top coat layer 4 laminated on one surface side of the base material layer 1. The decorative sheet 10 exemplified in FIG. 2 may be laminated. This is an example in which the pattern layer 2, the transparent resin layer 3, and the top coat layer 4 are laminated in this order on one surface of the decorative sheet 10. Either the transparent resin layer 3 or the top coat layer 4 may be omitted. Further, the pattern layer 2 may be omitted.

However, from the viewpoint of ensuring nonflammability, the decorative sheet 10 of the present embodiment is preferably designed so that the total thickness of the entire decorative sheet 10 is 140 μm or less. When the transparent resin layer 3 and the top coat layer 4 are provided, for example, the base material layer is 1: 55 μm, the transparent resin layer 3: 70 μm, and the top coat layer 4: 15 μm. Here, among the base material layer 1, the pattern layer 2, the transparent resin layer 3, and the top coat layer 4, the pattern layer 2 has a thin layer thickness, so the thickness of the pattern layer 2 is ignored and the entire decorative sheet 10 is used. It may be designed so that the total thickness is 140 μm or less.
Here, at least one of the transparent resin layer 3 and the top coat layer 4 may be embossed with an uneven shape depending on the design requirement. Further, from the requirement of scratch resistance and the like, it is possible to stack a plurality of layers of at least one of the transparent resin layer 3 and the top coat layer 4, and another known layer may be arranged.

In FIGS. 1 and 2, reference numeral B represents a substrate. The substrate B is a substrate on which the decorative sheet 10 is attached. The substrate B is not particularly limited, and examples thereof include wood boards, inorganic boards, metal plates, and composite boards made of a plurality of materials. Since the decorative sheet 10 of the present embodiment is nonflammable, it is preferable that the substrate B is also made of a noncombustible material.
A primer layer, a concealing layer, or the like may be appropriately provided between the decorative sheet 10 and the substrate B.
The range of the tensile elastic modulus of the decorative sheet 10 of the present embodiment, particularly the tensile elastic modulus of the base material layer 1 alone, is preferably 700 MPa or more and 2000 MPa or less. If the tensile elastic modulus is less than 700 MPa, it may not be possible to suppress defects during printing. When the tensile elastic modulus exceeds 2000 MPa, the crystallinity is too high, and even when the nucleating agent vesicle is used, there is a possibility that problems such as whitening and cracking may occur in the bending process. A suitable range of tensile elastic modulus is 1000 MPa or more and 1800 MPa or less. Within this range, it is possible to achieve both defects during printing processing, scratch resistance, and bending processing in excellent conditions.

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

(Polypropylene resin)
As the polypropylene resin, it is preferable to use the highly crystalline homopolypropylene described later, but the polypropylene resin is not limited to the highly crystalline homopolypropylene. In applications where workability such as bending is more important, a random polypropylene resin having ethylene content within a predetermined range or a known amorphous polypropylene resin can be mixed with the highly crystalline homopolypropylene.
The Martens hardness of the base material layer 1 made of the colored polypropylene film is adjusted to 30 N / mm ² or more and 100 N / mm ² or less.

When the martence hardness is less than 30 N / mm ² , it is highly possible that defects during printing cannot be suppressed and it becomes difficult to secure the scratch resistance required for practical use. On the other hand, when the Martens hardness exceeds 100 N / mm ² , the crystallinity is too high, and even when the nucleating agent vesicle is used, there is a possibility that problems such as whitening and cracking may occur in the bending process.
The preferred range of the Martens hardness of the base material layer 1 is 50 N / mm ² or more and 80 N / mm ² or less. Within this range, it is possible to achieve both defects during printing processing, scratch resistance, and bending processing in excellent conditions.

Here, the Martens hardness is a kind of index indicating the hardness (hardness) of a substance, and a load is applied to an indenter to push it into the surface of a sample, and the depth (pushing) of a dent (indentation) formed at that time. Depth) is measured and defined as the quotient of the pushing force calculated from the load and the surface area of the depression calculated from the pushing depth. The measurement is performed by the method specified in ISO14577.
Further, it is important that the thickness of the base material layer 1 made of the colored polypropylene film is 20 μm or more and 55 μm or less.

If the thickness of the base material layer 1 is less than 20 μm, the film strength will be insufficient even if the Martens hardness is within the optimum range, and it is difficult to suppress defects during printing and deterioration of scratch resistance. .. On the other hand, when the thickness of the base material layer 1 exceeds 55 μm, it becomes difficult to pass the nonflammability in the configuration in which the transparent resin layer 3 and the top coat layer 4 are laminated.
A more preferable range of the thickness of the base material layer 1 is 30 μm or more and 45 μm or less. Within this range, defects during printing processing, scratch resistance, and bending processing can be achieved with sufficient margin, and the non-combustible base material is not particularly limited in the non-combustible test, and the non-combustible material can be passed. can.

In the present embodiment, it is preferable to use a polypropylene resin having high crystallinity 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 used in a range of 50% or more and 100% or less with respect to the mass of the total polypropylene resin. Is preferable.
The crystallization temperature of the polypropylene resin is generally in the range of 100 to 130 ° C., and is in 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 Martens hardness is 30 N / mm by controlling the cooling time from the crystallization temperature to the curing completion temperature within this range by a known cooling process. It is adjusted to ² or more and 100 N / mm ² or less. Further, when a polypropylene resin having an isotactic pentad fraction (mmmm fraction) of less than 95% is used, the crystallinity is insufficient, so that the maltens hardness is lower than the preferable range even if the cooling process is controlled. It ends up. Further, when the amount of the highly crystalline homopolypropylene resin is less than 50%, the crystallinity is also insufficient, so that the Martens hardness becomes lower than the preferable range even if the cooling process is controlled.

Here, the isotactic pentad fraction (mm mm fraction) refers to a resin material having a predetermined resonance frequency by a 13C-NMR measurement method (nuclear magnetic resonance measurement method) using carbon C (nuclear species) having a mass of 13. It is calculated from the numerical value (electromagnetic wave absorption rate) obtained by resonating with the above, and defines the atomic arrangement, electronic structure, and molecular fine structure in the resin material. The pentad fraction of the crystalline polypropylene resin is a ratio in which five propylene units determined by 13C-NMR are lined up, and is used as a measure of crystallinity or stereoregularity. The pentad fraction is one of the important factors that mainly determine the scratch resistance of the surface, and 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 concealment can be used. Examples of the inorganic pigment for coloring include composite oxides such as iron-zinc, chromium-antimony, iron-aluminum, iron oxide and the like, and these can be freely adjusted according to a desired color. Further, as an inorganic pigment, a bright material such as an aluminum flake or a pearl pigment can be added. An organic pigment such as carbon black may be used in combination.
Further, an additive such as a fatty acid metal salt may be added in order to improve the dispersibility and the extrusion suitability.

(Nuclear agent vesicle)
Further, the base material layer 1 contains a nano-sized nucleating agent. The nano-sized nucleating agent is used by being added to a polypropylene resin in the form of a nucleating agent vesicle contained in a vesicle having an outer membrane of a monolayer film. Since the base material layer 1 contains a nucleating agent, the crystallinity can be improved, and the scratch resistance (scratch resistance) of the base material layer 1 can be improved. In the present embodiment, the nucleating agent in the resin constituting the base material layer 1 may be included in the vesicle with a part of the nucleating agent exposed.
The average particle size of the nano-sized nucleating agent is preferably 1/2 or less of the wavelength region of visible light, and specifically, since the wavelength region of visible light is 400 nm or more and 750 nm or less, the average particle size Is preferably 375 nm or less.

Since the particle size of nano-sized nucleating agents is extremely small, 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 end where the crystal is growing is immediately immediately. Since it comes into contact with the ends of crystals growing from the surface of another nucleating agent particle adjacent to one nucleating agent particle, the ends of each crystal inhibit the growth and the growth of each crystal stops. The average particle size of spherulites in the crystal part of the crystalline polypropylene resin can be made small, for example, the spherulite size can be made small to 1 μm or less. As a result, a colored polypropylene film having a high degree of crystallinity and a high hardness can be obtained, and the stress concentration between the spherulites generated during the bending process is efficiently dispersed, so that cracking and whitening during the bending process are suppressed. A colored polypropylene film can be realized.

Here, when the nucleating agent is simply added, the particle size increases due to the secondary aggregation of the nucleating agent in the polypropylene resin, and the number of crystal nuclei increases with respect to the amount of the added nucleating agent. It will be significantly less than when added as an agent vesicle. For this reason, the average particle size of the spherulites in the crystal portion of the polypropylene resin becomes large, and cracking and whitening during bending cannot be suppressed. Therefore, improvement in elastic modulus and processability by increasing the crystallinity cannot be achieved at the same time. ..
The base material layer 1 made of a colored polypropylene film constituting the decorative sheet 10 of the present embodiment is 0.05 parts by mass or more in terms of the amount of nucleating agent added to 100 parts by mass of the polypropylene resin as a main component. It is preferable that a nucleating agent vesicle of 0.5 parts by mass or less, preferably 0.1 parts by mass or more and 0.3 parts by mass or less is added. If the amount of the nucleating agent vesicle added is less than 0.05 parts by mass, the crystallinity may not be sufficiently improved and the required elastic modulus (hardness) may not be reached. Further, when the addition amount exceeds 0.5 parts by mass, the spherulite growth is conversely inhibited due to the excessive amount of crystal nuclei, and as a result, the crystallinity is not sufficiently improved and the required elastic modulus (hardness) is obtained. It may not reach.

In addition, as a method for nanonizing the nucleating agent, for example, a solid phase method in which the nucleating agent is mainly mechanically pulverized to obtain nano-sized particles, or the nucleating agent or the nucleating agent is dissolved. A liquid phase method for synthesizing and crystallizing nano-sized particles in a solution, and a gas phase method for synthesizing and crystallizing nano-sized particles from a gas / steam composed of a nucleating agent or a nucleating agent. It can be used as appropriate. Examples of the solid phase method include ball mills, bead mills, rod mills, colloidal mills, conical mills, disc 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, a hydrothermal synthesis method and the like. Further, examples of the gas phase method include an electric furnace method, a chemical flame method, a laser method, a thermal plasma method, and the like.

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

In addition, as a specific nano-ization treatment by the supercritical reverse phase evaporation method, first, the aqueous phase is injected into a mixed fluid of supercritical carbon dioxide, phospholipid as an outer film forming substance, and a nucleating agent as an encapsulating substance. Then, by stirring, an emulsion of supercritical carbon dioxide and an aqueous phase is produced. Next, when the pressure is reduced, carbon dioxide expands and evaporates to cause phase inversion, and phospholipids generate nanocapsules (nanovesicles) in which the surface of the nucleating agent particles is covered with a monolayer film. By using this supercritical reverse phase evaporation method, unlike the conventional encapsulation method in which the outer film is a multilayer film on the surface of the nucleating agent particles, a single-layer film capsule can be easily generated. Small diameter capsules can be prepared.
The nucleating agent vesicle can be prepared by a Bangham method, an extrusion method, a hydration method, a surfactant dialysis method, a reverse phase evaporation method, a freeze-thaw method, a supercritical reverse phase evaporation method, or the like. Among them, the supercritical reverse phase evaporation method is particularly preferable.

The outer membrane constituting the nucleating agent vesicle is composed of, for example, a monolayer membrane. The outer membrane is composed of a substance containing a biolipid such as a phospholipid.
In the present specification, a nucleating agent vesicle whose outer membrane is composed of a substance containing a biolipid 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, yellow egg lecithin, hydrogenated yellow egg lecithin, soybean lecithin, hydrogenated soybean lecithin and the like. Examples thereof include glycerophospholipids, sphingomyelin, ceramide phosphorylethanolamine, ceramide phosphorylglycerol and other sphingolin lipids.

Other substances that form the outer membrane of the vesicle include nonionic surfactants and dispersants such as cholesterols or a mixture of triacylglycerols thereof. Among these, examples of the nonionic surfactant include polyglycerin ether, dialkyl glycerin, 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-polycaprolactum copolymer, etc. Alternatively, two or more types can be used. As cholesterols, for example, cholesterol, α-cholestanol, β-cholestanol, cholestane, desmosterol (5,24-cholestadien-3β-ol), sodium cholic acid, choleciferol and the like can be used.

Further, the outer membrane of the liposome may be formed from a mixture of a phospholipid and a dispersant. 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 phospholipid, and by forming the outer membrane from phospholipid, the base material layer 1 It is possible to improve the compatibility between the resin material, which is the main component of the above, and the vesicle.
The nucleating agent is not particularly limited as long as it is a substance that becomes a starting point of crystallization when the resin crystallizes. Examples of the nucleating agent include phosphate ester metal salt, benzoic acid metal salt, pimelli acid metal salt, rosin metal salt, benziliden sorbitol, quinacridone, cyanine blue and talc. In particular, in order to maximize the effect of the nanonization treatment, it is preferable to use a phosphoric acid ester metal salt, a benzoic acid metal salt, a pimelic acid metal salt, or a rosin metal salt, which is a non-melt type and can be expected to have good transparency. If the material itself can be made transparent by nano-treatment, colored quinacridone, cyanine blue, talc and the like can also be used. Further, the melt-type benzylidene sorbitol may be appropriately mixed and used with the non-melt-type nucleating agent.

As described above, one of the features (invention-specific matters) of the decorative sheet 10 of the present embodiment is that the base material layer 1 contains a nucleating agent contained in a vesicle. Then, by adding the nucleating agent to the resin composition in a state of being encapsulated in the vesicle, the effect of dramatically improving the dispersibility of the nucleating agent in the resin material, that is, in the base material layer 1 is achieved. However, it can be said that it is impractical because it is assumed that it may be difficult depending on the situation to directly specify the characteristics by the structure and characteristics of the object in the state of the completed decorative sheet 10. The reason is as follows. The nucleating agent added in the vesicle state has a high dispersibility and is in a dispersed state, 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 step of producing the decorative sheet 10 after the nucleating agent is added to the resin composition constituting the base material layer 1 in the form of a vesicle to prepare the base material layer 1, the compression to the laminated body is usually performed. Various treatments such as treatment and hardening treatment are performed, and by such treatment, the outer membrane of the vesicle containing the nucleating agent is crushed or chemically reacted, and the nucleating agent is included in the outer membrane (cover). This is because there is a high possibility that the outer film has not been crushed or chemically reacted, and the state in which the outer film is crushed or chemically reacted varies depending on the treatment process of the decorative sheet 10. And, in the situation where this nucleating agent is not included in the outer membrane, it is difficult to specify the physical properties themselves in the numerical range, and is the constituent material of the crushed outer membrane 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, the present invention is different from the conventional one in that the nucleating agent is blended in a high dispersion with respect to the base material layer 1, but it is added in the state of a vesicle containing the nucleating agent. In the state of the decorative sheet 10, it is assumed that it is impractical to specify the structure and characteristics of the decorative sheet 10 within the numerical range analyzed based on the measurement.
Here, the nucleating agent vesicle having the above-mentioned structure may also be contained in the transparent resin layer 3 and the top coat layer 4.

(Picture layer 2)
On the surface of the colored polypropylene film 1, a pattern layer 2 for adding a pattern to the decorative sheet 10 can be provided. As the pattern, a wood grain pattern, a stone grain pattern, a sand grain pattern, a tiled pattern, a brick pile pattern, a cloth grain pattern, a leather squeezing pattern, a geometric figure or the like can be used.
Further, a base solid ink layer (not shown) may be provided between the base material layer 1 and the pattern layer 2 depending on the degree of the target design. The base solid ink layer is provided so as to cover the entire surface of the base material layer 1. Further, the base solid ink layer may be a plurality of layers, if necessary, such as concealment. Further, the pattern layer 2 may be formed by laminating as many plates as necessary to express the required design. As described above, the pattern layer 2 and the base solid ink layer have various combinations depending on the required design, that is, the design to be expressed, but are not particularly limited.

The constituent materials of the base solid ink layer and the pattern layer 2 are not particularly limited. For example, a printing ink or coating agent obtained by dissolving and dispersing a matrix and a colorant such as a dye or a pigment in a solvent can be used. The matrix includes oil-based vitrified cotton resin, two-component urethane resin, acrylic resin, styrene resin, polyester resin, urethane resin, polyvinyl resin, alkyd resin, epoxy resin, melamine resin, and fluororesin. Various synthetic resins such as silicone-based resins and rubber-based resins, or mixtures thereof, copolymers, and the like can be used. The colorants include inorganic pigments such as carbon black, titanium white, zinc flower, petals, yellow lead, dark blue, and cadmium red, azo pigments, lake pigments, anthraquinone pigments, phthalocyanine pigments, isoindolinone pigments, and dioxazines. Organic pigments such as pigments or mixtures thereof can be used. As the solvent, toluene, xylene, ethyl acetate, butyl acetate, methyl alcohol, ethyl alcohol, isopropyl alcohol, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, water and the like, or a mixture thereof can be used.

Further, in order to impart various functions to the base solid ink layer and the pattern layer 2, an extender pigment, a plasticizer, a dispersant, a surfactant, a tackifier, an adhesive aid, a desiccant, a curing agent, and a curing accelerator And functional additives such as a curing retarder may be added.
Here, the base solid ink layer and the pattern layer 2 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 1, 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. These printing methods and coating methods may be selected separately depending on the layer to be formed, but it is efficient to select the same method for batch 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 resin, and in addition to polypropylene, polyethylene, polybutene and the like, α-olefins (eg, propylene, 1-butene, 1-pentene, 1) -Hexen, 1-heptene, 1-octene, 1-nonen, 1-decene, 1-ethylene, 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 Examples thereof include those obtained by copolymerizing ethylene or α-olefin with other monomers such as a polymer, an ethylene / methyl acrylate copolymer, an ethylene / ethyl acrylate copolymer, and an ethylene / butyl acrylate copolymer. .. Further, when improving the surface strength of the decorative sheet 10, it is preferable to use highly crystalline polypropylene as in the base material layer 1.

Here, the main component in the present specification means 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 it is less than 50 μm, the effect of improving the scratch resistance on the surface of the transparent resin layer 3 is low, and the significance of providing the transparent resin layer 3 is reduced. If it exceeds 100 μm, the amount of organic matter per unit area increases, which may make it difficult to comply with non-combustible standards.
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 has various functionalities such as a heat stabilizer, a light stabilizer, a blocking inhibitor, a catalyst scavenger, a colorant, a light scattering agent, and a gloss adjusting agent, if necessary. Additives may be included. These various functional additives can be appropriately selected and used from well-known ones.

(Top coat layer 4)
When it is necessary to further improve the scratch resistance and adjust the gloss, the top coat layer 4 can be provided on the surface of the transparent resin layer 3.
The resin material of the main component of the top coat layer 4 is appropriately selected from resin materials such as polyurethane-based, acrylic silicon-based, fluorine-based, epoxy-based, vinyl-based, polyester-based, melamine-based, aminoalkyd-based, and urea-based. Can be used. The form of the resin material is not particularly limited, such as water-based, emulsion, and solvent-based. As for the curing method, a one-component type, a two-component type, an ultraviolet curing method, or the like can be appropriately selected.

As the resin material used as the main component of the topcoat layer 4, a urethane-based material using isocyanate is suitable from the viewpoints of workability, price, and cohesive force of the resin itself. The isocyanates include tolylene diisocyanate (TDI), xylylene diisocyanate (XDI), hexamethylene diisocyanate (HMDI), diphenylmethane diisocyanate (MDI), lysine diisocyanate (LDI), isophorone diisocyanate (IPDI), bis (isocyanatemethyl) cyclohexane ( It can be appropriately selected from curing agents such as adduct, buretto, and isocyanurate, which are derivatives such as HXDI) and trimethylhexamethylene diisocyanate (TMDI), but in consideration of weather resistance, it is a linear molecule. A curing agent based on hexamethylene diisocyanate (HMDI) or isophorone diisocyanate (IPDI) having a structure is suitable. In addition to this, when improving 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 a thermosetting type and a photocuring type, the surface hardness can be improved, the curing shrinkage can be suppressed, and the adhesion can be improved. Can be planned.

A gloss adjuster can be added to the top coat layer 4 for gloss adjustment. As the gloss adjuster, a commercially available known agent may be used. For example, fine particles made of an inorganic material such as silica, glass, alumina, calcium carbonate, and barium sulfate may be used. Alternatively, fine particles made of an organic material such as acrylic can be used. However, when high transparency is required, it is desirable to use fine particles such as silica, glass, and acrylic having high transparency. In particular, among the fine particles such as silica and glass, a gloss adjuster having a low bulk density in which fine primary particles are secondarily aggregated instead of solid subatomic particles has a high matting effect on the amount of addition. Therefore, by using such a gloss adjuster, the amount of the gloss adjuster added can be reduced.

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

<Manufacturing method>
An example of manufacturing the decorative sheet 10 will be described.
A vesicle is encapsulated with a nucleating agent to produce a vesicle of the nucleating agent, and the produced vesicle of the nucleating agent is added to a polypropylene resin together with an inorganic pigment to prepare a resin material for a base material layer. To make.
The nucleating agent vesicle is produced, for example, by encapsulating the nucleating agent in a vesicle having a single-layer film by a supercritical reverse-phase evaporation method to form a vesicle.
As the polypropylene resin to be used, it is preferable to use a highly crystalline homopolypropylene resin having an isotactic pentad fraction (mm mm fraction) of 95% or more in an amount of 50% by mass or more and 100% by mass or less.

The resin material for the base material layer is heated and melted and molded into a sheet having a thickness of 20 μm or more and 55 μm or less by extrusion molding or the like to obtain the base material layer 1.
At this time, the Martens hardness of the substrate layer 1 is controlled to 30 N / mm ² or more and 100 N / mm ² or less by adjusting the cooling time from the crystallization temperature to the curing completion temperature by a known adjusting 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 layer of the transparent resin layer 3 and the top coat layer 4 is formed on the pattern layer 2 by printing.
At this time, it is preferable that the thickness of the transparent resin layer 3 is in the range of 50 μm or more and 100 μm or less, the thickness of the top coat layer 4 is in the range of 3 μm or more and 15 μm or less, and the total thickness of the decorative sheet 10 is 140 μm or less.

<Action and others>
(1) The decorative sheet 10 of the present embodiment has a base material layer 1 made of a colored polypropylene film obtained by mixing an inorganic pigment with a polypropylene resin, and the base material layer 1 contains a nano-sized nucleating agent. The nucleating agent is added in the form of a vesicle of the nucleating agent contained in the outer film, and the base material layer 1 has a maltens hardness of 30 N / mm ² or more and 100 N / mm ² or less, and is a base material. The thickness of the layer 1 is 20 μm or more and 55 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 by optimizing the Martens hardness and film thickness, printing process suitability (difficulty in elongation) is achieved. Etc.), and it is possible to provide a decorative sheet 10 capable of achieving both scratch resistance and bending workability, as well as nonflammability, print processing aptitude (difficulty in elongation, etc.) and scratch resistance.

(2) The decorative sheet 10 of the present embodiment has a high isotactic pentad fraction (mm mm fraction) of 95% or more in 50% by mass or more and 100% by mass or less of the polypropylene resin constituting the base material layer 1. It is preferably made of a crystalline homopolypropylene resin.
According to this configuration, the Martens hardness can be more reliably adjusted to 30 N / mm ² or more and 100 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 in terms of the nucleating agent in the nucleating agent vesicle with respect to 100 parts by mass of the polypropylene resin. It is preferably 05 parts by mass or more and 0.5 parts by mass or less.
According to this configuration, the crystallinity of the colored polypropylene constituting the base material layer 1 is sufficiently improved, and the required elastic modulus (hardness) can be surely secured.

(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 base material layer 1, and the vesicle can be improved.
(5) In the decorative sheet 10 of the present embodiment, it is preferable that the pattern layer 2 is laminated on one surface of the base material layer 1.
According to 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 layer of the transparent resin layer 3 and the top coat layer 4 is laminated on one surface side of the base material layer 1, and the total thickness of the decorative sheet 10 is 140 μm. The following is preferable.
According to this configuration, even if the decorative sheet 10 has the transparent resin layer 3 and the top coat layer 4, it is possible to impart nonflammability to the decorative sheet 10.

Hereinafter, specific examples of the decorative sheet 10 of the present embodiment will be described.
(Manufacturing method of nucleating agent vesicle)
First, a method for producing the nucleating agent liposome used in this example will be described.
The nucleating agent liposome uses the above-mentioned supercritical reverse phase evaporation method, and has 100 parts by mass of methanol and 70 parts by mass of a phosphate ester metal salt-based nucleating agent (Adecastab 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 placed 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. Make it a critical state. Then, the inside of the container is vigorously stirred and 100 parts by mass of ion-exchanged water is injected. After stirring and mixing for another 15 minutes while keeping the temperature and pressure in a supercritical state, carbon dioxide is discharged from the container and returned to atmospheric pressure to apply a nucleating agent to the vesicle having a single-layered outer membrane made of phospholipids. The encapsulating nucleating agent vesicle was obtained.

(Example 1)
As a raw material for a colored polypropylene film, 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. To 78 parts by mass, 6 parts by mass of titanium oxide pigment as an inorganic pigment, 16 parts by mass of a chromium-antimon composite oxide pigment, and the above-mentioned vesicle of a nucleating agent were added so as to be 0.05 parts by mass as a nucleating agent. , A base material layer 1 made of a colored polypropylene film having a thickness of 20 μm was formed by extrusion molding using a melt extruder.
(Example 2)
Similar to Example 1, the base material layer 1 having a thickness of 20 μm was extruded using a melt extruder except that the above-mentioned vesicle of a nucleating agent 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 a colored polypropylene film, 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. 39 parts of random polypropylene resin with a melt flow rate (MFR) of 12 g / 10 min (230 ° C) containing 4% of ethylene component with respect to 39 parts by mass, 6 parts by mass of titanium oxide pigment as an inorganic pigment, chromium-antimon composite oxide A base material made of a colored polypropylene film having a thickness of 20 μm, which is extruded by using a melt extruder after adding 16 parts by mass of the pigment and the above-mentioned vesicle of the nucleating agent to 0.05 parts by mass as a nucleating agent. Layer 1 was formed.

(Example 4)
Similar to Example 1, the base material layer 1 having a thickness of 20 μm was extruded using a melt extruder except that the above-mentioned vesicle of a nucleating agent was added as a nucleating agent so as to be 0.5 parts by mass. A film was formed.
(Example 5)
In the same manner as in Example 1, a substrate layer 1 having a thickness of 55 μm was formed by extrusion molding using a melt extruder.
(Example 6)
In the same manner as in Example 2, the base material layer 1 having a thickness of 55 μm was formed by extrusion molding using a melt extruder.
(Example 7)
In the same manner as in Example 3, the base material layer 1 having a thickness of 55 μm was formed by extrusion molding using a melt extruder.
(Example 8)
In the same manner as in Example 4, the base material layer 1 having a thickness of 55 μm was formed by extrusion molding using a melt extruder.

(Example 9)
One surface of the base material layer 1 having a thickness of 20 μm prepared in the same manner as in Example 1 was subjected to corona treatment so that the wetting tension of the surface was 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 70 μm was prepared by extrusion molding using a machine, and both surfaces thereof were subjected to corona treatment to set the wet tension of the surface to 40 dyn / cm or more.
Subsequently, a pattern was printed on the corona-treated surface of the base material layer 1 with a two-component curable urethane ink (V180; manufactured by Toyo Ink Mfg. Co., Ltd.) to form the pattern layer 2. Further, the transparent resin layer 3 is applied to the surface of the pattern layer 2 by a dry laminating method via an adhesive layer made of a dry laminating adhesive (Takelac A540; manufactured by Mitsui Chemicals, Inc., coating amount 2 g / m ² ). I pasted them together. Next, after forming an embossed pattern on the surface of the transparent resin layer 3 using a mold roll for embossing, a two-component curable urethane top coat (W184; manufactured by DIC Graphics Co., Ltd.) is used so as to cover the embossed pattern. , A coating amount of 3 g / m ² ) was applied to form the top coat layer 4 to obtain a decorative sheet 10.

(Example 10)
The transparent resin layer 3 and the top coat layer 4 were formed on the base material layer 1 having a thickness of 20 μm prepared in the same manner as in Example 2 in the same manner as in Example 9 to obtain a decorative sheet 10.
(Example 11)
The transparent resin layer 3 and the top coat layer 4 were formed on the base material layer 1 having a thickness of 20 μm prepared in the same manner as in Example 3 in the same manner as in Example 9 to obtain a decorative sheet 10.
(Example 12)
The transparent resin layer 3 and the top coat layer 4 were formed on the base material layer 1 having a thickness of 20 μm prepared in the same manner as in Example 4 in the same manner as in Example 9 to obtain a decorative sheet 10.

(Example 13)
The transparent resin layer 3 and the top coat layer 4 were formed on the base material layer 1 having a thickness of 55 μm prepared in the same manner as in Example 5 in the same manner as in Example 9 to obtain a decorative sheet 10.
(Example 14)
The transparent resin layer 3 and the top coat layer 4 were formed on the base material layer 1 having a thickness of 55 μm prepared in the same manner as in Example 6 in the same manner as in Example 9 to obtain a decorative sheet 10.
(Example 15)
The transparent resin layer 3 and the top coat layer 4 were formed on the base material layer 1 having a thickness of 55 μm prepared in the same manner as in Example 7 in the same manner as in Example 9 to obtain a decorative sheet 10.
(Example 16)
The transparent resin layer 3 and the top coat layer 4 were formed on the base material layer 1 having a thickness of 55 μm prepared in the same manner as in Example 8 in the same manner as in Example 9 to obtain a decorative sheet 10.

(Comparative Example 1)
A base layer 1 having a thickness of 20 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 vesicle. ..
(Comparative Example 2)
A base layer 1 having a thickness of 20 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 vesicle. ..
(Comparative Example 3)
A base layer 1 having a thickness of 20 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 vesicle. ..

(Comparative Example 4)
A base layer 1 having a thickness of 20 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 vesicle. ..
(Comparative Example 5)
Similar to Example 5, the base material layer 1 having a thickness of 55 μm was formed by extrusion molding using a melt extruder except that an untreated nucleating agent was used instead of the nucleating agent vesicle described above. ..
(Comparative Example 6)
A 55 μm-thick substrate layer 1 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 vesicle. ..

(Comparative Example 7)
A 55 μm-thick substrate layer 1 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 vesicle. ..
(Comparative Example 8)
A 55 μm-thick substrate layer 1 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 vesicle. ..
(Comparative Example 9)
Similar to Comparative Example 2, the base material layer 1 having a thickness of 60 μm was formed by extrusion molding using a melt extruder. Then, the transparent resin layer 3 and the top coat layer 4 were formed in the same manner as in Example 9 to obtain a decorative sheet 10.

(Comparative Example 10)
In the same manner as in Example 2, the base material layer 1 having a thickness of 60 μm was formed by extrusion molding using a melt extruder. Then, the transparent resin layer 3 and the top coat layer 4 were formed in the same manner as in Example 9 to obtain a decorative sheet 10.
(Comparative Example 11)
In the same manner as in Example 2, the base material layer 1 having a thickness of 15 μm was formed by extrusion molding using a melt extruder.

(Comparative Example 12)
As a raw material for a colored polypropylene film, 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. 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 with respect to 31.2 parts by mass, 6 parts by mass of titanium oxide pigment as an inorganic pigment, chromium- 16 parts by mass of antimony composite oxide pigment and the above-mentioned vesicle of nucleating agent are added so as to be 0.5 parts by mass as a nucleating agent, and extruded using a melt extruder to form a colored polypropylene film having a thickness of 20 μm. A substrate layer 1 made of the same material was formed.

(Comparative Example 13)
As a raw material for a colored polypropylene film, 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. 39 parts of random polypropylene resin with a melt flow rate (MFR) of 12 g / 10 min (230 ° C) containing 4% of ethylene component with respect to 39 parts by mass, 6 parts by mass of titanium oxide pigment as an inorganic pigment, chromium-antimon composite oxide A base material made of a colored polypropylene film having a thickness of 20 μm, which is extruded by using a melt extruder after adding 16 parts by mass of the pigment and the above-mentioned vesicle of the nucleating agent to 1.0 part by mass as a nucleating agent. Layer 1 was formed.

(evaluation)
For Examples 1 to 16 and Comparative Examples 1 to 13 described above, the Martens hardness was measured, the tensile modulus was measured, printing defects, scratch resistance, bending suitability, and nonflammability were evaluated.
<Martens hardness>
The measurement was performed using a Martens hardness measuring device (Fisherscope HM2000; Fisher Instruments Co., Ltd.) compliant with ISO14577. The sample was taken from the cross section of the decorative sheet 10 in order to avoid the influence of the laminated resin layer 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-curable epoxy resin or a UV-curable resin and sufficiently cured, and then cut so that the cross section of the decorative sheet 10 appears and mechanically polished. A measurement surface was obtained by applying. As a specific measurement method, an indenter is pushed into the base material layer 1 on the measurement surface of each sample, and the Martens hardness is calculated from the pushing depth and the load. The measurement conditions were a test force of 10 mN, a test force load required time of 10 seconds, and a test force holding time of 5 seconds. The calculated Martens hardness of each sample is as shown in Table 1.

<Tension modulus>
The tensile elastic modulus was measured by using an autograph (AGS-500NX) manufactured by Shimadzu Corporation and conducting a tensile test at a tensile speed of 50 mm / min to calculate the tensile elastic modulus.
<Printing defects>
The pattern layer 2 was formed by gravure printing using a gravure printing machine, and at that time, a defect in which the base material layer 1 was stretched by tension and was misplaced when laminating each color was evaluated as a printing defect.
"◎" when registration adjustment is not required at all, "○" when easy adjustment is possible by automatic registration adjustment, "△" when registration adjustment requires attention, printing cannot be continued because registration adjustment is not possible. The case was set to "x". In addition, when the film being printed breaks frequently and there is a problem in mass productivity, it is also marked with "x". If the evaluation is "Δ" or higher, there is no problem in printing.

<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. (Compliant with the old JIS standard JIS K5400). The test was conducted 5 times to evaluate the scratches and marks on the pencil.
"◎" when no scratches or marks are seen, "○" when a slight pencil mark is visible, "△" when a pencil mark is visible, and when a pencil scratch or torn polypropylene film is visible. Was set to "x".
If the evaluation is "○" or higher, there is no practical problem. Further, if the evaluation is "Δ" or higher, the problem does not occur although it is limited to applications such as furniture and a vertical surface at a high position where people do not touch. It is preferable that the evaluation is "○" or higher.

<Appropriate bending>
In the bending suitability test, each of the decorative sheets 10 of Examples 1 to 16 and Comparative Examples 1 to 13 obtained by the above method was applied to one surface of the 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 other surface of the base layer 1 is not scratched. Insert up to the boundary where and is pasted together. Next, the base material layer 1 is bent up to 90 degrees along the V-shaped groove so that the surface of the decorative sheet 10 is mountain-folded, and whitening or cracks occur in the bent portion of the surface of the decorative sheet 10. The presence was observed using an optical microscope, and the state of bending workability was evaluated.
"◎" if no whitening or cracks are seen, "○" if some whitening is visible, "△" if some whitening is visible, or if whitening is visible on the entire surface or partly The case where a crack is visible is marked as "x". If the evaluation is "△" or higher, there is no problem in practical use.

<Nonflammable>
Using each of the decorative sheets 10 of Examples 1 to 16 and Comparative Examples 1 to 13, a heat generation test was carried out by a cone calorie meter tester compliant with ISO5660-1. Nonflammability was determined by whether or not the provisions of Article 108-2, Items 1 and 2 of the Building Standards Act Enforcement Ordinance were satisfied.
Passed is indicated by "○" and failed is indicated by "×".
The results of these evaluations are shown in Table 1.

As can be seen from Table 1, it can be seen that the decorative sheets 10 of Examples 1 to 8 are compatible with the bending process while ensuring a practically usable situation regarding defects and strength during the printing process. Further, in the decorative sheets 10 of Examples 9 to 16, the pattern layer 2, the transparent resin layer 3 and the top coat layer 4 are laminated on Examples 1 to 9, and the bending process is performed while achieving both high design and high scratch resistance. You can see that they are compatible. Further, since the film thickness of the base material layer 1 is 55 μm or less, the nonflammability is also passed.

On the other hand, in the decorative sheets 10 of Comparative Examples 1 to 8, since the nucleating agent which was not vesicled was used, the strength improvement by improving the crystallinity was not sufficient, especially when the film thickness was thin and the high crystalline homopolypropylene. When the blending ratio of the resin is low, a problem occurs during the printing process. Further, even if there is no defect in the printing process, there are cases where the strength required for the decorative sheet 10 is insufficient or a defect occurs in the bending process. It is considered that these are caused by the fact that the ability to improve the crystallinity is lower than that of the vesicled nucleating agent and that the spherulite size is larger than that of the vesicled nucleating agent.

Further, in the decorative sheets 10 of Comparative Examples 9 to 13, any one of the addition amount as a 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 scope of the present application. However, it can be seen that one of the evaluation results is problematic.
Here, in Comparative Example 11, although automatic register adjustment was possible, the film being printed was broken at a high frequency, and a product could not be produced. It is probable that this is because the Martens hardness and tensile elastic modulus were sufficient, but the thickness was too small, so that the film could not withstand the tension fluctuation during printing and the frequency of breakage increased.

From the above, it has been clarified that the decorative sheets 10 of Examples 1 to 16 are decorative sheets 10 that have all of defects, strength, bending, and nonflammability during printing processing.
The decorative sheet 10 of the present invention is not limited to the above-described embodiments and examples, and various modifications can be made as long as the characteristics of the invention are not impaired.

10 Decorative sheet 1 Base material layer 2 Picture layer 3 Transparent resin layer 4 Top coat layer B Substrate

Claims (11)

It has a base material layer made of a colored polypropylene film made by mixing an inorganic pigment with a polypropylene resin, and the base material layer is nano-sized in a vesicle having an outer film of a single layer film with respect to the polypropylene resin containing the inorganic pigment. It is formed by adding a nucleating agent vesicle containing a nucleating agent, and the maltens hardness of the base material layer is 30 N / mm ² or more and 100 N / mm ² or less, and the thickness of the base material layer is 20 μm. A decorative sheet having a size of 55 μm or more. The first aspect of claim 1, wherein 50% by mass or more and 100% by mass or less of the polypropylene resin is made of a highly crystalline homopolypropylene resin having an isotactic pentad fraction (mmmm fraction) of 95% or more. Cosmetic sheet. 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 claim 1 or 2. The decorative sheet according to any one of claims 1 to 3, wherein the nucleating agent vesicle is a nucleating agent liposome having an outer membrane made of phospholipid. The decorative sheet according to any one of claims 1 to 4, wherein the pattern layer is laminated on one surface of the base material layer. At least one layer of the transparent resin layer and the 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 5, wherein the total thickness of the decorative sheet is 140 μm or less. Any of claims 1 to 6, wherein the nucleating agent vesicle is formed by encapsulating the nucleating agent in a vesicle provided with a single-layer film by a supercritical reverse-phase evaporation method. The cosmetic sheet described in item 1. The method for manufacturing a decorative sheet according to any one of claims 1 to 7.
A vesicle is encapsulated with a nucleating agent to produce a vesicle of the nucleating agent to produce a vesicle.
From the resin material obtained by adding the inorganic pigment and the nucleating agent vesicle prepared above to the polypropylene resin, the base material layer having a maltens hardness of 30 N / mm ² or more and 100 N / mm ² or less and a thickness of 20 μm or more and 55 μm or less can be obtained. A method for manufacturing a decorative sheet, which comprises producing a decorative sheet. The eighth aspect of claim 8, wherein a highly crystalline homopolypropylene resin having an isotactic pentad fraction (mmmm fraction) of 95% or more is used in an amount of 50% by mass or more and 100% by mass or less of the polypropylene resin. How to make a decorative sheet. When the base material layer is manufactured, the maltens hardness of the base material layer is controlled to 30 N / mm ² or more and 100 N / mm ² or less by adjusting the cooling time from the crystallization temperature to the curing completion temperature. 9. The method for manufacturing a decorative sheet according to claim 9. At least one layer of the transparent resin layer and the top coat layer is laminated 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 set in the range of 50 μm or more and 100 μm or less, the thickness of the top coat layer is set in the range of 3 μm or more and 15 μm or less, and the total thickness of the decorative sheet is set. The method for producing a decorative sheet according to any one of claims 8 to 10, wherein the size is 140 μm or less.

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