JP7257879B2 - Multilayer film, decorative sheet, decorative molding, method for producing multilayer film, and method for producing decorative sheet - Google Patents

Description

TECHNICAL FIELD The present invention relates to a multilayer film, a decorative sheet, a decorative molding, a method for producing a multilayer film, and a method for producing a decorative sheet.

Films are sometimes attached to the surfaces of automobile interiors and exteriors, home appliances, furniture, building materials, smartphones, amusement products, etc., such as resin parts, metal parts, coatings, etc., to protect the surfaces of these objects. The film can prevent scratches on the target surface and deterioration due to ultraviolet rays or the like. In addition, when the film has a design property such as a metallic decorative property or a pattern, the design property can be imparted to the object.

For example, Patent Literature 1 discloses a paint-alternative film capable of being an alternative to paint, and a laminate molded body using the same, as a film for automobile interior materials, home appliances, furniture, building materials, and the like. It is also described that such a coating substitute film and laminated molded article have a good balance of properties such as film formability, toughness, surface glossiness, surface hardness, transparency and heat resistance.

Patent No. 5564336 Patent No. 6405004

Thus, various properties are required at the same time for the film that protects the target surface. In particular, from the viewpoint of protecting the surface of the resin part, metal part, coating film, etc. described above and imparting design properties, printability, scratch resistance, chemical resistance, moldability, impact resistance, weather resistance There is a growing demand for a film that satisfies all of these requirements at the same time. However, conventionally, no film has been realized that simultaneously satisfies all of these properties at a high level.

In view of the above problems, the present invention provides a multilayer film, a decorative sheet, a decorative molded product, and An object of the present invention is to provide a method for manufacturing a multilayer film and a method for manufacturing a decorative sheet.

In order to solve the above problems, the multilayer film of the present invention includes a laminate layer in which a fluorine-based resin layer and an acrylic resin layer are laminated, a polycarbonate-based resin layer, and the acrylic-based resin layer and the polycarbonate-based resin layer. and a polyurethane adhesive layer.

The thickness of the fluorine resin layer is 5 μm to 50 μm, the thickness of the acrylic resin layer is 50 μm to 125 μm, the thickness of the polyurethane adhesive layer is 5 μm to 10 μm, and the thickness of the polycarbonate resin layer is 125 μm. It may be ~500 μm.

The fluororesin used for the fluororesin layer may be polyvinylidene fluoride resin, and the acrylic resin used for the acrylic resin layer may be polymethyl methacrylate resin.

The laminate layer may include a polyurethane adhesive layer that joins the fluorine-based resin layer and the acrylic resin layer.

Further, in order to solve the above problems, the method for producing a multilayer film of the present invention is the above-described method for producing a multilayer film of the present invention, wherein a solvent-based polyurethane adhesive is applied to the surface of the acrylic resin layer. a drying step of drying the applied solvent-based polyurethane adhesive; after the drying step, the surface of the acrylic resin layer to which the solvent-based polyurethane adhesive is applied; and a joining step of joining the resin layer.

Moreover, in order to solve the above-mentioned problems, the decorative sheet of the present invention comprises the above-described multilayer film of the present invention and a design layer disposed on the polycarbonate-based resin layer of the multilayer film.

Further, in order to solve the above problems, the method for producing a decorative sheet of the present invention is the above-described method for producing a decorative sheet of the present invention, wherein the polycarbonate-based resin layer of the above-described multilayer film of the present invention includes: An arrangement step of arranging the design layer is included.

Moreover, in order to solve the above-mentioned problems, the decorative molded article of the present invention includes the above-described decorative sheet of the present invention, and the fluororesin layer on the surface thereof.

INDUSTRIAL APPLICABILITY According to the present invention, a multilayer film, a decorative sheet, a decorative molding, and a multilayer film which can satisfy all of printability, scratch resistance, chemical resistance, moldability, impact resistance, and weather resistance at the same time are produced. A method and a method for manufacturing a decorative sheet can be provided.

1 is a schematic diagram showing a cross section of a multilayer film according to one embodiment of the present invention; FIG. 1. It is a cross-sectional schematic diagram for demonstrating an example of the manufacturing method of the multilayer film 100 shown in FIG. 1. It is a cross-sectional schematic diagram for demonstrating an example of the manufacturing method of the multilayer film 110 shown in FIG. It is a cross-sectional schematic diagram for demonstrating an example of the manufacturing method of a decorating sheet. FIG. 2 is a cross-sectional view schematically showing a decorative molding;

Hereinafter, the multilayer film, the decorative sheet, the decorative molding, the method for manufacturing the multilayer film, and the method for manufacturing the decorative sheet according to the present invention will be described.

[Multilayer film]
A multilayer film according to one embodiment of the present invention includes a laminate layer, a polycarbonate-based resin layer, and a polyurethane adhesive layer.

<Laminate layer>
The laminate layer is a layer in which a fluororesin layer and an acrylic resin layer are laminated. The laminate layer may be formed by a co-extrusion method. Specifically, in the co-extrusion molding method, molten fluororesin and acrylic resin are extruded simultaneously using a plurality of extruders and passed through a single die to produce a molten fluororesin and acrylic resin. There is a method of obtaining a laminate layer by laminating and cooling the laminate.

Also, the laminate layer may be formed by bonding a fluorine-based resin layer and an acrylic resin layer with a polyurethane adhesive layer. The polyurethane adhesive layer may be the same layer as the polyurethane adhesive layer that joins the acrylic resin layer and the polycarbonate resin layer, which will be described later. You may join with a system resin layer.

In addition to the above, the laminate layer may be formed by an extrusion lamination method. Specific examples of the extrusion lamination method include a method in which a melted acrylic resin is extruded into a film by an extruder, and a separately fed fluororesin film is press-bonded with a cooling roll to obtain a laminate layer. .

(Fluorine resin layer)
Fluororesins are excellent in heat resistance, insulation, slidability, chemical resistance, and weather resistance. In order to utilize such properties, in the multilayer film of the present invention, a fluororesin layer formed by forming a sheet of fluororesin can be used as the outermost surface of the multilayer film.

As the fluororesin layer, a layer having clearness can be used so as not to impair the beauty of the object to be protected. As a measure of clearness, refractive index and light transmittance can be mentioned. For example, if the refractive index is 1.38 to 1.46 and the total light transmittance is 85% or more, it can be said that the clearness is satisfied.

Further, the luster and luster of the fluororesin layer can be set to gloss, matte, half-gloss, half-gloss, etc. so as to meet the needs. The glossiness can be adjusted, for example, by dispersing a delustering agent such as alumina or silica in a molten fluororesin and forming a film. Further, by treating the surface of the film-formed fluororesin layer, the luster and luster can be adjusted.

The thickness of the fluororesin layer is preferably 5 μm to 50 μm. Even if the thickness is less than 5 μm, there is no problem in performance such as heat resistance, insulation, slidability, chemical resistance, and weather resistance. It is difficult to obtain because it is difficult to form a film. If a thin fluororesin layer can be stably formed, the thickness may be less than 5 μm. If the thickness exceeds 50 μm, the fluororesin layer is soft, and the scratch resistance of the multilayer film may be reduced. There is Furthermore, since the fluororesin itself is expensive, the cost of the multilayer film may increase if the film is thick. If the thickness of the fluororesin layer is 5 μm to 50 μm, it is possible to obtain a multi-layer film having no problems in transparency and scratch resistance.

Examples of the fluororesin used for the fluororesin layer include polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (CTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), and perfluoroalkoxy fluororesin (PFA). , tetrafluoroethylene/hexafluoropropylene copolymer (FEP), ethylene/tetrafluoroethylene copolymer (ETFE), and ethylene/chlorotrifluoroethylene copolymer (ECTFE). Vinylidene dichloride (PVDF) is useful because of its excellent mechanical strength and workability compared to other fluororesins. Alloys and copolymers of fluororesins and acrylic resins, which are blended with various acrylic resins, and alloys and copolymers, which are blends of fluororesins with other resins and polymers, are also fluoropolymers. It can be included in the fluororesin layer as a resin.

(Acrylic resin layer)
Acrylic resin is a general term for polymers and copolymers of, for example, acrylic acid and its derivatives such as esters, and methacrylic acid derivatives such as methyl methacrylate. It is an amorphous synthetic resin with high transparency. Moreover, since the hardness is high, a layer having excellent scratch resistance can be formed. In particular, even if the fluorine-based resin layer, which is the upper layer of the acrylic resin layer, is softer than the acrylic resin and is inferior in scratch resistance, the acrylic resin layer, which is the lower layer of the fluorine-based resin layer, is a hard layer. Since the acrylic resin layer can cover the softness of the thin fluororesin layer, the multi-layer film has excellent scratch resistance.

As the acrylic resin layer, one having a clear property can be used so as not to impair the beauty of the object to be protected. As a measure of clearness, refractive index and light transmittance can be mentioned. For example, if the refractive index is 1.47 to 1.55 and the total light transmittance is 85% or more, it can be said that the clearness is satisfied.

The thickness of the acrylic resin layer is preferably 50 μm to 125 μm. Even if the thickness is less than 50 μm, there is no problem with the performance of the acrylic resin, but at present, it is difficult to stably form an acrylic resin layer of less than 50 μm, so it is difficult to obtain. As long as a thin acrylic resin layer can be stably formed, the thickness may be less than 5 μm. If the thickness exceeds 125 μm, the sheet is likely to crack, which may cause problems in lamination of each layer in the multilayer sheet, resulting in a decrease in yield in manufacturing the multilayer sheet. In addition, when the film becomes thick, there is a possibility that the flexibility as a multilayer film may be lowered and the cost may be increased. If the thickness of the acrylic resin layer is 50 μm to 125 μm, the production yield does not decrease, and a multilayer film having no problem in flexibility can be obtained.

Examples of the acrylic resin used for the acrylic resin layer include polyethyl methacrylate (PEMA), polybutyl methacrylate (PBMA), polycyclohexyl methacrylate (PCHMA), and polyethylhexyl methacrylate (PEHMA). Methyl methacrylate resin (PMMA) is useful because it has high transparency and excellent scratch resistance due to its high hardness, and it is thermoplastic and can be processed into a complicated shape. It is also useful in that coloring is easy and the appearance of the multilayer film can be adjusted. Also, an alloy obtained by blending an acrylic resin with another resin or polymer, a copolymer obtained by copolymerizing the acrylic resin, or the like can be included in the acrylic resin layer as the acrylic resin.

<Polycarbonate resin layer>
Polycarbonate resins (PC resins) are excellent in transparency, heat resistance, impact resistance, moldability, and adhesion, and are excellent in printing properties as a printing object. Utilizing such properties, in the multilayer film of the present invention, a polycarbonate-based resin layer formed into a sheet of polycarbonate resin can be used as the bottom layer of the multilayer film. Then, a decorative sheet can be produced by disposing a later-described design layer on the polycarbonate-based resin layer. In addition, an alloy obtained by blending a polycarbonate resin with another resin or polymer, a copolymer obtained by copolymerizing the polycarbonate resin, or the like can be included in the polycarbonate resin layer as the polycarbonate resin.

As the polycarbonate-based resin layer, a layer having clearness can be used so as not to impair the appearance of the object to be protected. As a measure of clearness, refractive index and light transmittance can be mentioned. For example, if the refractive index is 1.52 to 1.62 and the total light transmittance is 85% or more, it can be said that the clearness is satisfied.

The thickness of the polycarbonate-based resin layer is preferably 125 μm to 500 μm. If the thickness is less than 125 μm, the multilayer film may be shrunk by stretching during molding, or the molded product obtained by molding the multilayer film may be insufficient in rigidity. It may become impossible to do so. On the other hand, when the thickness exceeds 500 μm, moldability deteriorates, and it may become difficult to mold the multilayer film into a desired shape. Furthermore, the thick polycarbonate-based resin layer may increase the cost of the multilayer film. If the thickness of the polycarbonate-based resin layer is 125 μm to 500 μm, a multi-layer film can be obtained without problems in moldability.

<Polyurethane adhesive layer>
Polyurethane resins include polymers comprising a copolymer of a polyol component and an isocyanate component, and have high adhesion to various substrates and high impact resilience. In addition, it is possible to design a polymer according to the application, and it is a useful resin in a wide range of fields such as fibers, films, and metal adhesion. In the multilayer film of the present invention, polyurethane is used as an adhesive to form a polyurethane adhesive layer that joins the acrylic resin layer and the polycarbonate resin layer. The polyurethane adhesive layer can firmly bond the acrylic resin layer and the polycarbonate resin layer without impairing the transparency of the multilayer film, and has flexibility to follow deformation.

Examples of polyurethane adhesives include solvent-based, water-based, and solvent-free adhesives, as well as one-liquid type adhesives such as moisture-curable polyurethanes, and polyol components as the main component and isocyanate components as the curing agent. A two-liquid type adhesive can be used. Any polyurethane adhesive can be used as long as it does not impair the properties of the multilayer film of the present invention.

As the polyurethane adhesive layer, one having a clear property can be used so as not to impair the appearance of the object to be protected. As a measure of clearness, refractive index and light transmittance can be mentioned. For example, if the refractive index is 1.45 to 1.53 and the total light transmittance is 85% or more, it can be said that the clearness is satisfied.

The thickness of the polyurethane adhesive layer is preferably 5 μm to 10 μm. If the thickness is less than 5 μm, the adhesion between the acrylic resin layer and the polycarbonate resin layer may not be maintained due to poor adhesion. On the other hand, if the thickness exceeds 10 μm, foaming occurs during the drying process of the adhesive, and the appearance of the cured polyurethane adhesive layer may be poor due to air bubbles. If the thickness of the polyurethane adhesive layer is 5 μm to 10 μm, the adhesive layer satisfies the bondability and has a good appearance.

(Other layers)
The multilayer film of the present invention can contain other layers in addition to the layers described above. For example, on the fluororesin layer, a matting layer made of a clear resin whose luster and luster have been adjusted by addition of a matting agent or surface treatment may be included. Thus, the luster and luster of the multilayer film can be adjusted not only by adjusting the fluororesin layer but also by adding the matte layer.

FIG. 1 shows a schematic diagram showing a cross section of a multilayer film according to one embodiment of the present invention. As shown in FIG. 1( a ), the multilayer film 100 includes a fluororesin layer 10 , an acrylic resin layer 20 , a polycarbonate resin layer 30 and a polyurethane adhesive layer 40 . The fluorine-based resin layer 10 and the acrylic resin layer 20 form a laminate layer 50 formed by a co-extrusion method. Also, the polyurethane adhesive layer 40 bonds the acrylic resin layer 20 and the polycarbonate resin layer 30 .

In the multilayer film 110 shown in FIG. 1(b), the fluororesin layer 10 and the acrylic resin layer 20 are joined by the adhesive layer 60, and these constitute the laminate layer 51. FIG. Other configurations are the same as those of the multilayer film 100 .

With the multilayer film of the present invention described above, by appropriately arranging the fluorine-based resin layer, the acrylic resin layer, the polycarbonate-based resin layer, and the polyurethane adhesive layer, printability, scratch resistance, chemical resistance, and moldability are improved. All of the requirements for durability, impact resistance, and weather resistance can be met at the same time.

[Manufacturing method of multilayer film]
Next, the manufacturing method of the multilayer film of the present invention described above will be described with reference to the schematic cross-sectional views (FIGS. 2 and 3) for describing an example of the manufacturing method of the multilayer film shown in FIG. A method for producing a multilayer film according to one embodiment of the present invention includes a coating step, a drying step, and a joining step, which will be described below.

<Coating process>
This step is a step of applying a solvent-based polyurethane adhesive to the surface of the acrylic resin layer. For example, as shown in FIG. 2( a ), for a laminate layer 50 formed by co-extrusion using a fluorine-based resin layer 10 and an acrylic resin layer 20 , the entire surface of the acrylic resin layer 20 is A solvent-based polyurethane adhesive 45 is applied to the .

(Solvent-based polyurethane adhesive)
By using a solvent-based polyurethane adhesive, an anchoring effect is imparted by allowing the solvent to slightly dissolve the surface of the acrylic resin layer 20 without impairing the clearness of the multilayer film 100. The resin layer 20 and the polycarbonate resin layer 30 can be strongly bonded. With water-based adhesives, there is a risk of insufficient bonding due to the lack of such an anchoring effect, and solvent-free adhesives are not versatile, difficult to obtain, and expensive. may become Specifically, it is possible to use a one-component type adhesive such as moisture-curable polyurethane, or a two-component type adhesive having a polyol component as a main component and an isocyanate component as a curing agent. Polyurethane-based adhesives are versatile and useful from the standpoint of performance, availability, and cost. Solvents include common solvents for adhesives such as toluene, xylene, ethyl acetate, butyl acetate, methanol, ethanol, isopropyl alcohol, mineral spirits, and the like.

Note that the solvent contained in the solvent-based polyurethane adhesive 45 may dissolve the polycarbonate-based resin layer 30 and swell the layer itself, or the solvent that has entered the layer may evaporate over time and generate gas. There is a risk that the clearness of the multilayer film 100 cannot be satisfied due to whitening of the layers. Therefore, the solvent-based polyurethane adhesive 45 is applied to the surface of the acrylic resin layer 20 .

The amount of the solvent-based polyurethane adhesive 45 to be applied is not particularly limited, but it is preferable to apply so that the thickness of the polyurethane adhesive layer 40 after drying (dry film thickness) is 5 μm to 10 μm. If the dry film thickness is less than 5 μm, the adhesion between the acrylic resin layer and the polycarbonate resin layer may not be maintained due to poor adhesiveness. Further, if the dry film thickness exceeds 10 μm, foaming occurs during the drying process of the adhesive, and the appearance of the cured polyurethane adhesive layer 40 may be poor due to air bubbles. If the solvent-based polyurethane adhesive 45 is applied so that the polyurethane adhesive layer has a thickness of 5 μm to 10 μm, the adhesion between the acrylic resin layer 20 and the polycarbonate resin layer 30 is satisfied and the appearance is good. layer.

<Drying process>
This step is a step of drying the applied solvent-based polyurethane adhesive. By drying to volatilize the solvent contained in the solvent-based polyurethane adhesive 45 before bonding to the polycarbonate-based resin layer 30, the swelling and gas generation of the polycarbonate-based resin layer 30 described above can be prevented, resulting in whitening. The appearance of the multi-layer film 100 is not impaired due to the generation of air bubbles or the like, and the clearness can be maintained.

<Joining process>
This step is a step of joining the surface of the acrylic resin layer to which the solvent-based polyurethane adhesive is applied and the polycarbonate resin layer after the drying step. For example, as shown in FIG. 2B, bonding the polycarbonate-based resin layer 30 to the surface of the polyurethane adhesive layer 40 after drying corresponds to the joining step. Thereby, the multilayer film 100 is formed. The bonding of the polyurethane adhesive layer 40 and the polycarbonate resin layer 30 can be carried out by appropriately devising such that they are perfectly bonded so as not to generate air bubbles on the bonding surfaces. Moreover, the polyurethane adhesive layer 40 and the polycarbonate-based resin layer 30 may be pressure-bonded by applying pressure so that they can be firmly bonded.

(Other processes)
The method for producing a multilayer film of the present invention may include other steps in addition to the steps described above. For example, first, as shown in FIG. 3, a solvent-based polyurethane adhesive 45 is applied to the entire surface of the acrylic resin layer 20 (FIG. 3(a), application step), and the solvent-based polyurethane adhesive 45 is dried. (drying step), and the polyurethane adhesive layer 40 and the polycarbonate resin layer 30 are bonded together (FIG. 3(b) bonding step). After that, an adhesive 65 is applied to the acrylic resin layer 20 (Fig. 3(c)), and the fluororesin layer 10 is joined to form a laminate layer 51 (Fig. 3(d)). A laminate layer forming step may be included. As the adhesive 65, a solvent-based polyurethane adhesive is useful in the same manner as the solvent-based polyurethane adhesive 45, and the acrylic resin layer 20 and the polycarbonate-based resin layer 30 are adhered together by the same method. The resin layer 20 and the fluororesin layer 10 can be bonded.

[Decorative sheet]
Next, the decorative sheet of the present invention will be explained. A decorative sheet according to one embodiment of the present invention comprises the multilayer film of the present invention and a design layer disposed on a polycarbonate-based resin layer of the multilayer film. Polycarbonate resin is a resin having excellent printing properties as a printing object, so a design layer is arranged on a polycarbonate-based resin layer.

<Design layer>
As the design layer, various colors, designs, patterns, and the like can be used. Examples thereof include a plated portion used as a decorative portion, and a layer (metal layer) formed of a metal capable of imparting decorativeness and designability equivalent to parts made of a metal material. Further, a decorative pattern including a light-reflecting convex portion and a black layer formed on the light-reflecting convex portion with black ink, as disclosed in Patent Document 2, is also included as a design layer.

(Other configurations)
The decorative sheet may have other configurations in addition to the configurations described above. For example, until the decorative sheet is used, the surface 11 and the surface opposite to the surface 11 are kept clean, and in order to prevent staining, release paper, protective film, etc. are placed on the surface 11 and the surface 11. It can be attached to a surface opposite to the surface 11 or the like.

[Decorative sheet manufacturing method]
Next, the manufacturing method of the decorative sheet of the present invention described above will be described with reference to cross-sectional schematic diagrams (FIGS. 4 and 5) for describing an example of the manufacturing method of the decorative sheet. A method for manufacturing a decorative sheet according to one embodiment of the present invention includes an arrangement step described below.

<Arrangement process>
The placement step is a step of placing a design layer on the polycarbonate-based resin layer of the multilayer film of the present invention. For example, as shown in FIG. 4, if the surface 11 of the fluorine-based resin layer 10 is the front surface and the surface 31 of the polycarbonate-based resin layer 30 is the back surface, the metal layer 300 is arranged on the surface 31 as a design layer. Thus, the decorative sheet 200 can be manufactured.

(metal layer)
Specific examples of the metal layer 300 are particularly limited as long as it is a layer formed of a metal that can provide the same decorativeness and design as a plated portion used for a decorative portion or a part made of a metal material. not. As the metal that can be used, one or a combination of metals or alloys that can impart sufficient metallic luster to the metallic decorative sheet and has excellent malleability is used. Specifically, it is selected from the group consisting of aluminum, indium, chromium, zinc, gallium, nickel, tin, silver, gold, silicon, chromium, titanium, platinum, palladium, nickel, stainless steel, Hastelloy, etc., and alloys thereof. 1 type or 2 types or more can be used.

Among the metals mentioned above, indium, tin, or alloys thereof are particularly advantageous when three-dimensional deep drawing is performed. In particular, by using indium or an indium alloy, decorativeness and design can be satisfied while conforming to various shapes of molded bodies in the case of metal-like decorative molded bodies.

Furthermore, it is more preferable that the metal layer is made of indium with a high purity of 99.9% or more, because it can be applied to molding of compacts that are deep-drawn and have extremely small curvature radii. When forming a normal deep-drawn body, aluminum, zinc, gallium, nickel, tin, silver, gold, silicon, chromium, titanium, platinum, palladium, nickel, stainless steel and/or Hastelloy, etc. It can be used as a mixture mixed with indium. Also, these metals can be used by being alloyed with indium. In particular, by using indium or tin, these metals, or an indium-tin alloy, excellent decorativeness and design can be achieved.

The thickness of the metal layer 300 is not particularly limited, but is preferably 10 nm to 100 nm in consideration of decorativeness and design. If the thickness of the metal layer 300 is less than 10 nm, there is a risk that sufficient metallic luster cannot be imparted to the decorative sheet 200 with a metallic tone, and decorativeness and design are not satisfied. On the other hand, when the thickness of the metal layer 300 exceeds 100 nm, the effect on the decorativeness and design is saturated, and there is a possibility that the manufacturing cost of the metallic decorative sheet 200 will increase. In addition, the configuration of the metal-like decorative sheet 200 and the backlight may allow light to pass through the metal layer 300 to produce decorativeness and design. Even in such a case, if the thickness of the metal layer 300 is 10 nm to 100 nm, the decorativeness and design can be satisfied. Normally, the thickness of the metal layer 300 is 50 nm. For example, in the case of a metallic decorative sheet for light transmission, the thickness of the metal layer 300 can be set to 25 nm.

The metal layer 300 is an important layer for imparting excellent decorativeness and design, and is preferably a uniform and thin layer. For example, since the metal layer 300 has a sea-island structure in which islands of metal particles are spaced apart from each other, whitening or the like can be prevented and metallic luster can be maintained even when three-dimensional deep drawing is performed. Methods for forming such a metal layer include a vacuum deposition method, a sputtering method, an ion plating method, and the like, and the metal layer 300 can be formed by a conventional method such as a vacuum application technique.

[Decorative molding]
Next, the decorative molding of the present invention will be described. A decorative molded article according to one embodiment of the present invention includes the decorative sheet of the present invention, and has a fluororesin layer on its surface.

FIG. 5 shows a cross-sectional view schematically showing the decorative molding. The decorative molded body shown in this figure is molded into a desired shape according to the purpose by, for example, an extrusion lamination method or an injection molding method. is. Moreover, the surface 11 of the fluororesin layer 10 is the outermost surface of the decorative molding 210 .

Decorative moldings include, for example, smartphones, mobile phone housings, automobile door mirror housings, front grilles, door handles, center hubcaps, emblems, ornaments, garnishes, lamp reflectors, center consoles, installation panels, etc., personal computers and TVs. , housings and decorative parts of home appliances, housings and decorative parts of pachinko, pachislot, game machines, etc., and general use such as carry bags and suitcases.

(Other configurations)
The decorative molding may have other configurations in addition to the above configurations. For example, release paper, a protective film, or the like can be attached to the surface 11 in order to keep the surface 11 clean and prevent staining until the decorative molding is used.

Note that the decorative molding 210 shown in FIG. 5 is an example, and the present invention is not limited to this. Products molded into various shapes by various methods are also included in the decorative molded article of the present invention.

EXAMPLES The present invention will be described in more detail below using examples, but the present invention is not limited to the following examples.

[Manufacturing of multilayer film]
Using the sheets shown in Table 1 as raw materials, multilayer films were produced as shown in Examples 1-2 and Comparative Examples 1-4.

<Example 1>
On the surface of the PMMA layer of the laminate sheet, apply a polyurethane adhesive obtained by properly mixing a main agent, a curing agent and a solvent so that the dry film thickness becomes 5 μm (application step), and dry at 80° C. for 30 seconds. (drying process). After that, the surface of the PMMA layer coated with the adhesive was bonded to the polycarbonate resin sheet (bonding step), and then cured at 40° C. for 4 days. A multilayer film of Example 1 was produced by these steps.

<Example 2>
A polyurethane adhesive obtained by properly mixing a main agent, a curing agent and a solvent was applied to the surface of the acrylic resin sheet so that the dry film thickness was 5 μm (application step), and dried at 80° C. for 30 seconds ( drying process). After that, the surface of the acrylic resin sheet coated with the adhesive was bonded to the polycarbonate resin sheet by laminating (bonding step), and then cured at 40° C. for 4 days. Then, a polyurethane adhesive was similarly applied to the surface of the acrylic resin sheet opposite to the surface to which the polycarbonate resin sheet was bonded so that the dry film thickness was 5 μm, and dried at 80° C. for 30 seconds. After that, the acrylic resin sheet and the fluororesin sheet were joined by laminating the dried adhesive and the fluororesin sheet together, and then cured at 40° C. for 4 days. A multilayer film of Example 2 was produced by these steps.

<Comparative Example 1>
In the same manner as in Example 2, a polyurethane adhesive obtained by properly mixing a main agent, a curing agent and a solvent was applied to the surface of an acrylic resin sheet so that the dry film thickness was 5 μm, and dried at 80° C. for 30 seconds. rice field. Thereafter, the surface of the acrylic resin sheet to which the adhesive was applied and the polycarbonate resin sheet were adhered together and then cured at 40° C. for 4 days. A fluororesin sheet was not used. Through these steps, a multilayer film of Comparative Example 1 was produced.

<Comparative Example 2>
In the same manner as in Example 2, a polyurethane adhesive was applied to the surface of the acrylic resin sheet to a dry film thickness of 5 μm and dried at 80° C. for 30 seconds. After that, the acrylic resin sheet and the fluororesin sheet were joined by laminating the dried adhesive and the fluororesin sheet together, and then cured at 40° C. for 4 days. A polycarbonate resin sheet was not used. Through these steps, a multilayer film of Comparative Example 2 was produced.

[Evaluation of physical properties of multilayer film]
The physical properties of the multilayer films of Examples 1 and 2 and Comparative Examples 1 and 2 were evaluated by the methods shown below. As Comparative Examples 3 and 4, single-layer acrylic resin sheets and polycarbonate resin sheets were similarly evaluated for their physical properties.

(Printability)
Screen ink ISX911 (black) (manufactured by Teikoku Ink Mfg. Co., Ltd.) is screen-printed on PC layers (Examples 1 and 2, Comparative Examples 1 and 4) or PMMA layers (Comparative Examples 2 and 3) such as multilayer films, and dried. A test piece was prepared by forming a printed layer. After that, according to JIS K 5600 (cross-cut method), the surface of the printed layer was cut with a cutter knife at a pitch of 2 mm in 11 vertical and horizontal directions, and the surface was coated with Cellotape (registered trademark) manufactured by Nichiban Co., Ltd. (width 18 mm or 24 mm ) was firmly attached with the pad of a finger to confirm the adhesion state. After that, holding the tip of Sellotape (registered trademark), it was pulled off instantaneously while maintaining an angle of 45 degrees. The case where the printed layer was not peeled off was evaluated as ◯, and the case where the printed layer was peeled off was evaluated as x.

(Scratch resistance)
A multilayer film or the like was prepared in a 5% stretched state. Then, a friction element with a width of 20 mm and a radius of 10 mm is covered with cotton canvas (No. 6), the load of the friction element is set to 4.9 ± 0.49 N, and a laminate layer such as a multilayer film (Example 1), a PVDF layer Example 2, Comparative Example 2), PMMA layer (Comparative Examples 1 and 3), and PC layer (Comparative Example 4) were rubbed 10 times over a distance of 140 mm. As a result of rubbing, the case where there was no significant scratch residue was evaluated as ◯, and the case where significant scratch residue was observed was evaluated as x.

(water resistant)
The multilayer film and the like were immersed in hot water at 55°C for 4 hours. The multi-layer film, etc. taken out of the hot water immediately after the immersion treatment was evaluated as ◯ when there was no abnormality such as whitening, discoloration, or significant scarring, and as x when any of these abnormalities was observed.

(chemical resistance)
An acid resistance test was conducted by dropping 5 ml of a 0.1N H ₂ SO ₄ aqueous solution onto the surface of the multilayer film or the like and allowing it to stand at 20° C. for 24 hours. An alkali resistance test was conducted by dropping 5 ml of a 0.1 N NaOH aqueous solution onto the surface of the multilayer film or the like and allowing the film to stand at 55° C. for 4 hours. A chemical resistance test was performed by dropping 5 ml of white kerosene onto the surface of the multilayer film or the like and allowing the film to stand at 55° C. for 4 hours. In addition, as a chemical resistance test, 5 ml of 50% by mass ethanol is dropped on the surface of a multilayer film, etc., and a test of standing at 55 ° C. for 4 hours, a laminate layer such as a multilayer film (Example 1), a PVDF layer (Example 2, Comparative Example 2), PMMA layer (Comparative Examples 1 and 3), and PC layer (Comparative Example 4) were coated with sunscreen cream (SPF45), and then left to stand at 80°C for 24 hours. A removal test was performed. The multi-layer film, etc. from which each chemical was removed immediately after the test was evaluated as ◯ when there was no abnormality such as whitening, discoloration, or significant scarring, and as x when any of these abnormalities was observed.

(Moldability)
Using a vacuum and pressure molding machine (manufactured by Kiefel), after heating for 40 seconds so that the surface temperature of the multilayer film reaches 180 ° C., vacuum (1 barr) and compressed air (6 barr) are applied to perform shaping treatment and molding. manufactured the goods. The size of the clamp was 300×350 mm, and the heaters were set to 350° C. for the upper heater and 400° C. for the lower heater. The prototype size was 10.5 cm long, 8.5 cm wide, and 0.7 cm high. ○ indicates that the molded product was molded according to the prototype mold by visual evaluation and there is no abnormality in the molding. evaluated.

(shock resistance)
Using the molded product manufactured by performing shaping treatment in the evaluation of moldability described above, insert injection molding was performed using an injection molding machine (manufactured by Japan Steel Works, Ltd.) to manufacture a flat plate-shaped injection molded product. . A weight of 2.94 N was dropped on the manufactured injection molded product at a drop distance of 0.2 m. The case where there was no cracking or peeling in the injection molded product after that was evaluated as ◯, and the case where cracking or peeling was observed was evaluated as ×. As the injection resin used for injection molding, a PC/ABS alloy resin manufactured by SABIC was used.

(accelerated weather resistance)
Using the test pieces after evaluation of printability, an accelerated weather resistance test was performed under the following conditions using a super xenon weather meter (SX-75 manufactured by Suga Test Instruments Co., Ltd.).
・Irradiation method: Continuous irradiation ・Irradiance: 150W/m ² (300-400nm)
・Xenon long life arc lamp 7.5kW x 1 lamp ・Lamp cooling method Water cooling ・Glass filter (Inner filter: Quartz glass, Outer filter: #275)
・Black panel temperature 83℃
・Relative humidity 50%
・Integrated light intensity 150MJ/m ²
The color difference (ΔE) before and after the accelerated weather resistance test was 3.0 or less, and the same printability test as above was performed on the specimen after the accelerated weather resistance test, and the case where there was no peeling of the printed layer was evaluated as ◯. . In addition, if the color difference (ΔE) before and after these accelerated weather resistance tests is greater than 3.0, or if the test specimen after the accelerated weather resistance tests is subjected to the same printability test as above, the printed layer is peeled off. It was evaluated as ×.

(transparency)
The total light transmittance and haze of the multilayer film and the like were measured according to JIS K 7136. ○ when the total light transmittance is 85% or more and the haze value is 4.0% or less, and x when the total light transmittance is less than 85% or the haze value is greater than 4.0%. bottom.

Table 2 shows the layer structure of the multilayer film and the results of physical property evaluation.

In Examples 1 and 2, chemical resistance and weather resistance were satisfied because PVDF constituted the outermost surface. In addition, PMMA, which is harder than PVDF, constitutes the layer next to PVDF, thereby satisfying scratch resistance. The printability was satisfied by forming the layer to be printed as the lowermost layer with PC. As for water resistance, moldability, impact resistance and transparency, these performances were satisfied as a multilayer film.

On the other hand, in Comparative Example 1, the chemical resistance was not satisfied because PMMA constituted the outermost surface. In Comparative Example 2, printability was not satisfied because PMMA was the layer to be printed. In Comparative Example 3, since the sheet structure is only a single layer of PMMA, printability and chemical resistance are not satisfied, and cracks occur due to the hardness of the impact resistance, and the performance is not satisfied. I didn't. Furthermore, in Comparative Example 4, since the sheet structure was composed of only a single layer of PC, the scratch resistance, chemical resistance and weather resistance were not satisfied.

[summary]
From the results of the above examples, the multilayer film of the present invention has a laminate layer in which a fluorine-based resin layer and an acrylic resin layer are laminated, a polycarbonate-based resin layer, the acrylic-based resin layer, and the polycarbonate-based resin layer. By providing a polyurethane adhesive layer for bonding, all of printability, scratch resistance, chemical resistance, moldability, impact resistance, and weather resistance can be satisfied at the same time. Moreover, since such a multilayer film has excellent printability, it is clearly useful as a decorative sheet on which a design layer is arranged.

REFERENCE SIGNS LIST 10 fluorine-based resin layer 11 surface 20 acrylic resin layer 30 polycarbonate-based resin layer 31 surface 40 polyurethane adhesive layer 45 solvent-based polyurethane adhesive 50 laminate layer 51 laminate layer 60 adhesive layer 65 adhesive 100 multilayer film 110 multilayer film 200 decoration Sheet 210 Decorative molding 300 Metal layer

Claims (8)

a laminate layer in which a fluororesin layer and an acrylic resin layer are laminated;
a polycarbonate-based resin layer;
A multilayer film comprising a polyurethane adhesive layer that joins the acrylic resin layer and the polycarbonate resin layer, and having a total light transmittance of 85% or more . The thickness of the fluorine-based resin layer is 5 μm to 50 μm,
The acrylic resin layer has a thickness of 50 μm to 125 μm,
The polyurethane adhesive layer has a thickness of 5 μm to 10 μm,
2. The multilayer film according to claim 1, wherein the polycarbonate-based resin layer has a thickness of 125 μm to 500 μm. The fluororesin used for the fluororesin layer is a polyvinylidene fluoride resin,
3. The multilayer film according to claim 1, wherein the acrylic resin used for the acrylic resin layer is polymethyl methacrylate resin. 4. The multilayer film according to any one of claims 1 to 3 , wherein the laminate layer comprises a polyurethane adhesive layer that bonds the fluororesin layer and the acrylic resin layer. A method for producing a multilayer film according to any one of claims 1 to 4,
an applying step of applying a solvent-based polyurethane adhesive to the surface of the acrylic resin layer;
a drying step of drying the applied solvent-based polyurethane adhesive;
A method for producing a multilayer film, comprising, after the drying step, a joining step of joining the surface of the acrylic resin layer to which the solvent-based polyurethane adhesive is applied and the polycarbonate resin layer. A decorative sheet comprising the multilayer film according to any one of claims 1 to 4 and a design layer disposed on the polycarbonate-based resin layer of the multilayer film. A method for manufacturing the decorative sheet according to claim 6,
A method for manufacturing a decorative sheet, comprising a placement step of placing a design layer on the polycarbonate resin layer of the multilayer film according to any one of claims 1 to 4. A decorative molded article comprising the decorative sheet according to claim 6 and having the fluororesin layer on its surface.

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