JP2020189443A - Multilayer film, decorative sheet, decorative molded body, method for manufacturing multilayer film, and method for manufacturing decorative sheet - Google Patents

Abstract

To provide a multilayer film, a decorative sheet, a decorative molded body, a method for manufacturing a multilayer film, and a method for manufacturing a decorative sheet, each simultaneously satisfying all of printability, scratch resistance, chemical resistance, moldability, impact resistance and weather resistance.SOLUTION: A multilayer film includes: a laminate layer in which a fluorine-based resin layer and an acrylic resin layer are laminated one upon another; a polycarbonate resin layer; and a polyurethane adhesive layer for connecting the acrylic resin layer and the polycarbonate resin layer.SELECTED DRAWING: Figure 1

Description

The present invention relates to a multilayer film, a decorative sheet, a decorative molded body, a method for producing a multilayer film, and a method for producing a decorative sheet.

A film may be attached to the surface of these objects in order to protect the surface of resin parts, metal parts, coating films, etc. of automobile interiors and exteriors, home appliances, furniture, building materials, smartphones and amusement products. The film can prevent scratches on the target surface and deterioration due to ultraviolet rays and the like. Further, 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 Document 1 discloses a coating substitute film capable of substituting for coating and a laminated molded product using the same as a film for interior materials for automobiles, home appliances, furniture, building materials, and the like. It is described that such a coating substitute film or a laminated molded product has a good balance of characteristics of film forming formability, toughness, surface glossiness, surface hardness, transparency and heat resistance.

Patent No. 5564336 Patent No. 6405004

As described above, the film that protects the target surface is required to have various properties at the same time. In particular, from the viewpoint of protecting the surfaces of the above-mentioned resin parts, metal parts, coating films, etc., and imparting designability, printability, scratch resistance, chemical resistance, moldability, impact resistance, and weather resistance There is an increasing demand for films that meet all at the same time. However, conventionally, a film that simultaneously satisfies all of these characteristics at a high level has not been realized.

In view of the above problems, the present invention provides a multilayer film, a decorative sheet, a decorative molded body, which can simultaneously satisfy all of printability, scratch resistance, chemical resistance, moldability, impact resistance, and weather resistance. It is an object of the present invention to provide a method for producing a multilayer film and a method for producing a decorative sheet.

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

The thickness of the fluorine-based 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 a polyvinylidene fluoride resin, and the acrylic resin used for the acrylic resin layer may be a 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-mentioned method for producing a multilayer film of the present invention, in which a solvent-based polyurethane adhesive is applied to the surface of the acrylic resin layer. After the coating step, the drying step of drying the applied solvent-based polyurethane adhesive, and the surface of the acrylic resin layer to which the solvent-based polyurethane adhesive is applied, and the polycarbonate-based Includes a joining step of joining the resin layer.

Further, in order to solve the above problems, the decorative sheet of the present invention includes the above-mentioned multilayer film of the present invention and a design layer arranged on the polycarbonate 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-mentioned method for producing a decorative sheet of the present invention, and the polycarbonate resin layer of the multilayer film of the present invention described above is used. Includes an arrangement step of arranging the design layer.

Further, in order to solve the above problems, the decorative molded article of the present invention is provided with the above-mentioned decorative sheet of the present invention, and the fluorine-based resin layer is provided on the surface.

According to the present invention, a multilayer film, a decorative sheet, a decorative molded body, and a multilayer film capable of simultaneously satisfying all of printability, scratch resistance, chemical resistance, moldability, impact resistance, and weather resistance can be produced. A method and a method for manufacturing a decorative sheet can be provided.

It is a schematic diagram which shows the cross section of the multilayer film which concerns on one Embodiment of this invention. It is sectional drawing for demonstrating an example of the manufacturing method of the multilayer film 100 shown in FIG. It is sectional drawing for demonstrating an example of the manufacturing method of the multilayer film 110 shown in FIG. It is sectional drawing for demonstrating an example of the manufacturing method of a decorative sheet. It is sectional drawing which shows typically the decorative molded body.

Hereinafter, a method for producing a multilayer film, a decorative sheet, a decorative molded product, a multilayer film, and a method for producing a decorative sheet according to the present invention will be described.

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

<Laminate layer>
The laminated layer is a layer in which a fluorine-based resin layer and an acrylic resin layer are laminated. The laminate layer may be formed by a coextrusion molding method. Specifically, as a coextrusion molding method, a molten fluororesin and an acrylic resin are extruded at the same time using a plurality of extruders and passed through one die to obtain a molten fluororesin and an acrylic resin. Examples thereof include a method of obtaining a laminated layer by laminating and cooling the laminate.

Further, the laminate layer may be one in which a fluorine-based resin layer and an acrylic resin layer are bonded with a polyurethane adhesive layer. The polyurethane adhesive layer may be the same layer as the polyurethane adhesive layer for joining the acrylic resin layer and the polycarbonate resin layer described later, and the fluororesin layer and acrylic can be obtained by the same adhesive method as the method described later. It may be bonded to the based resin layer.

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

(Fluorine resin layer)
Fluororesin is excellent in heat resistance, insulation, slidability, chemical resistance, and weather resistance. In order to utilize such characteristics, in the multilayer film of the present invention, a fluororesin layer in which a fluororesin is formed in a sheet shape can be used as the outermost surface of the multilayer film.

As the fluorine-based resin layer, a layer having a clear property can be used so as not to spoil the aesthetic appearance of the protected object. Refractive index and light transmittance can be mentioned as a measure of clearness. 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 gloss and gloss of the fluorine-based resin layer can be set to gloss, matte, semi-gloss, three-minute gloss, or the like so as to meet the needs. The gloss can be adjusted, for example, by dispersing a matting agent such as alumina or silica in a molten fluororesin and then forming a film. Further, the gloss and gloss can be adjusted by treating the surface of the film-formed fluorine-based resin layer.

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, sliding property, chemical resistance, and weather resistance, but at present, the fluorine-based resin layer of such a thin film is stable. It is difficult to obtain because it is difficult to form a film. As long as the thin film fluorine-based resin layer can be stably formed, there is no problem even if the thickness is less than 5 μm. If the thickness exceeds 50 μm, the fluorine-based resin layer is soft, so that the scratch resistance of the multilayer film may decrease, and the thick film may reduce the transparency of the multilayer film. There is. Further, since the fluororesin itself is expensive, the cost of the multilayer film may increase if the film becomes thick. When the thickness of the fluorine-based resin layer is 5 μm to 50 μm, a multilayer film having no problem in transparency and scratch resistance can be obtained.

Examples of the fluororesin used for the fluororesin layer include polytetrafluoroethylene (PTFE), polychlorotrifluoroethylene (CTFE), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), and perfluoroalkoxy alkane resin (PFA). , Ethylene tetrafluoride / propylene hexafluoride copolymer (FEP), ethylene / ethylene tetrafluoride copolymer (ETFE), ethylene / chlorotrifluoroethylene copolymer (ECTFE), etc. Vinylidene compound (PVDF) is useful because it is superior in mechanical strength and workability as compared with other fluororesins. In addition, fluororesin blended with various acrylic resins and acrylic resin alloys and copolymers, and fluororesin blended with other resins and polymers and copolymerized copolymers 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 derivatives such as esters thereof, and methacrylic acid derivatives such as methyl methacrylate, but in particular, it is a polymer of acrylic acid ester or methacrylic acid ester. Yes, it is a highly transparent amorphous synthetic resin. Further, 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. As a result, the acrylic resin layer can cover the softness of the fluororesin layer of the thin film, so that the film has excellent scratch resistance as a multilayer film.

As the acrylic resin layer, a layer having a clear property can be used so as not to spoil the aesthetic appearance of the protected object. Refractive index and light transmittance can be mentioned as a measure of clearness. 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 in the performance of the acrylic resin, but at present, it is difficult to stably form an acrylic resin layer having a thickness of less than 50 μm, so that it is difficult to obtain. As long as a thin acrylic resin layer can be stably formed, there is no problem even if the thickness is less than 5 μm. If the thickness exceeds 125 μm, the layers are easily cracked, which may cause a problem in the lamination of each layer in the multilayer sheet, which may reduce the yield in the production of the multilayer sheet. In addition, the thick film may reduce the flexibility of the multilayer film and increase the cost. When 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), butyl polymethacrylate (PBMA), cyclohexylcyclomethacrylate (PCHMA), and ethylhexyl methacrylate (PEHMA), and in particular, poly. Methyl methacrylate resin (PMMA) is useful because it has high transparency, excellent scratch resistance due to its high hardness, and can be processed into a thermoplastic and complicated shape. It is also useful in that it is easy to color and the aesthetic appearance of the multilayer film can be adjusted. Further, an alloy obtained by blending an acrylic resin with another resin or a polymer, a copolymer obtained by copolymerizing the acrylic resin, or the like can also be included in the acrylic resin layer as the acrylic resin.

<Polycarbonate resin layer>
Polycarbonate resin (PC resin) is a resin having excellent transparency, heat resistance, impact resistance, moldability, and adhesion, and also having excellent printing characteristics as a printing target. Taking advantage of such characteristics, in the multilayer film of the present invention, a polycarbonate resin layer in which a polycarbonate resin is formed in a sheet shape can be used as the lowermost layer of the multilayer film. Then, the decorative sheet can be manufactured by arranging the design layer described later with respect to the polycarbonate resin layer. Further, an alloy obtained by blending another resin or polymer with a polycarbonate resin, a copolymer obtained by copolymerizing the polycarbonate resin, or the like can also be included in the polycarbonate resin layer as the polycarbonate resin.

As the polycarbonate-based resin layer, a layer having a clear property can be used so as not to spoil the aesthetic appearance of the protected object. Refractive index and light transmittance can be mentioned as a measure of clearness. 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 resin layer is preferably 125 μm to 500 μm. If the thickness is less than 125 μm, there is a risk that the multilayer film will be avoided due to stretching when molding the multilayer film, and the rigidity of the molded product obtained by molding the multilayer film will be insufficient. For example, the multilayer film can be successfully installed in an injection molding die. It may not be possible to do so. Further, if the thickness exceeds 500 μm, the moldability deteriorates, and it may be difficult to mold the multilayer film into a desired shape. Further, the thick film of the polycarbonate resin layer may increase the cost of the multilayer film. When the thickness of the polycarbonate resin layer is 125 μm to 500 μm, a multilayer film having no problem in moldability can be obtained.

<Polyurethane adhesive layer>
Examples of the polyurethane resin include a polymer composed of a copolymer of a polyol component and an isocyanate component, which has 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 an acrylic resin layer and a 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 also has the flexibility to follow the deformation.

Examples of the polyurethane adhesive include solvent-based, water-based, and solvent-free adhesives, and one-component type adhesives such as moisture-curable polyurethane and polyol components as main agents and isocyanate components as curing agents. A two-component type adhesive can be mentioned. 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, a layer having a clear property can be used so as not to spoil the aesthetic appearance of the protected object. Refractive index and light transmittance can be mentioned as a measure of clearness. 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 adhesiveness. On the other hand, if the thickness exceeds 10 μm, the cured polyurethane adhesive layer may have air bubbles due to foaming during the drying process of the adhesive, resulting in poor appearance. When 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 may include other layers in addition to the above layers. For example, a matte layer made of a clear resin whose luster and luster have been adjusted by adding a matting agent or surface treatment may be contained on the fluorine-based resin layer. As described above, the gloss and gloss of the multilayer film can be adjusted not only by adjusting the fluorine-based resin layer but also by adding a matte layer.

FIG. 1 shows a schematic view showing a cross section of a multilayer film according to an embodiment of the present invention. As shown in FIG. 1A, the multilayer film 100 includes a fluorine-based resin layer 10, an acrylic resin layer 20, a polycarbonate-based resin layer 30, and a polyurethane adhesive layer 40. The fluorine-based resin layer 10 and the acrylic resin layer 20 are laminated layers 50 formed by a coextrusion molding method. Further, the polyurethane adhesive layer 40 joins the acrylic resin layer 20 and the polycarbonate resin layer 30.

Further, in the multilayer film 110 shown in FIG. 1B, the fluorine-based resin layer 10 and the acrylic resin layer 20 are bonded by an adhesive layer 60, and these form a laminate layer 51. Other configurations are the same as those of the multilayer film 100.

In the above-mentioned multilayer film of the present invention, printability, scratch resistance, chemical resistance, and molding can be achieved by appropriately arranging the fluororesin layer, acrylic resin layer, polycarbonate resin layer, and polyurethane adhesive layer. It can satisfy all of resistance, impact resistance, and weather resistance 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 schematic cross-sectional views (FIGS. 2 and 3) for explaining an example of the manufacturing method of the multilayer film shown in FIG. The method for producing a multilayer film according to an embodiment of the present invention includes a coating step, a drying step, and a joining step described below.

<Applying 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. 2A, the entire surface of the acrylic resin layer 20 is the entire surface of the laminate layer 50 formed by the coextrusion molding method using the fluororesin layer 10 and the acrylic resin layer 20. Is coated with the solvent-based polyurethane adhesive 45.

(Solvent-based polyurethane adhesive)
By using a solvent-based polyurethane adhesive, the acrylic is provided with an anchor effect that is exhibited by the solvent slightly dissolving the surface of the acrylic resin layer 20 without impairing the clearness of the multilayer film 100. The based resin layer 20 and the polycarbonate resin layer 30 can be firmly bonded to each other. With water-based adhesives, bonding may be insufficient due to the lack of such an anchoring effect, and solvent-free adhesives are not versatile, difficult to obtain, and expensive. There is a risk of becoming. Specifically, a one-component type adhesive such as moisture-curable polyurethane or a two-component type adhesive containing a polyol component as a main component and an isocyanate component as a curing agent can be used, but a two-component type solvent can be used. Polyurethane adhesives are versatile and useful in terms of performance, availability, and cost. Examples of the solvent include solvents commonly used for adhesives such as toluene, xylene, ethyl acetate, butyl acetate, methanol, ethanol, isopropyl alcohol and mineral spirit.

In the solvent-based polyurethane adhesive 45, the solvent contained therein may dissolve the polycarbonate-based resin layer 30 to swell the layer itself, or the solvent that has entered the layer may vaporize over time to generate gas. There is a possibility that the clearness of the multilayer film 100 cannot be satisfied due to whitening of the layer or the like. 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 the solvent-based polyurethane adhesive 45 so that the thickness (dry film thickness) of the polyurethane adhesive layer 40 after drying 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. On the other hand, if the dry film thickness exceeds 10 μm, the cured polyurethane adhesive layer 40 may have air bubbles due to foaming during the drying process of the adhesive, resulting in poor appearance. If the solvent-based polyurethane adhesive 45 is applied so that the thickness of the polyurethane adhesive layer is 5 μm to 10 μm, the bondability between the acrylic resin layer 20 and the polycarbonate resin layer 30 is satisfied, and the appearance is also good. Become a layer.

<Drying process>
This step is a step of drying the applied solvent-based polyurethane adhesive. By volatilizing the solvent contained in the solvent-based polyurethane adhesive 45 by drying before joining with the polycarbonate-based resin layer 30, it is possible to prevent the polycarbonate-based resin layer 30 from swelling and generating gas, and thus whitening. The appearance of the multilayer film 100 is not impaired due to the generation of bubbles or bubbles, and the clearness can be maintained.

<Joining process>
This step is a step of joining the surface of the acrylic resin layer coated with the solvent-based polyurethane adhesive and the polycarbonate-based resin layer after the drying step. For example, as shown in FIG. 2B, bonding the polycarbonate resin layer 30 to the surface of the layer that has been dried to become the polyurethane adhesive layer 40 corresponds to the bonding step. As a result, the multilayer film 100 is formed. The polyurethane adhesive layer 40 and the polycarbonate resin layer 30 can be bonded to each other by appropriately devising so that the polyurethane adhesive layer 40 and the polycarbonate resin layer 30 are perfectly bonded so as not to generate air bubbles on the bonded surface. Further, the polyurethane adhesive layer 40 and the polycarbonate 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 above steps. For example, first, as shown in FIG. 3, the solvent-based polyurethane adhesive 45 is applied to the entire surface of the acrylic resin layer 20 (FIG. 3 (a) coating step), and the solvent-based polyurethane adhesive 45 is dried. The polyurethane adhesive layer 40 and the polycarbonate resin layer 30 are bonded together (drying step) (FIG. 3 (b) joining step). Then, the adhesive 65 is applied to the acrylic resin layer 20 (FIG. 3 (c)), and the fluorine-based resin layer 10 is joined to form the laminate layer 51 (FIG. 3 (d)). A step of forming a laminate layer may be included. As the adhesive 65, a solvent-based polyurethane adhesive is useful as in the case of the solvent-based polyurethane adhesive 45, and the acrylic-based resin layer 20 and the polycarbonate-based resin layer 30 are bonded together by the same method as the acrylic-based adhesive. The resin layer 20 and the fluororesin layer 10 can be bonded.

[Decorative sheet]
Next, the decorative sheet of the present invention will be described. The decorative sheet according to the embodiment of the present invention includes the multilayer film of the present invention and a design layer arranged on the polycarbonate resin layer of the multilayer film. Since the polycarbonate resin is a resin having excellent printing characteristics as a printing target, the design layer is arranged on the polycarbonate resin layer.

<Design layer>
Examples of the design layer include various colors, patterns, and patterns. For example, a plated portion used for a decorative portion, a layer made of a metal (metal layer) capable of imparting the same decorativeness and design as a part made of a metal material, and the like can be mentioned. Further, a decorative pattern including a light-reflecting convex portion and a black layer formed by black ink on the light-reflecting convex portion as shown in Patent Document 2 is also mentioned as a design layer.

(Other configurations)
The decorative sheet may have other configurations in addition to the above configurations. For example, until the decorative sheet is used, the surface 11 and the surface opposite to the surface 11 are kept in a clean state, and in order to prevent the surface 11 from getting dirty, a paper pattern, a protective film, etc. It can be attached to the surface opposite to the surface 11.

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

<Placement process>
The arranging step is a step of arranging the design layer on the polycarbonate resin layer of the multilayer film of the present invention. For example, as shown in FIG. 4, when 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. As a result, 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 made of a metal capable of imparting the same decorativeness and design as a plated portion used for a decorative portion and a part made of a metal material. Not done. The metal that can be used is one or a combination of metals or alloys that can impart sufficient metallic luster to the metallic decorative sheet and have excellent malleability. 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 and the like, and alloys thereof. One type or two or more types can be used.

Among the above-mentioned metals, indium, tin, or alloys thereof are particularly advantageous when deep-drawing three-dimensional molding is performed. In particular, by using indium or an indium alloy, it is possible to satisfy the decorativeness and design while following various shapes of the molded body in the case of a metallic decorative molded body.

Further, it is more preferable that the metal layer is made of high-purity indium of 99.9% or more because it can be applied to the molding of a molded product having a deep drawing and an extremely small radius of curvature. When molding a normal deep-drawing molded body, aluminum, zinc, gallium, nickel, tin, silver, gold, silicon, chromium, titanium, platinum, palladium, nickel, stainless steel and / or Hastelloy, etc. are appropriately used. It can be used as a mixture mixed with indium. Further, these metals can be used by alloying with indium. In particular, by using indium or tin and these metals or an indium tin alloy, excellent decorativeness and design can be satisfied.

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, it may not be possible to impart sufficient metallic luster when the metallic decorative sheet 200 is used, and the decorativeness and design may not be satisfied. On the other hand, when the thickness of the metal layer 300 exceeds 100 nm, the influence on the decorativeness and the design property is saturated, and the manufacturing cost of the metal-like decorative sheet 200 may increase. Further, depending on the configuration of the metal-like decorative sheet 200 and the backlight, light may be transmitted 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, decorativeness, designability, and the like can be satisfied. Normally, the thickness of the metal layer 300 is 50 nm. For example, in the case of a metal-like decorative sheet for transmitting light rays, 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 separated from each other, whitening phenomenon and the like can be prevented and metallic luster can be maintained even if deep-drawing three-dimensional molding is performed. Examples of the method for forming such a metal layer include a vacuum vapor deposition method, a sputtering method, an ion plating method, and the like, and the metal layer 300 can be formed by a usual method such as a vacuum application technique.

[Decorative molding]
Next, the decorative molded article of the present invention will be described. The decorative molded article according to the embodiment of the present invention includes the decorative sheet of the present invention and has a fluorine-based resin layer on the surface.

FIG. 5 shows a cross-sectional view schematically showing the decorative molded body. The decorative molded body shown in this figure is formed into a desired shape according to a purpose by, for example, an extrusion laminating method or an injection molding method, and the decorative molded body 210 is obtained by molding the decorative sheet 200. Is. Further, the surface 11 of the fluorine-based resin layer 10 is the outermost surface of the decorative molded product 210.

Decorative moldings include, for example, smartphones, mobile phone housings, automobile door mirror housings, front grilles, door handles, center wheel caps, emblems, ornaments, garnishes, lamp reflectors, center consoles, installation panels, etc. , Used for housings and decorative parts of home appliances, housings and decorative parts of pachinko, pachislot, game machines, etc., or for carry bags and suitcases for general purposes.

(Other configurations)
The decorative molded body may have other configurations in addition to the above configurations. For example, in order to keep the surface 11 in a clean state and prevent it from getting dirty until the decorative molded product is used, a release paper, a protective film, or the like can be attached to the surface 11.

The decorative molded product 210 shown in FIG. 5 is an example, and the present invention is not limited thereto. Those molded into various shapes by various methods are also included in the decorative molded product of the present invention.

Hereinafter, the present invention will be described in more detail with reference to 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 and 2 and Comparative Examples 1 to 4.

<Example 1>
A polyurethane adhesive, which is an appropriate mixture of a main agent, a curing agent, and a solvent, is applied to the surface of the PMMA layer of the laminate sheet so that the dry film thickness is 5 μm (application step), and dried at 80 ° C. for 30 seconds. (Drying process). Then, the surface coated with the adhesive of the PMMA layer and the polycarbonate resin sheet were bonded by bonding (bonding step), and then cured at 40 ° C. for 4 days. By these steps, the multilayer film of Example 1 was produced.

<Example 2>
A polyurethane adhesive, which is an appropriate mixture of 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 (application step). Drying process). Then, the surface coated with the adhesive of the acrylic resin sheet and the polycarbonate resin sheet were bonded by bonding (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. Then, the acrylic resin sheet and the fluororesin sheet were bonded by adhering the dried adhesive and the fluororesin sheet, and then cured at 40 ° C. for 4 days. By these steps, the multilayer film of Example 2 was produced.

<Comparative example 1>
Similar to Example 2, a polyurethane adhesive in which a main agent, a curing agent and a solvent are appropriately mixed is applied to the surface of the acrylic resin sheet so that the dry film thickness is 5 μm, and dried at 80 ° C. for 30 seconds. It was. Then, the surface of the acrylic resin sheet coated with the adhesive and the polycarbonate resin sheet were bonded by bonding, and then cured at 40 ° C. for 4 days. No fluororesin sheet was used. By these steps, the 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 so that the dry film thickness was 5 μm, and the acrylic resin sheet was dried at 80 ° C. for 30 seconds. Then, the acrylic resin sheet and the fluororesin sheet were bonded by adhering the dried adhesive and the fluororesin sheet, and then cured at 40 ° C. for 4 days. The polycarbonate resin sheet was not used. By these steps, the 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. Further, as Comparative Examples 3 and 4, the physical properties of the single-layer acrylic resin sheet and the polycarbonate resin sheet were similarly evaluated.

(Printability)
Screen printing of screen ink ISX911 (ink) (manufactured by Teikoku Inks Manufacturing Co., Ltd.) on a PC layer (Examples 1 and 2, Comparative Examples 1 and 4) or PMMA layer (Comparative Examples 2 and 3) such as a multilayer film and drying. The test piece was used to form a printed layer. After that, according to JIS K 5600 (cross-cut method), 11 cuts were made vertically and horizontally on the surface of the printing layer with a cutter knife at a pitch of 2 mm, and Nichiban's cellophane tape (registered trademark) (width 18 mm or 24 mm) was cut on that surface. ) Was firmly attached with the pad of the finger, and the state of close contact was confirmed. After that, the tip of cellophane tape (registered trademark) was held and pulled off momentarily while maintaining an angle of 45 degrees. The case where the print layer was not peeled off was evaluated as ◯, and the case where the print layer was peeled off was evaluated as x.

(Scratch resistance)
A multilayer film or the like was prepared in a state of being stretched by 5%. Then, a cotton canvas (No. 6) is put on a friction element having a width of 20 mm and a radius of 10 mm, 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) and a PVDF layer (implementation). The surfaces of Example 2, Comparative Example 2), PMMA layer (Comparative Examples 1 and 3), and PC layer (Comparative Example 4) were rubbed 10 times between 140 mm. As a result of friction, the case where there was no significant scar residue was evaluated as 〇, and the case where significant scar residue was observed was evaluated as ×.

(water resistant)
The multilayer film or the like was immersed in warm water at 55 ° C. for 4 hours. The case where there was no abnormality such as whitening, discoloration, or remarkable scarring on the multilayer film or the like taken out from warm water immediately after the completion of the dipping treatment was evaluated as ◯, and the case where any of these abnormalities was observed was evaluated as ×.

(chemical resistance)
An acid resistance test was carried out by dropping 5 ml of a 0.1 NH ₂ SO ₄ aqueous solution onto the surface of a multilayer film or the like and allowing it to stand at 20 ° C. for 24 hours. An alkali resistance test was carried out by dropping 5 ml of a 0.1 N NaOH aqueous solution onto the surface of a multilayer film or the like and allowing it to stand at 55 ° C. for 4 hours. A chemical resistance test was carried out by dropping 5 ml of white kerosene onto the surface of a multilayer film or the like and allowing it to stand at 55 ° C. for 4 hours. Further, as a chemical resistance test, 5 ml of 50% by mass ethanol was dropped on the surface of a multilayer film or the like and allowed to stand at 55 ° C. for 4 hours, a laminated layer such as a multilayer film (Example 1), a PVDF layer (Example 1). 2. Sunscreen cream (SPF45) is applied to the surfaces of the PMMA layer (Comparative Examples 1 and 3) and the PC layer (Comparative Example 4) in Comparative Example 2), and then the cream is applied after standing at 80 ° C. for 24 hours. A test to remove was performed. The case where there was no abnormality such as whitening, discoloration, or remarkable scarring on the multilayer film or the like from which each chemical was removed immediately after the end of the test was evaluated as 〇, and the case where any of these abnormalities was observed was evaluated as ×.

(Moldability)
Using a vacuum compressed air forming machine (manufactured by Kiefer), heat the multilayer film or the like for 40 seconds so that the surface temperature reaches 180 ° C., and then apply vacuum (1 bar) and compressed air (6 bar) to perform shaping treatment and molding. Manufactured the product. The size of the clamp was 300 x 350 mm, and the heater settings were 350 ° C for the upper heater and 400 ° C for the lower heater. The size of the prototype was 10.5 cm in length, 8.5 cm in width, and 0.7 cm in height. If the molded product can be molded according to the prototype mold by visual evaluation and there is no abnormality in the molding, 〇, if the molded product is deformed differently from the prototype mold, or if there is an abnormality in the molding, it is marked as ×. evaluated.

(Impact resistance)
Using the molded product manufactured by performing the shaping treatment in the above evaluation of moldability, insert injection molding was performed using an injection molding machine (manufactured by Japan Steel Works, Ltd.) to manufacture a flat plate injection molded product. .. A 2.94 N weight was dropped on the manufactured injection molded product at a drop distance of 0.2 m. Subsequent injection molded products were evaluated as 〇 when there was no cracking or peeling, and x when cracking or peeling was observed. As the injection resin used for injection molding, a PC / ABS alloy resin manufactured by SABIC was used.

(Promoted weather resistance)
Using the test piece after evaluating the printability, an accelerated weather resistance test was carried out under the following conditions using a super xenon weather meter (SX-75 manufactured by Suga Test Instruments Co., Ltd.).
・ Irradiation method Continuous irradiation ・ Irradiance 150 W / m ² (300-400 nm)
・ Xenon long life arc lamp 7.5kW 1 lamp ・ Lamp cooling method Water cooling type ・ 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 test piece after the accelerated weather resistance test, and the case where there was no peeling of the print layer was evaluated as 〇. .. In addition, when the color difference (ΔE) before and after these accelerated weather resistance tests is larger than 3.0, or when the same printability test as above is performed on the test piece after the accelerated weather resistance test and the printed layer is peeled off. It was evaluated as ×.

(transparency)
For multilayer films and the like, the total light transmittance and haze 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, it is evaluated as 〇, and when the total light transmittance is less than 85% or the haze value is larger than 4.0%, it is evaluated as ×. did.

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

In Examples 1 and 2, PVDF formed the outermost surface, thereby satisfying chemical resistance and weather resistance. In addition, PMMA, which is harder than PVDF, forms the next layer of PVDF, thereby satisfying scratch resistance. Then, the PC forms a layer to be printed as the lowest layer, thereby satisfying the printability. Regarding 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 formed the outermost surface. In Comparative Example 2, the printability was not satisfied because PMMA was the layer to be printed. Further, in Comparative Example 3, since the sheet configuration is only a single layer of PMMA, the printability and chemical resistance are not satisfied, and the impact resistance is satisfied because the sheet is hard and cracks occur. There wasn't. Further, in Comparative Example 4, since the sheet structure was only a single layer of PC, scratch resistance, chemical resistance and weather resistance were not satisfied.

[Summary]
From the results of the above examples, in the case of the multilayer film of the present invention, a laminate layer in which a fluorine-based resin layer and an acrylic-based resin layer are laminated, a polycarbonate-based resin layer, the acrylic-based resin layer, and the polycarbonate-based resin layer are used. By providing a polyurethane adhesive layer for joining with, all of printability, scratch resistance, chemical resistance, moldability, impact resistance, and weather resistance can be satisfied at the same time. Further, since such a multilayer film is excellent in printing characteristics, it is clear that it is also useful as a decorative sheet on which a design layer is arranged.

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 molded body 300 Metal layer

Claims (8)

A laminated layer in which a fluorine-based resin layer and an acrylic resin layer are laminated, and
Polycarbonate resin layer and
A multilayer film comprising a polyurethane adhesive layer for joining the acrylic resin layer and the polycarbonate resin layer. The thickness of the fluororesin 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.
The multilayer film according to claim 1, wherein the thickness of the polycarbonate resin layer is 125 μm to 500 μm. The fluororesin used for the fluororesin layer is a polyvinylidene fluoride resin.
The multilayer film according to claim 1 or 2, wherein the acrylic resin used for the acrylic resin layer is a polymethyl methacrylate resin. The multilayer film according to any one of claims 1 to 3, wherein the laminated layer includes a polyurethane adhesive layer for joining the fluorine-based resin layer and the acrylic resin layer. The method for producing a multilayer film according to any one of claims 1 to 4.
A coating step of applying a solvent-based polyurethane adhesive to the surface of the acrylic resin layer, and
A drying step of drying the applied solvent-based polyurethane adhesive, and
A method for producing a multilayer film, which comprises a step of joining the surface of the acrylic resin layer coated with the solvent-based polyurethane adhesive and the polycarbonate-based resin layer after the drying step. A decorative sheet comprising the multilayer film according to any one of claims 1 to 4 and a design layer arranged on the polycarbonate resin layer of the multilayer film. The method for manufacturing a decorative sheet according to claim 6.
A method for producing a decorative sheet, which comprises an arrangement step of arranging 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 fluorine-based resin layer on the surface.

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