Film, method for producing film, decorative sheet, and automobile pillar

Abstract

To provide a film, a method for producing film, a decorative sheet and a pillar for automobile that can suppress blooming due to environmental load and improve sunscreen resistance performance.SOLUTION: The subject matter contains a polymer alloy and a nucleating agent containing acrylic-modified polytetrafluoroethylene, and in which the polymer alloy is a polymer alloy in which a polyvinylidene fluoride and a copolymer composition containing a copolymer obtained by copolymerizing at least methyl methacrylate and N-cyclohexylmaleimide by 90 mass% or more, are dissolved each other, the mass ratio of the polyvinylidene fluoride and the copolymer composition is 6:4 to 7:3, and the mass ratio of the polymer alloy and the nucleating agent is 100:0.2 to 100:0.4.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a film, a method for manufacturing the film, a decorative sheet, and an automotive pillar.

Background Art

[0002] Conventionally, methods such as painting and plating have long been used as methods for decorating automotive parts. In recent years, for the purpose of reducing environmental impact and manufacturing processes, instead of painting and plating, film decoration methods such as insert molding and overlay molding using decorative films have been adopted. For example, in the interior and exterior of automobiles, exterior parts (front grille, emblem, center wheel cap, bumper, door handle, door mirror housing, various moldings, pillar, garnish, aerodynamic parts, etc.) and interior parts (instrument panel, center panel, door handle, door trim, shift gauge panel, etc.) have been decorated with decorative films.

[0003] Also, as a protective layer on the outermost layer of such a decorative sheet, an acrylic film may be used as disclosed in Patent Document 1, for example.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the case of a decorative sheet having an acrylic film as the outermost layer, for example, when a predetermined environmental test is conducted to confirm whether a decorative sheet for decorating automotive parts can withstand the use environment, problems such as clouding of the outermost layer film due to crystallization or blooming of the resin used in the film raw material, or peeling of the outermost layer film may occur. Here, examples of the environmental test include a heat aging test, an environmental cycle test, a moisture resistance test, and a hydrolysis aging test. Further, when used for interior parts, resistance to sunscreen is required, but similar to the environmental test, problems such as clouding of the acrylic film used as the outermost layer may occur.

[0006] Also, as a film used as the surface layer of a vehicle decorative film excellent in visible light transmittance, chemical resistance, weather resistance, heat resistance, and unevenness followability, a vinylidene fluoride-based resin film containing a crosslinked acrylic resin has been proposed. Further, it has also been proposed to mix a methacrylic acid ester-based resin with the vinylidene fluoride-based resin (see, for example, Patent Document 2). However, even when such a mixed resin is used, the problem that crystallization or blooming of the resin used in the film raw material may occur due to the environmental load and the film may become cloudy has not been completely solved.

[0007] Therefore, an object of the present invention is to provide a film, a method for manufacturing the film, a decorative sheet, and an automotive pillar that can suppress blooming due to environmental load and improve sunscreen performance.

Means for Solving the Problems

[0008] The film of the present invention comprises a polymer alloy and a nucleating agent containing acrylic-modified polytetrafluoroethylene. The polymer alloy is a polymer alloy in which a copolymer composition containing 90% by mass or more of a copolymer obtained by copolymerizing vinylidene fluoride, at least methyl methacrylate, and N-cyclohexylmaleimide is compatible. The mass ratio of the vinylidene fluoride to the copolymer composition is 6:4 to 7:3, and the mass ratio of the polymer alloy to the nucleating agent is 100:0.2 to 100:0.4.

[0009] In the film of the present invention, the copolymer may be a copolymer obtained by copolymerizing methyl methacrylate, N-cyclohexylmaleimide, and N-phenylmaleimide.

[0010] In the film of the present invention, it may contain an ultraviolet absorber, and the mass ratio of the polymer alloy to the ultraviolet absorber may be 100:0.05 to 100:3.0.

[0011] In the film of the present invention, the thickness may be 30 μm to 50 μm.

[0012] The method for producing the film of the present invention includes a casting step of casting a mixed solution in which the vinylidene fluoride is dispersed into a solution in which the copolymer composition and the nucleating agent are dissolved in a solvent onto a base film to form a solvent-containing film, and a heat drying step of heating and drying the solvent-containing film to remove the solvent from the solvent-containing film to form a polymer alloy.

[0013] The method for producing the film of the present invention may further include a mixed solution preparation step of dispersing the vinylidene fluoride into the solution in which the copolymer composition and the nucleating agent are dissolved in the solvent to prepare the mixed solution before the casting step.

[0014] In the method for manufacturing the film of the present invention, the copolymer contained in the copolymer composition may be a copolymer obtained by copolymerizing methyl methacrylate, N-cyclohexyl maleimide, and N-phenyl maleimide.

[0015] In the method for manufacturing the film of the present invention, the solvent may be diethylene glycol monobutyl ether acetate.

[0016] The decorative sheet of the present invention includes the film of the present invention as the outermost layer.

[0017] The pillar for an automobile of the present invention is a laminate of the film of the present invention, an adhesive layer, and a stainless steel pillar, in that order.

Advantages of the Invention

[0018] The film of the present invention can suppress blooming due to environmental loads such as heat and improve the anti-sun screen performance.

[0019] The method for manufacturing the film of the present invention can suppress blooming due to environmental loads such as heat and manufacture a film with improved anti-sun screen performance.

[0020] Since the decorative sheet of the present invention includes the film of the present invention as the outermost layer, it can suppress blooming due to environmental loads such as heat and improve the anti-sun screen performance.

[0021] Since the pillar for an automobile of the present invention includes the film of the present invention, it can suppress blooming due to environmental loads such as heat and improve the anti-sun screen performance.

Brief Description of the Drawings

[0022]

Figure 1

Figure 2

Figure 3

Figure 4

Mode for Carrying Out the Invention

[0023] [Film] A film according to an embodiment of the present invention will be described. The film of the present embodiment can be used as the outermost layer of a decorative sheet for decorating parts by a film decoration method such as insert molding or overlay molding using a decorative film. Further, the film may be used for laminating on the surface of a metal part or the like via an adhesive layer or an adhesive layer. For example, it can be used as a surface layer in automobile exterior parts such as automobile pillars, door moldings, roof moldings, entire doors, and entire roofs. Thus, the film of the present embodiment can be suitably used particularly for applications where it is laminated on the surface of parts that require high environmental performance and sunscreen resistance.

[0024] The film of the present embodiment contains a polymer alloy and a nucleating agent containing acrylic-modified polytetrafluoroethylene, and this polymer alloy is a polymer alloy in which a copolymer composition containing 90% by mass or more of a copolymer obtained by copolymerizing polyvinylidene fluoride, at least methyl methacrylate, and N-cyclohexylmaleimide is compatible. Further, the mass ratio of polyvinylidene fluoride to the copolymer composition is 6:4 to 7:3, and the mass ratio of the polymer alloy to the nucleating agent is 100:0.2 to 100:0.4. When the mass ratio of the nucleating agent is less than 0.2, the chemical resistance to xylene, sunscreen cream, etc. decreases. When the mass ratio of the nucleating agent is more than 0.4, the nucleating agent itself aggregates, resulting in a decrease in the uniform dispersibility of polyvinylidene fluoride and a decrease in the chemical resistance to xylene, sunscreen cream, etc.

[0025] In addition, the copolymer in the above-mentioned copolymer composition may be a copolymer obtained by copolymerizing methyl methacrylate, N-cyclohexyl maleimide, and N-phenyl maleimide. Further, a copolymer obtained by copolymerizing methyl methacrylate and N-cyclohexyl maleimide and a copolymer obtained by copolymerizing methyl methacrylate, N-cyclohexyl maleimide, and N-phenyl maleimide may be mixed and used. As the copolymer composition containing 90% by mass or more of the copolymer obtained by copolymerizing methyl methacrylate and N-cyclohexyl maleimide, for example, Del Powder SK 420N, Del Powder SK 430N (Asahi Kasei Corporation) can be used. Further, as the copolymer composition containing 90% by mass or more of the copolymer obtained by copolymerizing methyl methacrylate, N-cyclohexyl maleimide, and N-phenyl maleimide, for example, Del Powder SK540N (Asahi Kasei Corporation) can be used. By using a copolymer of methyl methacrylate, N-cyclohexyl maleimide, and N-phenyl maleimide, the handleability can be improved when producing a film by a casting method as described in [Film Production Method] below.

[0026] The resin mainly constituting the film of this embodiment is a polymer alloy in which polyvinylidene fluoride and a copolymer composition containing 90% by mass or more of a copolymer obtained by copolymerizing at least methyl methacrylate and N-cyclohexyl maleimide are compatible. By compatibilizing polyvinylidene fluoride and the copolymer composition, the performance such as environmental performance can be improved in the film as compared with the state in which the individual resin materials are phase-separated. The copolymer composition may contain unreacted monomers that have not copolymerized.

[0027] In addition, the copolymer composition may contain, as components other than the copolymer, unreacted ones among the monomers constituting the copolymer such as methyl methacrylate and N-cyclohexyl maleimide, antioxidants, weather stabilizers, lubricants, colorants, and the like.

[0028] In addition, the glass transition temperature (Tg) of the copolymer composition is preferably about 115°C to 130°C. A higher glass transition temperature can better suppress blooming.

[0029] Here, polyvinylidene fluoride is a crystalline plastic, and 30% to 50% of its molecules have crystal nuclei with aligned orientations. When the crystallization of polyvinylidene fluoride progresses and the crystal nuclei grow, changes in appearance such as cloudiness due to scattering and reflection of ultraviolet light are likely to occur in the film. Therefore, in the film of this embodiment, by using a nucleating agent containing acrylic-modified polytetrafluoroethylene, the size of the crystal nuclei of polyvinylidene fluoride can be reduced and the molecules can be uniformly dispersed, thereby improving the chemical resistance of the film.

[0030] Moreover, the film of this embodiment may contain other materials such as colorants like pigments and dyes, matting agents, and ultraviolet absorbers. By using colorants like pigments and dyes or matting agents, various design expressions such as gloss, matte, and piano black can be realized. When using an ultraviolet absorber, the mass ratio of the polymer alloy to the ultraviolet absorber can be about 100:0.05 to 100:3.0. By using an ultraviolet absorber, the weather resistance can be improved. Especially when the film has high light transmittance, in a decorative sheet or the like, discoloration of the decorative sheet due to yellowing of the adhesive layer or metal layer holding layer laminated between this film and the metal layer can be suppressed.

[0031] In addition, the thickness of the film of this embodiment is not particularly limited, but when used as the outermost layer of a decorative sheet or the surface layer of an automotive pillar, it can be 10 μm to 70 μm, preferably 30 μm to 50 μm. If the film thickness is too thin, it may be difficult to form the film. Also, if the film thickness is too thick, it may not be sufficiently dried during film production, and blocking may easily occur after winding.

[0032] The film of the present embodiment has both heat resistance and chemical resistance, can suppress blooming due to environmental loads such as heat, and can improve the sunscreen performance.

[0033] [Method for manufacturing the film] Next, a method for manufacturing the film of the above-described embodiment will be described. The method for manufacturing the film of the present embodiment includes a casting step of casting a mixed solution in which polyvinylidene fluoride is dispersed into a solution in which a copolymer composition and a nucleating agent are dissolved in a solvent onto a base film to form a solvent-containing film, and a heating and drying step of heating and drying the solvent-containing film to remove the solvent from the solvent-containing film to form a polymer alloy. Further, the method for manufacturing the film of the present embodiment may further include a mixed solution preparation step of dispersing polyvinylidene fluoride in a solution in which a copolymer composition and a nucleating agent are dissolved in a solvent to prepare a mixed solution before the casting step. Further, the method for manufacturing the film of the present embodiment may include a cooling step of cooling the laminate of the film and the base film after the heating and drying step.

[0034] Next, each step of the mixed solution preparation step, casting step, heating and drying step, and cooling step in the method for manufacturing the film will be described with reference to the drawings. FIG. 1 is a cross-sectional view schematically illustrating the film in each step of the method for manufacturing the film. FIG. 1(A) shows the base film 200, FIG. 1(B) shows the laminate 300A in which the solvent-containing film 100A is laminated on the base film 200, and FIG. 1(C) shows the laminate 300 in which the film 100 is laminated on the base film 200. FIG. 2 is a diagram schematically showing an example of a manufacturing apparatus used for manufacturing the film. FIG. 2(A) is a side view of the manufacturing apparatus 400, FIG. 2(B) is an enlarged view of a main part of a die coater 420A which is an example of the coater 420, and FIG. 2(C) is an enlarged view of a main part of a comma coater 420B which is an example of the coater 420.

[0035] (Mixed solution preparation step) The mixed solution preparation step is a step of preparing a mixed solution by dispersing polyvinylidene fluoride in a solution in which a copolymer composition and a nucleating agent are dissolved in a solvent. Specifically, a mixed solution can be prepared by adding raw materials for the film to the solvent and stirring. As described in the film embodiments above, the film may use raw materials other than polyvinylidene fluoride, a copolymer composition, and a nucleating agent. In that case, raw materials other than polyvinylidene fluoride, a copolymer composition, and a nucleating agent can also be added to the solvent in the mixed solution preparation step.

[0036] As the copolymer contained in the copolymer composition, a copolymer obtained by copolymerizing at least methyl methacrylate and N-cyclohexyl maleimide is used as in the film embodiments described above. Further, the copolymer used in the production method of the present embodiment preferably has high solubility in a solvent and does not have too high a viscosity when dissolved in the solvent from the viewpoint of handleability when casting on a base film. In this regard, as the copolymer, a copolymer obtained by copolymerizing methyl methacrylate, N-cyclohexyl maleimide, and N-phenyl maleimide can be preferably used. Similar to the above-described embodiments, as the copolymer composition containing 90% by mass or more of a copolymer obtained by copolymerizing methyl methacrylate and N-cyclohexyl maleimide, for example, Delpau Powder SK 420N, Delpau Powder SK 430N (Asahi Kasei Corporation) can be used. Further, as the copolymer composition containing 90% by mass or more of a copolymer obtained by copolymerizing methyl methacrylate, N-cyclohexyl maleimide, and N-phenyl maleimide, for example, Delpau Powder SK540N (Asahi Kasei Corporation) can be used.

[0037] The solvent used in the mixed solution is not particularly limited. However, it is preferable to impart an appropriate viscosity to the mixed solution so as to facilitate casting when casting the mixed solution, and it is preferable that polyvinylidene fluoride and the copolymer are not compatible in the solvent before casting the mixed solution on the base film. If a polymer alloy is formed before casting, the solubility in the solvent may decrease and the mixed solution may gel. If the mixed solution gels, it becomes difficult to cast it on the base film. That is, it is preferable that the solubility of polyvinylidene fluoride in the solvent is not too high. For example, diethylene glycol monobutyl ether acetate, which can be uniformly dispersed in the solvent without completely dissolving polyvinylidene fluoride, can be preferably used.

[0038] As a specific procedure for the mixed solution preparation step, for example, it can be as follows. When using an ultraviolet absorber, first, add the ultraviolet absorber to a solvent heated to about 60°C to 80°C and stir well (for example, for about 15 minutes). Next, add the copolymer composition and the nucleating agent in this order, and while heating to 60°C to 80°C, stir well until the copolymer composition and the nucleating agent are dissolved (until it can be confirmed that it has become a transparent liquid, for example, for about 2 hours) to obtain a solution in which the copolymer composition and the nucleating agent are dissolved. Further, while stirring the solution, add polyvinylidene fluoride to the solution and stir well so that the polyvinylidene fluoride is uniformly dispersed. At this time, since heat is easily generated when stirring with a high shear force, it is preferable to control the temperature so that the liquid temperature does not become too high and is maintained at an appropriate temperature (for example, about 80°C or lower). Also, other materials such as a matting agent can be added simultaneously with polyvinylidene fluoride. The mixed solution is prepared as described above.

[0039] Also, considering the handleability when casting on the base film 200, the viscosity of the mixed solution obtained by the mixed solution preparation step can be, for example, about 200 cps to 5,000 cps, and more preferably 1,000 cps to 1,500 cps.

[0040] Further, the obtained mixed solution may be immediately subjected to the casting process, or it may be stored as it is until being subjected to the casting process. The temperature conditions and the like when storing the mixed solution are not particularly limited, and for example, it can be stored in a sealed state at room temperature or in a cool and dark place.

[0041] (Casting process, heat drying process, and cooling process) The casting process, heat drying process, and cooling process can be performed by the manufacturing apparatus 400 shown in FIG. 2. The manufacturing apparatus 400 of the present embodiment is an apparatus having a roll-to-roll conveyance method, which unwinds the base material film 200 wound in a roll shape, casts the mixed solution 100B onto the base material film 200, heats and dries it and then cools it, and then winds up the laminate 300 of the film 100 and the base material film 200.

[0042] The manufacturing apparatus 400 includes a base material roll 410 around which the base material film 200 (FIG. 1(A)) is wound, a coater 420 for casting the mixed solution 100B onto the base material film 200, an oven 430 for heating and drying the solvent-containing film 100A (FIG. 1(B)), a cooling unit 440 for cooling the laminate 300 (FIG. 1(C)) of the film 100 from which the solvent has been removed and the base material film 200, and a winding unit 450 for winding up the cooled laminate 300. In the manufacturing apparatus 400 of the present embodiment, the side of the base material roll 410 is referred to as the upstream, and the side of the winding unit 450 is referred to as the downstream. Further, in the following description, as shown in FIGS. 1 and 2, with respect to the base material film 200, the surface on which the solvent-containing film 100A is laminated is referred to as the front surface 200a, and the opposite surface is referred to as the back surface 200b.

[0043] Also, the type of the coater 420 is not particularly limited. For example, a die coater 420A (FIG. 2(B)) or a comma coater 420B (FIG. 2(C)) can be used, and other coaters may also be used.

[0044] The die coater 420A shown in FIG. 2(B) has a back roll 421 that rotates to feed the base film 200 in the direction of arrow B, and a slit die 422 that is provided opposite to the back roll 421 with a predetermined gap therebetween and applies the mixed liquid 100B to the base film 200.

[0045] The slit die 422 has a pair of die bodies 422a and 422b, a slit portion 422c formed between the die bodies 422a and 422b, and a die lip 422d provided at the tip of the die bodies 422a and 422b. As shown in FIG. 2(C), the mixed liquid 100B supplied to the slit portion 422c of the slit die 422 is discharged from the die lip 422d and applied to the front surface 200a of the base film 200 being fed by the back roll 421. Thereby, the solvent-containing film 100A is formed on the front surface 200a of the base film 200.

[0046] The comma coater 420B shown in FIG. 2(C) has a back roll 425 that rotates to feed the base film 200 in the direction of arrow C, a comma roll 426 that is provided opposite to the back roll 425 with a predetermined gap therebetween and applies the mixed liquid 100B to the base film 200, and a liquid receiving portion 427 that stores the mixed liquid 100B supplied to the comma roll 426. The base film 200 is conveyed between the back roll 425 and the comma roll 426. Further, the comma roll 426 is provided such that a part thereof is immersed in the mixed liquid 100B in the liquid receiving portion 427.

[0047] As shown in FIG. 2(C), the comma roll 426 has two cutout portions 426a. When the comma roll 426 rotates in the direction of arrow D, the mixed liquid 100B stored in the liquid receiving portion 427 is supplied to the surface of the comma roll 426. Further, as the base film 200 is conveyed between the back roll 425 and the comma roll 426, the mixed liquid 100B is applied to the front surface 200a of the base film 200. Thereby, the solvent-containing film 100A is formed on the front surface 200a of the base film 200.

[0048] Further, as a configuration common to various coaters, the coater 420 has a tank 428 for the mixed liquid 100B and a pump (not shown) connected to the tank 428 for pumping out the mixed liquid 100B.

[0049] The oven 430 has four heating furnaces 431a, 431b, 431c, 431d and rollers 432 for conveying the laminate 300A toward the cooling unit 440 inside the heating furnaces 431a, 431b, 431c, 431d. The heating furnaces are arranged in the order of the heating furnaces 431a, 431b, 431c, 431d from the coater 420 side located upstream of the oven 430 toward the cooling unit 440 located downstream of the oven 430. Further, the heating furnaces 431a, 431b, 431c, 431d can be set to individual temperatures.

[0050] Also, by controlling the rotation of the rollers 432, the conveyance speed of the laminate 300A can be adjusted. Further, the oven 430 may further have a blowing unit for blowing air into the heating furnaces 431a, 431b, 431c, 431d in order to promote the volatilization of the solvent. In the present embodiment, it is configured to be able to set four temperature zones, but depending on the type of film to be manufactured, the number of temperature zones to be set may be increased or decreased.

[0051] The cooling unit 440 cools the laminate conveyed from the oven 430 and has rollers 441 for conveying the laminate 300 toward the winding unit 450 and a blowing unit (not shown) for blowing air toward the laminate 300. Note that the present invention is not limited to the mode of cooling the laminate 300 by blowing air as in the present embodiment, and the laminate 300 may be conveyed by the rollers 441 cooled by flowing a solvent for cooling inside the rollers 441 to cool the laminate 300, or the laminate 300 may be naturally air-cooled while being conveyed by the rollers 441.

[0052] Hereinafter, with reference to FIGS. 1 and 2, the procedure for performing the casting process, the heat drying process, and the cooling process by the manufacturing apparatus 400 will be described.

[0053] The casting process is a process of casting the mixed liquid 100B in which polyvinylidene fluoride is dispersed onto the base film 200 (Fig. 1(A)) from the solution in which the copolymer composition and the nucleating agent are dissolved, which was prepared in the mixed liquid preparation process, to form the solvent-containing film 100A (Fig. 1(B)). First, the base film 200 is drawn out from the base roll 410 in the direction of arrow A in Fig. 2(A) and supplied to the coater 420. In the coater 420, the mixed liquid 100B is cast on the front surface 200a of the base film 200.

[0054] The base film 200 is not particularly limited. For example, a resin film formed of polyethylene terephthalate (PET), polyethylene naphthalate, polyimide, or the like can be used. Further, the thickness of the base film can be appropriately set in consideration of handleability and the like, and can be, for example, about 30 μm to 100 μm. Further, depending on the properties of the film 100, the base film 200 may be appropriately subjected to a release treatment.

[0055] Further, the thickness of the solvent-containing film 100A formed by the casting process can be, for example, about 100 μm to 160 μm.

[0056] By the casting process, as shown in Fig. 1(B), a laminate 300A in which the solvent-containing film 100A is laminated on the front surface 200a of the base film 200 is obtained.

[0057] The heating and drying process is a process of heating and drying the solvent-containing film 100A of the laminate 300A obtained by the casting process to remove the solvent from the solvent-containing film 100A and form a polymer alloy. In the heating and drying process, the solvent volatilizes and is removed from the solvent-containing film 100A, and a polymer alloy is formed by compatibilization of polyvinylidene fluoride and the copolymer in a state of a mixed resin uniformly dispersed in the solvent. That is, an amorphous copolymer is incorporated into the amorphous portion of polyvinylidene fluoride and compatibilization proceeds, thereby forming a polymer alloy. The laminate 300A obtained by the casting process is conveyed to the oven 430, passes through the inside of the heating furnaces 431a, 431b, 431c, and 431d, and the solvent contained in the solvent-containing film 100A volatilizes and is removed by heating and drying the solvent-containing film 100A.

[0058] If the solvent-containing film 100A is placed at a temperature at which the solvent volatilizes immediately after casting, defects such as damage may occur in the obtained film 100. For this reason, it is preferable to set the set temperatures of the heating furnaces 431a, 431b, 431c, and 431d to increase stepwise from the heating furnace 431a upstream of the solvent-containing film 100A to the heating furnaces 431b, 431c, and 431d. Note that the plurality of heating furnaces may be set to the same temperature. For example, when the maximum temperature during drying is 204 °C, they can be set to 93 °C, 121 °C, 204 °C, and 204 °C in order.

[0059] The furnace lengths and the conveyance line speeds of the heating furnaces 431a, 431b, 431c, and 431d can be appropriately set according to the thickness dimension of the solvent-containing film 100A, the types of the solvent and the film raw material so that the solvent contained in the solvent-containing film 100A can be sufficiently volatilized and removed. For example, the total furnace length can be 30 m (the furnace length of each heating furnace is 7.5 m), and the conveyance line speed can be about 10 m / min to 15 m / min. Also, considering that the polymer alloy is sufficiently formed, the heating temperature can be set so that the maximum temperature of the film is 160 °C to 190 °C, for example.

[0060] Through the heat drying process, as shown in Fig. 1(C), a laminate 300 is obtained in which a film 100 with the solvent removed is laminated on a base film 200.

[0061] The cooling process is a process of cooling the laminate 300 obtained by the heat drying process by blowing air toward the laminate 300 in the cooling unit 440. The film 100 obtained through the above processes corresponds to the film of the aforementioned embodiment.

[0062] Finally, at the winding unit 450, the laminate 300 is wound up to obtain a roll-shaped laminate 300 in which the film 100 and the base film 200 are laminated.

[0063] The method for manufacturing the film of the present invention can suppress blooming due to environmental loads such as heat and manufacture a film with improved sunscreen performance.

[0064] Furthermore, by manufacturing the film 100 by the casting method, it is possible to handle small-lot production without losing a large amount of raw materials compared to the extrusion molding method that has been generally used in the past. That is, when manufacturing a film by the extrusion molding method, it takes time until the film is stably formed, and there are large losses (wastes) of materials such as not all materials being extruded and remaining in the apparatus. Therefore, in order to reduce the loss rate with respect to the entire material, it was not cost-effective to manufacture at a large production unit, such as manufacturing tens of thousands of meters of film using several tons (for example, 10 tons) of materials per batch. Thus, when producing in small lots, the price would increase, and it was not practical to perform multi-variety, small-lot production in film manufacturing by the extrusion molding method. Also, in film manufacturing by the extrusion molding method, appearance defects such as fish eyes may occur due to the remaining melted resin material.

[0065] On the one hand, in the case of the casting method, it can be stably manufactured at about several hundred kilograms (for example, 500 kg) per production, and since the material loss is extremely small compared to the extrusion molding method, the manufacturing cost can be suppressed even in small-lot production. Further, in the film production by the casting method, since the resin material is dissolved / dispersed in the solvent, the material uniformity is high, and since there is almost no undissolved material as in the extrusion molding method, the appearance quality can be improved.

[0066] From the above, in the manufacturing method of the present embodiment, it is possible to perform small-lot manufacturing without impairing the appearance quality and to cope with multi-variety and small-lot production.

[0067] Note that the film manufacturing method of the present embodiment is by the casting method, but the film manufacturing method of the above-described embodiment is not limited to the casting method, and for example, it may be manufactured by other methods such as extrusion molding.

[0068] [Decorative sheet] A decorative sheet according to an embodiment of the present invention will be described. The decorative sheet of the present embodiment includes, as the outermost layer, the film of the above-described embodiment. FIG. 3 is a cross-sectional view schematically showing a decorative sheet 500 which is an example of the decorative sheet of the present embodiment.

[0069] The decorative sheet 500 has a base material layer 510, a first adhesive layer 520, a metal layer 530, a metal layer holding layer 540, a second adhesive layer 550, and a film 100 which is the outermost layer laminated in this order.

[0070] The base material layer 510 can use resins such as polyvinyl chloride-based, polyolefin-based, polystyrene-based, polyacrylic-based, polyurethane-based, polyamide-based, polycarbonate-based, acrylonitrile-butadiene-styrene copolymer-based, etc. according to the application. Further, the thickness of the base material layer 510 can be a general thickness as a decorative sheet, and for example, it can be 25 μm to 500 μm.

[0071] The first adhesive layer 520 and the second adhesive layer 550 are composed of a mixture containing an adhesive or the like. For example, various forms of adhesives such as solvent-based adhesives, solventless adhesives, water-dispersion adhesives, one-component adhesives, two-component adhesives, etc., urethane resin-based adhesives, acrylic resin-based adhesives, ethylene-vinyl acetate copolymer resin-based adhesives, and other polymer adhesives can be used. The first adhesive layer 520 and the second adhesive layer 550 can have a thickness of about 1 μm to 30 μm when dried, and an average thickness of about 2 μm to 20 μm, for example.

[0072] The metal layer 530 is held by the metal layer holding layer 540. The metal constituting the metal layer 530 is not particularly limited and can be appropriately selected according to the desired color tone or the like. Specifically, examples of the metal constituting the metal layer 530 include tin, indium, chromium, aluminum, etc. Also, the metal layer 530 can be formed by vacuum-depositing indium on the metal layer holding layer 540 described later. For example, the thickness can be set to about 10 nm to 200 nm, and the average thickness can be set to 20 nm to 100 nm.

[0073] The metal layer holding layer 540 can be composed of a resin such as modified polyethylene terephthalate, polyurethane, polypropylene, etc. Also, the thickness of the metal layer holding layer 540 can be, for example, about 5 μm to 200 μm, and the average thickness can be about 5 μm to 100 μm. In addition to the resin, additives such as stabilizers, ultraviolet absorbers, lubricants, flame retardants, pigments, and dyes may be included. Also, the metal layer holding layer 540 may be colorless and transparent or color clear.

[0074] Such a decorative sheet 500 can be manufactured, for example, as follows. First, a metal layer holding layer 540 that holds the metal layer 530 is laminated on the film 100 of the laminate 300 shown in FIG. 1(C) via the second adhesive layer 550, and then the base material layer 510 is laminated via the first adhesive layer 520. Further, by removing the base material film 200 of the laminate 300, the decorative sheet 500 is obtained.

[0075] Since the decorative sheet 500 of the present embodiment includes the film 100 of the above-described embodiment as the outermost layer, blooming due to environmental loads such as heat can be suppressed, and the environmental performance and anti-sun screen performance can be improved.

[0076] [Automobile pillar] An automobile pillar according to an embodiment of the present invention will be described. The automobile pillar of the present embodiment is a laminate of, in order, the film of the above-described embodiment, an adhesive layer, and a stainless steel pillar which is the main body of the automobile pillar.

[0077] FIG. 4 is a cross-sectional view schematically showing an automobile pillar 800 according to an embodiment of the present invention. FIG. 4(A) is a side view showing the position of the automobile pillar 800 in the automobile V. FIGS. 4(B) to (D) are diagrams schematically showing an example of the procedure for manufacturing the automobile pillar 800. FIG. 4(B) is a cross-sectional view of a laminate 700A in which a solvent-containing film 600A is laminated on a base film 200. FIG. 4(C) is a cross-sectional view of a laminate 700 in which a film 600 is laminated on the base film 200. FIG. 4(D) is a cross-sectional view showing the automobile pillar 800 and the removed base film 200. Note that the film 600 is obtained by using a black pigment in the film 100 of the above-described embodiment, and the basic configuration such as other raw materials is the same as that of the film 100.

[0078] The automobile pillar 800 is a member provided to support the roof of the automobile V and maintain the strength of the body of the automobile V. For the automobile pillar 800, for example, as shown in FIG. 4(C), there are an A pillar 800a provided in front of the passenger compartment, a B pillar 800b provided at the center in the longitudinal direction of the vehicle body, a C pillar 800c provided at the rear of the vehicle body, etc., and changes such as appropriate addition can be made according to the structure of the automobile V.

[0079] As the film 600 used for the automobile pillar 800, the film of the above-described embodiment is used, and materials such as pigments can be used according to the design of the automobile V. For the film 600 of the present embodiment, in order to express a piano black design, for example, carbon black can be used as the black pigment.

[0080] The automobile pillar 800 can be manufactured as follows, for example, using the above-described manufacturing apparatus 400. First, a solvent-containing film 600A is formed on the base film 200 to obtain a laminate 700A. Further, through a heat drying process, a laminate 700 in which the film 600 is laminated on the base film 200 is obtained. Finally, the base film 200 is removed from the laminate 700 and laminated on the stainless steel pillar 810 via the adhesive layer 820, whereby the automobile pillar 800 is obtained.

[0081] Since the decorative sheet 500 of the present embodiment includes the film 600, blooming due to environmental loads such as heat can be suppressed, and the sunscreen performance can be improved.

[0082] In addition, the best configuration, method, etc. for carrying out the present invention are disclosed in the above description, but the present invention is not limited thereto. That is, although the present invention has been mainly described with respect to specific embodiments, without departing from the scope of the technical idea and purpose of the present invention, those skilled in the art can make various modifications to the above-described embodiments in terms of shape, material, quantity, and other detailed configurations. Therefore, the descriptions limiting the shape, material, etc. disclosed above are exemplified for the purpose of facilitating the understanding of the present invention and do not limit the present invention. Therefore, the descriptions using the names of members with some or all of the limitations of those shapes, materials, etc. removed are included in the present invention.

Example

[0083] Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited by the following examples.

[0084] [Film Evaluation: Examination of the Mass Ratio between Polyvinylidene Fluoride and the Copolymer Composition] (Film Production) A film was produced using the aforementioned production apparatus 400. In this example, the furnace length of the oven was set to 7.5 m for each heating furnace, and the total of the four heating furnaces was 30 m. Also, the line speed for transporting the base film and the laminate was set to 15 m / min. Further, a die coater 420A was used as the coater. In Examples 1 to 3 and Comparative Examples 1 and 2, kyner301 (manufactured by Arkema) was used as polyvinylidene fluoride, Dellpowder SK540N (manufactured by Asahi Kasei) was used as the copolymer composition containing the copolymer, Tinuvin900 (manufactured by BASF) was used as the ultraviolet absorber, A3000 (manufactured by Mitsubishi Chemical) was used as the nucleating agent, MV1010 (Nippon Shokubai) was used as the matting agent, and diethylene glycol monobutyl ether acetate (DBA) was used as the solvent. The copolymer contained in Dellpowder SK540N, which is the copolymer composition, is a copolymer obtained by copolymerizing methyl methacrylate, N-cyclohexyl maleimide, and N-phenyl maleimide, and the content of the copolymer is >94.7%.

[0085] In the conventional example, Kyner500FSF (manufactured by Arkema) was used as polyvinylidene fluoride, polymethyl methacrylate resin (PMMA) Acrylic2042 (manufactured by Lucite) was used instead of the copolymer composition, and dimethyl phthalate (DMP) and diethylene glycol monobutyl ether acetate were used as the solvents. Also, no nucleating agent or matting agent was used. In the examples, comparative examples, and conventional examples, each raw material was used in the composition shown in Table 1. Note that the numerical values in Table 1 indicate parts by mass. Also, in Table 1, "polymer alloy" indicates the total of polyvinylidene fluoride and the copolymer composition.

[0086]

Table 1

[0087] First, a mixed solution preparation step was carried out. First, an ultraviolet absorber was added to a solvent heated to 70°C and stirred for 15 minutes. Next, the copolymer composition and the nucleating agent were added in sequence, and while heating to 70°C, stirring was continued for 2 hours until the copolymer composition and the nucleating agent were dissolved into a transparent liquid, obtaining a solution in which the copolymer composition and the nucleating agent were dissolved. Further, temperature control was performed so that the liquid temperature was 80°C or lower, and while stirring the solution, polyvinylidene fluoride and a matting agent were added to the solution and sufficiently stirred so that the polyvinylidene fluoride was uniformly dispersed. The mixed solution was prepared as described above. At this time, the viscosities were 1,000 cps (Example 1), 1,200 cps (Example 2), 1,500 cps (Example 3), 1,000 cps (Comparative Example 1), 4,500 cps (Comparative Example 2), and 12,500 cps (Conventional Example), respectively. Next, a casting step, a heat drying step, and a cooling step were carried out using the manufacturing apparatus 400. As the base film, a 50-μm-thick PET film was used. The coating amount in the casting step was 100 μm in thickness, and the thickness of the dried coating film of the film after the solvent was removed was 30 μm.

[0088] Also, in the heat drying step, a thermo label (registered trademark) (manufactured by NOF Corporation) was attached to the back surface of the base film (the surface opposite to the surface on which the mixed solution was applied), and the maximum temperature of the film in the heating furnace was measured. This maximum temperature was used as the drying temperature in the heat drying step. In Examples 1 to 3, the four heating furnaces were set to 110°C, 160°C, 200°C, and 220°C, respectively, the drying temperature was 170°C, and the drying time was 2 minutes. Further, a cooling step was performed by blowing air toward the laminate obtained by the heat drying step, and the laminate was wound up. Thus, a roll-shaped laminate in which the film and the base film were laminated was obtained.

[0089] (Film evaluation method and evaluation results) Regarding the obtained film, using a laminate cut into 100 mm × 100 mm as a sample, a blooming test and a sunscreen resistance test were performed.

[0090] The blooming test was carried out by placing the film in a 105°C environment for 500 hours, and visually checking the degree of powdering on the film after 500 hours. The evaluation criteria were as follows: no powdering at all was given a rating of "5", powdering that could be removed by wiping lightly was given a rating of "4", powdering that could be removed by wiping hard was given a rating of "3", powdering that could be removed with detergent etc. was given a rating of "2", and powdering that could not be removed was given a rating of "1". Evaluation results of "4" and "5" were considered to be pass. The results are shown in Table 2.

[0091] The sunscreen resistance test was carried out by placing gauze on the film, applying sunscreen (Neutrogena SPF30) on top of it, and leaving the film in an 80°C environment for 24 hours. After 24 hours, the film was washed with detergent, and then visually inspected to see if there were any abnormalities in the appearance of the film. The evaluation criteria were as follows: no abnormalities at all was given a rating of "5", gloss change and sunscreen residue remaining was given a rating of "4", appearance changed to white was given a rating of "3", cracks were given a rating of "2", and through holes were given a rating of "1". Evaluation results of "4" and "5" were considered to be pass. The results are shown in Table 2.

[0092] [Table 2]

[0093] As shown in the above evaluation results, all of the films of Examples 1 to 3 passed the blooming test and the sunscreen resistance test, and it was shown that they have sufficient environmental performance and sunscreen resistance. On the other hand, the film of Comparative Example 1 caused powdering to an extent that could not be removed in the blooming test. Furthermore, the film of Comparative Example 2 caused cracks in the sunscreen resistance test. The film of the conventional example caused powdering to an extent that could not be removed in the blooming test.

[0094] [Film evaluation: examination of the mass ratio of polymer alloy to nucleating agent] Next, the mass ratio of the polymer alloy to the nucleating agent was examined. Films were produced in the same manner as in Example 1 except that the mass ratio of the raw materials was changed as shown in Table 3.

[0095] [Table 3]

[0096] In the same manner as in Example 1, a sunscreen resistance test was conducted to evaluate chemical resistance. The results are shown in Table 4.

[0097] Also, for the obtained film, using a laminate cut into 100 mm × 100 mm as a sample, a xylene resistance test was conducted. In the xylene resistance test, 0.2 ml of xylene was dropped onto the film, left at room temperature for 30 minutes, then the dropped xylene was wiped off, and the surface state was visually observed 24 hours after wiping. The evaluation criteria were: "5" when no abnormality was observed at all, "4" when a change in glossiness occurred and xylene remained, "3" when the appearance changed to white, "2" when cracks occurred, and "1" when through-holes occurred. For the evaluation results, cases of "4" and "5" were considered qualified. The results are shown in Table 4.

[0098] [Table 4]

[0099] As shown in the above evaluation results, the films of Examples 4 to 6 all passed the sunscreen resistance test and the xylene resistance test, indicating that they have sufficient chemical resistance performance.

[0100] [Evaluation of Decorative Sheet] Decorative sheets were produced using the films of the examples, comparative examples, and conventional examples, and the performance of the decorative sheets was evaluated.

[0101] (Production of Decorative Sheet) Decorative sheets were manufactured using the films of the examples, comparative examples, and conventional examples. The configuration of the decorative sheet was the same as that of the decorative sheet 500 of the above-described embodiment. That is, a polypropylene sheet (average thickness 250 μm, manufactured by Inovex) was used as the base material layer 510, a polyurethane-based adhesive (dry film thickness 5 μm) was used as the first adhesive layer 520 and the second adhesive layer 550, an indium layer (average thickness 50 nm) was used as the metal layer 530, and a modified PET film (average thickness 25 μm, Teflex FT3, manufactured by Toyobo) was used as the metal layer holding layer 540.

[0102] First, indium was vacuum-deposited on the metal layer holding layer 540 to obtain a metal layer holding layer 540 that holds the metal layer 530. Further, a metal layer holding layer 540 that holds the metal layer 530 was laminated on the film 100 of the laminate 300 shown in FIG. 1(C) via the second adhesive layer 550, and then the base material layer 510 was laminated via the first adhesive layer 520. Further, the base material film 200 of the laminate 300 was removed to obtain a decorative sheet 500.

[0103] (Performance Evaluation of Decorative Sheet) The obtained decorative sheet was subjected to environmental tests. The environmental tests were a heat aging test, an environmental cycle test, a moisture resistance test, and a hydrolysis aging test.

[0104] In the heat aging test, the decorative sheet was placed in an environment of 105°C for 500 hours, and the decorative sheet after 500 hours was subjected to the inspections described below. In the environmental cycle test, the temperature of the decorative sheet was raised to 80°C over 1 hour, then the sheet was placed in an 80°C environment for 4 hours, the temperature was lowered to -40°C over 1 hour, then the sheet was placed in a -40°C environment for 4 hours, the temperature was raised to 23°C over 1 hour, and the decorative sheet after being placed in these environments was subjected to the inspections described below. In the hydrolysis aging test, the decorative sheet was placed in an environment of 90°C and 95% RH (relative humidity) for 72 hours, and the decorative sheet after 72 hours was subjected to the inspections described below.

[0105] The evaluation of the decorated sheet subjected to the environmental test was carried out by visual appearance inspection and evaluation of the film adhesion by the cross-cut test (JIS-K-5600 cross-cut method). The cuts on the decorated sheet in the cross-cut test were made into 25 squares in a grid pattern at 1 mm intervals. In the visual appearance inspection, it was considered qualified when no abnormalities such as discoloration, cracks, bubbles, and deformation were observed, and unqualified when even the slightest abnormality was observed. Also, in the cross-cut test, it was considered qualified when there was no peeling at all in all squares, and unqualified when peeling occurred in even one square.

[0106] The evaluation results are shown in Table 5. When a decorated sheet was manufactured using the film of Comparative Example 2, the base film 200 could not be removed and the decorated sheet could not be produced. Therefore, in Comparative Example 2, the evaluation of the decorated sheet could not be carried out. It was considered that as the ratio of the copolymer composition increased, the adhesion between the formed film and the base film 200 became higher, making it difficult to remove the base film 200.

[0107]

Table 5

[0108] As a result of Table 5, all the decorated sheets of the examples met the passing criteria for the heat aging test, environmental cycle test, and hydrolysis aging test. However, although the decorated sheets of Comparative Example 1 and the conventional example met the passing criteria for the cross-cut test in the heat aging test, environmental cycle test, and hydrolysis aging test, cloudiness was confirmed in the visual appearance inspection and they were unqualified. As described above, it was shown that the decorated sheet using the film which is an exemplary aspect of the present invention as the outermost layer does not cause problems such as clouding or film peeling even when subjected to an environmental test.

[0109] In the examples manufactured in the examples which are exemplary embodiments of the present invention, the films of Examples 1 to 3 all passed the blooming test and the sunscreen resistance test, and it was shown that they suppressed blooming due to heat load and had sunscreen resistance performance. For the film of the present invention, blooming due to environmental loads such as heat can be suppressed, and the sunscreen resistance performance can be improved.

Explanation of Signs

[0110] 100,600 film 100A,600A solvent-containing film 100B mixture 200 base film 500 decorative sheet 800 automobile pillar 810 adhesive layer 820 stainless steel pillar

Claims

1. A polymer alloy and, a nucleating agent containing acrylic-modified polytetrafluoroethylene, and comprising: the polymer alloy is a polymer alloy in which a copolymer composition containing 90% by mass or more of a copolymer obtained by copolymerizing vinylidene fluoride, at least methyl methacrylate, and N-cyclohexylmaleimide is compatible with; the mass ratio of the vinylidene fluoride to the copolymer composition is 6:4 to 7:3; a film in which the mass ratio of the polymer alloy to the nucleating agent is 100:0.2 to 100:0.

4.

2. The film according to claim 1, wherein the copolymer is a copolymer obtained by copolymerizing methyl methacrylate, N-cyclohexylmaleimide, and N-phenylmaleimide.

3. containing an ultraviolet absorber; The film according to claim 1 or 2, wherein the mass ratio of the polymer alloy to the ultraviolet absorber is 100:0.05 to 100:3.

0.

4. The film according to any one of claims 1 to 3, having a thickness of 30 μm to 50 μm.

5. A method for producing the film according to any one of claims 1 to 4, comprising: a casting step of casting a mixed solution in which the vinylidene fluoride is dispersed into a solution in which the copolymer composition and the nucleating agent are dissolved in a solvent onto a base film to form a solvent-containing film; a heat drying step of heating and drying the solvent-containing film to remove the solvent from the solvent-containing film to form a polymer alloy. A method for producing a film.

6. The method for producing a film according to claim 5, further comprising a mixed solution preparation step of dispersing the vinylidene fluoride into the solution in which the copolymer composition and the nucleating agent are dissolved in the solvent to prepare the mixed solution before the casting step.

7. The method for producing a film according to claim 5 or 6, wherein the copolymer contained in the copolymer composition is a copolymer obtained by copolymerizing methyl methacrylate, N-cyclohexylmaleimide, and N-phenylmaleimide.

8. The method for producing a film according to any one of claims 5 to 7, wherein the solvent is diethylene glycol monobutyl ether acetate. 5 to 7.

9. A decorative sheet having, as an outermost layer, the film according to any one of claims 1 to 4.

10. In order, the film according to any one of claims 1 to 4, an adhesive layer, A stainless steel pillar and, An automobile pillar laminated with

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