Laminated sheet, method for producing same, sheet molded article, and solar cell sheet

Abstract

As a member that can be applied to a large molded article, it is possible to provide a laminated sheet which has excellent rigidity, particularly excellent homogeneity of in-plane rigidity when a large area is formed, and which has little unevenness in physical properties. This laminate sheet has a structure in which layers a comprising a biaxially stretched polypropylene film and layers b comprising an olefin resin having a melting point of 110-160 DEG C are alternately laminated. When the direction of one side of the laminated sheet is the x direction and the direction orthogonal to the x direction is the y direction, the tensile elastic moduli in the x direction and the y direction at three positions including the center position in the y direction and two positions passing through the center position and located at a distance of 200 mm from the center position in the y direction are both within the range of 2000-5000 MPa.

Description

TECHNICAL FIELD

[0001] The present application relates to a laminated sheet, a method for manufacturing the same, a sheet molded product, and a solar cell sheet.

[0002] This application claims priority based on Japanese Patent Application No. 2023-047359 filed in Japan on March 23, 2023, the contents of which are incorporated herein. BACKGROUND

[0003] From the viewpoint of excellent moldability, heat resistance, and chemical resistance, polypropylene sheets are widely used, centering on food trays. However, in large molded products such as building materials, vehicles, and automobile parts, the mechanical strength of polypropylene sheets as sheet molded products is poor, and thus polypropylene sheets are not used. As a result, polypropylene is mainly used to obtain molded products by injection molding. On the other hand, polypropylene sheet molded products have the advantage that they can be easily recycled as a single material, and are a material that meets the demand for reducing environmental load in recent years, and are expected to be used for industrial products.

[0004] Therefore, as a method for improving the rigidity of polypropylene sheet molded products, for example, a technique is disclosed in Patent Literature 1 in which two kinds of three-layer stretched polypropylene films in which a plurality of low-melting-point polypropylene films are laminated on both surface layers of a high-melting-point polypropylene film are joined by heating to produce a laminated sheet that can be molded.

[0005] PRIOR ART DOCUMENTS

[0006] PATENT LITERATURE

[0007] Patent Literature 1: International Publication No. 2020 / 75755 SUMMARY

[0008] PROBLEMS TO BE SOLVED BY THE INVENTION

[0009] However, the laminated sheet described in the above Patent Literature 1 is a method in which the laminated sheet is laminated and joined using a roll molding machine, and thus the laminated sheet is pressed only at the roll contact points of the nip rolls, and thus it is difficult to laminate, the adhesion of each layer is insufficient, and air is sucked into the entire sheet, and in addition, the obtained sheet is easily warped and uneven.

[0010] In addition, even if the sheet is slowly fed in order to reliably join, there is a problem that wrinkles and the like are generated on the surface layer due to radiant heat from the roll (165°C).

[0011] In addition, the problems of air suction, warping, and unevenness of the entire sheet are the main reasons why it is difficult to apply the sheet to large-area molded sheets for mobile use and the like.

[0012] Thus, the present application provides a biaxially stretched laminate sheet having excellent rigidity, which can be applied to large molded products, and in particular, a biaxially stretched laminate sheet in which the in-plane rigidity is homogenized and the mechanical property unevenness is small even when the area is large.

[0013] Further, the present application provides a biaxially stretched laminate sheet having excellent surface smoothness and small unevenness in a wide range in the plane.

[0014] Method for solving the problem

[0015] The present disclosure includes the following embodiments.

[0016] [1] A laminate sheet having a structure in which an a layer composed of a biaxially stretched polypropylene film and a b layer composed of an olefin-based resin having a melting point of 110 to 160°C are alternately laminated, characterized in that,

[0017] When one edge direction of the above-described laminate sheet is set as an x direction and a direction orthogonal thereto is set as a y direction, the tensile elastic modulus in the x direction and the y direction at three positions including a center position in the y direction and two positions through the center position and located 200 mm from the center position in the y direction are in the range of 2000 to 5000 MPa.

[0018] [2] The laminate sheet according to [1], wherein when the above-described laminate sheet is observed in plan view, the diagonal intersection when a 595 mm x 595 mm square is drawn with the diagonal intersection being the center position of the y direction is set as a, the middle position from the intersection on the diagonal to the corner is set as β, the corner is set as γ, and the surface roughness at each of the positions of a, β, and γ is set as Ra(a), Ra(β), and Ra(γ), Ra(a), Ra(β), and Ra(γ) satisfy the following formulas (1) to (2),

[0019] Ra(a) - Ra(β) < 0.3 (1)

[0020] Ra(a) - Ra(γ) < 0.3 (2)

[0021] wherein Ra(a), Ra(β), and Ra(γ) are each an average value (average roughness) when the surface roughness is measured at two positions of each of the test pieces a, β, and γ cut out in a long strip shape with the y direction as the long side from the positions of a, β, and γ.

[0022] [3] The laminated sheet according to [1] or [2], wherein the laminated sheet is formed by overlapping and heat-welding a plurality of the multilayer biaxially-stretched film (X) in which a biaxially-stretched polypropylene film (A) constituting the a layer and a biaxially-stretched olefin-based resin film (B) constituting the b layer on at least one surface thereof are laminated, and the multilayer biaxially-stretched film (X) has a stretching ratio of 2.8 to 8 in the MD direction and a stretching ratio of 2.8 to 12 in the TD direction.

[0023] [4] The laminated sheet according to [3], wherein the multilayer biaxially-stretched film (X) is a BAB-type film in which the biaxially-stretched olefin-based resin film (B) is contained on both surfaces of the biaxially-stretched polypropylene film (A), and has a thickness of 30 to 80 μm; and the laminated sheet is formed by laminating 30 to 60 of the BAB-type film and laminating a BA-type film or a BAA-type film on both surfaces thereof with the a layer as the surface.

[0024] [5] The laminated sheet according to [4], wherein the multilayer biaxially-stretched film (X) is a BAB-type film in which the biaxially-stretched olefin-based resin film (B) is contained on both surfaces of the biaxially-stretched polypropylene film (A), and is a 3-layer film having a thickness of 100 to 400 μm; and the laminated sheet is formed by laminating 2 to 20 of the BAB-type film and laminating a BA-type film or a BAA-type film on both surfaces thereof with the a layer as the surface.

[0025] [6] A molded article of the laminated sheet according to [1] or [2].

[0026] [7] A method for manufacturing a laminated sheet having a structure in which an a layer composed of a biaxially-stretched polypropylene film and a b layer composed of an olefin-based resin having a melting point of 110 to 160°C are alternately laminated, the method comprising a preparation step in which a multilayer biaxially-stretched film (X) in which a biaxially-stretched polypropylene film (A) constituting the a layer and a biaxially-stretched olefin-based resin film (B) constituting the b layer on at least one surface thereof are laminated is overlapped a plurality of times to form a laminated sheet precursor (pMS), and a pressing step in which the laminated sheet precursor (pMS) is heated while being pressed on a surface.

[0027] [8] A method for manufacturing a laminate sheet in which a layer a composed of a biaxially-stretched polypropylene film and a layer b composed of an olefin-based resin having a melting point of 110 to 160°C are alternately laminated, characterized by comprising a preparation step in which a plurality of multilayer biaxially-stretched films (X) in which a biaxially-stretched polypropylene film (A) constituting the layer a and a biaxially-stretched olefin-based resin film (B) constituting the layer b are laminated on at least one surface thereof are overlapped to form a laminate sheet precursor (pMS), and a pressing step in which the laminate sheet precursor (pMS) is continuously heated and pressed using a continuous pressing device, and then cooled, the continuous pressing device having a plurality of heating zones and cooling zones, in which the laminate sheet precursor (pMS) is heated and pressed using upper and lower flat molds in the heating zones, and then the laminate sheet precursor (pMS) is continuously pressed using upper and lower flat molds in the cooling zones.

[0028] [9] The method for manufacturing a laminate sheet according to [8], wherein the laminate sheet precursor (pMS) is inserted between the upper and lower flat molds constituting the heating zones in the continuous pressing device, and pressed under a pressure condition of 110 to 170°C and 1 to 40 MPa, and then, after the pressing is released, the sheet is fed by a predetermined length in a running direction (MD direction), and the heating and pressing are performed again, and this operation is repeated, so that the laminate sheet is continuously transferred from the heating zones to the cooling zones, and then, in the cooling zones, the pressing is performed under a pressure condition of 25 to 125°C and 1 to 40 MPa, and then, after the pressing is released, the sheet is fed in the predetermined running direction, and the laminate sheet after heat fusion is continuously taken out.

[0029]

[10] The method for manufacturing a laminate sheet according to [9], wherein the heating zones are divided into 2 to 10 zones in the MD direction and composed of molds having flat contact surfaces in a manner of sandwiching the sheet therebetween, and the cooling zones are divided into 1 zone or 2 to 5 zones in the MD direction and composed of molds having flat contact surfaces in a manner of sandwiching the sheet therebetween.

[0030]

[11] The method for manufacturing a laminate sheet according to [9] or

[10] , wherein the temperature conditions of the heating zones divided into 2 to 10 zones in the MD direction are such that the temperature of the first heating zone closest to the inlet of the sheet is 110 to 160°C, the temperature of the second heating zone following the first heating zone is +10 to +40°C relative to the set temperature of the first heating zone, and the maximum temperature of the heating zones is 170°C.

[0031]

[12] The manufacturing method of the laminated sheet according to [7] or [8], wherein the stretch ratio in the MD direction of the multilayer biaxially-stretched film (X) is 2.8 to 8 times, and the stretch ratio in the TD direction is 2.5 to 12 times.

[0032]

[13] The manufacturing method of the laminated sheet according to

[12] , wherein the multilayer biaxially-stretched film (X) is a BAB-type film in which the biaxially-stretched polypropylene film (A) has the biaxially-stretched olefin-based resin film (B) bonded to both surfaces thereof, and the thickness of the biaxially-stretched polypropylene film (A) is 30 to 80 μm; and the laminated sheet precursor (pMS) is formed by laminating 30 to 60 sheets of the BAB-type film, and laminating a BA-type film or a BAA-type film on both surfaces thereof such that the biaxially-stretched polypropylene film (A) is on the surface.

[0033]

[14] The manufacturing method of the laminated sheet according to [7], wherein a single-plate vacuum laminating device having a metal plate in a chamber in a face shape is used, the laminated sheet precursor (pMS) is placed on the lower metal plate in the chamber, the chamber is made into a vacuum state of 170 Pa or less, and heating and pressing are performed, and after the pressing is released, the metal plate for cooling is used for clamping.

[0034]

[15] The manufacturing method of the laminated sheet according to

[14] , wherein the heating and pressing is performed under conditions in which the temperature of the metal plate is 140 to 160°C, and the cylinder pressure is 0.1 to 1 MPa.

[0035]

[16] A solar cell sheet obtained by laminating a flexible solar cell module to the laminated sheet according to any one of [1] to [5].

[0036] Effects of Invention

[0037] According to the present application, a biaxially-stretched laminated sheet having excellent rigidity, which can be applied to large molded products, can be provided, and in particular, a biaxially-stretched laminated sheet in which the rigidity is uniform in the plane and the mechanical properties are uniform can be provided even when the area is large.

[0038] Further, a biaxially-stretched laminated sheet having excellent surface smoothness and in which unevenness in the plane is small over a wide range can be provided. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 is a view showing a press device having a continuous press molding mechanism.

[0040] Figure 2 is a view showing a planar mold having a plurality of regions divided by heat as an example of the continuous press molding mechanism of the present disclosure.

[0041] Figure 3is a view showing a planar mold having a plurality of regions divided by heat as other examples of the continuous press molding mechanism of the present disclosure.

[0042] Figure 4 is a view showing temperature settings of upper and lower molds in the press device in Example 1.

[0043] Figure 5 is a plan view of the transparent laminate obtained in Example 1, and is a view showing a cutout position of a test piece for evaluation of mechanical properties.

[0044] Figure 6 is a plan view of the transparent laminate obtained in Example 4 (single sheet vacuum lamination), and is a view showing a cutout position of a test piece for evaluation of mechanical properties.

[0045] Figure 7 In (a), a view showing the shape and size of a dumbbell-shaped test piece for tensile elastic modulus measurement, and (b) is a view showing the shape and size of a long strip-shaped test piece for flexural elastic modulus measurement.

[0046] Figure 8 is a plan view of the transparent laminate obtained in Example 1, and is a view showing a cutout position of a test piece for evaluation of surface smoothness.

[0047] Figure 9 is a plan view of the transparent laminate obtained in Example 4 (single sheet vacuum lamination), and is a view showing a cutout position of a test piece for evaluation of surface smoothness.

[0048] Figure 10 is a view showing the size of a test piece for smoothness evaluation.

[0049] Figure 11 is a view showing temperature settings of upper and lower molds in the press device in Example 2.

[0050] Figure 12 is a plan view of the transparent laminate obtained in Example 2, and is a view showing a cutout position of a test piece for evaluation of surface smoothness.

[0051] Figure 13 is a plan view of the transparent laminate obtained in Example 2, and is a view showing a cutout position of a test piece for evaluation of surface smoothness.

[0052] Figure 14 is a conceptual view showing a cross section of a single sheet vacuum lamination device used in Example 4.

[0053] Figure 15 is a conceptual view showing a cross section of a cooling device used in Example 4.

[0054] Figure 16is a graph showing temperature settings of upper and lower molds in a press device in Example 3.

[0055] Figure 17 is a conceptual diagram showing a state before and after bonding according to the present application.

[0056] Figure 18 is a sectional view schematically showing a cross section of a solar cell sheet according to one embodiment of the present application.

[0057] Figure 19 is a perspective view showing an example of a solar cell integrated carport using a laminated sheet according to the present application. DETAILED DESCRIPTION

[0058] Hereinafter, the present application will be described in more detail. It should be noted that the present application is not limited to the following embodiments.

[0059] It should be noted that "〜" means a value equal to or greater than a value before the notation of "〜" and a value equal to or less than a value after the notation of "〜".

[0060] (Laminated sheet)

[0061] The laminated sheet according to the present application is a laminated sheet in which an a layer composed of a biaxially-stretched polypropylene film and a b layer composed of an olefin-based resin having a melting point of 110 to 160°C are alternately laminated. In the present application, it is characterized in that, when one edge direction of the above laminated sheet is set as an x direction and a direction orthogonal thereto is set as a y direction, the tensile elastic modulus in the x direction and the y direction at three positions including a center position in the y direction and two positions through the center position and located 200 mm from the center position in the y direction are all in the range of 2000 to 5000 MPa.

[0062] In addition, in the present application, the biaxially-stretched film as a raw material of the above laminated sheet is preferably stretched to a ratio of 2.8 x 2.8 times or more, and particularly 3 x 3 times or more. Here, the x direction and the y direction in the above laminated sheet are preferably coincident with the stretching directions in the biaxially-stretched film, for example, the MD direction is preferably set as the x direction and the TD direction is preferably set as the y direction.

[0063] Here, the tensile elastic modulus in the x direction and the y direction at the above three positions is a value evaluated using a test piece cut out with the three positions as centers. Specifically, if the laminated sheet shown in FIG. 1 is described as an example, the above three positions mean, for example, positions at 200 mm from the center position in the y direction, 200 mm from the center position in the x direction, and the center position in the y direction. Figure 5 Figure 5 In the present application, the tensile elastic modulus in the x direction and the y direction at the above three positions is a value evaluated using a test piece cut out with the three positions as centers. Specifically, if the laminated sheet shown in FIG. 1 is described as an example, the above three positions mean, for example, positions at 200 mm from the center position in the y direction, 200 mm from the center position in the x direction, and the center position in the y direction.When the sheet length direction in (a) is set as the x direction (MD direction), the point at the center of the imaginary straight line in the y direction (TD direction) is set as (2), the points at 200 mm left and right of the center from (2) are set as (1) and (3), respectively. Note that the imaginary straight line in the y direction (TD direction) can be at any position, and (1), (2), and (3) can be determined by appropriately moving up and down in the x direction according to the position of the test piece. Here, the test pieces for the tensile elastic modulus measurement can be cut out as shown by the dotted lines in the drawing, and dumbbell-shaped test pieces with the y direction (TD direction) as the long side and dumbbell-shaped test pieces with the x direction (MD direction) as the long side can be used for the flexural elastic modulus measurement. Here, the cut-out position of the dumbbell-shaped test piece with the y direction (TD direction) as the long side is a position where the center of the length of the dumbbell shape coincides with (1), (2), and (3), and the cut-out position of the dumbbell-shaped test piece with the x direction (MD direction) as the long side is a position where the center axis of the dumbbell shape (for example Figure 7 (a) is indicated by the single-dot chain line) coincides with (1), (2), and (3). The shape and size of the dumbbell-shaped test piece are as shown in (a). Figure 7 (a).

[0064] In addition, the tensile elastic modulus measurement can be performed according to JIS K 7161.

[0065] In the present application, the advantage is that since both the x direction and the y direction, which are orthogonal, are tensile elastic modulus within a predetermined range, the sheet becomes one in which the physical properties change little in a wide range in the plane and the physical properties are uniform.

[0066] In addition, in the present application, the preferred range of the tensile elastic modulus differs depending on the film thickness of the biaxially-stretched film to be used as a raw material and the stretching ratio. For example, in the case of using a film having a thickness of 20 μm or more and less than 100 μm as the biaxially-stretched film forming the core layer of the non-surface layer, the biaxially-stretched film itself can be stretched at a high stretching ratio, and the biaxially-stretched film is preferably stretched at a stretching ratio of 2.8 to 8 times in the MD direction and at a stretching ratio of 8 to 12 times in the TD direction. In this case, in the case of the laminated sheet produced by the method 1 (pressing method using a continuous pressing device) described later, when the length direction is set as the x direction, the tensile elastic modulus in the x direction (MD direction) is preferably in the range of 2000 to 3000 MPa, and the tensile elastic modulus in the y direction (TD direction) is preferably in the range of 3000 to 5000 MPa; and in the case of the laminated sheet produced by the method 2 (single sheet pressing method) described later, when the direction of one side is set as the x direction, the tensile elastic modulus in the x direction is preferably in the range of 2000 to 3000 MPa, and the tensile elastic modulus in the y direction is preferably in the range of 3000 to 5000 MPa.

[0067] In particular, in the case of production by the method 2 (single sheet pressing method), in the case of laminating the raw material biaxially-stretched films with the MD direction / TD direction aligned, the tensile elastic modulus in the x direction (MD direction of the raw material biaxially-stretched film) is preferably in the range of 2000 to 3000 MPa, and the tensile elastic modulus in the y direction (TD direction of the raw material biaxially-stretched film) is preferably in the range of 3000 to 5000 MPa.

[0068] On the other hand, in the case of using a film having a thickness of 100 to 400 μm as the raw material biaxially-stretched film forming the core layer of the non-surface layer, the stretching ratio at the time of production of the raw material biaxially-stretched film is preferably 2.8 to 8 times in the MD direction, preferably 3 to 6 times, and 2.8 to 8 times in the TD direction, preferably 3 to 6 times, and in this case, in the case of the laminated sheet produced by the method 1 (pressing method using a continuous pressing device) described later, when the length direction is set as the x direction, the tensile elastic modulus in the x direction (MD direction) is preferably in the range of 2000 to 3200 MPa, and the tensile elastic modulus in the y direction (TD direction) is preferably in the range of 2000 to 3200 MPa.

[0069] In addition, with respect to the three tensile elastic moduli in the y direction evaluated at the above three positions, the coefficient of variation is preferably 6% or less, particularly preferably 5% or less, and particularly preferably 4.5% or less, from the viewpoint of uniformity of the rigidity of the sheet. In addition, the coefficient of variation can be 0.5% or more.

[0070] Here, the coefficient of variation is a value calculated from the standard deviation divided by the average [(standard deviation / average) x 100 (%)].

[0071] Further, the coefficient of variation of the three x-direction tensile elastic moduli evaluated at the above three positions is preferably 3% or less, more preferably 2.5% or less, and particularly preferably 2% or less. Further, the coefficient of variation can be 0.2% or more.

[0072] Further, if the biaxially-stretched film obtained in Example 1 described later is used, for example, Figure 5 As shown in the example of the laminate sheet, the bending elastic modulus at the above three positions is described, as shown in Figure 5 As shown in the example of the laminate sheet, the bending elastic modulus at the above three positions is described, as shown in Figure 7 (b). Here, the bending elastic modulus measurement can be performed in accordance with JIS K 7171.

[0073] Specifically, in the case where the biaxially-stretched film having a thickness of 20 μm or more and less than 100 μm, 2.8 to 8 times in the MD direction, and 8 to 12 times in the TD direction is used as a raw material for forming a core layer other than a surface layer, in the case of the laminate sheet manufactured by the method 1 (pressing method using a continuous pressing device) described later, when the length direction is set as the x direction, the bending elastic modulus in the x direction (MD direction) is preferably in the range of 2000 to 3500 MPa, and the bending elastic modulus in the y direction (TD direction) is preferably in the range of 3500 to 6000 MPa; in the case of the laminate sheet manufactured by the method 2 (single-piece pressing method) described later, when the direction of one side is set as the x direction, the bending elastic modulus in the x direction is preferably in the range of 2000 to 3500 MPa, and the bending elastic modulus in the y direction is preferably in the range of 3500 to 6000 MPa.

[0074] In particular, in the case where the MD direction / TD direction of the raw material stretched film is aligned in the laminate, the bending elastic modulus in the x direction (raw material film MD direction) is preferably in the range of 2000 to 3500 MPa, and the bending elastic modulus in the y direction (raw material film TD direction) is preferably in the range of 3500 to 6000 MPa.

[0075] On the other hand, in the case of the laminate sheet manufactured by the method 1 (pressing method using a continuous pressing device) using a biaxially stretched film having a thickness of 100 to 400 μm as a raw material for forming the core layer other than the surface layer, the film having a biaxial stretching ratio of 2.8 to 8 times in the MD direction, preferably 3 to 6 times, and 2.8 to 8 times in the TD direction, preferably 3 to 6 times, it is preferable that the bending elastic modulus in the x direction (MD direction) is in the range of 2500 to 3500 MPa and the bending elastic modulus in the y direction (TD direction) is in the range of 2500 to 3500 MPa.

[0076] Further, the coefficient of variation of the three bending elastic moduli in the y direction evaluated at the above three positions is preferably 6.5% or less, more preferably 5.5% or less, and particularly preferably 4.8% or less. Further, the coefficient of variation can be 0.5% or more.

[0077] Further, the coefficient of variation of the three bending elastic moduli in the x direction evaluated at the above three positions is preferably 4% or less, more preferably 3.5% or less, and particularly preferably 3% or less. Further, the coefficient of variation can be 0.2% or more.

[0078] As described above, the laminate sheet of the present application is characterized by a large area and uniform physical properties, and thus it is preferable to produce a sheet having a length of one side of 400 mm or more, particularly preferably 500 mm or more, 600 mm or more, 1300 mm or more, or 2000 mm or more. Particularly in the case of producing a laminate sheet by the above-described method 1 (pressing method using a continuous pressing device), in the case where the sheet feeding direction is set as the x direction, it is possible to produce a laminate sheet having a length in the y direction orthogonal thereto, i.e., a laminate sheet having a width of 400 mm or more, 500 mm or more, 600 mm or more, 1300 mm or more, or 2000 mm or more. In this case, in the case of the method 1 (pressing method using a continuous pressing device), if the biaxially stretched film as a raw material is supplied from a roll, the length in the x direction is not limited, and can be appropriately selected according to the purpose.

[0079] Further, the laminate sheet of the present application preferably has the following characteristics.

[0080] Further from the viewpoint of appearance, the laminate of the present application preferably has a uniform surface smoothness, and for example, can be used to produce a design material having excellent cosmetic properties and no painting by laminating a decorative film or sandwiching an interlayer. Specifically, when the laminate is observed in plan view, a square of 595 mm x 595 mm is drawn with the intersection of the diagonals as the center of the x direction or y direction, and with one side of the square parallel to one side of the laminate, and when the intersection of the diagonals is denoted as α, the midpoint from the intersection on the diagonal to the corner of the square is denoted as β, and the corner of the square is denoted as γ, and when the surface roughness at each of the positions α, β, and γ is denoted as Ra(α), Ra(β), and Ra(γ), respectively, it is preferable that the difference (ΔRa) between Ra(β) or Ra(γ) and Ra(α) satisfy the following relationships of Equations (1) and (2).

[0081] Regarding the positions α, β, and γ, for example, if the laminate shown in Figure 8 is used, the positions α, β, and γ are, for example, those shown in Figure 8 .

[0082] ΔRa(α, β) = Ra(α) - Ra(β) < 0.3 (1)

[0083] ΔRa(α, γ) = Ra(α) - Ra(γ) < 0.3 (2)

[0084] Note that Ra(α), Ra(β), and Ra(γ) are each the average value (average roughness) of the surface roughness measured at two positions in each of the test pieces α, β, and γ, which are long strips cut from the positions α, β, and γ in the MD direction. The test pieces can be, for example, those shown in Figure 10 . Further, the measurement positions of the two positions in one test piece can be, for example, the measurement position (1) and the measurement position (2) shown in Figure 10 .

[0085] Further, the relative roughnesses ΔRa(β) and ΔRa(γ) of β and γ can be expressed as follows based on Ra(α), and ΔRa(β) is preferably 100% or less and ΔRa(γ) is preferably 100% or less.

[0086] ΔRa(β) = [(Ra(β) - Ra(α)) / Ra(α)] x 100 (3)

[0087] ΔRa(γ) = [(Ra(γ) - Ra(α)) / Ra(α)] x 100 (4)

[0088] The biaxially-stretched film as a raw material of the laminated sheet of the present application can be produced separately into a biaxially-stretched polypropylene film (A) constituting the a layer described above, a biaxially-stretched olefin-based resin film (B) constituting the b layer described above, and preferably used as a multilayer biaxially-stretched film (X) in which the biaxially-stretched polypropylene film (A) constituting the a layer described above and the biaxially-stretched olefin-based resin film (B) constituting the b layer described above are laminated on at least one surface thereof. Here, the multilayer biaxially-stretched film (X) is particularly preferably produced by a co-extrusion method from the viewpoint of excellent adhesion between (A) / (B). That is, in the present application, the laminated sheet is preferably produced by overlapping a plurality of the multilayer biaxially-stretched film (X) and heat-welding. Therefore, the stretching ratio in the MD direction and the TD direction of the biaxially-stretched film as the raw material described above is preferably the stretching ratio of the multilayer biaxially-stretched film (X) described above.

[0089] In the present application, as described above, the stretching ratio in the MD direction of the biaxially-stretched film as a raw material, particularly the multilayer biaxially-stretched film (X), is 2.8 to 8 times, and the stretching ratio in the TD direction is 2.8 to 12 times, which is preferable from the viewpoint of maintaining a high orientation of the biaxially-stretched polypropylene film (A) in the laminated sheet and excellent rigidity. Such a laminated sheet of the present application can be produced by the production method described in the "Production method of laminated sheet" described later.

[0090] The multilayer biaxially-stretched film (X) described above can be exemplified by an AB type in which the biaxially-stretched olefin-based resin film (B) is laminated on one surface of the biaxially-stretched polypropylene film (A), an AAB type in which the film (A) is further laminated on one surface of the biaxially-stretched polypropylene film (A) on which the film (B) is laminated, a BAB type in which the film (B) is laminated on both surfaces of the biaxially-stretched polypropylene film (A), and the like, and can be used in appropriate combinations, and particularly preferably a BAB type film is overlapped a plurality of times, and an AB type film or an AAB type film is laminated on both surfaces thereof with the A layer as the surface.

[0091] The size of the laminated sheet of the present application can be appropriately selected depending on the use. In the present application, the laminated sheet has an advantage that it can be large-sized and high-rigid, which has not been achieved in the past, and therefore, as described above, it is preferable to produce a sheet having a length of 400 mm or more, particularly 500 mm or more, 600 mm or more, 1300 mm or more, or 2000 mm or more on one side, and particularly in the case where the laminated sheet is produced by the following method 1 (pressing method using a continuous pressing device), in the case where the sheet feeding direction is set as the x direction, it is preferable to produce a laminated sheet having a length of 400 mm or more, 500 mm or more, 600 mm or more, 1300 mm or more, or 2000 mm or more in the y direction orthogonal to the x direction, that is, a laminated sheet having a width of 400 mm or more, 500 mm or more, 600 mm or more, 1300 mm or more, or 2000 mm or more, for example, it is preferable that the length of at least one side of the laminated sheet is 500 to 2000 mm, and the length of the side orthogonal thereto is 2000 mm or more.

[0092] For example, in the case of the laminated sheet produced by the method 1 (pressing method using a continuous pressing device) described later, the length in the y direction (TD direction) is preferably 500 to 2000 mm, and the length in the x direction (MD direction) is preferably a length of 1000 to 3000 mm.

[0093] In the case of the laminated sheet produced by the method 2 (single piece pressing method) described later, in order to produce in a batch manner, the length of one side (length in the x direction or the y direction) is preferably 500 to 2000 mm.

[0094] (Method for producing a laminated sheet)

[0095] As a method for producing the laminated sheet described above, there are a preparation step and a pressing step. In the preparation step, a plurality of biaxially-stretched polypropylene films (A) and biaxially-stretched olefin-based resin films (B) are alternately overlapped to form a laminated sheet precursor (pMS), or a plurality of multilayer biaxially-stretched films (X) are overlapped to form a laminated sheet precursor (pMS), the multilayer biaxially-stretched film (X) being a film in which a biaxially-stretched polypropylene film (A) and a biaxially-stretched olefin-based resin film (B) are laminated on at least one surface thereof and is preferably produced by a co-extrusion method; in the pressing step, the laminated sheet precursor (pMS) is heated while being subjected to heat pressing on a surface.

[0096] In the present application, since the laminated sheet precursor (pMS) is heat-pressed on a surface rather than by a roll, a laminated sheet having high rigidity and excellent homogeneity and small unevenness in the physical properties based on the site can be obtained.

[0097] <Preparation step of the laminated sheet precursor (pMS)>

[0098] Specifically, the preparation step of the laminated sheet precursor (pMS) can include:

[0099] Preparation step 1: a step of alternately overlapping a plurality of biaxially-stretched polypropylene films (A) and biaxially-stretched olefin-based resin films (B) to form a laminated sheet precursor (pMS); and

[0100] Preparation step 2: a step of overlapping a plurality of multilayer biaxially-stretched films (X) in which a biaxially-stretched polypropylene film (A) and a biaxially-stretched olefin-based resin film (B) are laminated on at least one surface thereof to form a laminated sheet precursor (pMS).

[0101] Among them, in terms of the adhesion between (A) / (B) becoming good, particularly preferably, Preparation Step 2 is prepared. In addition, the multilayer biaxially-stretched film (X) can be manufactured by laminating the biaxially-stretched polypropylene film (A) and the biaxially-stretched olefin-based resin film (B), but in terms of the adhesion between the layers becoming good, it is preferable to be manufactured by the co-extrusion method.

[0102] Here, the biaxially-stretched polypropylene film (A) preferably has a stretch ratio of 2.8 to 8 times in the MD direction and a stretch ratio of 2.8 to 12 times in the TD direction at the time of manufacturing the film, and on the other hand, in terms of the rigidity of the final obtained laminated sheet being dramatically improved and exhibiting a moderate secondary moldability, the biaxially-stretched olefin-based resin film (B) preferably has a stretch ratio of 2.8 to 8 times in the MD direction and a stretch ratio of 2.5 to 12 times in the TD direction.

[0103] In the case where the multilayer biaxially-stretched film (X) is manufactured by the co-extrusion method, in the case where a film of 20 μm or more and less than 100 μm is manufactured as the multilayer biaxially-stretched film (X), the film itself can be highly stretched, and in terms of the rigidity of the laminated sheet becoming good, it is preferable to have a stretch ratio of 2.8 to 8 times in the MD direction and 8 to 12 times in the TD direction at the time of manufacturing the raw film. In addition, the biaxial stretching can be performed by sequential stretching or simultaneous stretching. On the other hand, in the case where a film of 100 to 400 μm is manufactured, the stretch ratio at the time of manufacturing the film is preferably a stretch ratio of 2.8 to 8 times in the MD direction and 2.8 to 8 times in the TD direction, and particularly preferably a stretch ratio of 3 to 6 times in the MD direction and 3 to 6 times in the TD direction.

[0104] In addition, the multilayer biaxially-stretched film (X) can be exemplified by a BA type film in which the biaxially-stretched polypropylene film (A) is laminated with the biaxially-stretched olefin-based resin film (B) on only one surface, a BAA type film in which two sheets of the biaxially-stretched polypropylene film (A) are overlapped and laminated with the biaxially-stretched olefin-based resin film (B) on only one surface, a BAB type film in which the biaxially-stretched polypropylene film (A) is laminated with the biaxially-stretched olefin-based resin film (B) on both surfaces, a BAC type film in which the biaxially-stretched polypropylene film (A) is laminated with the biaxially-stretched olefin-based resin film (B) on one surface and a modified polypropylene-based resin film (C) on the other surface, and the like.

[0105] The multilayer biaxially-stretched film (X) can be appropriately selected and used in combination according to the purpose to obtain the precursor (pMS), but in the present application, it is preferable to overlap multiple sheets of the BAB type film to use the BA type film and the BAA type film in a manner in which the surface layer film (A) is on the surface, as shown below.

[0106] AB / BAB / BAB / BAB / ... / BAB / BAB / BAB / BA

[0107] AAB / BAB / BAB / BAB / ... / BAB / BAB / BAB / BAA

[0108] Alternatively, in the case of further laminating a decorative film, in the case of performing printing, for example, as shown below, it is preferable to use a BAC type film as a surface layer in a manner that the surface of the film (C) is formed on the surface.

[0109] CAB / BAB / BAB / BAB / ... / BAB / BAB / BAB / BAA

[0110] The multilayer biaxially stretched film (X) can be exemplified by, for example, two 3-layer films (xl) having a thickness of 30 μm or more and less than 100 μm or two 3-layer films (x2) having a thickness of 100 to 400 μm, of a BAB type film.

[0111] Further, the thickness ratio of B / A / B in the BAB type film is, for example, preferably B / A / B = 2 to 20 / 96 to 60 / 2 to 20, and from the viewpoint of improving rigidity, it is preferable to ensure the thickness of the A layer as much as possible, and particularly preferably B / A / B = 2 to 15 / 96 to 70 / 2 to 15.

[0112] In the case where the multilayer biaxially stretched film (X) is two 3-layer films (xl) having a thickness of 30 μm or more and less than 100 μm, it is preferable to laminate 30 to 60 sheets, and to overlap a BA type film or a BAA type film in a manner that the surface of the A layer is formed on the surface layer thereof. Alternatively, in the case of performing printing or laminating a decorative film on the laminated sheet, it is preferable to overlap a BAC type film in a manner that the surface of the C layer is formed instead of the BA type film or the BAA type film.

[0113] On the other hand, in the case where the multilayer biaxially stretched film (X) is two 3-layer films (x2) having a thickness of 100 to 400 μm, it is preferable to laminate 2 to 20 sheets, and to overlap a BA type film or a BAA type film in a manner that the surface of the A layer is formed on the surface layer thereof. Alternatively, in the case of performing printing or laminating a decorative film on the laminated sheet, it is preferable to overlap a BAC type film in a manner that the surface of the C layer is formed instead of the BA type film or the BAA type film.

[0114] Note that the thickness of the BA type film is preferably 20 to 300 μm, and the thickness ratio of each layer (B / A) is preferably 5 to 20 / 95 to 80. The thickness of the BAA type film is preferably 30 to 300 μm, and the thickness ratio of each layer (B / A / A) is preferably 5 to 20 / 95 to 80 / 95 to 80. The thickness of the BAC type film is preferably 30 to 300 μm, and the thickness ratio of each layer (B / A / C) is preferably 2 to 20 / 96 to 60 / 2 to 20.

[0115] The size of the laminate sheet precursor (pMS) in the present application can be appropriately selected depending on the size of the laminate sheet to be produced in the pressing process of the following Method 1 (pressing method using a continuous pressing device) or Method 2 (single sheet pressing method).

[0116] In laminating the multilayer biaxially-stretched films (X), they can be laminated in the same MD direction / TD direction or in a manner crossing each other, but in the case of producing the laminate sheet by Method 1 (pressing method using a continuous pressing device), it is preferable to laminate them in the same MD direction / TD direction from the viewpoint of being able to mount the multilayer biaxially-stretched films (X) in a roll state to a continuous pressing press to perform film feeding.

[0117] On the other hand, in the case of producing the laminate sheet by the following Method 2 (single sheet pressing method), it is preferable to laminate them in the same MD direction / TD direction from the viewpoint of operability and productivity, on the other hand, it is preferable to laminate them in a manner crossing each other from the viewpoint of the homogeneity of orientation.

[0118] [Biaxially-stretched polypropylene film (A)]

[0119] Here, the above-mentioned biaxially-stretched polypropylene film (A) can be obtained by biaxially stretching a polypropylene composition containing a polypropylene-based polymer or the polypropylene-based polymer and an additive such as a crystallization nucleating agent by a publicly-known method.

[0120] For example, the above-mentioned polypropylene or the like can be extruded to obtain an unstretched sheet, and the sheet can be biaxially stretched to obtain a biaxially-stretched film, but as mentioned above, in the present application, it is preferable to perform film formation and stretching by a co-extrusion method together with other layers.

[0121] The polypropylene-based polymer used here, specifically, can include a propylene homopolymer, a propylene random copolymer obtained by polymerizing a monomer component containing at least one kind selected from 1% by weight or less of C2 to C10-α-olefin (excluding C3-α-olefin), and a substance composed of a mixture thereof.

[0122] Among them, it is particularly preferable to be a propylene random copolymer (hereinafter, sometimes simply referred to as "propylene random copolymer") obtained by polymerizing a monomer component containing 1% by weight or less of ethylene from the viewpoint of being able to impart excellent stretchability to the sheet while maintaining high rigidity and toughness of the sheet.

[0123] Here, by having a relatively wide molecular weight distribution with Mw / Mn of the polypropylene-based polymer being 6 to 20, the thickness accuracy becomes good, in addition to this, it is possible to have high rigidity and high stretchability, and film formation becomes easy, and thus it is preferable.

[0124] Further, the amount of the xylene-insoluble component of the polypropylene-based polymer is preferably more than 96.5% by mass and 99.5% by mass or less. The xylene-insoluble component of the polypropylene corresponds to the isotactic component having crystallinity. In contrast, the small amount of the xylene-soluble component contained in the polypropylene corresponds to the atactic component having no crystallinity and has a lower molecular weight than the xylene-insoluble component. Further, when the amount of the xylene-insoluble component of the polypropylene-based polymer is more than 96.5% by mass and 99.5% by mass or less, the crystalline component of the polypropylene-based resin material is more than 96.5% by mass and 99.5% by mass or less. Further, from the viewpoint of the rigidity and heat resistance, particularly the rigidity, of the (secondary) molded article obtained by thermoforming the sheet, the amount of the xylene-insoluble component is particularly preferably in the range of more than 97.0% by mass and 99.5% by mass or less.

[0125] Further, the isotacticity (mmmm) of the crystalline component of the polypropylene-based polymer is preferably 97.5 to 99.5%. When the mmmm is less than 97.5%, the rigidity and heat resistance, particularly the heat resistance, of the (secondary) molded article obtained by thermoforming the sheet formed of the polypropylene composition can be reduced.

[0126] In the case where the above-described propylene random copolymer is used as the polypropylene-based polymer, from the viewpoint of maintaining the toughness, rigidity, and stretchability of the above-described sheet, the content of ethylene in the raw monomer component is preferably 0.1% by mass or more and less than 1% by mass, preferably 0.1% by mass or more and less than 0.6% by mass, and particularly preferably 0.1% by mass or more and less than 0.3% by mass.

[0127] Here, the above-described propylene random copolymer also has the advantage that the transparency is improved by random copolymerization of ethylene and propylene. Further, when the content of ethylene in the raw monomer component is less than 1% by mass, the rigidity is excellent. The lower limit of the content of ethylene is not particularly limited, and is preferably 0.1% by mass or more, from the viewpoint of easily obtaining the effect of improving the transparency.

[0128] The MFR of the polypropylene-based polymer is 1 to 15 g / 10 minutes, and is preferably 2 to 6 g / 10 minutes. When the MFR is in the above-described range, the moldability when the polypropylene composition is molded into a sheet is excellent.

[0129] From the viewpoint of the transparency, the above-described polypropylene-based polymer is preferably used as a polypropylene composition containing a crystalline nucleating agent, but in the present application, by using a smaller amount of the crystalline nucleating agent than usual, the haze can be reduced, and the transparency can be further improved.

[0130] The content of the crystallization nucleating agent is preferably less than 0.18 parts by mass, and particularly preferably 0.15 parts by mass or less, relative to 100 parts by mass of the ethylene-containing propylene polymer in the polypropylene composition. If it is less than the above upper limit value, excellent thickness accuracy is easily obtained, and a polypropylene composition that maintains strength and rigidity and has excellent film formability is obtained. Here, the lower limit of the content of the crystallization nucleating agent is not particularly limited, and is preferably 0.01 parts by mass or more from the viewpoint of the effect of improving transparency.

[0131] The crystallization speed parameter (t 1 / 2) of the polypropylene composition of the present application is preferably more than 1 second, and more preferably 2 seconds or more. If the amount of the crystallization nucleating agent is reduced, the crystallization speed decreases, and there is a tendency for (t 1 / 2) to increase. If (t 1 / 2) is greater than the above lower limit value, excellent thickness accuracy is easily obtained. In addition, the upper limit of (t 1 / 2) is not particularly limited, and is preferably around 5 seconds or less.

[0132] [Crystallization nucleating agent]

[0133] The blending amount of the above crystallization nucleating agent is preferably more than 0 parts by weight and 1.0 parts by weight or less, and is preferably 0.05 to 0.5 parts by weight, relative to 100 parts by weight of the polypropylene. The crystallization nucleating agent is an additive (transparent crystallization nucleating agent) used to control the size of the crystalline component in the resin to be small in order to improve transparency. The crystallization nucleating agent is not particularly limited, and a crystallization nucleating agent generally used in the field can be used, but it is preferably selected from nonanol-based crystallization nucleating agents, sorbitol-based crystallization nucleating agents, phosphate-based crystallization nucleating agents, trisaminobenzene derivative crystallization nucleating agents, carboxylic acid metal salt crystallization nucleating agents, and xylitol-based crystallization nucleating agents. As the nonanol-based crystallization nucleating agent, for example, 1,2,3-trideoxy-4,6:5,7-bis-[(4-propylphenyl)methylene]-nonanol can be exemplified. As the sorbitol-based crystallization nucleating agent, for example, 1,3:2,4-bis-o-(3,4-dimethylbenzylidene)-D-sorbitol can be exemplified. As the phosphate-based crystallization nucleating agent, for example, phosphoric acid-2,2'-methylenebis(4,6-di-t-butylphenyl) lithium salt-based crystallization nucleating agents can be exemplified.

[0134] [Other additives]

[0135] In a range that does not impair the effects of the present application, other additives than the crystallization nucleating agent can be contained in the polypropylene composition of the present application.

[0136] As examples of other additives, there can be mentioned antioxidants, neutralizing agents, chlorine absorbers, heat-resistant stabilizers, light stabilizers, ultraviolet absorbers, internal lubricants, external lubricants, antiblocking agents, antistatic agents, antifogging agents, flame retardants, dispersants, copper inhibitors, plasticizers, crosslinking agents, peroxides, oil extension (oil exudation), and other organic and inorganic pigments, and the like, which are generally used in polyolefins. The amounts of the respective additives to be added can be the amounts known per se.

[0137] [Preparation of polypropylene-based polymer or polypropylene composition]

[0138] The polypropylene-based polymer or polypropylene composition described in detail above can be prepared, for example, by Production Example 2 to Production Example 7 of Japanese Patent No. 6845001.

[0139] [Olefin-based resin film (B)]

[0140] The biaxially stretched olefin-based resin film (B) having a melting point of 110 to 160°C used in the production method of the laminate of the present application can be obtained by biaxially stretching an olefin-based resin or an olefin-based resin composition containing the olefin-based resin and an additive by a known method. For example, the above olefin-based resin or the like is extruded to obtain an unstretched sheet, and the sheet is biaxially stretched to obtain a biaxially stretched film. As described above, in the present application, it is preferable to produce a film and stretch it by a co-extrusion method together with other layers.

[0141] The olefin-based resin constituting the biaxially stretched olefin-based resin film (B) has a melting point of 110 to 160°C. Here, the melting point is a melting point determined using DSC at 30°C to 230°C at a temperature increase rate of 10°C / minute. If the melting point is in this range, the melting point is sufficiently lower than the polypropylene constituting the A layer, and thus the fusion property at the time of heat-pressing becomes good. Specifically, the olefin-based resin is preferably formed of a propylene homopolymer (HOMO), a propylene random copolymer (RACO) containing 5% by weight or less of at least one comonomer selected from C2 to C10-a-olefins (other than C3-a-olefins), or a resin composition containing the HOMO or the RACO. If the comonomer content is too small, the fusion property with the first layer is sometimes insufficient, and if it is too large, the rigidity of the laminate is sometimes reduced. From this viewpoint, the comonomer content is preferably more than 0% by weight and 4.5% by weight or less. As the comonomer, ethylene (C2-a-olefin) is preferable. The MFR (230°C, load 2.16 kg) of the polymer or the resin composition constituting the second layer is not limited, and is preferably 1 to 15 g / 10 minutes, more preferably 2 to 10 g / 10 minutes, and further preferably 3 to 8 g / 10 minutes.

[0142] The above olefin-based resin, etc. can contain a nucleating agent, or can be composed of a resin composition or a polymer not containing a nucleating agent. In the case of containing a nucleating agent, the amount of the nucleating agent is preferably 1 part by weight or less, relative to 100 parts by weight of the polymer forming the second layer, from the viewpoint of economy. Therefore, the biaxially stretched olefin-based resin film (B) is preferably composed of a resin composition containing HOMO and a nucleating agent, or a resin composition containing RACO and a nucleating agent.

[0143] The thickness of the above biaxially stretched olefin-based resin film is preferably 1 to 20 μm, and particularly preferably 2 to 10 μm, per layer.

[0144] [Modified olefin-based resin film (C)]

[0145] Next, the modified olefin-based resin film (C) can be obtained by biaxially stretching a modified olefin-based resin or an olefin-based resin composition containing the olefin-based resin and an additive, by a publicly known method. For example, the above modified olefin-based resin, etc. can be extruded to obtain an unstretched sheet, and the sheet can be biaxially stretched to obtain a biaxially stretched film, but as described above, in the present application, it is preferable to perform film formation and stretching by a co-extrusion method together with other layers.

[0146] The modified olefin-based resin constituting the biaxially stretched olefin-based resin film (B) can be exemplified by, for example, polypropylene having various functional groups such as a carboxyl group, an anhydride group, a sulfonic acid group, a phosphoric acid group, a phosphoric acid ester group, an imino group, an amino group, etc. in the molecular structure, and particularly preferably polypropylene having a carboxyl group, an anhydride group, an imino group, from the viewpoint of excellent adhesion to a printing layer or adhesion to other members.

[0147] As such a functional group-containing modified olefin, for example, "ADMER FILM QB515", "ADMER FILM QB 550", "ADMER FILM QB 515", "ADMER FILM QF 500", "ADMER FILM QF 551", "ADMER FILM QF 580", "ADMER FILM QE 840", and "ADMER FILM QE 060", etc. manufactured by Mitsui Chemicals, Inc. can be exemplified.

[0148] [Pressing step]

[0149] The step of heating and pressing the thus obtained laminated sheet precursor (pMS) can be performed by Method 1 or Method 2 described below, in detail.

[0150] [Method 1] Continuous pressure pressing method

[0151] Method 1 is a method having a process of continuously heating and pressing the laminated sheet precursor (pMS) using a flat mold using a continuous compression device, followed by a cooling press process. The flat mold refers to a mold having a flat contact surface.

[0152] In the case of using this method 1, it is preferable in terms of the surface state of the obtained laminated sheet becoming good, the surface unevenness such as so-called surface undulation, and the transparency of the laminated sheet itself being excellent.

[0153] Hereinafter, method 1 will be further described.

[0154] The continuous compression device used in method 1 is a compression device (CCM: continuous compression molding) having a continuous compression molding mechanism, having a plurality of heating and cooling regions, having a mechanism for heating and pressing the laminated sheet precursor (pMS) using upper and lower flat molds in the heating region, and a mechanism for subsequent curing by continuously cooling and pressing the laminated sheet using upper and lower flat molds in the cooling region.

[0155] By using such a continuous compression device, the design freedom of the size in the MD direction is improved. In addition, since it is continuously transferred from the heating region to the cooling region and pressed, a laminated sheet excellent in surface state, transparency in addition to uniformity of rigidity and strength can be obtained.

[0156] A specific method of pressing the laminated sheet precursor (pMS) using the above continuous compression device can be exemplified as follows: the laminated sheet precursor (pMS) is continuously or intermittently introduced into the gap between the upper and lower flat molds constituting the heating region in the continuous compression device, heated to 110 to 170°C while being pressed under a pressure of 1 to 40 MPa, then, after the press release, the sheet is fed out by a predetermined length in the predetermined travel direction, heated and pressed again, and this operation is repeated, whereby it is continuously or intermittently transferred from the heating region to the cooling region, and in the cooling region, it is pressed under a temperature condition of 25 to 125°C and a pressure condition of 1 to 40 MPa, pressure release, transfer, whereby the heat-fused laminated sheet is gradually discharged from the gap between the upper and lower flat molds. Here, in the cooling region, it is preferable to cure under a higher temperature condition, and the temperature condition of the cooling region is particularly preferably 60 to 125°C.

[0157] Here, the size (pitch) at which the laminated sheet is fed out at the time of press release is not particularly limited, and it is preferably in the range of 10 to 300 mm. In addition, from the viewpoint of uniformity of adhesion, the press release time is preferably 0.5 to 3 seconds.

[0158] To explain a press device (continuous press device) having a continuous press molding mechanism more specifically, as shown in Figure 1 the continuous press device 100 has an upper and lower pair of molds 2 formed in a planar shape. In the upper and lower portions of each of the upper and lower pair of molds 2, an upper and lower pair of heat plate / cooling plate modules 4 is provided, and the upper and lower pair of molds 2 can be heated / cooled. In addition, the upper flat plate-shaped mold is configured to be pressurized from above by a hydraulic cylinder 6, a lifting unit 8, and a lifting guide 10.

[0159] In addition, the front end of the mold unit in the traveling direction has an extraction unit 12 having a function of extracting a laminated sheet (MLS) by being movable forward and backward in the MD direction (machine direction).

[0160] Here, the upper and lower pair of molds 2 formed in a planar shape are thermally divided into a heating region and a cooling region with respect to the sheet traveling direction (MD direction), and are preferably also thermally divided in a direction (TD direction) orthogonal to the sheet traveling direction, for example, as shown in Figure 2 Note that, here, "thermally divided" does not necessarily mean that the temperature is set to be different, but can mean that the regions are divided in a manner in which the heat source is different.

[0161] As an example, for example, as shown in Figure 2 the regions H1 to H3 are heating regions, and C1 to C2 are cooling regions. In addition, with respect to the TD direction, an example in which the regions are thermally divided into five parts is shown.

[0162] Further, as an example in which the heating regions are divided into multiple segments, for example, an example in which Figure 3 can be given.

[0163] In Figure 3 , the regions H1 to H4 are heating regions, and C1 to C3 are cooling regions. Further, in the heating regions, the regions are thermally divided into four parts in the MD direction and are thermally divided into twelve parts in the TD direction, and in the cooling regions, the regions are thermally divided into three parts in the MD direction and are thermally divided into five parts in the TD direction.

[0164] In the present application, the number of segments in the MD direction of the above-described heating regions and cooling regions is appropriately selected according to the size of the laminated sheet (MLS) to be manufactured, and from the viewpoint of being able to manufacture a laminated sheet in which the thermal control becomes easy, the in-plane rigidity corresponding to the desired thickness is excellent, the uniformity of the physical properties is small, and further the surface smoothness is excellent, it is preferable that the heating regions be thermally divided into two to ten segments, preferably two to six segments, in the MD direction, and the cooling regions be thermally divided into one segment or two to five segments in the MD direction.

[0165] Here, the so-called thermal division is not only physically dividing the mold itself into individual parts, but also a planar metal plate that appears to be the same and is extended, and is in a state of being thermally controlled in a multi-stage manner by adjusting the temperature with the heater corresponding to each region.

[0166] As for the set temperature of each heating region, the temperature of the first heating region closest to the sheet inlet (insertion inlet) of the stretched film laminated in multiple layers can be set to 110 to 160°C, the second heating region can be set to +10 to +40°C relative to the set temperature of the first heating region, and the subsequent regions can be set to +0 to 30°C relative to the immediately preceding region, preferably a maximum of 170°C. On the other hand, the set temperature of the cooling region is preferably set to -30 to -60°C relative to the set temperature of the immediately preceding cooling region in the case where there is a continuous cooling region starting from the final heating region, further -2 to -10°C. In addition, the temperature of the final cooling region is preferably 25 to 125°C, and particularly preferably 60 to 125°C.

[0167] In addition, as described above, the laminated film inserted between the upper and lower molds 2 is pressed by the plurality of cylinders 6 provided on the upper side of the upper mold.

[0168] The pressing pressure at this time is preferably 1 to 40 MPa as described above, and the laminated sheet (MLS) is fed out at a predetermined width at the time of pressing release.

[0169] In addition, in order to improve the surface smoothness of the laminated sheet (MLS), it is preferable to interpose a sheet-shaped release material between the laminated sheet and the planar mold 2. As the sheet-shaped release material used here, for example, paper materials, polyethylene terephthalate sheets, polycarbonate sheets, polypropylene sheets, steel sheets, etc. can be mentioned, and from the viewpoint of being able to further improve the surface state of the laminated sheet, polycarbonate sheets and steel sheets are preferable.

[0170] The laminated sheet thus obtained moderately maintains the orientation of the polypropylene constituting each layer, and the interlayers are sufficiently fused, and the entire body becomes a laminated sheet with high rigidity, as described above, a laminated sheet with excellent uniformity of in-plane strength and small physical property unevenness, and in particular, exhibits the performance of having uniform strength in the TD direction when large-sized.

[0171] [Method 2] Single-piece pressing method

[0172] Next, the method 2 is a method of manufacturing the laminated sheet (MLS) of the present application by a single sheet press method, and specifically, has the following procedure: for the laminated sheet precursor (pMS), using a single sheet vacuum lamination device having a pair of metal plates with a face shape above and below in a chamber, loading the laminated sheet precursor (pMS) on the lower metal plate in the chamber, setting the chamber to a degree of vacuum of 170 Pa or less, and performing heat press, and after the press is released, clamping with a cooling metal plate.

[0173] Here, specifically, for example, as schematically shown in Figure 14 , in the chamber (202) of the single sheet vacuum lamination device (200), a film laminate in which a plurality of biaxially stretched films are laminated is installed between a pair of heat plates (204, 205) disposed above and below in the chamber, and then after the chamber (202) is closed, the heat plates (204, 205) are heated to a predetermined temperature and the inside is reduced in pressure, after which the cylinder (203) is pressurized, maintained for a predetermined time, then the inside is returned to normal pressure and the cylinder pressure is released, and the laminated sheet (MLS) is taken out. Next, a method in which the laminated sheet (MLS) is quickly transferred to Figure 15 the cooling device (300) shown in , clamped with a pair of cooling metal plates (301, 302) above and below, and cooled at room temperature can be cited.

[0174] The film laminate can be directly disposed in the chamber of the single sheet vacuum lamination device, but as shown in Figure 14 , it is preferable from the viewpoint of the surface state of the laminated sheet (MLS) being supplied to heating and pressurization in a state of being clamped with a stainless steel plate (s) on its upper and lower surfaces becoming good. Here, the stainless steel plate (s) clamping the film laminate is preferably 0.3 to 1 mm in thickness. Further, as shown in Figure 14 , a partition (d) can be clamped just below the upper heat plate, and in addition, a polytetrafluoroethylene sheet (pt) can be clamped between the heat plate and the stainless steel plate (s) for the purpose of heat plate protection.

[0175] The set temperature of the heat plate of the single sheet vacuum lamination device is preferably 140 to 155°C, and the pressure of the hydraulic cylinder is preferably 0.1 to 10 MPa.

[0176] By being manufactured by using such a single sheet press method, a laminated sheet that is more rigid and strong and whose uniformity is excellent can be obtained.

[0177] [Laminated sheet]

[0178] One example of the laminated sheet (MLS, 70) obtained by the above-described method 1 or method 2 is, for example, Figure 17As shown, the laminate sheet precursor (pMS) (60) including a plurality of multilayer biaxially-stretched films (X) (62, 64a, 64b) is laminated, and is welded at the boundary of B / B, as a result, the welded layer is integrated to constitute a b layer, as a result, a structure in which the a layer and the b layer are laminated with each other is obtained.

[0179] [Shaped product]

[0180] The shaped product in the present application is shaped from the laminate sheet (MLS) of the present application. By shaping the laminate sheet of the present embodiment, various shaped products can be obtained. As the shaping method, known press molding, hot plate molding, stretching molding, calender molding, deep drawing processing molding, pressure bonding molding, fusion bonding molding, vacuum molding, pressure air molding, vacuum pressure air molding, and the like can be exemplified.

[0181] In the present application, since it has an advantage that a large-area laminate sheet can be industrially produced, which has not been possible in the past, it is preferable to process various shaped products by press molding. The temperature conditions when the laminate sheet is subjected to secondary molding can be appropriately selected depending on the shape, the depth of deep drawing, and the like, and for example, it can be molded at a temperature of 100°C or higher and less than the melting point of the laminate sheet (MLS), and particularly, when molded into a deep-drawing shallow shaped product such as a mobile exterior material, a housing material, and the like, it can be molded at 120 to 150°C.

[0182] [Use of the laminate sheet]

[0183] The laminate sheet of the present application described in detail above has excellent rigidity as a plastic material, and can be widely used in industry as an aluminum alternative material, a CFRP alternative material, a steel sheet alternative material, and the like, and for example, automobile exterior materials, automobile interior materials, automobile structure materials, flying automobile exterior materials, building exterior wall materials, building interior materials, solar cell substrates, substrate sheets for flexible solar cells, quantum cloaking optical materials, logistics drone main materials, surfboards, wind power generation boards, ship exterior wall materials, lithium ion battery housing materials, electrode substrates for lithium ion batteries, hydrogen tank structure materials, food trays, medical trays, and the like can be exemplified.

[0184] For example, by being used as a main material for automobile exterior, in addition to being able to be recycled as a main material, it can be used as a non-painted automobile exterior material by adhering a decorative film to the polypropylene laminate sheet of the present application or by sandwiching the laminate sheet of the present application between layers.

[0185] In the case of using the decorative film, for example, as a substrate film, a decorative film can be produced by performing a corona treatment on the B layer surface or the C layer surface of the above-mentioned AB film, BAB film, BAC film and printing.

[0186] In this case, by adhering the printed surface of the decorative film to the laminated sheet of the present application, a decorative sheet with an excellent appearance can be produced. At this time, in the case where the printed layer is easily peeled off, the surface of the laminated sheet of the present application is subjected to a corona treatment, and the printed surface of the decorative film is overlaid and bonded to the printed surface of the laminated sheet in a manner that the printed surfaces contact each other, whereby peeling from the printed surface can be prevented well.

[0187] In addition, the hydrogen tank structure material can be used, for example, as a tank structure material for high-pressure hydrogen of Type 2 or Type 4.

[0188] (Solar cell sheet)

[0189] The solar cell sheet of the present application is produced by adhering a flexible solar cell module to the laminated sheet of the present application described above. The solar cell sheet of the present application can include a solar cell sheet produced by adhering a flexible solar cell module to the surface or back surface of the laminated sheet of the present application or sandwiching the flexible solar cell module with the laminated sheet of the present application from both surfaces and adhering it.

[0190] Here, as the flexible solar cell module described above, a film-shaped or sheet-shaped solar cell module such as a thin-film silicon type solar cell, an organic thin-film solar cell, a perovskite type solar cell, and the like can be included.

[0191] Figure 18 An embodiment of the solar cell sheet of the present application is shown. Figure 18 is a cross-sectional view schematically showing the cross section of the solar cell sheet of the present application, and has a structure in which a flexible solar cell module is sandwiched with the laminated sheet of the present application from both surfaces and adhered.

[0192] The solar cell sheet of the present application can achieve a sense of unity with the appearance of the adherend by, for example, pre-forming the laminated sheet of the present application in a manner along the shape of the wall surface of a building, a roof material, or the shape of a columnar structure, and can achieve a dramatic improvement in the aesthetic appearance in the state of solar installation compared to the conventional panel-shaped silicon type solar cell.

[0193] Further, in this case, the sense of unity with the adherend such as a building is improved, and thus the solar cell sheet can be stably fixed for a long period after installation, and can be used for a long period compared to the case where only a film-shaped solar cell module is adhered to an existing building.

[0194] Furthermore, the solar cell of the present invention is preferably used, for example, as a solar cell with an arched, single-curved surface. This arched, single-curved solar cell can be obtained, for example, by molding the laminate of the present invention into a single-curved surface with curvature in only one direction, then attaching a flexible solar cell module to the surface or back of the laminate, or by clamping the flexible solar cell module between two laminated sheets molded into a single-curved surface, or by attaching the flexible solar cell module to the laminate of the present invention and then bending it in one direction to fix it to the substrate. Such an arched, single-curved solar cell can extend the time for receiving sunlight more linearly, thereby increasing power generation.

[0195] The solar cell of the present invention can also be further three-dimensionally shaped. For example, a solar cell obtained by attaching a flexible solar cell module to the surface or back of the laminate of the present invention, particularly as... Figure 18 The solar cell, which is formed by clamping and bonding the flexible solar cell module from both sides with the laminated sheets of the present invention, can be three-dimensionally shaped to produce a solar cell of a desired shape.

[0196] Furthermore, the tandem wafers constituting the solar cell of the present invention exhibit a water vapor transmission coefficient of 0.10 to 0.13 cc·mm / m. 2 With a value of 25 h / atm lower than other materials, this laminate functions as a barrier substrate by applying barrier evaporation to the outermost surface as needed, thus exhibiting the durability and long-term reliability of a solar cell.

[0197] Furthermore, by providing a linear groove structure on the laminated sheet constituting the solar cell of the present invention, the rigidity and strength of the sheet itself can be significantly improved.

[0198] Next, the flexible solar cell constituting the solar cell of the present invention is particularly preferably a perovskite solar cell. Perovskite solar cells are lightweight, highly flexible, and have strong strain resistance, making them suitable for various structures. Furthermore, in addition to generating electricity even in low light conditions, they offer advantages such as lower limitations in terms of placement, considering locations with good sunlight and orientation. On the other hand, due to their flexibility, besides poor workability when installed on building walls and roofs, there are concerns that they may easily peel off during storms such as typhoons or earthquakes when simply bonded to walls with adhesives. Therefore, how to stably and permanently fix the lightweight, film-like solar cell, which is not inherently suitable for specific installation locations, to the bonded structure becomes a challenge.

[0199] Therefore, by using the laminated sheet of the present invention as a support sheet for perovskite solar cell films, it can be stably fixed to buildings and the like for a long period of time.

[0200] Here, the method of fixing the solar cell sheet of the present application to a building or the like can be exemplified by a method of fixing by fitting the end of the sheet into a predetermined shape and fitting into a structure, a method of fixing by screw fastening, a method of fixing by using a sealing material, and a method of fixing by bonding to an adherend using an adhesive.

[0201] Further, a method of using the above-mentioned laminated sheet itself as a structural material such as an exterior wall material or a roof material can be exemplified. Here, Figure 19 An example of using the above-mentioned laminated sheet as a solar cell integrated carport is shown.

[0202] Here, as a method of manufacturing the solar cell sheet of the present application using a film-shaped perovskite solar cell, the following methods can be exemplified.

[0203] 1. A method of shaping the laminated sheet according to the shape of the adherend structure or into a desired shape as needed, and then attaching a perovskite solar cell film to the surface or back of the shaped product;

[0204] 2. A method of attaching a perovskite solar cell film to the surface or back of the laminated sheet, and then shaping it into a predetermined shape;

[0205] 3. A method of shaping the laminated sheet according to the shape of the adherend structure or into a desired substantially same shape as needed, preparing two pieces, and then sandwiching from the upper surface side and lower surface side of the perovskite solar cell film using these shaped products;

[0206] 4. A method of attaching the laminated sheet to the upper surface and lower surface of the perovskite solar cell film, and shaping it into a predetermined shape;

[0207] 5. A method of sandwiching the perovskite solar cell film between the layers of the above-mentioned precursor (pMS) and heat welding, thereby forming a perovskite solar cell sheet in which the perovskite solar cell film is embedded, and shaping it by press molding or the like.

[0208] Here, in the case of manufacturing the solar cell sheet of the present application by the method of the above-mentioned 5., since the solar cell unit is completely embedded in the laminated sheet of the present application, moisture and water can be completely blocked, and deterioration due to moisture can be prevented well.

[0209] The solar cell molded body thus obtained can be used for a car roof material, a solar carport, a balcony parapet, a residential roof material, or the like.

[0210] Example

[0211] Hereinafter, the present application will be described in detail by way of examples, but the present application is not limited thereto.

[0212] (Preparation of raw materials)

[0213] Using the following polypropylene Al (melting point 163°C, MFR 4 g / 10 minutes, ethylene content 0.2 mass%, Mw / Mn = 9, xylene insoluble content 98.2 mass%, mmmm = 98.3, nucleating agent content 0.05 mass%, t 1 / 2: 2.3 seconds) and the following ethylene-propylene random copolymer Bl (melting point 153°C, MFR 5 g / 10 minutes) or ethylene-propylene random copolymer B2 (melting point 137°C, MFR 7.5 g / 10 minutes), a co-extruded sheet of the following layer constitution was obtained by a T-die molding machine, and then a biaxially stretched film stretched to a predetermined stretch ratio by a biaxial stretching device was used.

[0214] [BAB co-extruded film 1]

[0215] 2 kinds of 3-layer co-extruded films of layer constitution B / A / B (thickness: 50 μm, thickness ratio of B / A / B: 5 / 90 / 5, stretch ratio: 5 x 9 times)

[0216] A: polypropylene Al

[0217] B: ethylene-propylene random copolymer Bl

[0218] [BAB co-extruded film 2]

[0219] 2 kinds of 3-layer co-extruded films of layer constitution B / A / B (thickness: 200 μm, thickness ratio of B / A / B: 5 / 90 / 5, stretch ratio: 3.5 x 3.5 times)

[0220] A: polypropylene Al

[0221] B: ethylene-propylene random copolymer B2

[0222] [BAA co-extruded film 1]

[0223] 2 kinds of 3-layer co-extruded films of layer constitution B / A / A (thickness: 50 μm, thickness ratio of B / A / A: 5 / 90 / 5, stretch ratio: 5 x 9 times)

[0224] A: polypropylene Al

[0225] B: ethylene-propylene random copolymer Bl

[0226] [BAA co-extruded film 2]

[0227] 2 kinds of 3-layer co-extruded films of layer constitution B / A / A (thickness: 50 μm, thickness ratio of B / A / A: 5 / 90 / 5, stretch ratio: 3.5 x 3.5 times)

[0228] A: polypropylene Al

[0229] B: Ethylene-propylene random copolymer B2

[0230] (Evaluation)

[0231] (Tensile Test)

[0232] The tensile elastic modulus was measured in accordance with JIS K 7161 under the following conditions to measure the x-direction and y-direction tensile elastic modulus of each of (1), (2), and (3) of Example 12. Note that in Example 4, the MD direction of the raw material film was set as the x-direction. Figure 5 6

[0233] • Apparatus used: AUTOGRAPH AG-X plus (manufactured by Shimadzu Corporation)

[0234] • Test piece: Figure 7 (a) dumbbell-shaped test piece (Dumbbell No. 1) shown below

[0235] • Distance between chucks: 100 mm

[0236] • Test speed: 1 mm / min

[0237] • Stroke: 1 mm

[0238] • Elastic modulus calculation method: gradient of 2 points at strokes of 0.05 mm and 0.25 mm

[0239] • Draw start point: 3 N

[0240] (Bending Test)

[0241] The tensile elastic modulus was measured in accordance with JIS K 7171 under the following conditions to measure the TD direction (x-direction) and MD direction (y-direction) bending elastic modulus of each of (1), (2), and (3) of Example 12. Note that in Example 4, the MD direction of the raw material film was set as the x-direction. Figure 5

[0242] • Apparatus used: AUTOGRAPH AG-X plus (manufactured by Shimadzu Corporation)

[0243] • Test piece: Figure 7 (b) 150 x 25 mm long test piece shown below

[0244] • Distance between lower supports: 47 mm

[0245] • Test speed: 1.26 mm / min

[0246] • Stroke: 1 mm

[0247] ​​​• Elastic modulus calculation method: gradient of 2 points of stroke 0.05 mm and 0.25 mm

[0248] • Draw acquisition start point: 3 N

[0249] Evaluation of surface state

[0250] The test pieces for evaluation of surface state were cut out at positions indicated by positions of α, β, and γ described below. Figure 8 Figure 9 or Figure 13 The size of the test pieces is indicated below. Figure 10

[0251] Note that the method of determining each of the positions of α, β, and γ and the method of collecting each test piece are the same as those described above in (Laminated sheet).

[0252] The arithmetic surface roughness (Ra) was measured in accordance with JIS2001 under the following conditions.

[0253] • Apparatus used: Surftest SJ-400 (manufactured by Mitutoyo)

[0254] • Test speed: 1 mm / min

[0255] • Filter: GAUSS

[0256] • λc (cut-off parameter of undulation): 8 mm

[0257] • λs (cut-off parameter of noise): 25 μm

[0258] • Measurement speed: 1 mm / s

[0259] • Evaluation length: 16.0 mm

[0260] • Tip end radius: 2 μm

[0261] • Tip end accuracy: 60°

[0262] The size of the test pieces and the measurement position are indicated below. Figure 10

[0263] (Example 1)

[0264] As a preparation step, 48 pieces of the above-mentioned BAB co-extruded film 1 were overlapped, and 48 pieces of the BAA film 1 were overlapped in such a manner that the A layer becomes the surface on both surfaces thereof to obtain a precursor (pMS1). Next, the precursor was inserted into a pressurizing device having a continuous press molding mechanism indicated below, and press molding, pressure release, and laminated sheet delivery were repeatedly performed continuously. Figure 1

[0265] Note that the temperature setting of the upper and lower molds in the pressurizing device is as follows.​​​​Figure 4 The pressure was 30 MPa for the cylinder pressure of the 4-cylinder, the pressing time was 5 seconds, and the sheet delivery length at the time of pressure release was 25 mm.

[0266] Thus, a transparent laminate sheet (MLS) of 595 x 1500 mm and 2.5 mm in thickness was obtained. Figure 5

[0267] From the obtained transparent laminate sheet, dumbbell-shaped test pieces for tensile testing and long strip-shaped test pieces for bending testing were cut out from the positions indicated by Figure 5 The results are shown in Table 1.

[0268] In addition, from the obtained laminate sheet, test pieces for surface state evaluation were cut out from the positions indicated by Figure 8 The results are shown in Table 2.

[0269] (Example 2)

[0270] A precursor (pMS2) was obtained in the same manner as in Example 1, except that the BAB film 1 and the BAA film 1 were 700 mm in width.

[0271] Next, the lamination was performed in the same manner as in Example 1, except that the temperature settings of the upper and lower molds in the pressurizing device were set as indicated by Figure 11

[0272] Thus, a transparent laminate sheet (MLS) of 700 x 1500 mm and 2.5 mm in thickness was obtained. Figure 12

[0273] From the obtained transparent laminate sheet (MLS), dumbbell-shaped test pieces for tensile testing and long strip-shaped test pieces for bending testing were cut out from the positions indicated by Figure 12 The results are shown in Table 1.

[0274] In addition, from the obtained laminate sheet, test pieces for surface state evaluation were cut out from the positions indicated by Figure 13 The results are shown in Table 2.

[0275] (Example 3)

[0276] As a preparation step, 15 sheets of the BAB co-extruded film 2 were overlapped, and the AAB film 2 (200 μm in thickness) was overlapped on both surfaces thereof in a manner in which the A layer becomes the surface, and the operation was performed in the same manner as in Example 1, except for this, to obtain a precursor (pMS3).​​​

[0277] Next, the temperature of the upper and lower molds in the pressurizing device is set to... Figure 16 Under the conditions shown, except for the conditions described, the bonding was performed in the same manner as in Example 1 to obtain a transparent laminated sheet measuring 700 × 1500 mm and 3 mm in thickness. From the obtained transparent laminated sheet, from Figure 12 Dumbbell-shaped test pieces for tensile testing and strip-shaped test pieces for bending testing were cut from the specified locations. The mechanical properties were evaluated using the testing methods described in the <Tensile Test> and <Bending Test> sections above. The results are shown in Table 1.

[0278] (Example 4)

[0279] Forty sheets of BAB co-extruded film 1 are overlapped, and BAA film 1 is overlapped with layer A as the surface on both sides, and then cut into 700×700mm sizes. Here, the above-mentioned B / A / B co-extruded film and B / A co-extruded film are stacked with the MD direction aligned with the TD direction.

[0280] use Figure 14 The chamber of the single-piece vacuum bonding device shown Figure 15 The cooling device shown is bonded together. The bonding conditions are as follows.

[0281] upper heating plate temperature 150℃

[0282] Lower heating plate temperature 145℃

[0283] Vacuuming time 120 seconds

[0284] Pressurization time: 300 seconds

[0285] Hold for 300 seconds

[0286] Hot plate pressing time: 300 seconds

[0287] Hot plate pressing pressure: 0.3 MPa

[0288] Composition during lamination

[0289] From top to bottom, PTFE sheet / SUS board / laminated sheet / materials on SUS board / PTFE sheet

[0290] From the obtained transparent laminate, from Figure 6 Dumbbell-shaped test pieces for tensile testing and strip-shaped test pieces for bending testing were cut from the specified locations. Mechanical properties were evaluated using the measurement methods described in the <Tensile Test> and <Bending Test> sections above. Here, the MD direction of each film of the raw material was taken as the x-direction, and the TD direction as the y-direction for various evaluations. The results are shown in Table 1.

[0291] In addition, the obtained laminated sheets are as followsFigure 9 The test piece for evaluating the state of the position cut surface was used to evaluate the surface state using the measurement method described in the above <Evaluation of the surface state>. The results are shown in Table 2.

[0292] (Comparative Example 1)

[0293] A precursor (pMS1) having the same configuration as that of Example 1 and cut to 400 x 400 mm was used to attempt lamination using a roll forming machine (dielectric heating jacket roll, Model "JR-D0-W" by TOKUDEN Co., Ltd., roll diameter 400 mm, roll face length 400 mm). Roll face length 400 mm)

[0294] Heating roll temperature 165°C

[0295] Heating roll forming draw speed 0.8 m / min

[0296] Preheating roll: 130 to 155°C

[0297] However, in the resulting laminated sheet, the portions where air was sucked in and lamination failed were scattered throughout, and in addition, warping and undulations were generated. Further, the heating roll forming draw speed was reduced and lamination was attempted again, but wrinkles were generated in the surface layer due to the influence of the radiant heat from the heating roll, and a smooth laminated sheet could not be obtained.

[0298] [Table 1]

[0299]

[0300] [Table 2]

[0301]

[0302] Explanation of Reference Signs

[0303] 2: mold, 4: hot plate / cold plate module, 6: hydraulic cylinder, 8: lifting unit, 10: lifting guide, 12: lead-out unit, 20: product travel direction, 60: laminated sheet precursor (pMS), 62: multilayer biaxially stretched film (X), 64a: multilayer biaxially stretched film (X), 64b: multilayer biaxially stretched film (X), 100: continuous pressing device, 200: single-sheet vacuum lamination device, 201: device main body, 202: chamber, 203: hydraulic cylinder, 204: hot plate, 205: hot plate, 300: cooling device, 301: cooling metal plate, 302: cooling metal plate, d: partition, s: stainless steel plate, sl: silicon sheet, pt: polytetrafluoroethylene sheet, MLS, 70: laminated sheet, PV: flexible solar cell module, 400: solar cell sheet, 500: solar cell integrated carport.

Claims

1. A laminated sheet having a structure in which a layer a composed of a biaxially-stretched polypropylene film and a layer b composed of an olefin-based resin having a melting point of 110 to 160°C are alternately laminated, characterized in that, when one edge direction of the laminated sheet is set as an x direction and a direction orthogonal thereto is set as a y direction, the tensile elastic modulus in the x direction and the y direction at three positions including a center position in the y direction and two positions through the center position and located 200 mm from the center position in the y direction are in the range of 2000 to 5000 MPa.

2. The laminated sheet according to claim 1, wherein, when a 595 mm x 595 mm square is drawn so that a diagonal intersection point becomes a center position in a TD direction, the diagonal intersection point is set as a, an intermediate position from the intersection on the diagonal to a corner is set as β, and the corner is set as γ, when the surface roughness at each of the positions of a, β, and γ is set as Ra(a), Ra(β), and Ra(γ), Ra(a), Ra(β), and Ra(γ) satisfy the following equations (1) and (2), Ra(a) - Ra(β) < 0.3 (1) Ra(a) - Ra(γ) < 0.3 (2) wherein Ra(a), Ra(β), and Ra(γ) are each an average value of the surface roughness when a test piece a, a test piece β, and a test piece γ are cut out in a long strip shape with the x direction as a long side from the positions of a, β, and γ, and the surface roughness is measured at two positions in each test piece, i.e., average roughness.

3. The laminated sheet according to claim 1 or 2, wherein the laminated sheet is formed by overlapping and heat-welding a plurality of biaxially-stretched films (X) in which a biaxially-stretched polypropylene film (A) constituting the layer a and a biaxially-stretched olefin-based resin film (B) constituting the layer b on at least one surface thereof are laminated, and the biaxially-stretched film (X) has a stretch ratio of 2.8 to 8 times in the MD direction and a stretch ratio of 2.8 to 12 times in the TD direction.

4. The laminated sheet according to claim 3, wherein the biaxially-stretched film (X) is a BAB-type film in which the biaxially-stretched olefin-based resin film (B) is contained on both surfaces of the biaxially-stretched polypropylene film (A), and has a thickness of 30 to 80 μm, and the laminated sheet is formed by laminating the BAB-type film 30 to 60 times and laminating a BA-type film or a BAA-type film with A as a surface on both surfaces thereof.

5. The laminated sheet according to claim 4, wherein the biaxially-stretched film (X) is a BAB-type film in which the biaxially-stretched olefin-based resin film (B) is contained on both surfaces of the biaxially-stretched polypropylene film (A), and has a thickness of 100 to 400 μm, and the laminated sheet is formed by laminating the BAB-type film 2 to 20 times and laminating a BA-type film or a BAA-type film with A as a surface on both surfaces thereof.

6. A molded article of the laminated sheet according to claim 1 or 2. including: ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 7. A method for manufacturing a laminate sheet, which is a method for manufacturing a laminate sheet having a structure in which a layer a composed of a biaxially-stretched polypropylene film and a layer b composed of an olefin-based resin having a melting point of 110 to 160°C are alternately laminated, characterized by comprising: ​ a preparation step of stacking a plurality of multilayer biaxially-stretched films (X) to form a stacked sheet precursor (pMS), the multilayer biaxially-stretched film (X) being formed by stacking a biaxially-stretched polypropylene film (A) constituting the a layer and a biaxially-stretched olefin-based resin film (B) constituting the b layer on at least one surface thereof; and a pressing step of performing heat pressing on the stacked sheet precursor (pMS) while heating the same.

8. A method for manufacturing a laminate sheet, which is a method for manufacturing a laminate sheet in which a layer a composed of a biaxially-stretched polypropylene film and a layer b composed of an olefin-based resin having a melting point of 110 to 160°C are alternately laminated, characterized by comprising: has: a preparation step of stacking a plurality of multilayer biaxially-stretched films (X) to form a stacked sheet precursor (pMS), the multilayer biaxially-stretched film (X) being formed by stacking a biaxially-stretched polypropylene film (A) constituting the a layer and a biaxially-stretched olefin-based resin film (B) constituting the b layer on at least one surface thereof; and a pressing step of continuously performing heat pressing on the stacked sheet precursor (pMS) using a continuous pressing device, followed by cooling, the continuous pressing device having a plurality of heating zones and a cooling zone, in which the stacked sheet precursor (pMS) is heat-pressed using upper and lower planar molds in the heating zones, followed by continuously pressing the stacked sheet precursor (pMS) using upper and lower planar molds in the cooling zone.

9. The method of manufacturing a stacked sheet according to claim 8, wherein the stacked sheet precursor (pMS) is inserted between the upper and lower planar molds constituting the heating zones in the continuous pressing device, the pressing is performed at a temperature of 110 to 170°C and a pressure of 1 to 40 MPa, followed by, after the pressing is released, feeding the sheet by a predetermined length in the running direction, i.e., the MD direction, and again performing heat pressing and pressing, and the above operations are repeated to continuously transfer the stacked sheet from the heating zones to the cooling zone, followed by, in the cooling zone, performing pressing at a temperature of 25 to 125°C and a pressure of 1 to 40 MPa, followed by, after the pressing is released, feeding the sheet by a predetermined length in the running direction, i.e., the MD direction, and continuously taking out the stacked sheet after heat fusion.

10. The method of manufacturing a laminated sheet according to claim 9, wherein has the following structure: the heating zones are divided into 2 to 10 zones in the MD direction and are composed of molds having planar contact surfaces in a manner of sandwiching the sheet therebetween, and the cooling zone is divided into 1 zone or 2 to 5 zones in the MD direction and is composed of molds having planar contact surfaces in a manner of sandwiching the sheet therebetween.

11. The method of manufacturing a stacked sheet according to claim 9 or 10, wherein the temperature conditions of the heating zones divided into 2 to 10 zones in the MD direction are such that the temperature of the first heating zone closest to the inlet of the sheet is 110 to 160°C, the temperature of the second heating zone following the first heating zone is +10 to +40°C relative to the set temperature of the first heating zone, and the maximum temperature of the heating zones is 170°C.

12. The method of manufacturing a stacked sheet according to claim 7 or 8, wherein the multilayer biaxially-stretched film (X) has a stretch ratio of 2.8 to 8 times in the MD direction and a stretch ratio of 2.5 to 12 times in the TD direction.

13. The method of manufacturing a stacked sheet according to claim 12, wherein The multilayer biaxially stretched film (X) is a BAB type film in which the biaxially stretched polypropylene film (A) is bonded to both surfaces of the biaxially stretched olefin-based resin film (B), and the thickness of the biaxially stretched polypropylene film (A) is 30 to 80 μm, The laminate precursor (pMS) is obtained by laminating 30 to 60 of the BAB type film and laminating a BA type film or a BAA type film on both surfaces thereof with the A surface on the outside.

14. The laminate manufacturing method according to claim 7, wherein The laminate precursor (pMS) is placed on the lower metal plate in the chamber using a single-chip vacuum lamination device having metal plates with a flat surface on the upper and lower sides, the chamber is set to a vacuum degree of 170 Pa or less, and heating and pressing are performed, after which the laminate is released and clamped with a cooling metal plate.

15. The laminate manufacturing method according to claim 14, wherein The heating and pressing is performed at a metal plate temperature of 140 to 160°C and a cylinder pressure of 0.1 to 1 MPa.

16. A solar cell sheet obtained by laminating a flexible solar cell module to the laminate according to claim 1 or 2.

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