Film-bonded resin plate and method for manufacturing film-bonded resin plate

Abstract

To prevent bubble formation between a resin plate and a functional film, which is caused by vaporization of moisture contained in the resin plate or an adhesive.SOLUTION: A film-bonded resin plate 10 includes a laminate 12 having: a resin plate 11 made of polycarbonate; a functional film 31; and an adhesive 21 that forms a layer interposed between the resin plate 11 and the functional film 31, and that bonds the functional film 31 to a first main surface 11a of the resin plate 11. The adhesive 21 has an adhesive force higher than the saturated water vapor pressure at a first upper limit temperature, which is the upper limit of a heat-resistance temperature required in the use environment of the film-bonded resin plate 10.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a film-laminated resin plate and a method for manufacturing a film-laminated resin plate. [Background technology]

[0002] A film-laminated resin plate is manufactured, for example, by laminating a functional film having functions such as heat insulation and gas barrier properties on the surface of a resin plate. A resin plate made of, for example, polycarbonate is known. The functional film is laminated on one side of the resin plate by an adhesive layer. A method for manufacturing a film-laminated resin plate is disclosed, for example, in Patent Document 1. In the method disclosed in Patent Document 1, an adhesive is first interposed between the resin plate and the functional film to manufacture a laminate in which the resin plate, the adhesive layer, and the functional film are laminated in this order. This laminate is pressed to manufacture a laminate in which the resin plate and the functional film are laminated by the adhesive. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2013-4902 A Summary of the Invention [Problem to be solved by the invention]

[0004] Depending on the type of adhesive used in the film-laminated resin plate, the adhesive strength between the resin plate and the functional film may decrease when the film-laminated resin plate is used in a high-temperature environment. If the adhesive strength decreases in this way, air bubbles may be generated between the resin plate and the functional film, which is undesirable. [Means for solving the problem]

[0005] The film-laminated resin plate for solving the above problems is a film-laminated resin plate including a laminate having a resin plate made of polycarbonate, a functional film, and an adhesive that forms a layer between the resin plate and the functional film and bonds the functional film to one side of the resin plate, and is characterized in that the adhesive has an adhesive strength higher than the saturated water vapor pressure at a first upper limit temperature, which is the upper limit of the heat resistance temperature required in the usage environment of the film-laminated resin plate.

[0006] To solve the above problems, a method for manufacturing a film-laminated resin plate includes a laminate having a resin plate made of polycarbonate, a functional film, and an adhesive that forms a layer between the resin plate and the functional film and bonds the functional film to one side of the resin plate, and is characterized in that the adhesive has an adhesive strength higher than the saturated water vapor pressure at a first upper limit temperature, which is the upper limit of the heat resistance temperature required in the usage environment of the film-laminated resin plate.

[0007] According to the above configuration and method, even if the temperature of the film-laminated resin plate reaches the first upper limit temperature, which is the upper limit of the heat resistance temperature required in the usage environment of the film-laminated resin plate, the moisture contained in the resin plate or the adhesive is unlikely to evaporate. Therefore, it is possible to suppress the generation of air bubbles between the resin plate and the functional film caused by the evaporation of the moisture contained in the resin plate or the adhesive.

[0008] The manufacturing method for a film-laminated resin plate may include a curving step of curving the laminate while heating it, and the adhesive may have an adhesive strength higher than the saturated water vapor pressure at a second upper limit temperature, which is the upper limit temperature of the laminate in the curving step and is higher than the first upper limit temperature.

[0009] According to the above method, even if the temperature of the film-laminated resin plate reaches the second upper limit temperature, which is the upper limit of the temperature of the laminate in the bending process, the moisture contained in the resin plate and the adhesive is unlikely to evaporate. Therefore, even when bending the film-laminated resin plate, it is possible to suppress the generation of air bubbles between the resin plate and the functional film caused by the evaporation of the moisture contained in the resin plate and the adhesive. Effect of the Invention

[0010] According to this invention, it is possible to suppress the generation of air bubbles between the resin plate and the functional film, which is caused by evaporation of moisture contained in the resin plate or adhesive. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is a cross-sectional view showing a film-laminated resin plate. [Diagram 2] FIG. 2 is a schematic side view for explaining the peel test. [Diagram 3] FIG. 3 is a schematic top view for explaining the peel test. [Figure 4] FIG. 4 is a table showing the adhesive strength and bubble test results of the adhesive. [Diagram 5] FIG. 5 is a graph showing the relationship between temperature and saturated water vapor pressure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the film-laminated resin plate and the manufacturing method thereof will be described with reference to the drawings. The film-laminated resin plate is useful for various applications such as automobile parts, electronic devices, office automation equipment, machine parts, agricultural materials, fishing materials, transport containers, packaging containers, play equipment, and miscellaneous goods. The film-laminated resin plate in this embodiment is exemplified as a vehicle window member as an automobile part. Specific examples of vehicle window members include a back door window, a sunroof, and a roof panel. The film-laminated resin plate has a three-dimensional shape.

[0013] <Film-laminated resin plate> 1, the film-laminated resin plate 10 includes a laminate 12 having a resin plate 11, a functional film 31, and an adhesive 21. The adhesive 21 is in the form of a layer interposed between the resin plate 11 and the functional film 31.

[0014] <Resin plate> The resin plate 11 is made of polycarbonate. The resin plate 11 is manufactured by, for example, extrusion molding or injection molding. The resin plate 11 has a first main surface 11a and a second main surface 11b which are opposite to each other in the plate thickness direction. Of the first main surface 11a and the second main surface 11b, the first main surface 11a is a surface facing the outside of the vehicle in the vehicle window member in which the film-laminated resin plate 10 is used, and the second main surface 11b is a surface facing the inside of the vehicle in the vehicle window member.

[0015] <Functional films> Examples of the types of functional film 31 include a heat ray reflection film, a barrier film, a light control film, a Low-E film, a conductive film-forming film, a screen film, a perovskite solar cell, etc. In short, the type of functional film 31 is not limited as long as the functional film 31 imparts a function to the resin plate 11 by being attached to the resin plate 11.

[0016] <Adhesive> The adhesive 21 bonds the functional film 31 to the first main surface 11a, which is one side of the resin plate 11. In other words, the functional film 31 is bonded to the first main surface 11a of the resin plate 11 by the adhesive 21.

[0017] The adhesive 21 is made of, for example, a thermosetting resin. For example, the adhesive 21 is made of an epoxy resin as a main component. The adhesive 21 may be made of only an epoxy resin, or may be made of a resin other than an epoxy resin as a main component. The epoxy resin may be a one-liquid type or a two-liquid type. Examples of resins other than the epoxy resin include polyurethane resin, acrylic resin, and polyester resin. The adhesive 21, which is a thermosetting resin, is softened by heating and then hardened by a crosslinking reaction. Such adhesive 21 is provided in advance on the entire surface of one side of the functional film 31 before being attached to the resin plate 11. Therefore, the functional film 31 before being attached to the resin plate 11 has the adhesive 21 integrally therewith. The adhesive 21, which is a thermosetting resin, does not generate adhesive force at room temperature and can be deformed integrally with the functional film 31. In addition, when the adhesive 21, which is a thermosetting resin, is heated to a predetermined temperature, the adhesive 21 begins to generate adhesive force. As the adhesive 21 is heated further, the cross-linking reaction progresses, and the adhesive 21 strongly bonds the objects together.

[0018] Although not shown, at least one surface in the stacking direction of the laminate 12 may be provided with a hard coat or a decorative layer. Examples of the decorative layer include a decorative layer having good adhesion to resin, such as black printing. When only one of the hard coat and the decorative layer is provided on the laminate 12, the one surface in the stacking direction of the laminate 12 corresponds to the second main surface 11b of the resin plate 11. The other surface in the stacking direction of the laminate 12 corresponds to the surface of both sides of the functional film 31 on which the adhesive 21 is not provided. When both the hard coat and the decorative layer are provided on the laminate 12, for example, the decorative layer may be provided on the hard coat. In this case, for example, the one surface in the stacking direction of the laminate 12 corresponds to the surface of the hard coat provided on the second main surface 11b of the resin plate 11. The other surface in the stacking direction of the laminate 12 corresponds to the surface of the hard coat provided on the functional film 31.

[0019] <Adhesive strength> The adhesive 21 has an adhesive strength higher than the saturated water vapor pressure at a first upper limit temperature T1. The first upper limit temperature T1 is the upper limit of the heat resistance temperature required in the usage environment of the film-laminated resin plate 10. In this embodiment, it is the upper limit of the heat resistance temperature required in the driving environment of the vehicle in which the film-laminated resin plate 10 is used. The first upper limit temperature T1 is, for example, 120°C.

[0020] Moreover, the adhesive 21 in this embodiment has an adhesive strength higher than the saturated water vapor pressure at a second upper limit temperature T2 higher than the first upper limit temperature T1. The second upper limit temperature T2 is the upper limit of the temperature of the laminate 12 in a bending process described below that is performed when manufacturing the film-laminated resin plate 10. The second upper limit temperature T2 is, for example, 150°C.

[0021] <Manufacturing method of film-laminated resin plate> The manufacturing method of the film-laminated resin plate 10 is a method of manufacturing the laminate 12 by laminating a functional film 31 having an adhesive 21 to a first main surface 11a, which is one surface of the resin plate 11. Then, the thermosetting adhesive 21 of the laminate 12 is cured, thereby completing the film-laminated resin plate 10.

[0022] The manufacturing method of the film-laminated resin plate 10 in this embodiment includes a lamination step. In the lamination step, for example, first, at least one of the resin plate 11 and the functional film 31 integrated with the adhesive 21 is heated. While performing such heating, the functional film 31 is laminated to the first main surface 11a of the resin plate 11. Thereby, in the lamination step, a laminate 12 in which the adhesive 21 is interposed between the resin plate 11 and the functional film 31 is manufactured. Note that the manufacturing method of the film-laminated resin plate 10 does not have to include the lamination step. In this case, the film-laminated resin plate 10 is manufactured using the laminate 12 that has already been manufactured.

[0023] The manufacturing method of the film-laminated resin plate 10 includes a bending process. The bending process is a process of bending the laminate 12 while heating it. In detail, in the bending process, the laminate 12 is deformed so that the laminate 12 is curved in the plate thickness direction of the resin plate 11 while heating it. At this time, the laminate 12 may be supported by a support member (not shown) from both sides in the stacking direction. This support member may apply pressure to the laminate 12 in the stacking direction. In the bending process, the temperature of the laminate 12 is set to a temperature at which the resin plate 11, which is polycarbonate, can be deformed. This temperature is set to, for example, 120°C or higher and 150°C or lower.

[0024] In the bending process, the laminate 12 is bent while being heated, so that the laminate 12 is bent in a state in which the functional film 31 is bonded to the first main surface 11a of the resin plate 11. When the bending process is completed, a film-laminated resin plate 10 having a curved shape is manufactured. Thereafter, the thermosetting adhesive 21 of the laminate 12 is cured, so that the film-laminated resin plate 10 in a curved state is completed. This film-laminated resin plate 10 is used as a window member for a vehicle.

[0025] <Comparison with Comparative Examples> The inventors conducted a peel test on a number of thermosetting test adhesives. This test was conducted using five types of thermosetting adhesives, namely, Adhesive A, Adhesive B, Adhesive C, Adhesive D, and Adhesive E, as the test adhesives. Adhesive A and Adhesive B are thermosetting adhesives made of epoxy resin. Adhesive C is a thermosetting adhesive made of polyester resin. Adhesive D and Adhesive E are thermosetting adhesives made of acrylic resin.

[0026] As shown in Fig. 2 and Fig. 3, the peel test was performed using a test laminate 112 having a test resin plate 111, a test functional film 131, and a test adhesive 121. The test adhesive 121 is a layer interposed between the test resin plate 111 and the test functional film 131. The test resin plate 111 has a test first main surface 111a as one surface and a test second main surface 111b as the other surface. The test adhesive 121 adheres the test functional film 131 to the test first main surface 111a, which is one surface of the test resin plate 111.

[0027] In the test laminate 112 used in the peel test, the test resin plate 111 was the same as the above-mentioned resin plate 11 except for the shape. The test functional film 131 was the same as the above-mentioned functional film 31 except for the shape. Then, the peel test was performed on each of the test laminates 112 using adhesive A, adhesive B, adhesive C, adhesive D, and adhesive E as the test adhesive 121.

[0028] In the test laminate 112 used in the peel test, the test resin plate 111, the test functional film 131, and the test adhesive 121 are each a rectangular flat plate. The test resin plate 111, the test functional film 131, and the test adhesive 121 have the same width W. The width W is, for example, the dimension in the direction in which the short edge of each of the test resin plate 111, the test functional film 131, and the test adhesive 121 extends. For example, the width W is 10 mm.

[0029] In the peel test, for example, as shown by the white arrows in Fig. 2, the test resin plate 111 and the test functional film 131 were first pulled in opposite directions in the direction in which their long edges extend. Then, after increasing the load pulling the test functional film 131, the load acting on the test functional film 131 was measured at the time when the test functional film 131 peeled off from the test resin plate 111. The magnitude of the load thus measured was taken as the adhesive strength of each of the adhesives A, B, C, D, and E. Note that this adhesive strength is the load (N) when the width W is 10 mm, and therefore the adhesive strength is expressed in units of "N / 10 mm".

[0030] 4 and 5, the above peel test was carried out under the condition that the test laminate 112 was at 120° C. The results showed that under the condition that the test laminate 112 was at 120° C., adhesives A and B made of epoxy resins had stronger adhesive strength than adhesive C made of polyester resin and adhesives D and E made of acrylic resin.

[0031] Additionally, in conjunction with the peel test conducted under conditions where the test laminate 112 was at 120°C, an air bubble test was conducted to check whether air bubbles were generated in the test adhesive 121. No air bubbles were found in the test adhesive 121 using adhesive A and adhesive B, but air bubbles were found in the test adhesive 121 using adhesive C, adhesive D, and adhesive E. From the results of this air bubble test, it can be determined that air bubbles were generated in adhesives C, D, and E, which are made of a resin other than an epoxy resin, due to an early decrease in adhesive strength, compared to adhesive A and adhesive B, which are made of an epoxy resin.

[0032] Assuming that the test adhesive 121 is adhered to the test resin plate 111 under conditions of a width W of 10 mm and a length of 1 mm, for example, the saturated water vapor pressure of the test adhesive 121 with an adhesive strength of 5 N / 10 mm can be estimated to be 0.5 MPa. From the test results shown in Fig. 4, therefore, when the test laminate 112 is at 120°C, the saturated water vapor pressure of adhesive A with an adhesive strength of 3.14 N / 10 mm can be estimated to be 0.314 MPa. When the test laminate 112 is at 120°C, the saturated water vapor pressure of adhesive B with an adhesive strength of 2.89 N / 10 mm can be estimated to be 0.289 MPa.

[0033] The saturated water vapor pressure can be calculated as e(T) using the Tetens equation, Equation 1 below. A graph of the saturated water vapor pressure calculated using Equation 1 is shown in Figure 5.

[0034]

number

[0035] As shown in Fig. 5, if the temperature falls below the saturated water vapor pressure, the moisture contained in the test resin plate 111 and the test adhesive 121 will evaporate, which may cause air bubbles to form between the test resin plate 111 and the test functional film 131. Fig. 5 shows that the saturated water vapor pressure at a temperature of 120°C is 0.2 MPa, and the saturated water vapor pressure at a temperature of 150°C is 0.5 MPa.

[0036] As described above, under the condition that the test laminate 112 is at 120°C, the saturated water vapor pressure of the adhesive A can be estimated to be 0.314 MPa, and the saturated water vapor pressure of the adhesive B can be estimated to be 0.289 MPa. Therefore, both the adhesive A and the adhesive B exceed the saturated water vapor pressure of 0.2 MPa under the condition that the temperature is 120°C. Therefore, it can be determined that air bubbles are unlikely to occur between the test resin plate 111 and the test functional film 131 in the test laminate 112 that employs either the adhesive A or the adhesive B under the condition that the test laminate 112 is at 120°C. Therefore, the adhesive 21 has an adhesive strength higher than the saturated water vapor pressure at the first upper limit temperature T1, which is the upper limit of the heat resistance temperature required in the usage environment of the film-laminated resin plate 10.

[0037] [Actions and Effects of the Embodiments] The operation and effects of this embodiment will be described. (1) The film-laminated resin plate 10 includes a laminate 12 having a resin plate 11 made of polycarbonate, a functional film 31, and an adhesive 21. The adhesive 21 forms a layer between the resin plate 11 and the functional film 31, and laminates the functional film 31 to a first main surface 11a, which is one side of the resin plate 11. The adhesive 21 has an adhesive strength higher than the saturated water vapor pressure at a first upper limit temperature T1, which is the upper limit of the heat resistance temperature required in the usage environment of the film-laminated resin plate 10. Therefore, even if the temperature of the film-laminated resin plate 10 reaches the first upper limit temperature T1, which is the upper limit of the heat resistance temperature required in the usage environment of the film-laminated resin plate 10, the moisture contained in the resin plate 11 and the adhesive 21 is unlikely to evaporate. Therefore, it is possible to suppress the generation of air bubbles between the resin plate 11 and the functional film 31 caused by the evaporation of the moisture contained in the resin plate 11 and the adhesive 21.

[0038] (2) The manufacturing method of the film-laminated resin plate 10 includes a bending process in which the laminate 12 is bent while being heated. The adhesive 21 has an adhesive strength higher than the saturated water vapor pressure at a second upper limit temperature T2, which is the upper limit of the temperature of the laminate 12 in the bending process and is higher than the first upper limit temperature T1. Therefore, even if the temperature of the film-laminated resin plate 10 reaches the second upper limit temperature T2, which is the upper limit of the temperature of the laminate 12 in the bending process, the moisture contained in the resin plate 11 and the adhesive 21 is unlikely to evaporate. Therefore, even when the film-laminated resin plate 10 is bent, the generation of air bubbles between the resin plate 11 and the functional film 31 caused by the evaporation of the moisture contained in the resin plate 11 and the adhesive 21 can be suppressed.

[0039] [Example of change] The embodiment can be modified as follows: The embodiment and the following modified examples can be combined with each other to the extent that there is no technical contradiction.

[0040] The second upper limit temperature T2 may be lower than 150° C. or higher than 150° C. In short, the second upper limit temperature T2 may be any temperature as long as it is higher than the first upper limit temperature. The manufacturing method of the film-laminated resin plate 10 does not have to include a bending step. In this case, the film-laminated resin plate 10 may be, for example, in the shape of a flat plate that is not curved.

[0041] When the manufacturing method of the film-laminated resin plate 10 does not include a bending step as in the above modification, the adhesive 21 does not need to have an adhesive strength higher than the saturated water vapor pressure at the second upper limit temperature T2. In this case, the adhesive 21 only needs to have an adhesive strength higher than the saturated water vapor pressure at the first upper limit temperature T1.

[0042] Of the first main surface 11a and the second main surface 11b, the first main surface 11a may be the surface facing the inside of the vehicle in the vehicle window member in which the film-laminated resin plate 10 is used, and the second main surface 11b may be the surface facing the outside of the vehicle in the vehicle window member. [Explanation of symbols]

[0043] T1: first upper limit temperature; T2: second upper limit temperature; 10: film-laminated resin plate; 11: resin plate; 11a: first main surface (as one side); 12: laminate; 21: adhesive; 31: functional film.

Claims

1. A resin plate made of polycarbonate, A functional film, A laminated adhesive layer interposed between the resin plate and the functional film and bonding the functional film to one side of the resin plate, the film-bonded resin plate comprising a laminate having the same, The film-bonded resin plate is adopted as a window member for a vehicle as an automotive part, The adhesive is made of an epoxy resin, and the film-bonded resin plate has an adhesive strength of the adhesive of 2.89 N / 10 mm or more under the condition that the film-bonded resin plate is at 120°C. The film-bonded resin plate is characterized by this.

2. A resin plate made of polycarbonate, A functional film, A method for manufacturing a film-bonded resin plate comprising a laminate having a laminated layer interposed between the resin plate and the functional film and bonding the functional film to one side of the resin plate, The method includes a step of bonding the functional film to the resin plate while heating at least one of the resin plate and the functional film integrated with the adhesive, The film-bonded resin plate is adopted as a window member for a vehicle as an automotive part, The adhesive is made of an epoxy resin, and the film-bonded resin plate has an adhesive strength of the adhesive of 2.89 N / 10 mm or more under the condition that the film-bonded resin plate is at 120°C. The method for manufacturing a film-bonded resin plate is characterized by this.

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