Method for manufacturing resin film and film before cutting

Abstract

The present invention provides a method for manufacturing a resin film capable of more effectively suppressing cracking of the film when holding both ends of the film by a tenter conveyor. The present invention is a method for manufacturing a resin film, characterized by having the following steps A to G: Step A, coating a first resin composition solution on the central portion of a support; Step B, coating a second resin composition solution on both end portions adjacent to the central portion; Step C, drying the first resin composition solution and the second resin composition solution to obtain a pre-cut film; Step D, peeling the pre-cut film from the support; Step E, after Step D, holding both end portions of the pre-cut film by a tenter conveyor; Step F, conveying the pre-cut film in a state of holding both end portions of the pre-cut film; and Step G, after Step F, removing the portion formed by the second resin composition solution from the pre-cut film to obtain a resin film; the first resin composition solution contains a first resin and a filler, and the content of the filler is 0.1% by mass or more and 50% by mass or less relative to the first resin, the second resin composition solution contains a second resin, does not contain a filler or, even if it contains a filler, the content thereof is less than that of the first resin composition solution and is 2% by mass or less relative to the second resin; in the pre-cut film after Step C and before Step F, the tear strength of the portion formed by the second resin composition solution is greater than the tear strength of the portion formed by the first resin composition solution.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a resin film and a film before cutting. Background Art

[0002] Conventionally, in a film manufacturing process, there is known a tenter type conveying device that, when conveying, drying, heat-treating, etc. a film, conveys the film in a state where tension is applied to the film in the width direction by holding both end portions in the width direction of the film with multiple needles or jigs (for example, refer to Patent Document 1).

[0003] There are several conveying methods for the tenter type conveying device. Among these conveying methods, a needle plate tenter type conveying device that holds a film by piercing multiple needles in the machine direction at both end portions of the film has multiple needles disposed on a needle plate supported by a pair of moving chains arranged in parallel with each other. When the film shrinkage force (tensile force) becomes large in this needle plate tenter type conveying device, there are problems such as holes formed by the piercing of the needles on the film cracking and growing into long holes in the width direction of the film. When the holes formed on the film crack, the film cannot maintain an appropriately stretched state, and as a result, the quality of the film deteriorates, such as the generation of wrinkles. As a result, the rupture of the holes becomes a cause of production loss and leads to a decrease in production efficiency. In addition, even in the case of using a jig tenter type conveying device that holds both end portions with jigs, there are the same problems as in the case of using a needle plate tenter type conveying device, such as cracking of the portion of the film held by the jigs.

[0004] In recent years, resin films characterized by a low coefficient of thermal expansion (CTE) have a tendency to be brittle due to the rigidity of the molecular chains and are less likely to entangle with each other, resulting in a decrease in tear strength. Especially in fields where a low CTE is strongly required, such as the field of replacing glass in display substrates, etc., it is difficult to meet the required physical properties with only resin materials, so a scheme of introducing fillers such as silica has been proposed (refer to Patent Document 2). For such resin films containing fillers, the tear strength is further reduced, and the problem of breakage of the holding portion becomes more significant.

[0005] Conventionally, to solve this problem, a scheme has been proposed to overlap a film with a high tear strength as a reinforcing film at the holding portion (end portion) of a film with a low tear strength (refer to Patent Document 3). In addition, a scheme has been proposed to make the arrangement density of needles at both end portions of a sheet larger on the inner side in the width direction than on the outer side when conveying the sheet, etc. (refer to Patent Document 4).

[0006] Prior Art Documents

[0007] Patent Documents

[0008] Patent Document 1: Japanese Patent Publication No. 39-29211

[0009] Patent Document 2: Publication No. WO2013 / 161970

[0010] Patent Document 3: Japanese Patent Laid-Open No. 11-254521

[0011] Patent Document 4: Japanese Patent Laid-Open No. 9-77315 Summary of the Invention

[0012] Problems to be Solved by the Invention

[0013] However, in the method of Patent Document 3, since a film with low tear strength overlaps with a film with high tear strength, there is a problem of increased waste of raw materials. That is, the holding part is a part that will be cut and discarded sooner or later after conveyance. When the holding part is a two-layer structure, there is a problem of increased discarded parts.

[0014] In addition, in the method of Patent Document 4, it is impossible to cope with cases such as a resin film containing a filler with even lower tear strength, a resin film characterized by a low CTE, etc., and there is a problem that the holes formed by the puncture of the needle on the film crack.

[0015] The present invention has been completed in view of the above problems, and an object thereof is to provide a method for manufacturing a resin film and a film before cutting that can more effectively suppress film cracking when holding both ends of the film by a tenter conveyor.

[0016] Means for Solving the Problems

[0017] The present inventors have conducted in-depth research on a method for manufacturing a resin film characterized by exhibiting a low CTE and a film before cutting. As a result, it has been found that by adopting the following configuration, it is possible to more effectively suppress film cracking when holding both ends of the film by a tenter conveyor, and thus the present invention has been completed.

[0018] That is, the present invention relates to a method for manufacturing a resin film, characterized by having the following steps A to G:

[0019] Step A, coating a first resin composition solution on the central part of the support;

[0020] Step B, coating a second resin composition solution on both end parts adjacent to the central part;

[0021] Step C, drying the first resin composition solution and the second resin composition solution to obtain a film before cutting;

[0022] Step D, peeling the film before cutting from the support;

[0023] Step E, after Step D, holding both end parts of the film before cutting by a tenter conveyor;

[0024] Step F, conveying the pre-cut film in a state of holding both end portions of the pre-cut film; and

[0025] Step G, after the Step F, removing the portion formed from the second resin composition solution from the pre-cut film to obtain a resin film;

[0026] The first resin composition solution contains a first resin and a filler, and the content of the filler is 0.1% by mass or more and 50% by mass or less relative to the first resin.

[0027] The second resin composition solution contains a second resin, does not contain a filler or, even if it contains a filler, the content is less than that of the first resin composition solution and is 2% by mass or less relative to the second resin.

[0028] In the pre-cut film after the Step C and before the Step F, the tear strength of the portion formed from the second resin composition solution is greater than the tear strength of the portion formed from the first resin composition solution.

[0029] According to the above configuration, the first resin composition solution is coated on the central portion of the support (Step A), the second resin composition solution is coated on both end portions (Step B), and the first resin composition solution and the second resin composition solution are dried to obtain a pre-cut film (Step C). Both end portions of the thus obtained pre-cut film become portions formed only from the second resin composition solution. Here, the tear strength of the portion formed only from the second resin composition solution is greater than the tear strength of the portion formed from the first resin composition solution. Therefore, even when conveying in a state of holding both end portions of the pre-cut film by a tenter conveyor (Step F), cracking of the holding portions (both end portions) is not likely to occur.

[0030] In addition, according to the above configuration, after the Step F, the portion formed from the second resin composition solution is removed from the pre-cut film to obtain a resin film (Step G). According to such a method, even for a resin film with low tear strength, it can be conveyed using an existing well-known tenter conveyor. In addition, both end portions of the pre-cut film are portions formed only from the second resin composition solution, so that waste of the raw material of the portion removed through the Step G can be limited to a minimum.

[0031] The resin film obtained by the Step G preferably has a CTE of 5 ppm / K or more and 50 ppm / K or less.

[0032] According to the above configuration, since the CTE of the resin film is within a specified range, the heat resistance is excellent.

[0033] In the above-described configuration, the step E is preferably a step of gripping both end portions of the film before cutting with needles of a pin stenter conveyor.

[0034] In the film before cutting, since the tear strength of the portion formed from the first resin composition solution is greater than that of the portion formed from the second resin composition solution, cracking caused by the needles of the pin stenter conveyor can be more appropriately suppressed.

[0035] The present invention can be applied to films of all solution-formable resins. Solution film formation can be applied to all resins or resin precursors dissolved in a solvent, but from an industrial perspective, it is preferably applied to resins that are difficult to form into films by melting, such as cellulose triacetate, aromatic polyamide, polyimide, polyetherimide, polyamideimide, polyesterimide, polybenzoxazole, polybenzimidazole, polybenzothiazole, etc. Among these, it is particularly preferably applied to polyimide-based resins such as polyimide, polyamideimide, polyetherimide, and polyimide benzoxazole.

[0036] In the above-described configuration, it is preferred that the support is a polymer film.

[0037] In the above-described configuration, it is preferred that the filler is silica.

[0038] In recent years, there has been a high demand for polyimide-based resin films characterized by being colorless, transparent, and having a low CTE. Such polyimide-based resin films tend to have a low tear strength. In addition, for the purpose of achieving both transparency and a low CTE, the introduction of fillers has also been studied, and in this case, the tear strength becomes even lower. Therefore, according to the above-described configuration, a polyimide-based resin film with a low tear strength can be particularly suitably obtained.

[0039] In addition, the present invention relates to a film before cutting, characterized by having a central portion and both end portions continuously formed at both ends of the central portion.

[0040] The central portion is composed of a first resin composition containing a first resin and a filler, and the content of the filler is 0.1% by mass or more and 50% by mass or less with respect to the first resin.

[0041] Both end portions are composed of a second resin composition containing a second resin. The second resin composition does not contain a filler or, if it contains a filler, its content is less than that of the first resin composition and is 2% by mass or less with respect to the second resin.

[0042] The tear strength of both end portions is greater than that of the central portion.

[0043] According to the above configuration, since the tear strength of the two end portions is greater than that of the central portion, even when the two end portions of the pre-cut film are conveyed while being gripped by a tenter conveyor, the gripped portions (the two end portions) are less likely to tear.

[0044] Furthermore, since both end portions of the film before cutting are composed only of the second resin composition, when the both end portions are removed to obtain a resin film, waste of the raw material of the removed portion can be minimized.

[0045] In the above configuration, the first resin is preferably a polyimide-based resin.

[0046] When the first resin is a polyimide resin, a polyimide resin film having a low tear strength can be preferably obtained by removing both end portions after conveying the film through a tenter conveyor.

[0047] The CTE of the central portion is preferably 5 ppm / K or more and 50 ppm / K or less. According to the above configuration, by removing both end portions, a resin film having a CTE of 5 ppm / K or more and 50 ppm / K or less can be obtained.

[0048] In the above configuration, the filler is preferably silicon dioxide.

[0049] Effects of the Invention

[0050] According to the present invention, it is possible to provide a method for producing a resin film and a pre-cutting film, which can more effectively suppress film tearing when both ends of the film are gripped by a tenter conveyor. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] [ Figure 1 ] Figure 1 This is a side cross-sectional view for explaining the coating method of the resin composition solution according to the first embodiment.

[0052] [ Figure 2 ] Figure 2 for Figure 1 Floor plan.

[0053] [ Figure 3 ] Figure 3 for Figure 2 A partial enlarged plan view of the vicinity of the side plate 18b is shown in FIG.

[0054] [ Figure 4 ] Figure 4 This is a cross-sectional view showing the case where only the side surfaces of the respective coating films are connected.

[0055] [ Figure 5 ] Figure 5 This is a cross-sectional view showing a case where the coating film 64a and the coating film 64c only slightly overlap on the coating film 64b.

[0056] Figure 6 Figure 6 Cross-sectional view showing that the coating film 64b only slightly overlaps the coating film 64a and the coating film 64c.

[0057] Figure 7 Figure 7 Side cross-sectional view for explaining the coating method of the resin composition solution according to the second embodiment.

[0058] Figure 8 Figure 8 For Figure 7 plan view.

[0059] Figure 9 Figure 9 Side cross-sectional view for explaining the coating method of the resin composition solution according to the third embodiment.

[0060] Figure 10 Figure 10 For Figure 9 plan view.

[0061] Figure 11 Figure 11 Cross-sectional view showing that the end of the coating film 64a only slightly overlaps the coating film 64b, and the end of the coating film 64b only slightly overlaps the coating film 64c.

[0062] Figure 12 Figure 12 Side cross-sectional view for explaining the coating method of the resin composition solution according to the fourth embodiment.

[0063] Figure 13 Figure 13 For Figure 12 plan view.

[0064] Symbol Explanation

[0065] 10, 30, 40, 50 Coating device

[0066] 12 Support roller

[0067] 14 Comma roller

[0068] 16 (16a, 16b, 16c) Coating liquid storage part

[0069] 18 (18a, 18b, 18c, 18d) Side plate

[0070] 20 Back plate

[0071] 22 Gap

[0072] 60 Support​​​​​​​​​​​​​​​​

[0073] Coating liquid 62 (62a, 62b, 62c)

[0074] Coating film 64 (64a, 64b, 64c) Detailed implementation mode

[0075] Hereinafter, the implementation modes of the present invention will be described.

[0076] [Manufacturing method of resin film]

[0077] The manufacturing method of the resin film according to the present embodiment is characterized in that it has the following steps A to G:

[0078] Step A: Coating a first resin composition solution on the central part of the support;

[0079] Step B: Coating a second resin composition solution on both end parts adjacent to the central part;

[0080] Step C: Drying the first resin composition solution and the second resin composition solution to obtain a pre-cut film;

[0081] Step D: Peeling the pre-cut film from the support;

[0082] Step E: After Step D, gripping both end parts of the pre-cut film by a tenter conveyor;

[0083] Step F: Conveying the pre-cut film in a state of gripping both end parts of the pre-cut film; and

[0084] Step G: After Step F, removing the part formed by the second resin composition solution from the pre-cut film to obtain a resin film,

[0085] The first resin composition solution contains a first resin and a filler, and the content of the filler is 0.1% by mass or more and 50% by mass or less with respect to the first resin.

[0086] The second resin composition solution contains a second resin, does not contain a filler or, even if it contains a filler, the content is less than that of the first resin composition solution and is 2% by mass or less with respect to the second resin.

[0087] In the pre-cut film after Step C and before Step F, the tear strength of the part formed by the second resin composition solution is greater than the tear strength of the part formed by the first resin composition solution.

[0088] <Steps A and B>

[0089] In the method for manufacturing a resin film according to this embodiment, first, a first resin composition solution is coated on the central portion of a support (step A). In addition, a second resin composition solution is coated on both end portions adjacent to the central portion (step B). Step A and step B may be performed simultaneously, step B may be performed after step A, or step A may be performed after step B.

[0090] The support is not particularly limited, and a product that is resistant to the solvents of the first resin composition solution and the second resin composition solution is preferred. Examples include resin-made polymer films such as PET (polyethylene terephthalate), PI (polyimide), and PAI (polyamideimide), a metal drum, an endless steel belt, and the like. Among them, a polymer film is preferred.

[0091] The coating methods for step A and step B are not particularly limited. Examples include a comma coating method, a T-die coating method, a spin coating method, a spraying method, a bar coating method, a knife coating method, an impregnation method, and the like. Two methods may also be combined from these. If it is a comma coating method, a T-die coating method, or a combination thereof, it is preferred from the viewpoint of productivity.

[0092] Hereinafter, specific examples of step A and step B will be described.

[0093] [First Embodiment]

[0094] Figure 1 FIG. is a side cross-sectional view for explaining a coating method of the resin composition solution according to the first embodiment, Figure 2 and FIG. is a plan view thereof.

[0095] As shown in Figure 1 , Figure 2 the coating apparatus 10 includes a backup roll 12, a comma roll 14, and three coating liquid storage portions 16 (16a, 16b, 16c).

[0096] The coating liquid storage portions 16 (16a, 16b, 16c) include four side plates 18 (18a, 18b, 18c, 18d) and a back plate 20 for partitioning the coating liquid storage portions 16. The coating liquid storage portions 16 (16a, 16b, 16c) can store the coating liquid 62 in the region surrounded by the back plate 20 and the side plates 18.

[0097] In the coating liquid storage portions 16a and 16c located on both end sides among the three coating liquid storage portions 16 (16a, 16b, 16c), the second resin composition solutions 62a and 62c are stored, and in the coating liquid storage portion 16b located in the center, the first resin composition solution 62b is stored.

[0098] The support roller 12 continuously conveys the support 60 by rotation. The support 60 conveyed by the support roller 12 passes through the gap 22 formed between the support roller 12 and the comma roller 14. When the support 60 passes through the gap 22, the coating liquid 62 (the second resin composition solution 62a, 62c, and the first resin composition solution 62b) is supplied from the coating liquid storage unit 16 to the support 60, and a coating film 64 (64a, 64b, 64c) is formed. Specifically, a coating film 64 having a thickness equivalent to subtracting the thickness of the support 60 from the gap 22 is formed.

[0099] The thickness of the coating film 64 can be controlled by the gap 22 between the support roller 12 and the comma roller 14 or the like.

[0100] Figure 3 is Figure 2 a partially enlarged plan view near the side plate 18b shown in

[0101] After each coating liquid 62 (the second resin composition solution 62a, 62c, and the first resin composition solution 62b) is coated on the support 60, it spreads in the width direction. Specifically, as Figure 3 shown, the second resin composition solution 62a coated near the side plate 18b spreads inward in the width direction ( Figure 2 , Figure 3 the right side in Figure 2 , Figure 3 ). On the other hand, the first resin composition solution 62b coated near the side plate 18b spreads outward in the width direction ( Figure 2 , Figure 3 the left side in

[0102] ). Then, in the part without the side plate 18b in the machine direction ( Figure 2 the upper side in Figure 2 ), the second resin composition solution 62a (coating film 64a) is connected to the first resin composition solution 62b (coating film 64b).

[0103] Similarly, the first resin composition solution 62b coated near the side plate 18c spreads outward in the width direction ( Figure 2 the right side in Figure 2 ). On the other hand, the second resin composition solution 62c coated near the side plate 18c spreads inward in the width direction ( Figure 2 the left side in

[0103] ). Then, in the part without the side plate 18c in the machine direction, the first resin composition solution 62b (coating film 64b) and the second resin composition solution 62c (coating film 64c) are connected.

[0104] As the connection method of each coating film 64, there is no particular limitation, and examples include the case where each coating film is only connected on the side (refer to Figure 4 ), the case where any one coating film overlaps only a small part on another coating film (refer to Figure 5 , Figure 6 ).

[0105] Figure 4 FIG. is a cross-sectional view showing the case where each coating film is only connected on the side.

[0106] Figure 4 In the example shown, the coating film 64a and the coating film 64b are only connected on the side. In addition, the coating film 64b and the coating film 64c are only connected on the side. Immediately after coating, they are only connected on the side, but before the subsequent process C is to be carried out, the second resin composition solution 62a (coating film 64a) and the first resin composition solution 62b (coating film 64b), or the first resin composition solution 62b (coating film 64b) and the second resin composition solution 62c (coating film 64c) form a composition gradient region by mixing. The width of the composition gradient region is preferably in the range of 10 to 2500 times the thickness of the coating film 64b in the non-composition gradient region part. More preferably, it is 100 to 1000 times, and further preferably 250 to 500 times. For example, when the thickness of the coating film 64b is 20 μm, the width of the composition gradient region is preferably 0.2 mm (10 times the thickness of the coating film 64b) to 5 cm (2500 times the thickness of the coating film 64b). If it is within this range, it is not easy to generate fractures from the composition gradient region during manufacturing.

[0107] Figure 5 FIG. is a cross-sectional view showing the case where the coating film 64a and the coating film 64c overlap only a small part on the coating film 64b.

[0108] Figure 5In the example shown, the end of the coating film 64a only slightly overlaps the coating film 64b. In addition, the end of the coating film 64c only slightly overlaps the coating film 64b. The overlapping part is a composition gradient region formed by the mixing of the second resin composition solution 62a (coating film 64a) and the first resin composition solution 62b (coating film 64b), or the first resin composition solution 62b (coating film 64b) and the second resin composition solution 62c (coating film 64c). The width of the composition gradient region is preferably in the range of 10 to 2500 times the thickness of the non-composition gradient region part of the coating film 64b. More preferably, it is 100 to 1000 times, and even more preferably 250 to 500 times. For example, when the thickness of the coating film 64b is 20 μm, the width of the composition gradient region is preferably 0.2 mm (10 times the thickness of the coating film 64b) to 5 cm (2500 times the thickness of the coating film 64b). If it is within this range, it is not easy to generate fractures from the composition gradient region during manufacturing.

[0109] Figure 6 It is a cross-sectional view showing that the coating film 64b only slightly overlaps the coating film 64a and the coating film 64c.

[0110] Figure 6 In the example shown, the end of the coating film 64b ( Figure 6 the left end in this case) only slightly overlaps the coating film 64a. In addition, the end of the coating film 64b ( Figure 6 the right end in this case) only slightly overlaps the coating film 64c. As an example of the width of the overlapping part, similar to Figure 5 the case of, it is preferably in the range of 10 to 2500 times that of the coating film 64b in the non-composition gradient region part. More preferably, it is 100 to 1000 times, and even more preferably 250 to 500 times. If it is within this range, it is not easy to generate fractures from the composition gradient region during manufacturing.

[0111] The connection method can be determined by, for example, the gap 22. If the gap 22 through which the second resin composition solutions 62a and 62c pass is the same as the gap 22 through which the first resin composition solution 62b passes, it is easy to form Figure 4 the connection method in the form shown in. If the gap 22 through which the second resin composition solutions 62a and 62c pass is slightly larger than the gap 22 through which the first resin composition solution 62b passes, it is easy to form Figure 5 the connection method in the form shown in. If the gap 22 through which the first resin composition solution 62b passes is slightly larger than the gap 22 through which the second resin composition solutions 62a and 62c pass, it is easy to form Figure 6The connection method in the form shown. In addition, the connection method can be controlled not only through the gap 22, but also through the viscosities of the first resin composition solution 62b, the second resin composition solutions 62a and 62c, or the width of the side plate 18.

[0112] In the first embodiment, through the coating device 10 described above, processes A and B are performed simultaneously.

[0113] As described above, process A and process B related to the first embodiment have been described.

[0114] [Second Embodiment]

[0115] Figure 7 FIG. is a side cross-sectional view for explaining a method of coating a resin composition solution according to the second embodiment. Figure 8 FIG. is a plan view thereof. In addition, in the coating device 30 of the second embodiment, the same reference numerals are attached to the components common to the coating device 10 of the first embodiment, and the description thereof is omitted or briefly explained.

[0116] As Figure 7 , Figure 8 shown, the coating device 30 includes a support roller 12, a comma roller 14, and two coating liquid storage portions 16 (16a, 16c) on both sides in the width direction. The coating liquid storage portions 16 (16a, 16c) can store the coating liquid 62 in the region surrounded by the back plate 20 and the side plate 18.

[0117] In the two coating liquid storage portions 16 (16a, 16c), the second resin composition solutions 62a and 62c are stored. In addition, different from the first embodiment, in the coating device 30 according to the second embodiment, the coating liquid storage portion 16 does not store the first resin composition solution.

[0118] The support roller 12 continuously conveys the support 60 by rotation. The support 60 conveyed by the support roller 12 passes through the gap 22 formed between the support roller 12 and the comma roller 14. When the support 60 passes through the gap 22, the second resin composition solutions 62a and 62c are supplied from the coating liquid storage portion 16 to the support 60, and coating films 64a and 64c are formed.

[0119] The coating device 30 further includes a T-die coater 32. The T-die coater 32 is provided at a later stage than the support roller 12 and the comma roller 14. The T-die head coater 32 is provided such that the ejection port is located above the central portion of the support 60.

[0120] When the support 60 after the coating films 64a and 64c are formed is conveyed, the T-die coater 32 coats the first resin composition solution 62b on the central portion of the support 60.

[0121] In the second embodiment, through the coating device 30 described above, first, process B is performed, and then, process A is performed. In the case of the second embodiment, the connection mode of each coating film 64 is easily formed Figure 6 into the connection mode shown in, but is not limited thereto. In addition, as a modification of the second embodiment, the first resin composition solution may be coated at the center of the support by a comma coater first, and then the second resin composition solution may be coated at both ends by a T-die coater.

[0122] Above, process A and process B related to the second embodiment have been described.

[0123] [Third Embodiment]

[0124] Figure 9 FIG. is a side sectional view for explaining the coating method of the resin composition solution according to the third embodiment, Figure 10 and FIG. is its plan view. In addition, the same reference numerals are attached to the components common to the coating device 40 of the third embodiment and the coating device 30 of the second embodiment, and are omitted or briefly described.

[0125] The coating device 40 includes a T-die coater 42a, a T-die coater 42b, and a T-die coater 42c. The T-die coater 42a and the T-die coater 42c are arranged in a more upstream stage than the T-die coater 42b.

[0126] The T-die coater 42a and the T-die coater 42c are respectively arranged such that the discharge port is located above the end of the support 60. Figure 10 In, the T-die coater 42a is arranged such that the discharge port is located above the left end of the support 60, and the T-die coater 42c is arranged such that the discharge port is located above the right end of the support 60.

[0127] The T-die coater 42b is arranged such that the discharge port is located above the center of the support 60.

[0128] When the support 60 after forming the coating films 64a and 64c is conveyed, the T-die coater 42b coats the first resin composition solution 62b at the center of the support 60.

[0129] In the case of the third embodiment, the joining mode of each coating film 64 is easily formed Figure 5 into the joining mode shown in, but is not limited thereto. In addition, as a modification of the third embodiment, the second resin composition may be coated on both ends by a T-die coater, and then the first resin composition may be coated on the center by a T-die coater. In this case, the joining mode of each coating film 64 is easily formed Figure 6 into the joining mode shown in, but is not limited thereto.

[0130] Further, as another modification example, the second resin composition may be coated on one end portion by a T-die coater, and then the first resin composition may be coated on the central portion by a T-die coater. Then, the second resin composition may be coated on one end portion on the other end portion by a T-die coater. In this case, the bonding method of each coating film 64 is easily formed Figure 11 into the bonding method shown in

[0131] Figure 11 In the example shown in Figure 11 the end portion of the coating film 64a only slightly overlaps on the coating film 64b. In addition, the end portion of the coating film 64b (

[0132] As shown in the third embodiment and its modification examples, the process A and the process B may also be a method of vertically arranging a plurality of T-die coaters and sequentially coating the first resin composition and the second resin composition.

[0133] [Fourth Embodiment]

[0134] Figure 12 FIG. is a side cross-sectional view for explaining a coating method of a resin composition solution according to the fourth embodiment, Figure 13 and FIG. is a plan view thereof. In addition, the common configurations of the coating apparatus 50 in the fourth embodiment and the coating apparatus 40 in the third embodiment are denoted by the same reference numerals and are omitted or briefly described.

[0135] The coating apparatus 50 includes a T-die coater 52, and the T-die coater 52 has ejection ports divided into three in the width direction. The T-die coater 52 coats the first resin composition on the central portion of the support 60 and coats the second resin composition on both end portions.

[0136] As shown in Figure 12 and Figure 13 in the fourth embodiment, the process A and the process B are methods of simultaneously coating the first resin composition and the second resin composition. In the case of the fourth embodiment, the bonding method of each coating film 64 is easily formed Figure 4 into the bonding method shown in

[0137] <Process C>

[0138] After the said process A and the said process B, the solution of the first resin composition and the solution of the second resin composition are dried to obtain a film before cutting (process C). As the drying conditions, they can be appropriately set within the range where the solvent can be sufficiently volatilized. As an example, the drying temperature can be set within the range of 60°C to 140°C, and the drying time can be set within the range of 1 minute to 60 minutes. When dimethylacetamide is used as the solvent, these drying conditions are particularly preferred because its boiling point is 165°C.

[0139] After process C and before process D, a process (process C-1) of winding the film before cutting together with the support into a roll shape can also be performed. At this time, as long as the film before cutting is unrolled again before process D.

[0140] <Process D>

[0141] After the said process C, the film before cutting is peeled off from the support (process D). As the method of peeling the film before cutting from the support, there is no particular limitation, and the following methods can be adopted: a method of rolling it up from the end with tweezers, etc.; a method of cutting a cut in the film before cutting, pasting an adhesive tape on one side of the cut portion, and then rolling it up from the adhesive tape portion; a method of vacuum adsorbing one side of the cut portion of the film before cutting and then rolling it up from this portion, etc. As the rolling-up method, it is preferably rolled up while winding around a roller.

[0142] As the method of cutting a cut in the film before cutting, there are methods of cutting the film before cutting with a cutting tool such as a knife, methods of cutting the film before cutting with a laser, methods of cutting the film before cutting with a water jet, etc., but there is no particular limitation. For example, when adopting the above methods, methods such as attaching ultrasonic waves to the cutting tool, applying a reciprocating motion or an up-and-down motion to improve the cutting performance, etc. can also be appropriately adopted.

[0143] After process D and before process E, a process (process D-1) of winding the film before cutting into a roll shape can also be performed. At this time, as long as the film before cutting is unrolled again before process E. When winding the film before cutting, it is preferably wound with a liner (anti-adhesion film) sandwiched.

[0144] If the processes of process C-1 and / or process D-1 are implemented, a certain period can be set after the drying process (process C) and before the cutting process (process G) is implemented.

[0145] After the drying process (process C), by winding the film before cutting once and maintaining this state for a certain period, the solvent distribution in the thickness direction of the film can be equalized. This will be described below.

[0146] As Figure 5 、 Figure 6As shown, when only a small part of the two coating films overlaps, the solvent distribution in the film just after drying on the support is such that the residual amount of solvent in the coating film on the support side is larger than that in the coating film on the surface side. If the heating process (for example, process F described later) is carried out in this state, there will be a difference in the amount of solvent volatilized, and this part (the overlapping part) may be prone to cracking.

[0147] Therefore, by implementing the above-mentioned process C-1 and / or the above-mentioned D-1, the solvent distribution in the thickness direction of the overlapping part is equalized, so that the residual amounts of solvent in the two coating films become relatively equal, and the overlapping part can be made less prone to cracking.

[0148] After the above-mentioned process C-1 and / or after the above-mentioned process D-1, as the time for maintaining the roll state, it is preferably 30 minutes or more, and more preferably 3 hours or more. If the above-mentioned time is maintained in the roll state, the solvent can be appropriately diffused in the thickness direction.

[0149] In addition, if the above-mentioned process C-1 and / or the above-mentioned D-1 are implemented, since the film before cutting is wound up once during the process, the production apparatus can be miniaturized. That is, when all the processes are continuously connected, it will become a quite long production line, and sometimes there will be restrictions on the location of the factory, etc. On the other hand, if a winding process is implemented during manufacturing, the production line can be divided into two, and the two divided production lines can be arranged in parallel, and a relatively small manufacturing apparatus can be formed.

[0150] Furthermore, by winding up once during manufacturing, quality inspection can be carried out during the process.

[0151] <Process E>

[0152] After the above-mentioned process D, both ends of the film before cutting are held by a tenter conveyor (process E). Specifically, when a needle plate tenter conveyor is used as the tenter conveyor, both end portions of the film before cutting are held by piercing with a plurality of needles of the needle plate tenter conveyor. In addition, when a clamp tenter conveyor is used as the tenter conveyor, both end portions of the film before cutting are held by clamping with a plurality of clamps of the clamp tenter conveyor. As the tenter conveyor, existing publicly known apparatuses (for example, the tenter conveyors disclosed in Japanese Patent No. 4843996, Japanese Patent No. 4821960, etc.) can be used.

[0153] <Process F>

[0154] After the step E, the pre-cut film is conveyed while holding both end portions of the pre-cut film (step F). Heating may be performed during the conveyance. The heating temperature is not particularly limited, and when the first resin composition solution and the second resin composition solution are polyimide-based resin composition solutions, for example, it can be set within the range of 150°C to 500°C for 1 minute to 60 minutes.

[0155] In addition, in step E and step F, the pre-cut film may or may not be stretched in the width direction.

[0156] In step F, generally, the pre-cut film shrinks in the width direction during conveyance. Therefore, a tensile tension is applied to the portion held by the tenter conveyor. Here, although it will be described in detail later, the tear strength of both end portions (the portions formed by the second resin composition solution) of the pre-cut film is greater than the tear strength of the central portion (the portions formed by the second resin composition solution). Therefore, cracking of the pre-cut film at the holding portion (both end portions) is suppressed. In particular, when a needle tenter conveyor is used as the tenter conveyor, cracking caused by the needles of the needle tenter conveyor is better suppressed.

[0157] <Step G>

[0158] After the step F, the portions formed by the second resin composition solution are removed from the pre-cut film to obtain a resin film (step G). In step G, it is only necessary to remove at least the portions formed by the second resin composition solution, and a part of the portions formed by the first resin composition solution may also be removed together with the portions formed by the second resin composition solution. The resin film thus obtained is only the portion formed by the first resin composition solution. That is, a resin film formed only by the portions with relatively low tear strength is obtained.

[0159] The CTE (coefficient of thermal expansion) of the resin film is 5 ppm / K or more and 50 ppm / K or less. It is preferably 45 ppm / K or less, more preferably 40 ppm / K or less, and further preferably 35 ppm / K or less due to good heat resistance. Industrially, it can be 6 ppm / K or more, or 7 ppm / K or more.

[0160] The thickness of the resin film is not particularly limited, and it is preferably 5 μm to 125 μm, more preferably 7.5 μm to 75 μm, and further preferably 12.5 μm to 50 μm.

[0161] As a method for removing the portions formed by the second resin composition solution from the pre-cut film, there is no particular limitation, and existing well-known cutting machines, etc. can be used.

[0162] As described above, according to the method for manufacturing a resin film according to the present embodiment, even a resin film with low tear strength can be conveyed using a known tenter conveyor. In addition, since both end portions of the film before cutting are portions formed only of the second resin composition solution, waste of the raw material of the portion removed in step G can be minimized.

[0163] Hereinafter, the first resin composition solution and the second resin composition solution will be described.

[0164] The first resin composition solution and the second resin composition solution are not particularly limited as long as, in the film before cutting after step C and before step F, the tear strength of the portion formed of the second resin composition solution is greater than the tear strength of the portion formed of the first resin composition solution, and the CTE of the resin film is 5 ppm / K or more and 50 ppm / K or less.

[0165] The first resin composition solution contains a first resin and a filler, and the content of the filler is 0.1% by mass or more and 50% by mass or less relative to the first resin.

[0166] The first resin is not particularly limited as long as it is a resin that can be formed into a film from a solution, and it can be not only a resin but also a precursor of the resin. Particularly from the perspective of industrial rights, a resin that is difficult to be formed into a film by melting is preferably applied. Specifically, examples include cellulose triacetate, aromatic polyamide, polyimide, polyetherimide, polyamideimide, polyesterimide, polybenzoxazole, polybenzimidazole, polybenzothiazole, etc. In addition, as a precursor of polyimide, polyamic acid can be cited. Among these, resins that can be particularly preferably applied are polyimide-based resins such as polyimide, polyamideimide, polyetherimide, and polyimide benzoxazole.

[0167] The filler content of the first resin composition solution is 0.1% by mass or more relative to the first resin. It is preferably 0.2% by mass or more and more preferably 0.3% by mass or more because the CTE of the resin film can be reduced. In addition, the filler content of the first resin composition solution is 50% by mass or less relative to the first resin. It is preferably 40% by mass or less, more preferably 30% by mass or less, further preferably 20% by mass or less, and particularly preferably 15% by mass or less because the mechanical properties of the resin film become good.

[0168] As the first resin composition solution, it preferably contains a specified amount of the first resin and a filler. Specifically, examples thereof include a cellulose triacetate resin composition solution, a polyetherimide resin composition solution, a polyesterimide resin composition solution, a polybenzoxazole resin composition solution, a polybenzimidazole resin composition solution, a polybenzothiazole resin composition solution, a polyimide-based resin composition solution, an aromatic polyamide-based resin composition solution, a polyamideimide-based resin composition solution, and the like. Among them, a polyimide-based resin composition solution is preferred. Most resin films generally referred to as transparent polyimides in polyimide-based resin films have weak tear strength. According to the method for manufacturing a resin film according to the present embodiment, even a transparent polyimide-based resin film with weak tear strength can be suitably manufactured.

[0169] From the viewpoints of workability (coating property) and economy, the concentration of the first resin in the first composition solution is preferably 1% by mass or more, more preferably 5% by mass or more, and still more preferably 10% by mass or more. In addition, it is preferably 80% by mass or less, more preferably 60% by mass or less, and still more preferably 40% by mass or less.

[0170] The first polyimide-based resin composition solution may be a polyamic acid (polyimide precursor) solution or a polyimide solution. When using a polyamic acid solution, a dehydration ring-closure reaction is carried out by heat treatment in step F to form a polyimide film. When using a polyimide solution, a polyimide film is formed by volatilizing the solvent in step C.

[0171] As the heat treatment conditions, they can be appropriately set within a range that can cause a reaction between polyamic acid and polyimide. As an example of the heat treatment temperature, it is in the range of 250 to 500 °C, preferably in the range of 300 to 400 °C. In addition, the heat treatment time can be appropriately set according to the heat treatment temperature. As an example, it is in the range of 5 to 60 minutes, preferably in the range of 10 to 30 minutes.

[0172] The polyamic acid solution is obtained by reacting diamines and tetracarboxylic acids in a solvent.

[0173] As the tetracarboxylic acids, aromatic tetracarboxylic acids (including their acid anhydrides), aliphatic tetracarboxylic acids (including their acid anhydrides), and alicyclic tetracarboxylic acids (including their acid anhydrides) commonly used in polyimide synthesis can be used. Among them, aromatic tetracarboxylic anhydrides and alicyclic tetracarboxylic anhydrides are preferred. From the viewpoint of heat resistance, aromatic tetracarboxylic anhydrides are more preferred, and from the viewpoint of light transmittance, alicyclic tetracarboxylic acids are more preferred. When these are acid anhydrides, the number of acid anhydride structures in the molecule can be 1 or 2, and preferably has 2 acid anhydride structures (diacid anhydrides). The tetracarboxylic acids can be used alone or in combination of two or more.

[0174] In the polyamic acid solution, a solution capable of obtaining a polyimide with high colorless transparency is preferably obtained.

[0175] As the aromatic tetracarboxylic acids for obtaining a polyimide with high colorless transparency, examples include 4,4'-(2,2-hexafluoroisopropylidene)diphthalic acid, 4,4'-oxydiphthalic acid, 3,4'-oxydiphthalic acid, bis(1,3-dioxo-1,3-dihydro-2-benzofuran-5-carboxylic acid) 1,4-phenylene ester, bis(1,3-dioxo-1,3-dihydro-2-benzofuran-5-yl)benzene-1,4-dicarboxylate, 4,4'-[4,4'-(3-oxo-1,3-dihydro-2-benzofuran-1,1-diyl)bis(benzene-1,4-diyloxy)]diphenyl-1,2-dicarboxylic acid, 4,4'-[(3-oxo-1,3-dihydro-2-benzofuran-1,1-diyl)bis(toluene-2,5-diyloxy)]diphenyl-1,2-dicarboxylic acid, 4,4'-[(3-oxo-1,3-dihydro-2-benzofuran-1,1-diyl)bis(1,4-dimethylbenzene-2,5-diyloxy)]diphenyl-1,2-dicarboxylic acid, 4,4'-[4,4'-(3-oxo-1,3-dihydro-2-benzofuran-1,1-diyl)bis(4-isopropyl-toluene-2,5-diyloxy)]diphenyl-1,2-dicarboxylic acid, 4,4'-[4,4'-(3-oxo-1,3-dihydro-2-benzofuran-1,1-diyl)bis(naphthalene-1,4-diyloxy)]diphenyl-1,2-dicarboxylic acid, 4,4'-[4,4'-(3H-2,1-benzoxathiol-1,1-dioxide-3,3-diyl)bis(benzene-1,4-diyloxy)]diphenyl-1,2-dicarboxylic acid, 4,4'-benzophenone tetracarboxylic acid, 4,4'-[(3H-2,1-benzoxathiol-1,1-dioxide-3,3-diyl)bis(toluene-2,5-diyloxy)]diphenyl-1,2-dicarboxylic acid, 4,4'-[(3H-2,1-benzoxathiol-1,1-dioxide-3,3-diyl)bis(1,4-dimethylbenzene-2,5-diyloxy)]diphenyl-1,2-dicarboxylic acid, 4,4'-[4,4'-(3H-2,1-benzoxathiol-1,1-dioxide-3,3-diyl)bis(4-isopropyl-toluene-2,5-diyloxy)]diphenyl-1,2-dicarboxylic acid, 4,4'-[4,4'-(3H-2,1-benzoxathiol-1,1-dioxide-3,3-diyl)bis(naphthalene-1,4-diyloxy)]diphenyl-1,2-dicarboxylic acid, 3,3',4,4'-benzophenone tetracarboxylic acid, 3,3',4,4'-diphenylsulfone tetracarboxylic acid, 3,3',4,4'-biphenyltetracarboxylic acid, 2,3,3',4'-biphenyltetracarboxylic acid, 2,2',3,3'-biphenyltetracarboxylic acid, pyromellitic acid, 4,4'-[spiro(xanthene-9,9'-fluorene)-2,6-diylbis(oxycarbonyl)]diphthalic acid, 4,4'-[spiro(xanthene-9,9'-fluorene)-3,tetracarboxylic acids such as 6-dicarboxyldi(oxycarbonyl)diphthalic acid and acid anhydrides thereof. Among these, dianhydrides having two acid anhydride structures are preferred, and 4,4'-(2,2-hexafluoroisopropylidene)diphthalic dianhydride and 4,4'-oxydiphthalic dianhydride are particularly preferred. In addition, the aromatic tetracarboxylic acids may be used alone or in combination of two or more. When heat resistance is emphasized, for example, the aromatic tetracarboxylic acids are preferably 50% by mass or more, more preferably 60% by mass or more, further preferably 70% by mass or more, and still further preferably 80% by mass or more of the total tetracarboxylic acids.,

[0176] As alicyclic tetracarboxylic acids, examples include 1,2,3,4-cyclobutanetetracarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic acid, 1,2,3,4-cyclohexanetetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic acid, 3,3',4,4'-bicyclohexyltetracarboxylic acid, bicyclo[2,2,1]heptane-2,3,5,6-tetracarboxylic acid, bicyclo[2,2,2]octane-2,3,5,6-tetracarboxylic acid, bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic acid, tetrahydroanthracene-2,3,6,7-tetracarboxylic acid, tetradecahydro-1,4:5,8:9,10-trimethanoanthracene-2,3,6,7-tetracarboxylic acid, decahydronaphthalene-2,3,6,7-tetracarboxylic acid, decahydro-1,4:5,8-dimethanonaphthalene-2,3,6,7-tetracarboxylic acid, decahydro-1,4-ethano-5,8-methanonaphthalene-2,3,6,7-tetracarboxylic acid, norbornane-2-spiro-α-cyclopentanone-α'-spiro-2"-norbornane-5,5",6,6"-tetracarboxylic acid (alias "norbornane-2-spiro-2'-cyclopentanone-5'-spiro-2"-norbornane-5,5",6,6"-tetracarboxylic acid"), methylnorbornane-2-spiro-α-cyclopentanone-α'-spiro-2"-(methylnorbornane)-5,5",6,6"-tetracarboxylic acid, norbornane-2-spiro-α-cyclohexanone-α'-spiro-2"-norbornane-5,5",6,6"-tetracarboxylic acid (alias "norbornane-2-spiro-2'-cyclohexanone-6'-spiro-2"-norbornane-5,5",6,6"-tetracarboxylic acid"), methylnorbornane-2-spiro-α-cyclohexanone-α'-spiro-2"-(methylnorbornane)-5,5",6,6"-tetracarboxylic acid, norbornane-2-spiro-α-cyclopropanone-α'-spiro-2"-norbornane-5,5",6,6"-tetracarboxylic acid, norbornane-2-spiro-α-cyclobutanone-α'-spiro-2"-norbornane-5,5",6,6"-tetracarboxylic acid, norbornane-2-spiro-α-cycloheptanone-α'-spiro-2"-norbornane-5,5",6,6"-tetracarboxylic acid, norbornane-2-spiro-α-cyclooctanone-α'-spiro-2"-norbornane-5,5",6,6"-tetracarboxylic acid, norbornane-2-spiro-α-cyclononanone-α'-spiro-2"-norbornane-5,5",6,6"-tetracarboxylic acid, norbornane-2-spiro-α-cyclodecanone-α'-spiro-2"-norbornane-5,5",6,6"-tetracarboxylic acid, norbornane-2-spiro-α-cycloundecanone-α'-spiro-2"-norbornane-5,5",6,6"-tetracarboxylic acid, norbornane-2-spiro-α-cyclododecanone-α'-spiro-2"-norbornane-5,5",6,6"-tetracarboxylic acid, norbornane-2-spiro-α-cyclotridecanone-α'-spiro-2"-norbornane-5,5",6,6"-tetracarboxylic acid, norbornane-2-spiro-α-cyclotetradecanone-α'-spiro-2"-norbornane-5,5",6,6"-tetracarboxylic acid, norbornane-2-spiro-α-cyclopentadecanone-α'-spiro-2"-norbornane-5,5",6,6"-tetracarboxylic acid, norbornane-2-spiro-α-(methylcyclopentanone)-α'-spiro-2"-norbornane-5,5",6,6"-tetracarboxylic acid, norbornane-2-spiro-α-(methylcyclohexanone)-α'-spiro-2"-norbornane-5,5",6,6"-tetracarboxylic acid and other tetracarboxylic acids and anhydrides thereof. Among these, dianhydrides having 2 anhydride structures are preferred, and 1,2,3,4-cyclobutanetetracarboxylic dianhydride, 1,2,3,4-cyclohexanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic dianhydride are particularly preferred, 1,2,3,4-cyclobutanetetracarboxylic dianhydride and 1,2,4,5-cyclohexanetetracarboxylic dianhydride are more preferred, and 1,2,3,4-cyclobutanetetracarboxylic dianhydride is further preferred. In addition, these can be used alone or in combination of two or more. When transparency is emphasized, for example, alicyclic tetracarboxylic acids are preferably 50% by mass or more of the total tetracarboxylic acids, more preferably 60% by mass or more, further preferably 70% by mass or more, and still further preferably 80% by mass or more.,

[0177] The polyamic acid solution may contain tricarboxylic acids and dicarboxylic acids.

[0178] Examples of tricarboxylic acids include aromatic tricarboxylic acids such as trimellitic acid, 1,2,5-naphthalenetricarboxylic acid, diphenyl ether-3,3',4'-tricarboxylic acid, diphenyl sulfone-3,3',4'-tricarboxylic acid, or hydrides of the above aromatic tricarboxylic acids such as hexahydrotrimellitic acid, alkylene glycol trimellitic acid esters such as ethylene glycol bistrimellitic acid ester, propylene glycol bistrimellitic acid ester, 1,4-butanediol bistrimellitic acid ester, polyethylene glycol bistrimellitic acid ester, and monoesters and esterified products thereof. Among these, monoesters having 1 anhydride structure are preferred, and trimellitic anhydride and hexahydrotrimellitic anhydride are particularly preferred. In addition, these can be used alone or in combination of multiple types.

[0179] Examples of dicarboxylic acids include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, 4,4'-oxydibenzoic acid, or hydrides of the above aromatic dicarboxylic acids such as 1,6-cyclohexanedicarboxylic acid, and oxalic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, 2-methylsuccinic acid, and their acid chlorides or esterified products. Among these, aromatic dicarboxylic acids and their hydrides are preferred, and terephthalic acid, 1,6-cyclohexanedicarboxylic acid, 4,4'-oxydibenzoic acid are particularly preferred. In addition, dicarboxylic acids can be used alone or in combination of multiple types.

[0180] The diamines or isocyanates used to obtain polyimides with high colorless transparency are not particularly limited, and aromatic diamines, aliphatic diamines, alicyclic diamines, aromatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, etc. commonly used in polyimide synthesis, polyamide-imide synthesis, and polyamide synthesis can be used. From the viewpoint of heat resistance, aromatic diamines are preferred, and from the viewpoint of transparency, alicyclic diamines are preferred. In addition, if aromatic diamines having a benzoxazole structure are used, high elastic modulus, low thermal shrinkage, and low linear expansion coefficient can be exhibited while exhibiting high heat resistance. The diamines and isocyanates can be used alone or in combination of two or more.

[0181] As aromatic diamines, for example, 2,2'-dimethyl-4,4'-diaminobiphenyl, 1,4-bis[2-(4-aminophenyl)-2-propyl]benzene, 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-bis(3-aminophenoxy)biphenyl, bis[4-(3-aminophenoxy)phenyl]ketone, bis[4-(3-aminophenoxy)phenyl]sulfide, bis[4-(3-aminophenoxy)phenyl]sulfone, 2,2-bis[4-(3-aminophenoxy)phenyl]propane, 2,2-bis[4-(3-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, m-aminobenzylamine, p-aminobenzylamine, 4-amino-N-(4-aminophenyl)benzamide, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 2,2'-trifluoromethyl-4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfide, 3,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfoxide, 3,4'-diaminodiphenyl sulfoxide, 4,4'-diaminodiphenyl sulfoxide, 3,3'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone, 4,4'-diaminobenzophenone, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, bis[4-(4-aminophenoxy)phenyl]methane, 1,1-bis[4-(4-aminophenoxy)phenyl]ethane, 1,2-bis[4-(4-aminophenoxy)phenyl]ethane, 1,1-bis[4-(4-aminophenoxy)phenyl]propane, 1,2-bis[4-(4-aminophenoxy)phenyl]propane, 1,3-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 1,1-bis[4-(4-aminophenoxy)phenyl]butane, 1,3-bis[4-(4-aminophenoxy)phenyl]butane, 1,4-bis[4-(4-aminophenoxy)phenyl]butane, 2,2-bis[4-(4-aminophenoxy)phenyl]butane, 2,3-bis[4-(4-aminophenoxy)phenyl]butane, 2-[4-(4-aminophenoxy)phenyl]-2-[4-(4-aminophenoxy)-3-methylphenyl]propane, 2,2-bis[4-(4-aminophenoxy)-3-methylphenyl]propane, 2-[4-(4-aminophenoxy)phenyl]-2-[4-(4-aminophenoxy)-3,5-dimethylphenyl]propane, 2,2-bis[4-(4-aminophenoxy)-3,5-dimethylphenyl]propane, 2,2-Bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 1,4-bis(3-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, bis[4-(4-aminophenoxy)phenyl]ketone, bis[4-(4-aminophenoxy)phenyl]sulfide, bis[4-(4-aminophenoxy)phenyl]sulfoxide, bis[4-(4-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)phenyl]ether, bis[4-(4-aminophenoxy)phenyl]ether, 1,3-bis[4-(4-aminophenoxy)benzoyl]benzene, 1,3-bis[4-(3-aminophenoxy)benzoyl]benzene, 1,4-bis[4-(3-aminophenoxy)benzoyl]benzene, 4,4'-bis[(3-aminophenoxy)benzoyl]benzene, 1,1-bis[4-(3-aminophenoxy)phenyl]propane, 1,3-bis[4-(3-aminophenoxy)phenyl]propane, 3,4'-diaminodiphenyl sulfide, 2,2-bis[3-(3-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, bis[4-(3-aminophenoxy)phenyl]methane, 1,1-bis[4-(3-aminophenoxy)phenyl]ethane, 1,2-bis[4-(3-aminophenoxy)phenyl]ethane, bis[4-(3-aminophenoxy)phenyl]sulfoxide, 4,4'-bis[3-(4-aminophenoxy)benzoyl]diphenyl ether, 4,4'-bis[3-(3-aminophenoxy)benzoyl]diphenyl ether, 4,4'-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]benzophenone, 4,4'-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]diphenyl sulfone, bis[4-{4-(4-aminophenoxy)phenoxy}phenyl]sulfone, 1,4-bis[4-(4-aminophenoxy)phenoxy-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-aminophenoxy)phenoxy-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-amino-6-trifluoromethylphenoxy)-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-amino-6-fluorophenoxy)-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-amino-6-methylphenoxy)-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-amino-6-cyanophenoxy)-α,α-dimethylbenzyl]benzene, 3,3'-diamino-4,4'-diphenoxybenzophenone, 4,4'-diamino-5,5'-diphenoxybenzophenone, 3,4'-diamino-4,5'-diphenoxybenzophenone, 3,3'-diamino-4-phenoxybenzophenone, 4,4'-diamino-5-phenoxybenzophenone, 3,4'-diamino-4-phenoxybenzophenone, 3,4'-diamino-5'-phenoxybenzophenone, 3,3'-diamino-4,4'-Biphenyloxybenzophenone, 4,4'-diamino-5,5'-biphenyloxybenzophenone, 3,4'-diamino-4,5'-biphenyloxybenzophenone, 3,3'-diamino-4-biphenyloxybenzophenone, 4,4'-diamino-5-biphenyloxybenzophenone, 3,4'-diamino-4-biphenyloxybenzophenone, 3,4'-diamino-5'-biphenyloxybenzophenone, 1,3-bis(3-amino-4-phenoxybenzoyl)benzene, 1,4-bis(3-amino-4-phenoxybenzoyl)benzene, 1,3-bis(4-amino-5-phenoxybenzoyl)benzene, 1,4-bis(4-amino-5-phenoxybenzoyl)benzene, 1,3-bis(3-amino-4-biphenyloxybenzoyl)benzene, 1,4-bis(3-amino-4-biphenyloxybenzoyl)benzene, 1,3-bis(4-amino-5-biphenyloxybenzoyl)benzene, 1,4-bis(4-amino-5-biphenyloxybenzoyl)benzene, 2,6-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]benzonitrile, 4,4'-[9H-fluorene-9,9-diyl]dianiline (alias 9,9-bis(4-aminophenyl)fluorene), spiro(xanthene-9,9'-fluorene)-2,6-diylbis(oxycarbonyl)]dianiline, 4,4'-[spiro(xanthene-9,9'-fluorene)-2,6-diylbis(oxycarbonyl)]dianiline, 4,4'-[spiro(xanthene-9,9'-fluorene)-3,6-diylbis(oxycarbonyl)]dianiline, and aromatic diamines obtained by substituting some or all of the hydrogen atoms on the aromatic rings of the above aromatic diamines (the substituents are halogen atoms, alkyl or alkoxy groups having 1 to 3 carbon atoms, cyano groups, or halogenated alkyl or alkoxy groups having 1 to 3 carbon atoms in which some or all of the hydrogen atoms of the alkyl or alkoxy groups are substituted by halogen atoms), etc. In addition, as the aromatic diamines having the benzoxazole structure, there is no particular limitation, and examples thereof include 5-amino-2-(p-aminophenyl)benzoxazole, 6-amino-2-(p-aminophenyl)benzoxazole, 5-amino-2-(m-aminophenyl)benzoxazole, 6-amino-2-(m-aminophenyl)benzoxazole, 2,2'-p-phenylene bis(5-aminobenzoxazole), 2,2'-p-phenylene bis(6-aminobenzoxazole), 1-(5-aminobenzoxazole)-4-(6-aminobenzoxazole)benzene, 2,6-(4,4'-diaminodiphenyl)benzo[1,2-d:5,4-d']bisoxazole, 2,6-(4,4'-diaminodiphenyl)benzo[1,2-d:4,5-d']bisoxazole, 2,6-(3,4'-diaminodiphenyl)benzo[1,2-d:5,4-d']bisoxazole, 2,6-(3,4'-diaminodiphenyl)benzo[1,2-d:4,5-d']bisoxazole, 2,6-(3,3'-diaminodiphenyl)benzo[1,2-d:5,4-d']bisoxazole, 2,6-(3,3'-diaminodiphenyl)benzo[1,2-d:4,5-d' bisoxazoles and the like. Among these, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 4-amino-N-(4-aminophenyl)benzamide, 4,4'-diaminodiphenylsulfone, and 3,3'-diaminobenzophenone are particularly preferred. In addition, the aromatic diamines can be used alone or in combination of multiple types.

[0182] Examples of the alicyclic diamines include 1,4-cyclohexanediamine, 1,4-diamino-2-methylcyclohexane, 1,4-diamino-2-ethylcyclohexane, 1,4-diamino-2-n-propylcyclohexane, 1,4-diamino-2-isopropylcyclohexane, 1,4-diamino-2-n-butylcyclohexane, 1,4-diamino-2-isobutylcyclohexane, 1,4-diamino-2-sec-butylcyclohexane, 1,4-diamino-2-tert-butylcyclohexane, 4,4'-methylenebis(2,6-dimethylcyclohexylamine), and the like. Among these, 1,4-cyclohexanediamine and 1,4-diamino-2-methylcyclohexane are particularly preferred, and 1,4-cyclohexanediamine is more preferred. In addition, the alicyclic diamines can be used alone or in combination of multiple types.

[0183] As the diisocyanates, for example, diphenylmethane-2,4'-diisocyanate, 3,2'- or 3,3'- or 4,2'- or 4,3'- or 5,2'- or 5,3'- or 6,2'- or 6,3'-dimethyl diphenylmethane-2,4'-diisocyanate, 3,2'- or 3,3'- or 4,2'- or 4,3'- or 5,2'- or 5,3'- or 6,2'- or 6,3'-diethyl diphenylmethane-2,4'-diisocyanate, 3,2'- or 3,3'- or 4,2'- or 4,3'- or 5,2'- or 5,3'- or 6,2'- or 6,3'-dimethoxy diphenylmethane-2,4'-diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane-3,3'-diisocyanate, diphenylmethane-3,4'-diisocyanate, diphenyl ether-4,4'-diisocyanate, benzophenone-4,4'-diisocyanate, diphenyl sulfone-4,4'-diisocyanate, toluene-2,4-diisocyanate, toluene-2,6-diisocyanate, m-xylylene diisocyanate, p-xylylene diisocyanate, naphthalene-2,6-diisocyanate, 4,4'-(2,2-bis(4-phenoxyphenyl)propane) diisocyanate, 3,3'- or 2,2'-dimethylbiphenyl-4,4'-diisocyanate, 3,3'- or 2,2'-diethylbiphenyl-4,4'-diisocyanate, 3,3'-dimethoxybiphenyl-4,4'-diisocyanate, 3,3'-diethoxybiphenyl-4,4'-diisocyanate and other aromatic diisocyanates, and diisocyanates obtained by hydrogenating any one of these (for example, isophorone diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, hexamethylene diisocyanate), etc. Among these, from the viewpoints of low hygroscopicity, dimensional stability, price, and polymerizability, diphenylmethane-4,4'-diisocyanate, toluene-2,4-diisocyanate, toluene-2,6-diisocyanate, 3,3'-dimethylbiphenyl-4,4'-diisocyanate, naphthalene-2,6-diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 1,4-cyclohexane diisocyanate are preferred. In addition, the diisocyanates can be used alone or in combination of multiple kinds.

[0184] As the solvent, any solvent that can dissolve the polyimide or polyimide precursor may be used, and aprotic polar solvents etc. are preferably used. For example, N,N-dialkylcarboxamides such as N,N-dimethylformamide, N,N-dimethylacetamide, N,N-diethylacetamide, N,N-dimethylmethoxyacetamide; N-methyl-2-pyrrolidone, N-ethyl-2-pyrrolidone, dimethyl sulfoxide, dimethyl sulfone, 1,3-dimethyl-2-imidazolidinone, γ-butyrolactone, diglyme, m-cresol, hexamethylphosphoramide, N-acetyl-2-pyrrolidone, hexamethylphosphoramide, ethyl cellosolve acetate, diethylene glycol dimethyl ether, sulfolane, p-chlorophenol etc. In addition, the solvent may also be a mixture of two or more.

[0185] There is no particular limitation on the filler, and organic particles, inorganic particles etc. may be mentioned, and inorganic particles are particularly preferred. As the inorganic particles, metal oxide particles such as silica, zirconia, alumina, titanium dioxide, titanium oxide, zinc oxide, germanium oxide, indium oxide, tin oxide, indium tin oxide (ITO), antimony oxide, cerium oxide; metal fluoride particles such as magnesium fluoride, sodium fluoride etc. may be mentioned. In addition, a transparent or colorless filler is preferred. From the viewpoints of dispersibility in the resin and heat resistance, silica is more preferred.

[0186] The shape of the filler is not particularly limited and may be particulate or fibrous.

[0187] The size of the filler is not particularly limited, and is preferably 0.5 to 180 nm, more preferably 2 to 100 nm. If it is 0.5 nm or more, the low CTE effect of the resin film can be exhibited. In addition, if it is 180 nm or less, turbidity, cloudiness or coloring of the resin film can be suppressed.

[0188] The filler may be used alone or in combination of multiple kinds.

[0189] The position of the filler present in the resin film is not particularly limited, and it may be dispersed throughout the resin film, may be concentrated at a specific position within the resin film, or may be exposed from the surface of the resin film.

[0190] The second resin composition solution contains a second resin, does not contain a filler or even if it contains a filler, its content is less than that of the first resin composition solution, and is 2% by mass or less relative to the second resin.

[0191] The second resin composition solution does not contain a filler, or even if it contains a filler, the content is less than that of the first resin composition solution and is 2% by mass or less relative to the second resin. Considering the aspect that the tear strength at both ends becomes good, the filler amount relative to the second resin is preferably 1% by mass or less, more preferably 0.5% by mass or less, still more preferably 0.1% by mass or less, and particularly preferably 0% by mass.

[0192] As the second resin, as long as it can be made into a film from a solution and has a greater tear strength than the first resin when forming a film, there is no particular limitation. It may have the same composition as the first resin or a different composition. Specifically, examples include cellulose triacetate, aromatic polyamide, polyimide, polyetherimide, polyamideimide, polyesterimide, polybenzoxazole, polybenzimidazole, polybenzothiazole, etc. In addition, as a polyimide precursor, polyamic acid can be cited. Among these, polyimide-based resins such as polyimide, polyamideimide, polyetherimide, and polyimide benzoxazole are particularly preferably applicable. In addition, as the second resin composition solution, for example, a polyimide-based resin composition solution, a polyamide-based resin composition solution, a polyamideimide-based resin composition solution, etc. can be cited. Among them, when using a polyimide-based resin composition solution as the first resin composition solution, from the viewpoint of heat resistance proximity, etc., it is preferable to also use a polyimide-based resin composition solution as the second resin composition solution. It is preferred that the second resin composition solution has heat resistance equal to or higher than that of the first resin composition solution.

[0193] From the viewpoints of workability (coating property) and economy, the concentration of the second resin in the second resin composition solution is preferably 1% by mass or more, more preferably 5% by mass or more, still more preferably 10% by mass or more. In addition, it is preferably 80% by mass or less, more preferably 60% by mass or less, still more preferably 40% by mass or less.

[0194] The second polyimide-based resin composition solution may be a polyamic acid (polyimide precursor) solution or a polyimide solution. When using a polyamic acid solution, a dehydration ring-closure reaction is carried out by heat treatment in step F to form a polyimide film. When using a polyimide solution, a polyimide film is formed by volatilizing the solvent in step C. The heat treatment conditions are the same as those of the first polyimide-based resin composition solution.

[0195] The polyamic acid solution is obtained by reacting diamines and tetracarboxylic dianhydrides in a solvent.

[0196] As the tetracarboxylic acids, aromatic tetracarboxylic acids (including their acid anhydrides), aliphatic tetracarboxylic acids (including their acid anhydrides), and alicyclic tetracarboxylic acids (including their acid anhydrides) that are generally used in polyimide synthesis can be used. Among them, aromatic tetracarboxylic anhydrides and alicyclic tetracarboxylic anhydrides are preferred. The tetracarboxylic acids can be used alone or in combination of two or more.

[0197] As the alicyclic tetracarboxylic acids, for example, alicyclic tetracarboxylic acids such as cyclobutane tetracarboxylic acid, 1,2,4,5-cyclohexane tetracarboxylic acid, 3,3’,4,4’-bicyclohexyltetracarboxylic acid, and acid anhydrides thereof can be cited. Among these, dianhydrides having two acid anhydride structures (for example, cyclobutane tetracarboxylic dianhydride, 1,2,4,5-cyclohexane tetracarboxylic dianhydride, 3,3’,4,4’-bicyclohexyltetracarboxylic dianhydride, etc.) are preferred. In addition, the alicyclic tetracarboxylic acids can be used alone or in combination of two or more.

[0198] When transparency is emphasized, for example, the alicyclic tetracarboxylic acids are preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 95% by mass or more of the total tetracarboxylic acids.

[0199] The aromatic tetracarboxylic acids are not particularly limited, and examples thereof include pyromellitic dianhydride, 3,3’,4,4’-biphenyltetracarboxylic dianhydride, 4,4’-oxydiphthalic dianhydride, 3,3’,4,4’-benzophenonetetracarboxylic dianhydride, 3,3’,4,4’-biphenylsulfonetetracarboxylic dianhydride, 2,2-bis[4-(3,4-dicarboxyphenoxy)phenyl]propanoic anhydride, etc.

[0200] When heat resistance is emphasized, for example, the aromatic tetracarboxylic acids are preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 95% by mass or more of the total tetracarboxylic acids.

[0201] As the diamines, there is no particular limitation, and aromatic diamines, aliphatic diamines, etc. that are generally used in polyimide synthesis can be used. From the viewpoint of heat resistance, aromatic diamines are preferred, and among the aromatic diamines, aromatic diamines having a benzoxazole structure are more preferred. When using aromatic diamines having a benzoxazole structure, high heat resistance, high elastic modulus, low thermal shrinkage, and low linear expansion coefficient can be exhibited. The diamines can be used alone or in combination of two or more.

[0202] The aromatic diamines having a benzoxazole structure are not particularly limited. For example, 5-amino-2-(p-aminophenyl)benzoxazole, 6-amino-2-(p-aminophenyl)benzoxazole, 5-amino-2-(m-aminophenyl)benzoxazole, 6-amino-2-(m-aminophenyl)benzoxazole, 2,2'-p-phenylene bis(5-aminobenzoxazole), 2,2'-p-phenylene bis(6-aminobenzoxazole), 1-(5-aminobenzoxazole)-4-(6-aminobenzoxazole)benzene, 2,6-(4,4'-diaminodiphenyl)benzo[1,2-d:5,4-d']bisoxazole, 2,6-(4,4'-diaminodiphenyl)benzo[1,2-d:4,5-d']bisoxazole, 2,6-(3,4'-diaminodiphenyl)benzo[1,2-d:5,4-d']bisoxazole, 2,6-(3,4'-diaminodiphenyl)benzo[1,2-d:4,5-d']bisoxazole, 2,6-(3,3'-diaminodiphenyl)benzo[1,2-d:5,4-d']bisoxazole, 2,6-(3,3'-diaminodiphenyl)benzo[1,2-d:4,5-d']bisoxazole, etc. can be cited.

[0203] As aromatic diamines other than the aromatic diamines having the above benzoxazole structure, for example, 2,2'-dimethyl-4,4'-diaminobiphenyl, 1,4-bis[2-(4-aminophenyl)-2-propyl]benzene (bisaniline), 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-bis(3-aminophenoxy)biphenyl, bis[4-(3-aminophenoxy)phenyl]ketone, bis[4-(3-aminophenoxy)phenyl]sulfide, bis[4-(3-aminophenoxy)phenyl]sulfone, 2,2-bis[4-(3-aminophenoxy)phenyl]propane, 2,2-bis[4-(3-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, m-phenylenediamine, o-phenylenediamine, p-phenylenediamine, m-aminobenzylamine, p-aminobenzylamine, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl sulfide, 3,3'-diaminodiphenyl sulfoxide, 3,4'-diaminodiphenyl sulfoxide, 4,4'-diaminodiphenyl sulfoxide, 3,3'-diaminodiphenyl sulfone, 3,4'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminobenzophenone, 3,4'-diaminobenzophenone, 4,4'-diaminobenzophenone, 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, bis[4-(4-aminophenoxy)phenyl]methane, 1,1-bis[4-(4-aminophenoxy)phenyl]ethane, 1,2-bis[4-(4-aminophenoxy)phenyl]ethane, 1,1-bis[4-(4-aminophenoxy)phenyl]propane, 1,2-bis[4-(4-aminophenoxy)phenyl]propane, 1,3-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 1,1-bis[4-(4-aminophenoxy)phenyl]butane, 1,3-bis[4-(4-aminophenoxy)phenyl]butane, 1,4-bis[4-(4-aminophenoxy)phenyl]butane, 2,2-bis[4-(4-aminophenoxy)phenyl]butane, 2,3-bis[4-(4-aminophenoxy)phenyl]butane, 2-[4-(4-aminophenoxy)phenyl]-2-[4-(4-aminophenoxy)-3-methylphenyl]propane, 2,2-bis[4-(4-aminophenoxy)-3-methylphenyl]propane, 2-[4-(4-aminophenoxy)phenyl]-2-[4-(4-aminophenoxy)-3,5-dimethylphenyl]propane, 2,2-bis[4-(4-aminophenoxy)-3,5-dimethylphenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 1,4-bis(3-aminophenoxy)benzene, 1,3-Bis(3-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, 4,4'-bis(4-aminophenoxy)biphenyl, bis[4-(4-aminophenoxy)phenyl]ketone, bis[4-(4-aminophenoxy)phenyl]sulfide, bis[4-(4-aminophenoxy)phenyl]sulfoxide, bis[4-(4-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)phenyl]ether, bis[4-(4-aminophenoxy)phenyl]ether, 1,3-bis[4-(4-aminophenoxy)benzoyl]benzene, 1,3-bis[4-(3-aminophenoxy)benzoyl]benzene, 1,4-bis[4-(3-aminophenoxy)benzoyl]benzene, 4,4'-bis[(3-aminophenoxy)benzoyl]benzene, 1,1-bis[4-(3-aminophenoxy)phenyl]propane, 1,3-bis[4-(3-aminophenoxy)phenyl]propane, 3,4'-diaminodiphenyl sulfide, 2,2-bis[3-(3-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, bis[4-(3-aminophenoxy)phenyl]methane, 1,1-bis[4-(3-aminophenoxy)phenyl]ethane, 1,2-bis[4-(3-aminophenoxy)phenyl]ethane, bis[4-(3-aminophenoxy)phenyl]sulfoxide, 4,4'-bis[3-(4-aminophenoxy)benzoyl]diphenyl ether, 4,4'-bis[3-(3-aminophenoxy)benzoyl]diphenyl ether, 4,4'-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]benzophenone, 4,4'-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]diphenyl sulfone, bis[4-{4-(4-aminophenoxy)phenoxy}phenyl]sulfone, 1,4-bis[4-(4-aminophenoxy)phenoxy-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-aminophenoxy)phenoxy-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-amino-6-trifluoromethylphenoxy)-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-amino-6-fluorophenoxy)-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-amino-6-methylphenoxy)-α,α-dimethylbenzyl]benzene, 1,3-bis[4-(4-amino-6-cyanophenoxy)-α,α-dimethylbenzyl]benzene, 3,3'-diamino-4,4'-diphenoxybenzophenone, 4,4'-diamino-5,5'-diphenoxybenzophenone, 3,4'-diamino-4,5'-diphenoxybenzophenone, 3,3'-diamino-4-phenoxybenzophenone, 4,4'-diamino-5-phenoxybenzophenone, 3,4'-diamino-4-phenoxybenzophenone, 3,4'-diamino-5'-phenoxybenzophenone, 3,3'-diamino-4,4'-dibiphenoxybenzophenone, 4,4'-diamino-5,5'-dibiphenoxybenzophenone, 3,4'-diamino-4,5'-Diphenoxydibenzophenone, 3,3'-diamino-4-biphenoxydibenzophenone, 4,4'-diamino-5-biphenoxydibenzophenone, 3,4'-diamino-4-biphenoxydibenzophenone, 3,4'-diamino-5'-biphenoxydibenzophenone, 1,3-bis(3-amino-4-phenoxybenzoyl)benzene, 1,4-bis(3-amino-4-phenoxybenzoyl)benzene, 1,3-bis(4-amino-5-phenoxybenzoyl)benzene, 1,4-bis(4-amino-5-phenoxybenzoyl)benzene, 1,3-bis(3-amino-4-biphenoxybenzoyl)benzene, 1,4-bis(3-amino-4-biphenoxybenzoyl)benzene, 1,3-bis(4-amino-5-biphenoxybenzoyl)benzene, 1,4-bis(4-amino-5-biphenoxybenzoyl)benzene, 2,6-bis[4-(4-amino-α,α-dimethylbenzyl)phenoxy]benzonitrile, and aromatic diamines formed by substituting a part or all of the hydrogen atoms on the aromatic ring of the above aromatic diamines (the substituents are halogen atoms, alkyl or alkoxy groups having 1 to 3 carbon atoms, cyano groups, or halogenated alkyl or alkoxy groups having 1 to 3 carbon atoms formed by substituting a part or all of the hydrogen atoms of the alkyl or alkoxy group with halogen atoms), etc.,

[0204] As the aliphatic diamines, for example, 1,2-diaminoethane, 1,4-diaminobutane, 1,5-diaminopentane, 1,6-diaminohexane, 1,8-diaminooctane, etc. can be cited.

[0205] In addition, as the aliphatic diamines, for example, 1,4-cyclohexanediamine, 4,4'-methylenebis(2,6-dimethylcyclohexylamine), etc. can be cited.

[0206] The total amount of diamines other than aromatic diamines (aliphatic diamines) is preferably 20% by mass or less, more preferably 10% by mass or less, and further preferably 5% by mass or less of the total diamines. In other words, the aromatic diamines are preferably 80% by mass or more, more preferably 90% by mass or more, and further preferably 95% by mass or more of the total diamines.

[0207] As the solvent, the same solvent as that described in the item of the first resin composition solution can be used.

[0208] [Pre-cut film]

[0209] The pre-cut film according to this embodiment has a central portion and both end portions continuously formed at both ends of the central portion.

[0210] The central portion is composed of a first resin composition containing a first resin and a filler, and the content of the filler is 0.1% by mass or more and 50% by mass or less with respect to the first resin.

[0211] Both end portions are made of a second resin composition containing a second resin. The second resin composition does not contain a filler, or even if it contains a filler, the content thereof is less than that of the first resin composition and is 2% by mass or less with respect to the second resin.

[0212] The tear strength of both end portions is greater than the tear strength of the central portion.

[0213] The film before cutting can be obtained through the processes A to C of the resin film manufacturing method according to this embodiment.

[0214] Here, the "first resin composition" refers to the composition (sheet) after drying the first resin composition solution in Process C, and the "second resin composition" refers to the composition (sheet) after drying the second resin composition solution in Process C.

[0215] The CTE of the central portion of the film before cutting is preferably 5 ppm / K or more and 50 ppm / K or less. From the aspect of improving the heat resistance of the resin film, it is preferably 45 ppm / K or less, more preferably 40 ppm / K or less, and further preferably 35 ppm / K or less. Industrially, it can be 6 ppm / K or more, or 7 ppm / K or more.

[0216] The total light transmittance of the central portion of the film before cutting is preferably 80% or more, more preferably 85% or more, and further preferably 88% or more. There is no particular limitation on the upper limit of the total light transmittance, and industrially, it can be 99% or less, or 98% or less.

[0217] The haze rate of the central portion of the film before cutting is preferably 5% or less, more preferably 3% or less, and further preferably 1% or less. There is no particular limitation on the lower limit of the haze rate, and industrially, it can be 0.01% or more, or 0.1% or more.

[0218] The YI (yellowness index) of the central portion of the film before cutting is preferably 10 or less, more preferably 7 or less, and further preferably 5 or less. There is no particular limitation on the lower limit of the YI (yellowness index), and industrially, it can be 1 or more.

[0219] The static friction coefficient of the central portion of the film before cutting is preferably 2.5 or less, more preferably 2 or less, and further preferably 1.5 or less. There is no particular limitation on the lower limit of the static friction coefficient, and industrially, it can be 0.01 or more, or 0.1 or more.

[0220] The tear strength of the central portion is preferably in the range of 0.1 to 15 N / mm, more preferably in the range of 1 to 10 N / mm, in the following measurement method.

[0221] The tearing strength at both ends is preferably in the range of 0.5 to 30 N / mm, more preferably in the range of 1 to 20 N / mm, in the following measurement method.

[0222] In addition, the tearing strength at both ends is preferably more than 1 times and 10 times or less of the tearing strength at the central part, and more preferably more than 1.1 times and 5 times or less.

[0223] <Measurement method of tearing strength>

[0224] According to the trouser-shaped tearing method described in JIS K7128-1, the test speed is set at 200 mm / min, and the average value of the remaining 50 mm after excluding the first 20 mm at the start of tearing and the last 5 mm before the end of tearing is taken as the tearing strength.

[0225] [Tearing strength (N / mm)] = [Tearing force of test piece (N)] / [Thickness (d) of test piece]

[0226] The width of both ends (width of each end) is not particularly limited as long as it can be held by an existing well-known tenter conveyor. Generally, it is 5 mm or more, more preferably 10 mm or more. The upper limit of the width is not particularly limited. For example, as long as the total of both ends is 50% or less of the total width of the film, more preferably 30% or less, and further preferably 10% or less.

[0227] The width of both ends (width of each end) is not particularly limited as long as it can be held by an existing well-known tenter conveyor. For example, the total of the widths of both ends is 0.1% or more of the total width of the film, more preferably 0.5% or more, and further preferably 1% or more. The upper limit of the width is not particularly limited. For example, as long as the total of the widths of both ends is 50% or less of the total width of the film, more preferably 30% or less, and further preferably 10% or less.

[0228] The film before cutting according to this embodiment has been described above.

[0229] Examples

[0230] Hereinafter, the present invention will be described in detail using examples, but the present invention is not limited to the following examples as long as it does not exceed its gist.

[0231] [Synthesis Example 1 (Preparation of polyamic acid solution A)]

[0232] After nitrogen replacement in a reaction vessel equipped with a nitrogen inlet tube, a thermometer, and a stirrer, 1,470.8 parts by mass of 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA), 775.6 parts by mass of 4,4'-oxydiphthalic acid (ODPA), 3,202.4 parts by mass of 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFMB), 5,448.8 parts by mass of dimethylacetamide-dispersed silica sol (DMAc-ST manufactured by Nissan Chemical), and 21,795 parts by mass of N,N-dimethylacetamide were added to the reaction vessel under a nitrogen atmosphere and dissolved, and then stirred at room temperature for 24 hours to obtain polyamic acid solution A with a specific viscosity of 4.5 dl / g and a solid content of 17.2 mass%.

[0233] [Synthesis Example 2 (Preparation of Polyimide Solution B)]

[0234] After nitrogen replacement in a reaction vessel equipped with a nitrogen inlet tube, a thermometer, and a stirrer, 551 parts by mass of N,N-dimethylacetamide (DMAC) and 64.1 parts by mass of 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl (TFMB) were added to the reaction vessel and stirred to dissolve TFMB in DMAC. Then, while stirring in the reaction vessel, 44.4 parts by mass of 4,4'-(2,2-hexafluoroisopropylidene)diphthalic anhydride (6FDA) and 29.4 parts by mass of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA) were introduced in a nitrogen stream over about 10 minutes, and the temperature was directly adjusted to the temperature range of 20 - 40 °C while continuously stirring for 6 hours to carry out a polymerization reaction, obtaining a viscous polyamic acid solution.

[0235] Next, after diluting the obtained polyamic acid solution with 410 parts by mass of DMAC, 25.83 parts by mass of isoquinoline as an imidization accelerator was added, and while stirring the polyamic acid solution, the temperature was maintained in the range of 30 - 40 °C. Here, as an imidizing agent, 122.5 parts by mass of acetic anhydride was slowly added dropwise over about 10 minutes, and then the liquid temperature was further maintained at 30 - 40 °C and continuously stirred for 12 hours to carry out a chemical imidization reaction, obtaining a polyimide solution.

[0236] Next, 1000 parts by mass of the obtained polyimide solution containing an imidizing agent and an imidization accelerator was transferred to a reaction vessel equipped with a stirring device and a stirring blade, and while stirring at a speed of 120 rpm and maintaining a temperature of 15 to 25°C, 1500 parts by mass of methanol was added dropwise thereto at a rate of 10 g / minute. When about 800 parts by mass of methanol was added, the turbidity of the polyimide solution was confirmed, and the precipitation of powdery polyimide was confirmed. The addition of a total of 1500 parts by mass of methanol was continued to complete the precipitation of the polyimide. Then, the content of the reaction vessel was filtered through a suction filtration device, and further washed and filtered using 1000 parts by mass of methanol. Then, using a dryer equipped with a local exhaust device, 50 parts by mass of the filtered polyimide powder was dried at 50°C for 24 hours and further dried at 260°C for 2 hours to remove the remaining volatile components, obtaining a polyimide powder. The inherent viscosity of the obtained polyimide powder was 2.1 dl / g. Next, 42 parts by mass of the obtained polyimide powder was dissolved in 168 parts by mass of DMAC to obtain a polyimide solution B having a solid content of 20% by mass.

[0237] [Synthesis Example 3 (Preparation of Polyimide Solution C)]

[0238] In a reaction vessel equipped with a nitrogen inlet tube, a Dean-Stark apparatus, a reflux tube, a thermometer, and a stir bar, while introducing nitrogen, 124.15 parts by mass of 4,4'-diaminodiphenyl sulfone (4,4'-DDS), 124.15 parts by mass of 3,3'-diaminodiphenyl sulfone (3,3'-DDS), and 750 parts by mass of γ-butyrolactone (GBL) were added. Next, 248.18 parts by mass of 4,4'-oxydiphthalic dianhydride (ODPA), 58.8 parts by mass of biphenyltetracarboxylic dianhydride (BPDA), 335 parts by mass of GBL, and 390 parts by mass of toluene were added at room temperature, and then the temperature was raised to an internal temperature of 160°C, and heating reflux was carried out at 160°C for 1 hour for imidization. After the imidization was completed, the temperature was raised to 180°C, and the reaction was continued while removing toluene. After reacting for 12 hours, it was taken out of the oil bath and returned to room temperature, and 1149 parts by mass of GBL was added to make the solid content 20% by mass, obtaining a polyimide solution C having an inherent viscosity of 0.6 dl / g.

[0239] [Synthesis Example 4 (Preparation of Polyamic Acid Solution D)]

[0240] After nitrogen replacement in a reaction vessel equipped with a nitrogen inlet tube, a thermometer, and a stirrer, 196.1 parts by mass of 1,2,3,4-cyclobutanetetracarboxylic dianhydride (CBDA), 227.3 parts by mass of 4-amino-N-(4-aminophenyl)benzamide (DABAN), and 1694 parts by mass of N,N-dimethylacetamide were added to the reaction vessel under a nitrogen atmosphere. After dissolution, the mixture was stirred at room temperature for 24 hours to obtain a polyamic acid solution D with a specific viscosity of 4.5 dl / g and a solid content of 20 mass%.

[0241] [Synthesis Example 5 (Preparation of polyamide-imide solution E)]

[0242] After nitrogen replacement in a reaction vessel equipped with a nitrogen inlet tube, a thermometer, and a stirrer, 153.7 parts by mass of trimellitic anhydride, 256.4 parts by mass of O-tolidine diisocyanate, 29.4 parts by mass of 3,3',4,4'-biphenyltetracarboxylic dianhydride (BPDA), 32.2 parts by mass of 3,3’,4,4’-benzophenonetetracarboxylic dianhydride (BTDA), 1 part by mass of triethylenediamine, and 1671 parts by mass of N-methyl-2-pyrrolidone were added. While stirring, the temperature was raised to 130 °C over 1 hour, and the reaction was further carried out at 130 °C for 5 hours to obtain a polyamide-imide resin solution E with a specific viscosity of 1.6 dl / g.

[0243] [Specific viscosity]

[0244] The specific viscosities (dL / g) of the prepared polyamic acid solutions A and D, polyimide solutions B and C, and polyamide-imide acid solution E were measured at 30 °C using an Ubbelohde viscometer by dissolving 0.02 g of each sample in 10 mL of a mixed solvent (phenol / tetrachloroethane = 60 / 40 (mass ratio)).

[0245] (Example 1)

[0246] Prepare polyamic acid solution A (Synthesis Example 1 (PAA-A)). To a part of it, Snowtex (registered trademark) DMAc-ST (a DMAc dispersion of silica with an average particle size of 10 nm. Active ingredient 20 mass%: Nissan Chemical Industries, Ltd.) was added while stirring polyamic acid solution A so that the active ingredient became 10 mass% relative to the resin. Then, stirring was continued for 6 hours to obtain polyamic acid solution A-1 (PAA-A1).

[0247] Use Figure 1 、 Figure 2The comma coater shown coats a polyamic acid solution A-1 on the central part with a width of 500 mm of a PET film (A4100 manufactured by Toyobo Co., Ltd.) serving as a support, and adjusts the gap so that the final film thickness becomes 22 μm. At the same time, the polyamic acid solution A is coated on both ends thereof with a width of 50 mm each. At this time, side plates with a width of 10 mm are used.

[0248] Next, it is dried at 100 to 110 °C for 10 minutes to form a polyamic acid film. After drying, it is wound together with the PET film around a 6-inch ABS core to obtain a polyamic acid film roll. The polyamic acid film and the PET film are unrolled from the obtained polyamic acid film roll, and the polyamic acid film is peeled off from the PET film to become a self-supporting polyamic acid film, thereby obtaining a polyamic acid film.

[0249] The obtained polyamic acid film is passed through a pin-type tenter. The above-mentioned pin-type tenter has a pin plate configured by arranging pins in a manner of fixing the pin intervals. The film ends are inserted into the pins to be held, and the pin plate intervals are adjusted so that the film does not break and no unnecessary slack is generated. It is conveyed in such a way that the final pin plate interval is 520 mm, and heating is carried out under the following conditions to carry out an imidization reaction: the first stage is at 200 °C for 3 minutes, the second stage is at 250 °C for 3 minutes, the third stage is at 300 °C for 3 minutes, and the fourth stage is at 350 °C for 3 minutes. Then, it is cooled to room temperature in 2 minutes. Next, the film ends formed from the polyamic acid solution A are cut into only the central part to obtain a polyimide film with a thickness of 22 μm and a width of 480 mm.

[0250] (Example 2)

[0251] Prepare polyamic acid solution A (Synthesis Example 1). To a part of it, Snowtex (registered trademark) DMAc-ST (a DMAc dispersion of silica with an average particle size of 10 nm. Active ingredient 20%: Nissan Chemical Industries, Ltd.) is added while stirring the polyamic acid solution A so that the active ingredient becomes 5% by mass relative to the resin. Then, stirring is continued for 6 hours to obtain polyamic acid solution A-2 (PAA-A2). Next, Snowtex (registered trademark) DMAc-ST-ZL (a DMAc dispersion of silica with an average particle size of 80 nm. Active ingredient 20%: Nissan Chemical Industries, Ltd.) is added while stirring to the remaining polyamic acid solution A so that the active ingredient becomes 0.5% by mass relative to the resin. Then, stirring is continued for 6 hours to obtain polyamic acid solution A-3 (PAA-A3).

[0252] The gap is adjusted so that the final film thickness becomes 10 μm, and polyamic acid solution A-2 is coated instead of polyamic acid solution A-1, and polyamic acid solution A-3 is coated instead of polyamic acid solution A. Except for this, in the same manner as in Example 1, a polyimide film with a thickness of 10 μm and a width of 480 mm is obtained.

[0253] (Example 3)

[0254] Prepare polyamic acid solution A (Synthesis Example 1). To a part of it, while further stirring polyamic acid solution A, add Snowtex (registered trademark) DMAc-ST (a DMAc dispersion of silica with an average particle size of 10 nm. Active ingredient: 20% by mass, Nissan Chemical Industries, Ltd.) and Snowtex (registered trademark) DMAc-ST-ZL (a DMAc dispersion of silica with an average particle size of 80 nm. Active ingredient: 20% by mass, Nissan Chemical Industries, Ltd.) such that the active ingredients become 0.3% by mass and 0.2% by mass relative to the resin, respectively. Then, continue stirring for 6 hours to obtain polyamic acid solution A-4 (PAA-A4).

[0255] Adjust the gap to achieve a final film thickness of 35 μm and coat polyamic acid solution A-4 (instead of polyamic acid solution A-1). Otherwise, in the same manner as in Example 1, a polyimide film with a thickness of 35 μm and a width of 480 mm is obtained.

[0256] (Example 4)

[0257] Prepare polyimide solution B (Synthesis Example 2 (PI-B)). To a part of it, while stirring polyimide solution B, add Snowtex (registered trademark) DMAc-ST (a DMAc dispersion of silica with an average particle size of 10 nm. Active ingredient: 20% by mass, Nissan Chemical Industries, Ltd.) such that the active ingredient becomes 10% by mass relative to the resin. Then, continue stirring for 6 hours to obtain polyimide solution B-1 (PI-B1).

[0258] Adjust the gap to achieve a final film thickness of 115 μm and coat polyimide solution B-1 instead of polyamic acid solution A-1 and polyimide solution B instead of polyamic acid solution A. Otherwise, in the same manner as in Example 1, a polyimide film with a thickness of 115 μm and a width of 480 mm is obtained.

[0259] (Example 5)

[0260] Prepare polyimide solution C (Synthesis Example 3 (PI-C)). To a part of it, while stirring polyimide solution B, add Snowtex (registered trademark) DMAc-ST (a DMAc dispersion of silica with an average particle size of 10 nm. Active ingredient: 20% by mass, Nissan Chemical Industries, Ltd.) such that the active ingredient becomes 10% by mass relative to the resin. Then, continue stirring for 6 hours to obtain polyimide solution C-1 (PI-C1).

[0261] With Figure 7 、 Figure 8The comma coater shown applies polyimide solution C on both end portions onto a mirror-finished stainless steel belt, and then applies polyimide solution C-1 in the central portion using a T-die and adjusts the gap so that the final film thickness becomes 25 μm. At this time, the coating is performed such that the width of the central portion is 1000 mm and each of the end portions is 50 mm wide.

[0262] Next, it is dried at 100 to 110 °C for 10 minutes, and after drying, it is peeled off from the support to obtain a self-supporting polyimide film.

[0263] The film before cutting obtained is passed through a pin stenter. The above-mentioned pin stenter has a pin board configured by arranging pins in a manner fixed at a pin interval. The film end portion is inserted into the pins to be held, and the pin board interval is adjusted so that the film does not break and no unnecessary slack is generated. It is conveyed in such a way that the final pin board interval becomes 1000 mm, and heating is performed under the following conditions to carry out the imidization reaction: the first stage is at 200 °C for 3 minutes, the second stage is at 250 °C for 3 minutes, the third stage is at 300 °C for 3 minutes, and the fourth stage is at 350 °C for 3 minutes. Then, it is cooled to room temperature in 2 minutes. Next, the film end portion formed from polyimide solution B is cut into only the central portion and continuously wound into a roll shape on a 3-inch ABS resin core to obtain a polyimide film with a thickness of 25 μm, a width of 980 mm, and a length of 500 m.

[0264] (Example 6)

[0265] Prepare polyimide solution A (Synthesis Example 1) and polyamic acid solution D (Synthesis Example 4 (PAA-D)). To a part of this polyamic acid solution A, while stirring polyimide solution A, Snowtex (registered trademark) DMAc-ST-ZL (a DMAc dispersion of silica with an average particle size of 80 nm. Active ingredient 20 mass%: Nissan Chemical Industries, Ltd.) is added so that the active ingredients each become 0.1 mass% relative to the resin. Then, stirring is continued for 6 hours to obtain polyimide solution A-5 (PAA-A5). Next, to a part of polyamic acid solution D, while stirring polyimide solution B, Snowtex (registered trademark) DMAc-ST-ZL (a DMAc dispersion of silica with an average particle size of 80 nm. Active ingredient 20 mass%: Nissan Chemical Industries, Ltd.) is added so that the active ingredients each become 0.5 mass% relative to the resin. Then, stirring is continued for 6 hours to obtain polyimide solution D-1 (PAA-D1).

[0266] Using Figure 9 、 Figure 10For the T-die shown, polyimide solution A-5 was coated on the mirror-finished stainless steel belt at both ends, and polyamic acid solution D-1 was coated in the central part with the T-die, and the gap was adjusted so that the final film thickness became 26 μm. At this time, the coating was performed such that the width of the central part was 1000 mm and the widths of both ends were 50 mm each.

[0267] Next, it was dried at 100 to 110 °C for 10 minutes, and after drying, it was peeled off from the support to obtain a self-supporting polyamic acid film.

[0268] The obtained film before cutting was passed through a pin-type tenter. The above-mentioned pin-type tenter has a pin plate configured by arranging pins in a manner that the pin intervals are fixed. The film end was inserted into the pins to hold it, and the pin plate interval was adjusted so that the film did not break and no unnecessary slack was generated. It was conveyed in such a way that the final pin plate interval became 520 mm, and heating was carried out under the following conditions to perform an imidization reaction: the first stage was at 200 °C for 3 minutes, the second stage was at 250 °C for 3 minutes, the third stage was at 300 °C for 3 minutes, and the fourth stage was at 350 °C for 3 minutes. Then, it was cooled to room temperature in 2 minutes. Next, the film end formed from polyimide solution A-5 was cut into only the central part and continuously wound into a roll shape on a 3-inch ABS resin core to obtain a polyimide film with a thickness of 26 μm, a width of 980 mm, and a length of 500 m.

[0269] (Example 7)

[0270] Prepare polyamide-imide solution E (Synthesis Example 5 (PAI-E)). To a part of this polyamide-imide solution E, Snowtex (registered trademark) DMAc-ST (DMAc dispersion of silica with an average particle size of 10 nm. Active ingredient 20%: Nissan Chemical Industries, Ltd.) was added while stirring the polyamide-imide solution E so that the active ingredients became 10% by mass with respect to the resin. Then, stirring was continued for 6 hours to obtain polyamide-imide solution E-1 (PAI-E1).

[0271] The gap was adjusted and polyamide-imide solution E was coated so that the final film thickness became 42 μm, replacing polyimide solution A-5, and polyamide-imide solution E-1 was used instead of polyamic acid solution D-1. Otherwise, in the same manner as in Example 6, a polyimide film with a thickness of 42 μm and a width of 480 mm was obtained.

[0272] (Example 8)

[0273] Prepare polyimide solution B (Synthesis Example 2) and polyamic acid solution A (Synthesis Example 1). Among them, while stirring polyimide solution B, Snowtex (registered trademark) DMAc-ST-ZL (a DMAc dispersion of silica with an average particle size of 80 nm. Active ingredient: 20% by mass, manufactured by Nissan Chemical Industries, Ltd.) was added so that the active ingredients were each 0.5% by mass based on the resin. Then, stirring was continued for 6 hours to obtain polyimide solution B-2 (PI-B2). Next, while stirring polyamic acid solution A, Snowtex (registered trademark) DMAc-ST (a DMAc dispersion of silica with an average particle size of 10 nm. Active ingredient: 20% by mass, manufactured by Nissan Chemical Industries, Ltd.) was added so that the active ingredients were each 10% by mass based on the resin. Then, stirring was continued for 6 hours to obtain polyimide solution A-1 (PI-A1).

[0274] The gap was adjusted so that the final film thickness became 25 μm, and polyimide solution B-2 was coated instead of polyamic acid solution A. Otherwise, in the same manner as in Example 1, a polyimide film with a thickness of 25 μm and a width of 480 mm was obtained.

[0275] (Example 9)

[0276] A pin stenter having pins arranged in a manner fixed at a needle interval during needle plate arrangement was replaced with a clip stenter that grips both ends with clips, and the gap was adjusted so that the final film thickness became 75 μm, and polyamic acid solution A was coated. Otherwise, in the same manner as in Example 1, a polyimide film with a thickness of 75 μm and a width of 480 mm was obtained.

[0277] (Example 10)

[0278] Prepare polyimide solution B (Synthesis Example 2) and polyamideimide solution E (Synthesis Example 5). Among them, while stirring polyamideimide solution E, Snowtex (registered trademark) DMAc-ST (a DMAc dispersion of silica with an average particle size of 10 nm. Active ingredient: 20% by mass, manufactured by Nissan Chemical Industries, Ltd.) was added so that the active ingredients were each 10% by mass based on the resin. Then, stirring was continued for 6 hours to obtain polyamideimide solution E-1 (PAI-E1).

[0279] The gap was adjusted so that the final film thickness became 25 μm, and polyimide solution B was coated instead of polyamic acid solution A, and polyamideimide solution E-1 was coated instead of polyamic acid solution A-1. Otherwise, in the same manner as in Example 1, a polyamideimide film with a thickness of 25 μm and a width of 480 mm was obtained.

[0280] (Example 11)

[0281] Titanium oxide (average particle size 200 nm) (PAA-A6) was added so that the active ingredient was 0.75% by mass relative to the resin, instead of adding Snowtex (registered trademark) DMAc-ST (DMAc dispersion of silica with an average particle size of 10 nm. Active ingredient 20% by mass: Nissan Chemical Industries, Ltd.) so that the active ingredient was 10% by mass relative to the resin. Except for this, a polyimide film with a thickness of 22 μm and a width of 480 mm was obtained in the same manner as in Example 1.

[0282] (Example 12)

[0283] Prepare polyimide solution B (Synthesis Example 2) and polyamide-imide solution E (Synthesis Example 5). Among them, to the polyimide solution B, Snowtex (registered trademark) DMAc-ST (DMAc dispersion of silica with an average particle size of 10 nm. Active ingredient 20% by mass: Nissan Chemical Industries, Ltd.) was added while stirring the polyimide solution B so that the active ingredient was 10% by mass relative to the resin. Then, stirring was continued for 6 hours to obtain polyimide solution B-1. Next, to the polyamide-imide solution E, Snowtex (registered trademark) DMAc-ST (DMAc dispersion of silica with an average particle size of 10 nm. Active ingredient 20% by mass: Nissan Chemical Industries, Ltd.) was added while stirring the polyamide-imide solution E so that the active ingredient was 1% by mass relative to the resin. Then, stirring was continued for 6 hours to obtain polyamide-imide solution E-2 (PAI-E2).

[0284] The gap was adjusted so that the final film thickness was 25 μm, and polyamide-imide solution E-2 was coated instead of polyamic acid solution A, and polyimide solution B-1 was coated instead of polyamic acid solution A-1. Except for this, a polyamide-imide film with a thickness of 25 μm and a width of 480 mm was obtained in the same manner as in Example 1.

[0285] (Comparative Example 1)

[0286] Prepare polyamic acid solution A (Synthesis Example 1). To a part of it, while stirring polyamic acid solution A, add Snowtex (registered trademark) DMAc-ST (a DMAc dispersion of silica with an average particle size of 10 nm. Active ingredient: 20% by mass, manufactured by Nissan Chemical Industries, Ltd.) so that the active ingredient becomes 10% by mass based on the resin. Then, continue stirring for 6 hours to obtain polyamic acid solution A-1. Next, to the remaining polyamic acid solution A, while stirring polyamic acid solution A, add Snowtex (registered trademark) DMAc-ST (a DMAc dispersion of silica with an average particle size of 10 nm. Active ingredient: 20% by mass, manufactured by Nissan Chemical Industries, Ltd.) so that the active ingredient becomes 5% by mass based on the resin. Then, continue stirring for 6 hours to obtain polyamic acid solution A-2.

[0287] Use Figure 1 、 Figure 2 the comma coater shown in, coat polyamic acid solution A-1 on the central part with a width of 500 mm of a PET film (A4100 manufactured by Toyobo Co., Ltd.) as a support and adjust the gap so that the final film thickness becomes 22 μm. At the same time, coat polyamic acid solution A-2 on both ends thereof with a width of 50 mm each. At this time, use side plates with a side plate width of 10 mm.

[0288] Next, dry at 100 - 110 °C for 10 minutes to form a polyamic acid film. After drying, wind it together with the PET film around a 6-inch ABS core to obtain a polyamic acid film roll. Unroll the polyamic acid film and the PET film from the obtained polyamic acid film roll, and peel the polyamic acid film from the PET film to obtain a self-supporting polyamic acid film, thus obtaining a polyamic acid film.

[0289] Pass the obtained polyamic acid film through a pin stenter. The above-mentioned pin stenter has pins arranged in a way that the pin intervals are fixed when arranging the pin plates. Hold the film by inserting the film ends into the pins, and adjust the pin plate intervals so that the film does not break and no unwanted slack occurs. Transfer it in such a way that the final pin plate interval is 520 mm, and perform heating under the following conditions to carry out an imidization reaction: the first stage is at 200 °C for 3 minutes, the second stage is at 250 °C for 3 minutes, the third stage is at 300 °C for 3 minutes, and the fourth stage is at 350 °C for 3 minutes. Then, cool it to room temperature in 2 minutes. Try to take the film off the pins, but it breaks from the hole part where the pins pass through, and the film cannot be obtained.

[0290] (Comparative Example 2)

[0291] Prepare polyimide solution B (Synthesis Example 2). Adjust the gap so that the final film thickness becomes 25 μm, and coat polyimide solution B instead of polyamic acid solution A and polyamic acid solution A-1. Otherwise, in the same manner as in Example 1, a polyimide film with a thickness of 25 μm and a width of 480 mm was obtained.

[0292] (Comparative Example 3)

[0293] Prepare polyimide solution A (Synthesis Example 2). To a part of it, while stirring the polyamic acid solution A, add Snowtex (registered trademark) DMAc-ST (a DMAc dispersion of silica with an average particle size of 10 nm. Active ingredient: 20% by mass, manufactured by Nissan Chemical Industries, Ltd.) so that the active ingredient becomes 60% by mass based on the resin. Then, continue stirring for 6 hours to obtain polyamic acid solution A-7 (PAA-A7).

[0294] Adjust the gap so that the final film thickness becomes 25 μm, and coat polyimide solution A-7 instead of polyamic acid solution A-1. Otherwise, in the same manner as in Example 1, an attempt was made to produce a film, but it ruptured from the hole part where the needle passed through, and a film could not be obtained.

[0295] (Comparative Example 4)

[0296] Prepare polyimide solution A (Synthesis Example 2). To this polyamic acid solution A, while stirring the polyamic acid solution A, add Snowtex (registered trademark) DMAc-ST (a DMAc dispersion of silica with an average particle size of 10 nm. Active ingredient: 20% by mass, manufactured by Nissan Chemical Industries, Ltd.) so that the active ingredient becomes 10% by mass based on the resin. Then, continue stirring for 6 hours to obtain polyamic acid solution A-1.

[0297] Adjust the gap so that the final film thickness becomes 25 μm, and coat polyimide solution A-1 instead of polyamic acid solution A. Otherwise, in the same manner as in Example 1, an attempt was made to produce a film, but it ruptured from the hole part where the needle passed through, and a film could not be obtained.

[0298] <CTE (Coefficient of Thermal Expansion in the Linear Direction)>

[0299] In the machine direction (MD direction) and width direction (TD direction) during coating, under the following conditions, measure the shrinkage rate of the film, measure the shrinkage rate / temperature at intervals of 15 °C such as 30 °C to 45 °C and 45 °C to 60 °C, perform this measurement up to 300 °C, calculate the average value of all the measured values as the CTE, and further calculate the average value of the measured values in the MD direction and TD direction.

[0300] Machine name: TMA4000S manufactured by MAC SCIENCE

[0301] Specimen length: 20 mm

[0302] Specimen width: 2 mm

[0303] Initial temperature for heating: 25 °C

[0304] Final temperature for heating: 300 °C

[0305] Heating rate: 5 °C / min

[0306] Atmosphere: Argon

[0307] <Total light transmittance>

[0308] The total light transmittance of the film was measured using a HAZEMETER (NDH5000, manufactured by Nippon Denshoku Industries Co., Ltd.). As the light source, a D65 lamp was used. In addition, the same measurement was carried out 3 times, and the arithmetic mean value was adopted.

[0309] <Haze ratio>

[0310] The haze of the film was measured using a HAZEMETER (NDH5000, manufactured by Nippon Denshoku Industries Co., Ltd.). As the light source, a D65 lamp was used. In addition, the same measurement was carried out 3 times, and the arithmetic mean value was adopted.

[0311] <YI (Yellowness index)>

[0312] Using a colorimeter (ZE6000, manufactured by Nippon Denshoku Industries Co., Ltd.) and a C2 light source, the tristimulus values XYZ of the film were measured according to ASTM D1925, and the YI (yellowness index) was calculated by the following formula. In addition, the same measurement was carried out 3 times, and the arithmetic mean value was adopted.

[0313] YI = 100×(1.28X - 1.06Z) / Y

[0314] <Coefficient of static friction>

[0315] According to JIS K-7125 (1999), using a tensile testing machine (Tensilon RTG-1210, manufactured by A&D Company), in an environment of 23 °C·65%RH, the coefficient of static friction when the inner surface and the outer surface of the film roll were joined was obtained. In addition, the weight of the line (weight) of the upper side film wound was 1.5 kg, and the size of the bottom area of the weight was 39.7 mm 2 . In addition, the stretching speed during friction measurement was 200 mm / min.

[0316] <Measurement of film thickness>

[0317] The thickness of the film was measured using a micrometer (Militron 1245D, manufactured by Feinprüf Company).

[0318] <Tear strength>

[0319] The tear strength of the central part and the tear strength of both end parts of the film before cutting obtained in the examples and comparative examples were determined. Specifically, according to the trouser tear method described in JIS K7128-1, the test speed was set to 200 mm / min, and the average value of the remaining 50 mm after excluding the first 20 mm at the start of tearing and the last 5 mm before the end of tearing was taken as the tear strength. The results are shown in Table 1.

[0320] [Tear strength (N / mm)] = [Tear stress of the test piece (N)] / [Thickness (d) of the test piece]

[0321] The tear strength obtained here (the tear strength recorded in Table 1) is the tear strength of the polyimide film (resin film) after Process G. However, if in the polyimide film after Process G, the tear strength of the part formed from the second resin composition solution is greater than the tear strength of the part formed from the first resin composition solution, then of course in the film before cutting after Process C and before Process F, the tear strength of the part formed from the second resin composition solution is also greater than the tear strength of the part formed from the first resin composition solution.

[0322] In addition, when the tear strength of the central part of the film before cutting after Process C and before Process F of Example 8 was measured by the same measurement method as above, it was 1.8 N / mm. From this, it can be known that if in the polyimide film after Process G, the tear strength of the part formed from the second resin composition solution is greater than the tear strength of the part formed from the first resin composition solution, then in the film before cutting after Process C and before Process F, the tear strength of the part formed from the second resin composition solution is also greater than the tear strength of the part formed from the first resin composition solution.

[0323] [Table 1]

[0324]

[0325] In the polyimide films of Examples 1 to 12, the tear strength of the part formed from the second resin composition solution was greater than the tear strength of the part formed from the first resin composition solution. Therefore, they did not break or deform after heat treatment. In addition, the CTE and transparency were also good. On the other hand, the films before cutting in Comparative Examples 1 to 4 were films formed from a single resin composition solution with a small tear strength. Therefore, they cracked from the holes through which the needles passed and no films could be obtained.

Claims

1. A method for manufacturing a resin film, characterized in that, It has the following processes A to G: Process A: Coating a first resin composition solution on the central part of the support; Process B: Coating a second resin composition solution on both end parts adjacent to the central part; Process C: Drying the first resin composition solution and the second resin composition solution to obtain a film before cutting; Process D: Peeling the film before cutting from the support; Process E: After Process D, gripping both end parts of the film before cutting by a tenter conveyor; Process F: Conveying the film before cutting in a state of gripping both end parts of the film before cutting; And Process G: After Process F, removing the part formed by the second resin composition solution from the film before cutting to obtain a resin film; The first resin composition solution contains a first resin and a filler, and the content of the filler is 0.1% by mass or more and 50% by mass or less with respect to the first resin. The second resin composition solution contains a second resin, does not contain a filler or, even if it contains a filler, the content is less than that of the first resin composition solution and is 2% by mass or less with respect to the second resin. In the film before cutting after Process C and before Process F, the tear strength of the part formed by the second resin composition solution is greater than the tear strength of the part formed by the first resin composition solution.

2. The manufacturing method of the resin film according to claim 1, characterized in that, The CTE of the resin film is 5 ppm / K or more and 50 ppm / K or less.

3. The method for manufacturing a resin film according to claim 1 or 2, characterized in that, Process E is a process of gripping both end parts of the film before cutting by needles of a needle tenter conveyor.

4. The method for manufacturing a resin film according to claim 1 or 2, characterized in that, The resin film is a polyimide-based resin film.

5. The method for manufacturing a resin film according to claim 1 or 2, characterized in that, The support is a polymer film.

6. The method for manufacturing a resin film according to claim 1 or 2, characterized in that, The filler is silica.

7. A cutting front film, characterized in that, It has a central part and both end parts continuously formed at both ends of the central part from the central part. The central part is composed of a first resin composition containing a first resin and a filler, and the content of the filler is 0.1% by mass or more and 50% by mass or less with respect to the first resin. Both end parts are composed of a second resin composition containing a second resin. The second resin composition does not contain a filler or, even if it contains a filler, the content is less than that of the first resin composition and is 2% by mass or less with respect to the second resin. The tear strength of both end parts is greater than the tear strength of the central part.

8. The front cutting film according to claim 7, characterized in that, The first resin is a polyimide-based resin.

9. The pre-cut film according to claim 7 or 8, characterized in that, The CTE of the central part is 5 ppm / K or more and 50 ppm / K or less.

10. The pre-cut film according to claim 7 or 8, characterized in that, The filler is silica.

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