Film web and method of manufacturing the same

Abstract

The present invention provides a membrane roll having a core and an elongated membrane wound on the core. The elongated membrane includes two knurled regions with multiple protrusions at both ends in the width direction and a flat region between the two knurled regions. The membrane roll includes two large-diameter portions of the knurled regions on which the elongated membrane is wound and a small-diameter portion of the flat region on which the elongated membrane is wound between the two large-diameter portions. The difference between the diameters of the large-diameter portions and the small-diameter portions of the membrane roll satisfies a specific condition. At the center of the winding axis of the membrane roll, the thickness of the air layer between the wound elongated membranes is within a specific range.

Description

Technical Field

[0001] This invention relates to a film roll and its manufacturing method. Background Technology

[0002] The membrane is usually manufactured as a long strip and then wound onto a suitable core to form a membrane roll, which is then stored and transported in the state of the membrane roll (Patent Documents 1, 2).

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent No. 6451338;

[0006] Patent Document 2: Japanese Patent Application Publication No. 2023-15895. Summary of the Invention

[0007] The problem the invention aims to solve

[0008] As a method for winding long strip films, the gap winding method is known in the past. That is, after the long strip film is wound on a gap roller that is separate from the film roll during the manufacturing process, the wound long strip film is wound on a core. However, in this gap winding method, there are a lot of air layers between the wound long strip films, which are prone to "buckling" in the film roll.

[0009] "Buckling" refers to a depression formed by a localized radial indentation in the membrane roll. This buckling is prone to occur in sections with thick air layers between overlapping wound membrane strips. Moreover, in the sections where buckling occurs, the membrane strips deform, potentially leading to membrane surface defects known as "granular defects." Granular defects generally occur as defects with a diameter of less than 10 mm. Granular defects are usually formed due to thick air layers inside the membrane roll, which increases the amount of vertical fall of the membrane strips due to gravity, causing the membrane strips to bend.

[0010] Contact winding is a known method for suppressing grainy defects caused by gravity-induced falling. In contact winding, a strip of film is wound around a pressure roller that presses the film roll along its entire axial direction during manufacturing. The winding process involves pressing the wound strip of film against the film roll while simultaneously winding it. Because the contact winding method presses the strip of film against the film roll along its entire width direction while winding, air gaps between the wound strips are reduced. This is expected to suppress buckling and thus grainy defects.

[0011] However, in the contact winding method, the air gap between the overlapping wound strips of film becomes too small, causing the strips to adhere to each other and easily resulting in "burrs". "Burs" refers to the strip-shaped protrusions (the thicker parts) extending circumferentially along the film roll. Usually, burrs are formed due to bending of the strips, and can therefore be a cause of defects in the strips.

[0012] Therefore, the applicant has developed a knurled contact winding method as a winding method capable of suppressing the aforementioned granular defects and rib breakage. In the knurled contact winding method, two knurled regions with multiple protrusions are formed at both ends of the strip film in the film width direction. Then, the strip film with the knurled regions is wound around a contact roller, and the wound strip film is wound onto a roll core. The winding is performed while the contact roller is in contact with the film roll during manufacturing. The knurled regions containing the protrusions are thicker than the flat regions between the knurled regions. Thus, the knurled regions of the normally wound film roll are in contact with the contact roller, while the flat regions are not in contact with the contact roller.

[0013] Because the knurled area of ​​the long strip film is thicker than the flat area, the resulting film roll has a large-diameter section with the knurled area and a small-diameter section with the flat area. The large-diameter section, formed by winding the knurled area with protrusions, has a relatively large diameter. Furthermore, since the large-diameter section is wound while in contact with the contact roller, the overlapping long strip films can be in close contact with each other. Therefore, in the large-diameter section, the air gap between the long strip films is relatively small, or non-existent. On the other hand, the small-diameter section, formed by winding the flat area without protrusions, has a relatively small diameter. Moreover, since the small-diameter section is wound without contact with the contact roller, there is a relatively large air gap between the overlapping long strip films, and typically the overlapping long strip films are not in contact with each other.

[0014] The membrane roll manufactured using this knurled contact winding method has a diameter difference between its large and small diameter portions. Therefore, a space is formed near the boundary between the large and small diameter portions, allowing the elongated membrane to move. When the elongated membrane in the small diameter portion falls due to gravity during storage, and subsequently moves partially or entirely inward towards the winding axis, buckling may occur near the boundary between the large and small diameter portions. Specifically, this buckling is more likely to occur in the inner portion of the large diameter portion, immediately adjacent to the winding axis. When this buckling occurs, defects may appear in the elongated membrane pulled from the roll. These defects typically form in the width direction, immediately adjacent to the knurled area, and from the perspective of the elongated membrane as a whole, occur near the ends in the width direction; therefore, they are sometimes referred to below as "end defects."

[0015] The present invention was created in view of the above-mentioned problems, and its purpose is to provide a film roll capable of suppressing ridges, granular defects and end defects, and a method for manufacturing the same.

[0016] Solution for solving the problem

[0017] The inventors conducted in-depth research to solve the aforementioned problems. As a result, the inventors discovered that by using a knurled contact winding method with an improved configuration of the protrusions formed in the knurled region, the shape profile of the film roll can be appropriately controlled, thereby achieving a film roll that solves the aforementioned problems, and thus completing the present invention.

[0018] That is, the present invention includes the following contents.

[0019] <1> A film roll has a core and an elongated film wound around the core; the elongated film includes two knurled regions with multiple protrusions at both ends in the width direction and a flat region between the two knurled regions; the film roll includes two large-diameter portions of the knurled regions around which the elongated film is wound and a small-diameter portion of the flat region between the two large-diameter portions around which the elongated film is wound; both a first roll diameter difference ΔD1 represented by the following formula (1) and a second roll diameter difference ΔD2 represented by the following formula (2) are less than 0.3 mm, and at least one of the first roll diameter difference ΔD1 and the second roll diameter difference ΔD2 is 0.05 mm or more; at the center of the roll axis of the film roll, the thickness of the air layer between the wound elongated films is 0.9 μm or more and 2.0 μm or less.

[0020] [Mathematical Expression 1]

[0021]

[0022] (In equation (1), D) N1(MAX) D represents the maximum diameter of one of the two major diameter portions of the aforementioned membrane roll. F1(AVE) The average diameter of the small diameter portion on the large diameter side of one of the aforementioned membrane rolls is represented by D in equation (2). N2(MAX) D represents the maximum diameter of the other of the two major diameter portions of the aforementioned membrane roll. F2(AVE) This refers to the average diameter of the smaller diameter portion on the larger diameter side of the other of the aforementioned film rolls.

[0023] <2> according to <1> The film roll, wherein the knurled area of ​​the strip film alternately includes knurled portions having the protrusions and spaced portions without the protrusions in the length direction of the film; the spacing between the knurled portions in the length direction of the film is 20 mm or more and 100 mm or less.

[0024] <3> according to <1> or <2> The membrane roll wherein the height of the protrusion is 1 μm or more and 10 μm or less.

[0025] <4> according to <1> ~ <3> The film roll according to any one of the following methods, wherein the strip film comprises a cyclic olefin polymer.

[0026] <5> according to <1> ~ <4> The film roll according to any one of the following methods, wherein the length of the strip film is more than 2000m and less than 10000m.

[0027] <6> A method for manufacturing a film roll, the film roll having a core and a strip film wound on the core; the strip film includes two knurled regions disposed at both ends in the film width direction and each having a plurality of protrusions, and a flat region disposed between the two knurled regions; the knurled regions of the strip film alternately include knurled portions having the protrusions and spaced portions without the protrusions in the film length direction; the spacing of the knurled portions in the film length direction is 20 mm or more and 100 mm or less; the manufacturing method includes: a step of winding the strip film on a contact roller; and a step of winding the strip film wound on the contact roller onto the core while contacting the contact roller with the knurled regions of the strip film.

[0028] <7> according to <6> The method for manufacturing the film roll includes a step of forming the knurled portion of the film before processing to obtain the strip film.

[0029] <8> according to <7> The method for manufacturing the film roll includes forming the knurled portion by irradiating with a laser.

[0030] <9> according to <7> or <8> The method for manufacturing the film roll, wherein the step of forming the knurled portion on the film before the above processing includes swinging the forming position of the knurled portion in the film width direction; the ratio of the swing amount of the knurled portion to the width of one of the knurled portions is 0.5 or more and 1.0 or less.

[0031] <10> according to <6> ~ <9> In any one of the methods for manufacturing a film roll, the height of the protrusion is 1 μm or more and 10 μm or less.

[0032] <11> according to <6> ~ <10> The method for manufacturing a film roll according to any one of the following, wherein the strip film comprises a cyclic olefin polymer.

[0033] <12> according to <6> ~ <11> The method for manufacturing a film roll according to any one of the following methods, wherein the length of the wound strip film is 2000m or more and 10000m or less.

[0034] <13> according to <6> ~ <12> In any one of the methods for manufacturing a film roll, the axial length of the contact roller is greater than or equal to the width of the strip film, and in the process of winding the strip film onto the core, the contact roller presses the film roll during manufacturing toward the center of the core with a load of 50 N / m to 200 N / m.

[0035] <14> according to <6> ~ <13> The method for manufacturing a film roll according to any one of the following methods, wherein the film winding speed of the above-mentioned strip film is 10 m / min or more and 150 m / min or less.

[0036] Invention Effects

[0037] According to the present invention, a membrane roll capable of suppressing ridges, granular defects, and end defects, and a method thereof are provided. Attached Figure Description

[0038] Figure 1 A front view of a film roll according to one embodiment of the present invention is shown schematically.

[0039] Figure 2 A top view showing the vicinity of one end (first end) of a strip of film according to an embodiment of the present invention, for schematic illustration.

[0040] Figure 3 This is a cross-sectional view schematically showing a section formed by cutting a linear irregularity in a strip film according to one embodiment of the present invention with a plane perpendicular to the extending direction of the irregularity.

[0041] Figure 4 A top view schematically illustrating the planar shape of a concave-convex portion of a strip film according to an embodiment of the present invention, viewed from the film thickness direction.

[0042] Figure 5 This is a top view showing the vicinity of the other end (second end) of a strip of film according to one embodiment of the invention, for schematic illustration.

[0043] Figure 6 This is a schematic perspective view illustrating the measurement method for the first roll diameter difference ΔD1 and the second roll diameter difference ΔD2 of the film roll.

[0044] Figure 7 To illustrate the thickness d of the air layer between the strips of film contained in the membrane roll air A schematic cross-sectional view of the membrane roll used in the measurement method.

[0045] Figure 8 This is a schematic illustration of the shape profile of the outermost circumferential surface of a film roll near the end of the roll axis, used to illustrate an example.

[0046] Figure 9 A side view of a film roll manufacturing apparatus according to one embodiment of the present invention is shown schematically.

[0047] Figure 10 This is a top view schematically illustrating the state of a strip of film wound around a core in a film roll manufacturing method according to one embodiment of the present invention.

[0048] Figure 11 A front view of a film roll illustrating a modified embodiment of the present invention.

[0049] Figure 12 A top view showing the vicinity of one end (first end) of a strip of film in a modified embodiment of the present invention, for schematic representation. Detailed Implementation

[0050] The present invention will be described in detail below with examples and embodiments shown. However, the present invention is not limited to the examples and embodiments shown below, and can be implemented by any modifications without departing from the scope of the claims and their equivalents.

[0051] <Summary of the membrane roll>

[0052] Figure 1 A front view of a film roll 1 according to one embodiment of the present invention is shown schematically. Figure 1 This indicates the state where a portion of the long strip membrane 100 is pulled out from membrane roll 1, but the portion of the long strip membrane 100 may not be pulled out. For example... Figure 1 As shown, the film roll 1 of this embodiment has a core 10 and a strip film 100 wound around the core 10. Generally, the film length direction, film width direction, and film thickness direction of the strip film 100 correspond to the circumferential direction, axial direction, and radial direction of the film roll 1.

[0053] <Instructions for Core 10>

[0054] Typically, the core 10 uses a component with a circumferential surface 10S having a cylindrical side surface shape; for example, a cylindrical or cylindrical component can be used. The circumferential surface 10S of the core 10 generally forms a smooth curved surface, and a strip of film 100 is formed by overlapping and winding it on this circumferential surface 10S. The diameter of the core 10 can be appropriately selected based on factors such as the material, application, and length of the strip of film 100. In one example, the diameter of the core 10 is preferably 100 mm or more, more preferably 150 mm or more, preferably 400 mm or less, and more preferably 350 mm or less.

[0055] <Description of the shape of the long strip membrane 100>

[0056] The strip film 100 is a strip film. A "strip" film refers to a film with a length that is five times or more than five times its width, preferably ten times or more; specifically, it refers to a film long enough to be rolled up for storage or transport. There is no particular upper limit to the length of the strip film 100, and it can be, for example, less than 100,000 times its width.

[0057] The elongated film 100 includes two knurled regions 110L and 110R, each containing a plurality of protrusions, located at both ends in the film width direction; and a flat region 120 located between the two knurled regions 110L and 110R. Hereinafter, the end of the elongated film 100 on one side in the film width direction will be referred to as the "first end" and the end on the other side as the "second end". In this embodiment, an example is shown for illustration: by forming a plurality of concave and convex portions 130 in the elongated film 100, knurled regions 110L and 110R, each containing a protrusion among the plurality of concave and convex portions 130, are located at both ends of the elongated film 100 in the film width direction.

[0058] Figure 2 This is a top view schematically showing the vicinity of one end (first end) of an enlarged embodiment of the elongated film 100 according to the present invention. (See attached image.) Figure 2 As shown, the knurled region 110L located at the first end of the elongated film 100 alternately includes knurled portions 111L and spacers 112L in the film length direction.

[0059] Knurled portion 111L refers to a portion within the knurled region 110L that has a protrusion. As described above, in the example shown in this embodiment, by forming a concave-convex portion 130 including a concave portion and a protrusion in the strip film 100, a plurality of knurled portions 111L including the protrusions in the concave-convex portion 130 are formed side by side in the knurled region 110L.

[0060] In this embodiment, an example is shown where the uneven portion 130 is formed as a continuous line when viewed from the film thickness direction. Such a continuous linear uneven portion 130 can be formed, for example, by irradiating with a laser. Therefore, the uneven portion 130 can also be formed as a trace of the movement of the laser irradiation point, forming a continuous line in a single stroke. Here, "single stroke" refers to the shape of a line that is continuous without interruption.

[0061] Figure 3 This is a cross-sectional view schematically illustrating a section formed by cutting a linear uneven portion 130 of a strip film 100 according to one embodiment of the present invention with a plane perpendicular to the extending direction of the uneven portion 130. For example... Figure 3As shown, the uneven portion 130 may include a recess 131 and a protrusion 132. For example, the uneven portion 130 formed by laser irradiation typically has a recess 131 and protrusions 132 disposed on both sides of the recess 131. The recess 131 can correspond to the portion after resin removal due to thermal melting or ablation caused by laser irradiation. Furthermore, the protrusion 132 can correspond to the portion of resin protrusion that is heated and fluidized by the aforementioned laser irradiation. Since the protrusion 132 protrudes more than the surface 100U of the surrounding strip film 100, the substantial thickness of the strip film 100 becomes thicker in the knurled portion 111L having the uneven portion 130.

[0062] The height H of the protrusion 132 may be uniform or non-uniform. In one example, the height of the protrusion 132 is preferably 1 μm or more, more preferably 2 μm or more, even more preferably 3 μm or more, preferably 10 μm or less, more preferably 9 μm or less, and even more preferably 8 μm or less.

[0063] The width W of the line of the uneven portion 130 can be uniform or non-uniform. In one example, the width W of the line of the uneven portion 130 is preferably 0.1 μm or more, more preferably 0.15 μm or more, even more preferably 0.2 μm or more, preferably 1 μm or less, more preferably 0.75 μm or less, and even more preferably 0.5 μm or less.

[0064] The continuous linear protrusions 130 can also be formed to have a specific planar shape as needed. Unless otherwise specified, the term "planar shape" refers to the shape viewed from the film thickness direction. When the protrusions 130 have a specific planar shape, the recesses 131 and protrusions 132 included in the protrusions 130 can also have that specific planar shape. For example, the continuous linear protrusions 130 can also have a shape with multiple corners.

[0065] Figure 4 This is a top view schematically illustrating the planar shape of one of the irregular portions 130 of a strip film 10 according to an embodiment of the present invention, viewed from the film thickness direction. When viewing the irregular portion 130 from the film thickness direction, the corner portion 133 of the irregular portion 130 can be a connecting portion connecting two straight, linear portions 134 and 135 included in the irregular portion 130. Figure 4 In this diagram, the corner portion 133 corresponds to the vertex of the angle formed between the left-lower-right-higher straight line portion 134 and the left-higher-right-lower straight line portion 135. Therefore, the corner portion 133 can have an angle θ corresponding to the direction in which the straight line portion 134 extends and the direction in which the straight line portion 135 extends. 133 The angle θ at corner 133 133The range is preferably 80° or more, more preferably 85° or more, even more preferably 88° or more, preferably 100° or less, more preferably 95° or less, and even more preferably 92° or less. For example, angle θ 133 It can also be 90°. Furthermore, multiple angles θ of 133 degrees are also possible. 133 They can be the same or different.

[0066] The number of corners 133 included in a single protrusion 130 is not particularly limited. In this embodiment, an example is shown where a continuous linear protrusion 130 has a polygonal shape as a ring, and the number of corners 133 included in one protrusion 130 is 24. However, the number of corners 133 included in one protrusion 130 may be more than 24 (e.g., 32, 40, 48, 56) or less than 24 (e.g., 16, 8, 4). Furthermore, the planar shape of the protrusion 130 may be a shape other than a ring, for example, it may be a zigzag or other end-shaped shape.

[0067] like Figure 2 As shown, the length L of each knurled portion 111L in the film length direction is... 111L The range is typically less than 20 mm, preferably less than 19 mm, more preferably less than 15 mm, and even more preferably less than 10 mm. In length L... 111L When the value is below the aforementioned upper limit, the knurled portion 111L (and the uneven portion 130 in the knurled portion 111L) can be formed in a short time, thus increasing the manufacturing speed of the film roll 1. The length L of the knurled portion 111L... 111L The lower limit of the range can be set within the range where a film roll 1 with the desired shape profile can be obtained, preferably 0.1 mm or more, more preferably 0.5 mm or more, and even more preferably 1 mm or more. As shown in the example of this embodiment, when a rough portion 130 is formed in a knurled portion 111L, the length of the rough portion 130 in the film length direction is equivalent to the length L of the knurled portion 111L. 111L The length L of multiple knurled sections 111L 111L They can be the same or different.

[0068] Furthermore, the width W of each knurled portion 111L in the film width direction 111L The range is preferably 3 mm or more, more preferably 5 mm or more, further preferably 7 mm or more, preferably 20 mm or less, more preferably 17 mm or less, and further preferably 15 mm or less. As shown in the example of this embodiment, when a rough portion 130 is formed in a knurled portion 111L, the width of the rough portion 130 in the film width direction corresponds to the width W of the knurled portion 111L. 111LThe width W of multiple knurled sections 111L 111L They can be the same or different.

[0069] The positions of the plurality of protrusions and recesses 130 formed in the knurled region 110L in the film width direction may be different, but are generally the same. When the positions of the plurality of protrusions and recesses 130 formed in the knurled region 110L in the film width direction are the same, the positions of the plurality of knurled portions 111L including the protrusions and recesses 130 in the film width direction can also be the same. In this case, the width W of each knurled portion 111L in the film width direction... 111L It can be consistent with the width (dimension in the film width direction) of the knurled area 110L containing the knurled portion 111L.

[0070] The spacing P of the knurled portion 111L along the length of the membrane 111L The preferred range is 20mm or more, more preferably 25mm or more, even more preferably 30mm or more, preferably 100mm or less, more preferably 85mm or less, and even more preferably 70mm or less. This spacing P 111L Typically equivalent to the length L of a knurled section 111L 111L The length L of the spacer portion 112L immediately downstream of the knurled portion 111L in the film length direction 112L The sum. Furthermore, when a raised or recessed portion 130 is formed on each knurled portion 111L using a laser, the spacing P of the knurled portions 111L... 111L This is equivalent to the distance along the film length from the starting point of forming the irregularity 130 using a laser (the point where the laser irradiation begins) to the starting point of forming the next irregularity 130. The spacing P of the plurality of knurled portions 111L 111L They can be the same or different.

[0071] The spacer portion 112L represents the portion within the knurled region 110L that does not have a protrusion. This spacer portion 112L is formed as a plurality of knurled portions 111L arranged side-by-side between each other. In the example shown in this embodiment, since the uneven portion 130 is not formed in the spacer portion 112L, this spacer portion 112L does not have a protrusion 132. Moreover, because it does not have a protrusion 132, the substantial thickness of the strip film 100 in the spacer portion 112L is thinner than that in the knurled portion 111L.

[0072] The length L of each spacer 112L along the membrane length direction 112LThe range is preferably 15 mm or more, more preferably 20 mm or more, even more preferably 25 mm or more, preferably 95 mm or less, more preferably 80 mm or less, and even more preferably 65 mm or less. As shown in the example of this embodiment, when a raised portion 130 is formed in a knurled portion 111L, the distance in the film length direction between adjacent raised portions 130 corresponds to the length L of the spacer portion 112L. 112L The length L of the multiple spacers 112L 112L They can be the same or different.

[0073] The length L of the spacer portion 112L in the longitudinal direction of the membrane 112L The length L of the knurled part 111L 111L The ratio (L) 112L / L 111L The range of ) is preferably 5 or more, more preferably 10 or more, further preferably 20 or more, preferably 100 or less, more preferably 60 or less, and further preferably 40 or less. The length L of the plurality of knurled portions 111L 111L In different cases, and in multiple intervals 112L, the length L 112L Their length L varies depending on the circumstances. 112L Average and length L 111L The average ratio is preferably within the range described above.

[0074] As described above, a knurled region 110L comprising the knurled portion 111L and the spacer portion 112L is provided at the first end of the elongated film 100. The distance from the edge 140L on the first end side of the elongated film 100 to the knurled region 110L can be 0 mm or greater than 0 mm. Thus, in the elongated film 100, in the film width direction, any region can be provided outside the knurled region 110L. However, generally speaking, since the flat region 120 of the elongated film 100 is used for the final application, from the viewpoint of expanding the scope of such final application, any arbitrary region is preferably small, and more preferably none. Typically, the knurled region 110L has a width W equal to the width of the knurled portion 111L included in the knurled region 110L. 111L The range is the same as the width of the range.

[0075] Figure 5 This is a top view schematically showing the vicinity of the other end (second end) of the elongated film 100 according to one embodiment of the invention, magnified. (See attached image.) Figure 5As shown, the knurled region 110R located at the second end of the elongated film 100 alternately includes knurled portions 111R and spacers 112R in the film length direction. Except for the second end of the elongated film 100 in the film width direction, the knurled region 110R and the knurled portions 111R and spacers 112R contained in the knurled region 110R can be formed in the same way as the knurled region 110L and the knurled portions 111L and spacers 112L contained in the knurled region 110L.

[0076] Therefore, the knurled portion 111R represents the portion within the knurled region 110R having protrusions. In the example shown in this embodiment, by forming the irregular portion 130 in the strip film 100, a plurality of protrusions 132 (see reference) including the irregular portion 130 are formed side by side in the knurled region 110R. Figure 3 ) knurled portion 111R. The uneven portion 130 and the concave portion 131 in the knurled portion 111R (refer to Figure 3 The protrusion 132 can be the same as the concave and convex portions 130, 131, and 132 in the knurled portion 111L. Furthermore, the length L of each knurled portion 111R in the film length direction... 111R The range, the width W of each knurled portion 111R in the film width direction 111R The range of the knurled portion 111R along the film length direction and the spacing P 111R The range is such that it can be related to the length L of each knurled portion 111L in the film length direction. 111L The range, the width W of each knurled portion 111L in the film width direction 111L The range, and the spacing P of the knurled portions 111L in the film length direction. 111L The range is the same. Furthermore, the positions of the plurality of protrusions and recesses 130 formed in the knurled region 110R in the film width direction may be different, but are generally the same. When the plurality of protrusions and recesses 130 formed in the knurled region 110R are in the same position in the film width direction, the positions of the plurality of knurled portions 111R including the protrusions and recesses 130 in the film width direction can also be the same. In this case, the width W of each knurled portion 111R in the film width direction... 111R It can be consistent with the width (dimension in the film width direction) of the knurled region 110R containing the knurled portion 111R.

[0077] Furthermore, the spacer portion 112R represents the portion within the knurled region 110R that does not have a protrusion. In the example shown in this embodiment, since the uneven portion 130 is not formed in the spacer portion 112R, the spacer portion 112R does not have a protrusion 132. The length L of each spacer portion 112R in the film length direction is... 112R The range, and the length L of the spacer portion 112R in the membrane length direction. 112R The length L of the knurled part 111R111R The ratio (L) 112R / L 111R The range of ) can be related to the length L of each spacer 112L in the membrane length direction. 112L The range, and the length L of the spacer portion 112L in the membrane length direction. 112L The length L of the knurled part 111L 111L The ratio (L) 112L / L 111L The range is the same. The length L of the multiple knurled sections 111R is... 111R Different situations, and the length L of multiple intervals 112R 112R Their length L varies depending on the circumstances. 112R Average and length L 111R The average ratio is preferably within the range described above.

[0078] Furthermore, in the elongated film 100, an arbitrary region can be provided on the outer side of the knurled region 110R in the film width direction. In this case, the distance from the edge 140R on the second end side of the elongated film 100 to the knurled region 110R can be 0 mm or greater than 0 mm. The arbitrary region is particularly preferably small, and more preferably absent. Typically, the knurled region 110R has a width W equal to the width of the knurled portion 111R included in the knurled region 110R. 111R The range is the same as the width of the range.

[0079] like Figure 1 As shown, in the membrane width direction, the elongated membrane 100 has a flat region 120 between two knurled regions 110L and 110R. This flat region 120 typically does not have a protrusion 132 (see reference). Figure 3 Therefore, the actual thickness is smaller than the knurled portions 111L and 111R of the knurled regions 110L and 110R. Generally, this flat region 120 is used for the final application of the strip film 100.

[0080] The length, width, and thickness of the strip film 100 can be set within a range according to the intended use of the strip film 100.

[0081] In one example, the length of the strip film 100 is preferably 2000m or more, more preferably 2500m or more, even more preferably 3000m or more, preferably 10000m or less, more preferably 8000m or less, and even more preferably 6000m or less.

[0082] In one example, the width of the strip film 100 is preferably 700 mm or more, more preferably 1000 mm or more, even more preferably 1200 mm or more, preferably 2500 mm or less, more preferably 2200 mm or less, and even more preferably 2000 mm or less.

[0083] In one example, the thickness of the strip film 100 is preferably 11 μm or more, more preferably 15 μm or more, even more preferably 20 μm or more, preferably 500 μm or less, more preferably 300 μm or less, and even more preferably 150 μm or less. Unless otherwise specified, "thickness of the strip film 100" refers to the thickness of the strip film 100 without the uneven portion 130, and generally refers to the thickness of the flat region 120. Generally speaking, thin films tend to be prone to defects due to their poor rigidity, but in the film roll 1 of this embodiment, bulging defects, granular defects, and end defects can be suppressed. Therefore, even when using such a thin strip film 100, the occurrence of defects caused by storage and handling in the state of film roll 1 can be suppressed, thereby achieving excellent quality stability.

[0084] <Description of the shape of membrane roll 1>

[0085] As described above, film roll 1 is a roll of a long strip of film 100 wound with two knurled regions 110L and 110R and a flat region 120 disposed between the two knurled regions 110L and 110R. Thus, as Figure 1 As shown, the membrane roll 1 includes two large-diameter portions 210L and 210R wound with knurled regions 110L and 110R, and a small-diameter portion 220 wound with a flat region 120.

[0086] Since the two knurled regions 110L and 110R are located at both ends of the strip film 100 in the film width direction, the large-diameter portions 210L and 210R are typically located at both ends of the film roll 1 in the winding direction. Hereinafter, the large-diameter portion 210L formed by winding the knurled region 110L located at the first end of the strip film 100 is sometimes referred to as the "first large-diameter portion" 210L, and the large-diameter portion 210R formed by winding the knurled region 110R located at the second end of the strip film 100 is sometimes referred to as the "second large-diameter portion" 210R. The first large-diameter portion 210L and the second large-diameter portion 210R have a relatively larger diameter than the small-diameter portion 220 because they are portions wound with knurled regions 110L and 110R that include knurled portions 111L and 111R with relatively large substantial thickness.

[0087] Since the flat region 120 is disposed between the two knurled regions 110L and 110R, the small diameter portion 220 is typically disposed between the two large diameter portions 210L and 210R along the winding axis of the film roll 1. Because the small diameter portion 220 is typically a portion of the flat region 120 wound around which the knurled portions 111L and 111R, which have a substantial thickness smaller than the knurled regions 110L and 110R, it has a relatively smaller diameter than the first large diameter portion 210L and the second large diameter portion 210R.

[0088] The membrane roll 1 assembly satisfies the following conditions (R1), (R2), and (R3).

[0089] (R1) The first diameter difference ΔD1 and the second diameter difference ΔD2 of membrane roll 1 are both less than 0.3 mm.

[0090] (R2) At least one of the first roll diameter difference ΔD1 and the second roll diameter difference ΔD2 of the membrane roll 1 is 0.05 mm or more.

[0091] (R3) At the center of the winding axis of the membrane roll 1, the thickness d of the air layer between the wound strip membranes 100 is... air It is above 0.9μm and below 2.0μm.

[0092] The following is an explanation of condition (R1).

[0093] Condition (R1): The first diameter difference ΔD1 and the second diameter difference ΔD2 of membrane roll 1 are generally less than 0.30 mm, preferably less than 0.20 mm, and more preferably less than 0.15 mm. Here, the first diameter difference ΔD1 of membrane roll 1 is represented by the value expressed by the following formula (1). Furthermore, the second diameter difference ΔD2 of membrane roll 1 is represented by the value expressed by the following formula (2).

[0094] [Mathematical Expression 2]

[0095]

[0096] (In equation (1), D) N1(MAX) This indicates the maximum diameter of the first major diameter section (one of the two major diameter sections) 210L of membrane roll 1; D F1(AVE) This represents the average diameter of the small diameter portion 220 on the side of the first large diameter portion (large diameter portion on one side) 210L of the membrane roll 1. Furthermore, in equation (2), D... N2(MAX) This indicates the maximum diameter of the second largest diameter portion (the other of the two largest diameter portions) 210R of membrane roll 1; D F2(AVE) This represents the average diameter of the small diameter portion 220 on the side of the second large diameter portion (the large diameter portion on the other side) 210R of membrane roll 1.

[0097] The first roll diameter difference ΔD1 and the second roll diameter difference ΔD2 of film roll 1 can be measured by the following measurement method. Figure 6 This is a schematic perspective view illustrating the measurement method for the first roll diameter difference ΔD1 and the second roll diameter difference ΔD2 of membrane roll 1. Figure 6As shown, laser displacement gauges 300L and 300R are positioned opposite to the membrane roll 1, away from the outermost circumferential surface 1S of the membrane roll 1. At this time, the laser displacement gauges 300L and 300R are positioned such that the optical axes 310L and 310R of the measuring lasers emitted from the laser displacement gauges 300L and 300R are perpendicular to the central axis 10A of the core 10. Furthermore, the distance from the laser displacement gauges 300L and 300R to the surface of the core 10 can be, for example, 580 mm. While rotating the membrane roll 1 circumferentially around the central axis 10A of the core 10, the distance from the laser displacement gauges 300L and 300R to the outermost circumferential surface 1S of the membrane roll 1 is measured using the laser displacement gauges 300L and 300R. Through this measurement, the distance from the laser displacement gauges 300L and 300R to the outermost circumferential surface 1S of the membrane roll 1 is obtained within the range of 0°≤φ<360° of the circumferential rotation angle φ of the membrane roll 1.

[0098] Therefore, by performing the above measurements on the first large-diameter portion 210L and the second large-diameter portion 210R of the film roll 1, the shape profile of the outermost peripheral surface 1S of the first large-diameter portion 210L and the second large-diameter portion 210R is obtained, and the diameters of the first large-diameter portion 210L and the second large-diameter portion 210R are obtained from the shape profiles. Therefore, among the measured values ​​of the diameter of the first large-diameter portion 210L with a rotation angle φ of 0°≤φ<360°, the largest value is adopted as D. N1(MAX) Furthermore, among the measured values ​​of the diameter of the second major diameter section 210R where the rotation angle φ is 0°≤φ<360°, the largest value is used as D. N2(MAX) .

[0099] Furthermore, by performing the aforementioned measurements on the minor diameter portion 220 of the film roll 1, the shape profile of the outermost peripheral surface 1S of the minor diameter portion 220 is obtained, and the diameter of the minor diameter portion 220 is obtained from this shape profile. Typically, in order to obtain D... F1(AVE) The shape profile of the outermost circumferential surface 1S is measured on the small diameter portion 220 on the side of the first large diameter portion 210L of the film roll 1. Specifically, the shape profile of the outermost circumferential surface 1S is measured within a measurement range 221L of the small diameter portion 220, which is 10cm to 20cm away from the inner end (the inner end on the roll axis) of the first large diameter portion 210L along the roll axis. Then, the diameter of the small diameter portion 220 on the side of the first large diameter portion 210L is obtained from this shape profile, and the average of the measured values ​​of the diameter of the small diameter portion 220 on the side of the first large diameter portion 210L when the rotation angle φ is 0°≤φ<360° is taken as D. F1(AVE) Calculation. Furthermore, it is usually necessary to obtain D. F2(AVE)The shape profile of the outermost circumferential surface 1S is measured on the small diameter portion 220 on the side of the second large diameter portion 210R of the film roll 1. Specifically, the shape profile of the outermost circumferential surface 1S is measured within a measurement range 221R of the small diameter portion 220 within 10cm to 20cm of the inner end (the inner end on the roll axis) of the small diameter portion 220 away from the second large diameter portion 210R along the roll axis. Then, the diameter of the small diameter portion 220 on the side of the second large diameter portion 210R is obtained from this shape profile, and the average of the measured values ​​of the diameter of the small diameter portion 220 on the side of the second large diameter portion 210R with a rotation angle φ of 0°≤φ<360° is taken as D. F2(AVE) calculate.

[0100] After that, the obtained D N1(MAX) and D F1(AVE) Substituting into equation (1), the first roll diameter difference ΔD1 of film roll 1 is calculated. This first roll diameter difference ΔD1 is equivalent to the difference in diameter between the first large diameter portion 210L and the inner small diameter portion 220 of the roll axis, corresponding to the size of the step that can be generated between the first large diameter portion 210L and the small diameter portion 220. Furthermore, the obtained D N2(MAX) and D F2(AVE) Substituting into equation (2), the second roll diameter difference ΔD2 of film roll 1 is calculated. This second roll diameter difference ΔD2 is equivalent to the difference between the diameter of the second large diameter portion 210R and the diameter of the small diameter portion 220 on the inner side of the roll axis, corresponding to the size of the step that can be generated between the second large diameter portion 210R and the small diameter portion 220. Condition (R1) indicates that these steps are less than a certain threshold.

[0101] Next, the condition (R2) will be explained.

[0102] Condition (R2): At least one of the first roll diameter difference ΔD1 and the second roll diameter difference ΔD2 of the film roll 1 is typically 0.05 mm or more, preferably 0.06 mm or more, and more preferably 0.07 mm or more. It is further preferred that both the first roll diameter difference ΔD1 and the second roll diameter difference ΔD2 of the film roll 1 are above the aforementioned threshold values.

[0103] As described above, the first roll diameter difference ΔD1 corresponds to the difference in diameter between the first large diameter portion 210L and the inner diameter portion 220 of the roll axis, and corresponds to the size of the step that can be generated between the first large diameter portion 210L and the small diameter portion 220. Furthermore, as described above, the second roll diameter difference ΔD2 corresponds to the difference in diameter between the second large diameter portion 210R and the inner diameter portion 220 of the roll axis, and corresponds to the size of the step that can be generated between the second large diameter portion 210R and the small diameter portion 220. Therefore, condition (R2) indicates that at least one of their step differences is above a certain threshold, preferably both are above a certain threshold.

[0104] Next, the condition (R3) will be explained.

[0105] Condition (R3): The air layer thickness d between the wound strips of film 100 at the center of the winding axis of film roll 1. air Typically, it is 0.9 μm or more, preferably 1.0 μm or more, typically 2.0 μm or less, preferably 1.7 μm or less, and more preferably 1.4 μm or less.

[0106] The aforementioned air layer thickness d air This indicates the thickness of each air layer between the overlapping strips of film 100 wound within film roll 1. The air layer thickness d air It can be measured using the following measurement methods.

[0107] Figure 7 For illustrating the thickness d of the air layer between the strip membranes 100 contained in membrane roll 1 air A schematic cross-sectional view of membrane roll 1, representing the measurement method. (See attached image.) Figure 7 As shown, the measurement method for the first roll diameter difference ΔD1 and the second roll diameter difference ΔD2 of the membrane roll 1 described above is the same, with a laser displacement meter 300L positioned opposite the membrane roll 1. While rotating the membrane roll 1 circumferentially about the central axis 10A of the core 10, the distance from the laser displacement meter 300L to the outermost circumferential surface 1S of the membrane roll 1 is measured at the center of the roll axis using the laser displacement meter 300L. Through this measurement, the circumferential rotation angle φ of the membrane roll 1 (reference) is determined. Figure 6 The distance from the laser displacement meter 300L to the outermost circumferential surface 1S of the membrane roll 1 is obtained within the range of 0°≤φ<360°. Then, the shape profile of the outermost circumferential surface 1S at the center of the roll axis of the membrane roll 1 is obtained from this measurement result, and the average radius Rb is obtained with a rotation angle φ of 0°≤φ<360°. In addition, the average radius Ra of the core 10 at the center of the roll axis of the membrane roll 1 and the thickness d of a single membrane at the center of the membrane width direction of the strip membrane 100 are also measured separately. film And the length L of the long strip membrane 100.

[0108] Generally, the average radius Rb of membrane roll 1 is represented by the following formula (M1). Furthermore, generally, the length L of the elongated membrane 100 contained in membrane roll 1 is represented by the following formula (M2). Here, n represents the total number of elongated membranes 100 wound in membrane roll 1.

[0109] [Mathematical Expression 3]

[0110]

[0111] In equation (M2), since n >> 1, it can be approximated as n+1 ≈ n. Therefore, when n+1 is approximated as n in equation (M2), the total number of windings n can be expressed by equation (M3). Furthermore, by solving equation (M1), the air layer thickness d... airIt can be expressed by equation (M4). Therefore, it is possible to determine the thickness of a single sheet of film at the center of the width direction of the strip film 100 based on the average radius Rb of the film roll 1, the average radius Ra of the core 10, and the thickness d of the single sheet of film at the center of the strip film 100. film And the length L of the elongated membrane 100, the air layer thickness d is calculated using formulas (M3) and (M4). air .

[0112] [Mathematical Expression 4]

[0113]

[0114] The film roll 1 of this embodiment, which satisfies the above conditions (R1), (R2), and (R3), can suppress fringe, granular defects, and end defects. Therefore, since it exhibits excellent appearance and quality stability during transportation and storage, an improvement in yield can be expected. Details are as follows.

[0115] The membrane roll 1 of this embodiment can suppress the occurrence of bulging defects. Therefore, in the elongated membrane 100 included in the membrane roll 1, the occurrence of defects caused by bending of the elongated membrane 100 can be suppressed. In one example, when the membrane roll 1 is stored in an environment with a temperature of 20°C to 25°C and a humidity of 50%RH to 70%RH for 14 days, the occurrence of bulging defects (localized, band-like defects extending circumferentially) can be suppressed.

[0116] As described above, cracking tendons tend to occur when the air gap between the strips of film 100 within the overlapping wound film roll 1 becomes too small. In this embodiment, as indicated by condition (R3), since a sufficient air gap capable of suppressing the occurrence of cracking tendons is formed between the strips of film 100 within the film roll 1, the formation of cracking tendons can be suppressed.

[0117] The membrane roll 1 of this embodiment can suppress buckling. Therefore, the occurrence of granular defects caused by buckling can be suppressed. In one example, after storing the membrane roll 1 in an environment with a temperature of 20°C to 25°C and a humidity of 50%RH to 70%RH for 14 days, the occurrence of granular defects in the strip membrane 100 contained in the membrane roll 1 can be suppressed. These granular defects are typically observed as defects with a depth of 3μm to 5μm and a width of 3mm to 5mm. Granular defects can be detected by unwinding the strip membrane 100 from the membrane roll 1 at a linear speed of 50m / min using a defect detector. As this defect detector, a detector that illuminates the strip membrane 100 and detects defects based on the state of the light reflected from the strip membrane 100 can be used. In the case of buckling in the strip membrane, since the light reflection state changes compared to the non-buckled area, the aforementioned defect detector can be used to detect granular defects. However, in order to distinguish and evaluate granular defects from end defects, defects in the film width direction, in the range of 0 mm to 40 mm further inside the knurling area, are not included in granular defects.

[0118] As described above, granular defects are often prone to buckling when the air layer between the strips of film 100 within the overlapping wound film roll 1 becomes too large. In this embodiment, as indicated by condition (R3), since the air layer between the strips of film 100 can be thinned to a degree that can suppress buckling, buckling can be suppressed, thereby also suppressing the occurrence of granular defects.

[0119] The membrane roll 1 of this embodiment can suppress end defects. In one example, after storing the membrane roll 1 in an environment with a temperature of 20°C to 25°C and a humidity of 50%RH to 70%RH for 14 days, the occurrence of end defects of the strip membrane 100 contained in the membrane roll 1 can be suppressed. The aforementioned end defects are typically observed as defects with a depth of 3μm to 5μm and a width of 3mm to 5mm. End defects can be detected by unwinding the strip membrane 100 from the membrane roll 1 at a linear speed of 50m / min and using the aforementioned defect detector. However, in order to distinguish and evaluate end defects from granular defects, only defects in the membrane width direction, within a range of 0mm to 40mm from the inner side of the knurled area, are detected as end defects.

[0120] Figure 8 This is a schematic illustration of the shape profile of the outermost circumferential surface near the end of the film roll 1 in the axial direction, used to illustrate an example. (See diagram below.) Figure 8As shown, the membrane roll 1 has a relatively large diameter in its large diameter portion (i.e., the first large diameter portion 210L and the second large diameter portion 210R) and a relatively small diameter in its small diameter portion 220 located inside the roll's axial direction. At this time, in the boundary portion 230 between the large diameter portion 210L or 210R and the small diameter portion 220, the local diameter can become particularly small due to the movement of the elongated membrane 100 caused by gravity. At this time, when the diameter difference between the large diameter portion 210L or 210R and the small diameter portion 220 is large, a large step can be formed in the aforementioned boundary portion 230. In the case of a large step, due to deep buckling at stress concentration points, the elongated membrane 100 bends significantly, sometimes resulting in end defects. In contrast, in this embodiment, as shown in condition (R1), the first roll diameter difference ΔD1 and the second roll diameter difference ΔD2 corresponding to the aforementioned step can be made less than an experimentally confirmed appropriate threshold. Therefore, buckling in the boundary portion 230 can be suppressed, and the occurrence of end defects can be suppressed.

[0121] If the sole purpose is to suppress end buckling, eliminating the first roll diameter difference ΔD1 and the second roll diameter difference ΔD2 could be considered. However, if the elimination of the first roll diameter difference ΔD1 and the second roll diameter difference ΔD2 is assumed, the air layer between the strip films 100 in the small diameter portion 220 becomes too small, making it difficult to suppress buckling. Therefore, in this embodiment, as in condition (R2), the lower limit of the first roll diameter difference ΔD1 and the second roll diameter difference ΔD2 is set above an appropriate threshold, thus achieving complete suppression of buckling, granular defects, and end defects.

[0122] Achieving a membrane roll 1 that satisfies conditions (R1) and (R2) has always been difficult. In conventional membrane rolls, it was believed that to suppress winding deviation of the long strip membrane (the phenomenon of the wound long strip membrane shifting along the roll axis), it was desirable to densely form protrusions in the knurled area. Therefore, if it was assumed that the first roll diameter difference ΔD1 and the second roll diameter difference ΔD2 were reduced, the protrusion formation would be low. However, due to the large number of times the long strip membrane is over-wound during winding, a large number of protrusions accumulate in the membrane roll, resulting in the inability to reduce the first roll diameter difference ΔD1 and the second roll diameter difference ΔD2. Therefore, even assuming that the first roll diameter difference ΔD1 and the second roll diameter difference ΔD2 could be zero without knurling, it has been difficult in conventional technology to control the first roll diameter difference ΔD1 and the second roll diameter difference ΔD2 within an appropriate range that satisfies conditions (R1) and (R2).

[0123] In contrast, in this embodiment, instead of densely arranging the knurled portions 111L and 111R containing protrusions in the knurled regions 110L and 110R, gaps 112L and 112R are left between them, with a large spacing P. 111L and P 111R To form. By using a large spacing P111L By providing knurled portions 111L, the stacking of the knurled portions 111L on the overlapping wound strip film 100 is reduced in the first large-diameter portion 210L where the knurled area 110L is wound. Therefore, since the knurled portions 111L can overlap in a staggered circumferential position in this first large-diameter portion 210L, the diameter of the first large-diameter portion 210L will not become excessively large and can be controlled within an appropriate range. Similarly, by using a large spacing P... 111R By providing the knurled portion 111R, the diameter of the second large-diameter portion 210R, where the knurled region 110R is wound, is kept within an appropriate range because the stacking of the knurled portions 111R of the overlapping wound strip film 100 can be reduced. Therefore, in this embodiment, the first roll diameter difference ΔD1 and the second roll diameter difference ΔD2 can be controlled within an appropriate range that satisfies conditions (R1) and (R2).

[0124] The method for satisfying conditions (R1) and (R2) is as described above. Therefore, the dimensions and positions of the knurled portions 111L and 111R and the spacers 112L and 112R of the strip film 100 are preferably set to satisfy conditions (R1) and (R2). For example, it is preferable to select and adopt values ​​within the range described above that yield the desired first roll diameter difference ΔD1 and second roll diameter difference ΔD2.

[0125] Furthermore, in order to obtain the air layer thickness d that satisfies condition (R3) air Preferably, protrusions 132 of appropriate height are formed according to the dimensions and positions of the knurled portions 111L and 111R and the spacers 112L and 112R, and the film roll 1 is manufactured by a method including the knurled contact winding method described later. Traditionally, the air layer thickness d... air Reducing it to the extent that condition (R3) is met is difficult. In contrast, in this embodiment, since the stacking of the knurled portions 111L and 111R can be reduced as described above, the air layer thickness d can be reduced compared to the height of the protrusions 132 of the knurled portions 111L and 111R. air Therefore, a small air layer thickness d that satisfies condition (R3) can be obtained. air .

[0126] <Manufacturing Method of Membrane Roll 1>

[0127] The aforementioned film roll 1 can be manufactured by a manufacturing method that includes winding the strip film 100 onto the core 10 using a knurled contact winding method. Specifically, the manufacturing method of the film roll 1 using the knurled contact winding method can be manufactured by a method comprising the following steps: a step (S2) of winding the strip film 100 onto a contact roller; and a step (S3) of winding the strip film 100 wound onto the contact roller onto the core 10 while contacting the contact roller with the knurled areas 110L and 110R of the strip film 100.

[0128] Furthermore, if the film to be wound does not have knurled portions, the manufacturing method of film roll 1 may include the following step before step (S2): forming knurled portions 111L and 111R on a strip film before forming knurled portions 111L and 111R, to obtain a strip film 100 having knurled portions 111L and 111R (S1).

[0129] Hereinafter, for the sake of distinction, the "long strip film before the formation of the knurled portions 111L and 111R" will sometimes be referred to as the "pre-processing film". Hereinafter, the manufacturing method of the film roll 1 including these steps (S1) to (S3) will be described with reference to the accompanying drawings.

[0130] Figure 9 A side view illustrating a film roll 1 manufacturing apparatus according to one embodiment of the present invention. Figure 9 As shown, the manufacturing method of film roll 1 typically involves winding a long strip of film 100 while continuously transporting it along its length. In this embodiment, an example is shown below: before processing, the film 400 is knurled using a processing device 410 (in... Figure 9 After obtaining the long strip film 100 (illustration omitted), the long strip film 100 is supplied to the contact roller 430 via the transport roller 420 and wound onto the core 10.

[0131] exist Figure 9 In the example shown, the long strip of pre-processing film 400 is transported along its length as indicated by arrow A9 and supplied to the processing apparatus 410. Protrusions are formed on the pre-processing film 400 supplied to the processing apparatus 410 to obtain a strip of film 100 including knurled portions (step (S1)).

[0132] As the processing apparatus 410, from the viewpoint of simply adjusting the height, spacing, and planar shape of the protrusions, a laser processing apparatus capable of forming knurled portions by irradiation with a laser is preferred. When using a laser processing apparatus, the laser 411 is irradiated onto the pre-processing film 400 while moving the laser 411 to the irradiation point. At the irradiated locations, the pre-processing film 400 undergoes localized thermal melting or ablation. Thus, a protrusion 130 (see reference) can be formed on the pre-processing film 400 at the irradiated locations of the laser 411. Figure 3 ), thus obtaining a strip film 100 with knurled portions 111L and 111R.

[0133] When the laser 411 is irradiated, it is moved such that the laser 411 irradiates the irradiation point of the pre-processing film 400 to trace the planar shape of the desired uneven portion 130. As a result, since the uneven portion 130 is formed by the trace of the movement of the irradiation point of the laser 411, it is possible to form an uneven portion 130 with the desired planar shape.

[0134] The moving speed of the irradiation point of the laser 411 can be appropriately set within a range that allows the desired unevenness 130 to be formed. In one example, the moving speed of the irradiation point of the laser 411 is preferably 500 mm / s or more, more preferably 1000 mm / s or more, further preferably 1500 mm / s or more, preferably 10000 mm / s or less, more preferably 9000 mm / s or less, and further preferably 8000 mm / s or less. A specific moving speed can be used to obtain a protrusion 132 with a desired height (see reference). Figure 3 The protrusions and concavities 130 are adjusted within the aforementioned range.

[0135] Examples of laser devices used for irradiation of laser 411 include ArF excimer lasers, XeCl excimer lasers, YAG lasers (especially third or fourth harmonic lasers), solid-state lasers of YLF or YVO4 (especially third or fourth harmonic lasers), Ti:S lasers, semiconductor lasers, fiber lasers, and carbon dioxide lasers. Among these laser devices, carbon dioxide lasers are preferred from the viewpoint of being relatively inexpensive and capable of efficiently obtaining output power suitable for film processing.

[0136] The output power of the laser is preferably 1W or more, more preferably 5W or more, even more preferably 15W or more, preferably 120W or less, more preferably 100W or less, even more preferably 80W or less, and even more preferably 70W or less. The specific output power can also be adjusted within the above range in such a way that the protrusion 132 with a desired height can be obtained from the concave-convex portion 130.

[0137] Since the knurled portions 111L and 111R are formed on the film 400 before processing by the processing device 410 described above, a long strip film 100 to be wound can be obtained. The long strip film 100 is supplied to the contact roller 430 via the transport roller 420. The long strip film 100 supplied to the contact roller 430 is wound around the contact roller 430 (step (S2)).

[0138] The contact roller 430 is a roller with a axial length exceeding the width of the strip film 100, and is configured to rotate circumferentially around its axis of rotation (not shown). The contact roller 430 may also be configured to rotate freely. When the contact roller 430 is configured to rotate freely, it can rotate circumferentially due to the frictional force provided by the wound strip film 100. Furthermore, the contact roller 430 can also be driven to rotate by a rotational driving force provided by a drive device (not shown). For example, if the frictional force between the contact roller 430 and the strip film 100 is small, or if the contact roller 430 is heavy, a rotational driving force can be provided to the contact roller 430 to reduce mechanical wear. The strip film 100 wound on the contact roller 430 is guided to the core 10 by this rotating contact roller 430.

[0139] The core 10 is typically driven to rotate circumferentially by a drive device (not shown). The strip film 100, which is guided to the core 10 while wound on the contact roller 430, is wound on the core 10 to obtain film roll 1 (process (S3)).

[0140] Figure 10 This is a top view illustrating the state of the strip film 100 wound around the core 10 in a method for manufacturing film roll 1 according to one embodiment of the present invention. Figure 10 As shown, the winding of the strip film 100 wound on the contact roller 430 to the core 10 is carried out while the contact roller 430 is in contact with the knurled areas 110L and 110R of the strip film 100 that has been wound on the core 10 and has become part of the film roll 1 in the manufacturing process.

[0141] During winding, the contact roller 430 preferably presses the film roll 1 in the manufacturing process towards the center of the core 10 radially. For example, a force-applying device such as a cylinder can be provided on the support arm (not shown) supporting the contact roller 430, and the contact roller 430 presses the film roll 1 by the force-applying device. As a result, the knurled regions 110L and 110R of the strip film (i.e., the strip film included in the film roll 1 in the manufacturing process) 100 wound on the core 10 can be pressed towards the center of the core 10 with a specific load. As a result, air can be prevented from being drawn into the overlapping knurled regions 110L and 110R. As a result, the diameter of the first large diameter portion 210L and the second large diameter portion 210R wound with these knurled regions 110L and 110R can be reduced, and the first roll diameter difference ΔD1 and the second roll diameter difference ΔD2 satisfying conditions (R1) and (R2) can be obtained. In addition, it can usually increase the friction between the long strip film 100 in the first large diameter portion 210L and the second large diameter portion 210R, and suppress winding deviation.

[0142] Furthermore, the winding of the strip film 100 wound on the contact roller 430 to the core 10 is performed while ensuring that the contact roller 430 does not come into contact with the flat area 120 of the strip film 100, which is already wound on the core 10 and becomes part of the film roll 1 during manufacturing. This allows air to be effectively drawn into the overlapping flat areas 120. Consequently, an air layer thickness d that satisfies condition (R3) can be obtained. air Air layer thickness d air The protrusions 132 (in the knurled portions 111L and 111R) are able to pass through the knurled portions 111L and 111R. Figure 10 The height (not shown in the figure) is adjusted. In this way, the air layer thickness d can be adjusted according to the height of the protrusion 132. air This is one of the advantages of the contact roller winding method.

[0143] The load applied by the contact roller 430 to the film roll 1 during manufacturing is preferably set such that the contact roller 430 contacts the knurled areas 110L and 110R of the strip film 100 wound on the core 10, but does not contact the flat area 120 of the strip film 100 wound on the core 10. In one example, the load range is preferably 50 N / m or more, more preferably 60 N / m or more, further preferably 70 N / m or more, preferably 200 N / m or less, more preferably 180 N / m or less, and further preferably 160 N / m or less. Here, the unit "N / m" of the load refers to the magnitude of the force applied to each 1m width of the strip film 100. The specific load magnitude is preferably selected and set from the above range in a manner that satisfies conditions (R1) to (R3).

[0144] The load applied by the contact roller 430 to the film roll 1 during manufacturing can be varied according to the roll diameter of the film roll 1 during manufacturing. In this case, for example, the load can be varied in a gradually decreasing manner, or in a gradually increasing manner, or a combination thereof.

[0145] When the strip film 100 is wound onto the core 10, the winding tension (film tension) of the strip film 100 at the start of winding is preferably 10 N / m or more, more preferably 50 N / m or more, even more preferably 80 N / m or more, preferably 200 N / m or less, more preferably 170 N / m or less, and even more preferably 140 N / m or less.

[0146] When the strip film 100 is wound onto the core 10, the winding tension can be fixed at the initial winding tension or it can be varied. For example, it can start from the initial winding tension Ts of the strip film 100 and gradually decrease the tension as winding progresses. When the winding tension at the end of winding the strip film 100 is Te, the tension taper ratio (%) is preferably 5% or more, more preferably 10% or more, even more preferably 15% or more, preferably 50% or less, more preferably 40% or less, and even more preferably 30% or less. Here, the tension taper ratio (%) is expressed as "tension taper ratio (%) = (Ts - Te) / Ts × 100".

[0147] When the strip film 100 is wound onto the core 10, the winding speed (linear speed) of the strip film 100 is preferably 10 m / min or more, more preferably 20 m / min or more, even more preferably 30 m / min or more, preferably 150 m / min or less, more preferably 125 m / min or less, and even more preferably 100 m / min or less. Since the film roll 1 described above can be manufactured by winding the strip film 100 at such a high speed, it can help improve manufacturing efficiency.

[0148] <Example of Change>

[0149] The above-described film roll can also be further modified. For example, step (S1) of the film roll manufacturing method can also include oscillating the position of the knurled portion in the film width direction.

[0150] Figure 11 A front view of film roll 2, illustrating a modified example of the above-described embodiment of the present invention, is shown. Furthermore, Figure 12 This is a schematic top view showing the vicinity of one end (first end) of the elongated film 500 according to the above embodiment of the present invention, magnified. Except that the position of the protrusion 130 swings in the film width direction, Figure 11 and Figure 12The membrane roll 2 and the long strip membrane 500 shown are arranged in the same manner as the membrane roll 1 and the long strip membrane 100 in the above embodiment. For example... Figure 11 and Figure 12 As shown, the knurled portion 111L (and knurled portion 111R) are formed; see reference. Figure 5 When the position of the knurled portions 111L and 111R of the overlapping wound strip film 500 is oscillating in the film width direction, the stacking of the knurled portions 111L or 111R can be effectively suppressed because the positions of the knurled portions 111L and 111R can be staggered in the roll axis. As a result, the first roll diameter difference ΔD1 and the second roll diameter difference ΔD2 can be easily reduced.

[0151] The degree of oscillation can be measured by the amount of oscillation A. O Let it be represented by the swing amount A. O This represents the amplitude of the oscillation along the membrane width direction. The amount of this oscillation, A... O The width W relative to each knurled section 111L and 111R 111L and W 111R The ratio (A) O / W 111L and A O / W 111R The range of ) is preferably 0.5 or more, more preferably 0.6 or more, preferably 1.0 or less, and more preferably 0.8 or less. The specific swing amount A O Alternatively, one can select from the above range in such a way that the first roll diameter difference ΔD1 and the second roll diameter difference ΔD2 satisfying conditions (R1) and (R2) can be obtained.

[0152] When performing the above-described oscillation, the oscillation period is preferably set appropriately in a way that satisfies the conditions (R1) and (R2) by obtaining the first roll diameter difference ΔD1 and the second roll diameter difference ΔD2. For example, the oscillation period can be in the range of 800 mm to 1500 mm. Here, the oscillation period refers to the distance along the length of the film from when the knurled portion is formed at a certain position in the width direction of the film during transport, until the position of the knurled portion changes due to oscillation and the knurled portion is formed again at the original position.

[0153] In the above embodiments, an example of forming one uneven portion in a knurled portion is shown, but it is also possible to form two or more uneven portions in a knurled portion.

[0154] In the above embodiments, an example is shown in which a combination of recesses and convexes is formed in the knurled portion, but it is also possible to form a convex portion without recesses in the knurled portion.

[0155] In the above embodiments, an example of forming a protrusion using a laser is shown, but protrusions can also be formed by other methods. For example, protrusions can also be formed by using embossing with heat and pressure.

[0156] Composition and Layer Structure of Long Strip Membranes

[0157] As the aforementioned long strip film, a resin film is typically used. This resin film can be a stretched film or an unstretched film. Furthermore, the aforementioned resin film can be a single-layer film having only a substrate layer, or a multilayer film having any combination of layers with a substrate layer.

[0158] As the substrate layer, a layer formed of resin is typically used. Various resins can be used depending on the application of the strip film, with cyclic olefin resins being particularly preferred. Films having a substrate layer formed of cyclic olefin resin generally tend to trap air during winding, thus exhibiting poor winding properties. In contrast, the strip film of the above-described embodiment can be wound well using a knurled contact winding method.

[0159] Cyclic olefin resins are resins containing cyclic olefin polymers. Cyclic olefin polymers exhibit excellent mechanical properties, heat resistance, transparency, low moisture absorption, dimensional stability, and lightweight properties. A cyclic olefin polymer refers to a polymer whose structural units have an alicyclic structure. Cyclic olefin polymers can be polymers with an alicyclic structure in the main chain, polymers with an alicyclic structure in the side chains, polymers with an alicyclic structure in both the main chain and side chains, and mixtures of two or more of these in any ratio. From the viewpoint of mechanical strength and heat resistance, polymers with an alicyclic structure in the main chain are particularly preferred.

[0160] Examples of alicyclic structures include saturated alicyclic hydrocarbons (cycloalkanes) and unsaturated alicyclic hydrocarbons (cycloalkenes, cycloalkynes). From the viewpoint of mechanical strength and heat resistance, cycloalkanes and cycloalkenes are particularly preferred, with cycloalkanes being especially preferred.

[0161] Regarding the number of carbon atoms constituting the alicyclic structure, each alicyclic structure preferably has 4 or more, more preferably 5 or more, more preferably 30 or less, more preferably 20 or less, and particularly preferably 15 or less. When the number of carbon atoms constituting the alicyclic structure is within this range, the resin exhibits a high balance between mechanical strength, heat resistance, and moldability.

[0162] In cyclic olefin polymers, the proportion of structural units with alicyclic structures is preferably 55% by weight or more, more preferably 70% by weight or more, and particularly preferably 90% by weight or more. When the proportion of structural units with alicyclic structures in the cyclic olefin polymer is within this range, good transparency and heat resistance are observed.

[0163] Examples of cyclic olefin polymers include norbornene polymers, monocyclic cyclic olefin polymers, cyclic conjugated diene polymers, vinyl alicyclic hydrocarbon polymers, and their hydrides. Among these, norbornene polymers and their hydrides are particularly preferred due to their good formability.

[0164] Examples of norbornene-based polymers and their hydrides include ring-opening polymers of monomers having a norbornene structure and their hydrides; addition polymers of monomers having a norbornene structure and their hydrides. Furthermore, examples of ring-opening polymers of monomers having a norbornene structure include: ring-opening homopolymers of a single monomer having a norbornene structure; ring-opening copolymers of two or more monomers having a norbornene structure; and ring-opening copolymers of a monomer having a norbornene structure and any monomer capable of copolymerizing therewith. Moreover, examples of addition polymers of monomers having a norbornene structure include: addition homopolymers of a single monomer having a norbornene structure; addition copolymers of two or more monomers having a norbornene structure; and addition copolymers of a monomer having a norbornene structure and any monomer capable of copolymerizing therewith. Among these, hydrides of ring-opening polymers of monomers having a norbornene structure are particularly preferred from the viewpoints of moldability, heat resistance, low moisture absorption, dimensional stability, and lightweight properties.

[0165] The weight-average molecular weight (Mw) of the cyclic olefin polymer is preferably 10,000 or more, more preferably 15,000 or more, particularly preferably 20,000 or more, more preferably 100,000 or less, more preferably 80,000 or less, and particularly preferably 50,000 or less. When the weight-average molecular weight is within the above range, the mechanical strength and molding processability of the resin are highly balanced.

[0166] The molecular weight distribution (weight-average molecular weight (Mw) / number-average molecular weight (Mn)) of the cyclic olefin polymer is preferably 1.2 or more, more preferably 1.5 or more, particularly preferably 1.8 or more, preferably 3.5 or less, more preferably 3.0 or less, and particularly preferably 2.7 or less. When the molecular weight distribution is at or above the lower limit of the above range, the polymer productivity can be improved and manufacturing costs can be reduced. Furthermore, when the molecular weight distribution is at or below the upper limit of the above range, since the amount of low molecular weight components is smaller, relaxation under high temperature exposure can be suppressed, and the stability of the membrane can be improved.

[0167] Weight-average molecular weight and number-average molecular weight are the weight-average molecular weights converted from polyisoprene or polystyrene determined by gel permeation chromatography using cyclohexane as a solvent. However, in the gel permeation chromatography method described above, toluene can also be used as a solvent if the sample is insoluble in cyclohexane.

[0168] The glass transition temperature of the cycloolefin polymer is preferably 130°C or higher, more preferably 135°C or higher, more preferably 150°C or lower, and even more preferably 145°C or lower. When the glass transition temperature is above the lower limit of the above range, the film exhibits good durability at high temperatures. Furthermore, when the glass transition temperature is below the upper limit of the above range, stretching treatment can be easily performed.

[0169] As the aforementioned cyclic olefin polymer, polymers such as those described in International Publication No. 2017 / 145718 can be used.

[0170] The proportion of cyclic olefin polymer in the cyclic olefin resin is preferably 50% to 100% by weight, more preferably 70% to 100% by weight, and particularly preferably 90% to 100% by weight. When the proportion of polymer is within the above range, sufficient heat resistance and transparency can be obtained.

[0171] Cycloolefin resins can also contain any components other than cycloolefin polymers in combination with cycloolefin polymers. Examples of any components include colorants such as pigments and dyes; fluorescent whitening agents; dispersants; heat stabilizers; light stabilizers; ultraviolet absorbers; antistatic agents; antioxidants; lubricants, etc. Furthermore, these can be used alone or in combination of two or more.

[0172] The aforementioned substrate layer can be manufactured by molding the resin using a suitable film forming method. Examples of film forming methods include casting, extrusion molding, and blow molding. From the viewpoints of efficiently reducing residual volatile components, environmental and operational conditions, and excellent manufacturing efficiency, solvent-free melt extrusion is particularly preferred. As a melt extrusion method, die-filled blow molding can also be used; from the viewpoints of excellent productivity and thickness accuracy, the T-die method is preferred.

[0173] When using a multilayer film with two or more layers as a strip film, the multilayer film preferably has a substrate layer and a functional layer. The functional layer can be disposed on one side of the substrate layer or on both sides. The functional layer is particularly preferably disposed on the knurled side of the substrate layer, and more preferably the knurled portion is provided on the surface of the functional layer.

[0174] Examples of such functional layers include antistatic layers, hard coatings, anti-seize layers, and easy-to-adhere layers.

[0175] An antistatic layer is a layer with a low surface resistivity. The preferred surface resistivity of the antistatic layer is 1.0 × 10⁻⁶. 6 Ω / □ or higher, more preferably 1.0×10 7 Ω / □ or higher, preferably 1.0 × 10 8Ω / □ or higher, preferably 1.0 × 10¹ 0 Ω / □ or less, more preferably 5.0 × 10 9 Ω / □ or less, especially preferably 1.0 × 10 9 Below Ω / □. The surface resistivity can be measured using a digital super-insulation / micro-ammeter (Hioki Electric Co., Ltd. "DSM-8104") according to JIS K6911. Such an antistatic layer can be formed, for example, from a resin containing conductive particles such as metal oxide particles and polymers.

[0176] A hard coating refers to a layer with high hardness. When the specific hardness of the hard coating is expressed in terms of JIS pencil hardness, it is preferably B or higher, more preferably HB or higher, and particularly preferably H or higher. Here, JIS pencil hardness is the pencil hardness at which scratches begin to appear when a pencil of various hardness is tilted at 45° and a load of 500g is applied from above to scratch the surface of the layer, according to JIS K5600-5-4. Such a hard coating can be formed, for example, from resin.

[0177] An anti-adhesion layer is a layer with a rough surface that can inhibit adhesion between membranes when overlapped with other membranes. Such an anti-adhesion layer can be formed, for example, from a resin containing polymers and particles.

[0178] An easy-adhesive layer is a layer that exhibits high adhesion when its surface is bonded to other components. Such an easy-adhesive layer can be formed, for example, from a resin containing a polymer.

[0179] Of the functional layers described above, an easy-to-adhere layer is preferred. The easy-to-adhere layer is preferably a layer containing an aqueous resin. An aqueous resin refers to a resin that can be prepared as a solution or dispersion in water. By applying an aqueous solution or dispersion containing the aqueous resin to the surface of the substrate layer and then drying it, a layer of the aqueous resin can be formed on the surface of the substrate layer. Examples of aqueous resins include, for example, polyurethane resins, polyester resins, and emulsions of their respective resins; aqueous polyurethane resins are preferred.

[0180] As the aforementioned functional layer, the functional layer described in, for example, International Publication No. 2017 / 145718 can be used.

[0181] <Applications of membrane rolls>

[0182] The film rolls manufactured by the above-described manufacturing method can be used for the storage and handling of a wide range of films, such as optical films, moisture-proof films, packaging films, conductive films, insulating films, antistatic films, barrier films, and wiring board films. From the viewpoint of effectively utilizing the advantage of suppressing defects, they are particularly suitable for optical films. Examples of optical films include, for instance, phase retardation films, protective films for polarizers, polarizing films, brightness-enhancing films, light-diffusing films, light-concentrating films, and reflective films.

[0183] Example

[0184] The following embodiments illustrate the invention in detail. However, the invention is not limited to the embodiments shown below, and can be implemented in any manner without departing from the claims and their equivalents. In the following description, unless otherwise stated, "%" and "parts" refer to quantities based on weight. Furthermore, unless otherwise stated, the operations described below are performed at normal temperature and pressure (23°C, one atmosphere).

[0185] <Description of Measurement Method>

[0186] (Method for measuring the height H of the protrusions in the knurled part)

[0187] The height of the protrusions formed on the membrane was measured using a digital micrometer (manufactured by Mitutoyo Corporation). Specifically, the micrometer was clamped over a flat area where no protrusions were formed, and zero-point calibration was performed. Then, the micrometer was clamped over the knurled portion where protrusions were formed, and the measured value was taken as the height of the protrusions. Since the knurling was performed under the same conditions at both ends of the membrane width direction in the embodiments and comparative examples described later, the height of the protrusions was measured by taking 50 points from each end of the membrane width direction, for a total of 100 points from both ends, and the arithmetic mean of these measurements was taken as the height of the membrane protrusions.

[0188] (Measuring methods for the diameter differences ΔD1 and ΔD2 of the membrane roll)

[0189] like Figure 6 As shown, laser displacement meters (Keyence Corporation "LJ-X8400") 300L and 300R are positioned opposite the membrane roll 1, away from the outermost circumferential surface 1S of the membrane roll 1. The laser displacement meters 300L and 300R are positioned such that the optical axes 310L and 310R of the measuring lasers (not shown) emitted from the laser displacement meters 300L and 300R are perpendicular to the central axis 10A of the core 10. Furthermore, the distance from the laser displacement meters 300L and 300R to the surface of the core 10 is set to 580 mm. While rotating the membrane roll 1 circumferentially around the central axis 10A of the core 10, the distance from the laser displacement meters 300L and 300R to the outermost circumferential surface 1S of the membrane roll 1 is measured using the laser displacement meters 300L and 300R at a sampling period of 50 ms. The above measurements were performed on a 100mm width measurement range at both ends of the roll axis of membrane roll 1 to obtain its shape profile. Based on the obtained shape profile, the maximum value D of the diameter of the first large diameter portion 210L was calculated. N1(MAX) The average diameter D of the small diameter portion 220 on the side of the first large diameter portion 210L F1(AVE) The maximum value D of the diameter of the second largest diameter section 210RN2(MAX) The average diameter D of the small diameter portion 220 on the side of the second large diameter portion 210R F2(AVE) And calculate the first roll diameter difference ΔD1 and the second roll diameter difference ΔD2 based on equations (1) and (2).

[0190] (The thickness d of the air layer between the membranes contained in the membrane roll) air (Measurement method)

[0191] like Figure 7 As shown, a long-distance laser displacement meter (Keyence Corporation "LK-G500") 300L is installed at a position opposite to and away from the outermost circumferential surface 1S of the membrane roll 1. The laser displacement meter 300L is positioned such that the optical axes 310L and 310R of the measuring laser emitted from the laser displacement meter 300L are perpendicular to the central axis 10A of the core 10. Furthermore, the distance from the laser displacement meter 300L to the surface of the core 10 is set to 580 mm. While rotating the membrane roll 1 circumferentially around the central axis 10A of the core 10, the distance from the laser displacement meter 300L to the outermost circumferential surface 1S of the membrane roll 1 is measured at the center of the winding axis of the membrane roll 1 using the laser displacement meter 300L, thus obtaining the shape profile of the membrane roll 1. Based on the shape profile obtained in this way, the average radius Rb at the center of the winding axis of the membrane roll 1 is obtained.

[0192] Next, the membrane was unwound from the roll, and a 50mm wide section, equal to one circumference of the roll, was cut out using scissors to obtain a test piece. The thickness of this test piece was measured using a benchtop thickness gauge (MRC-1 rotary caliper manufactured by Meisho Co., Ltd.), and the average thickness of one circumference of the roll was taken as the membrane thickness d. film .

[0193] Using the average radius Rb and film thickness d of the above-mentioned film roll 1 film Based on equations (M3) and (M4), and the pre-measured average radius Ra and film length L of the core 10, the air layer thickness d is calculated. air .

[0194] (Evaluation method for exposed ribs in membrane rolls)

[0195] The wound membrane roll was stored for 14 days in an environment with a temperature of 20℃~25℃ and a humidity of 50%RH~70%RH. Afterwards, a high-brightness lamp was shone on the ends of the membrane roll along its axial direction to observe its circumference. Localized band-like defects extending along the circumference of the roll were identified as ripples.

[0196] For the bulges detected by the above method, the surface roughness was measured using a small surface roughness measuring machine (Mitutoyo SURFTEST SJ-410 series). Since the bulges extend along the circumferential direction of the roll, measurements can be taken at any circumferential position. A surface roughness profile along the roll axis was obtained for the bulge-generating location. Based on the measurement data for the bulge-generating location, the range of the film roll surface shape was calculated. The aforementioned "range" represents the difference between the maximum and minimum heights of the film roll surface within the bulge (maximum value - minimum value). Based on the aforementioned range, the bulge defect was evaluated according to the following criteria. Since a larger range indicates a greater difference between the high portion (peak) and the low portion (valley) of the bulge, it is more likely to form a defect.

[0197] "A": Range is below 0.15mm

[0198] "B": Range greater than 0.15mm and less than 0.3mm

[0199] "C": Range greater than 0.3mm

[0200] (Evaluation method for granular defects in elongated membranes contained in a membrane roll)

[0201] The wound membrane roll was stored for 14 days at a temperature of 20°C–25°C and a humidity of 50%–70%RH. Afterward, the membrane was unwound from the roll at a linear speed of 50 m / min. For the unwound membrane, a defect detector was used to count the total number of defects. To distinguish these defects from end defects generated near the knurled area, defects detected within a 50 mm width range at each end of the membrane in the width direction were excluded, and defects detected in the remaining flat areas were counted as "granular defects." The defect detector's illumination was set to a positive reflection mode and configured to detect changes in the reflectivity of the membrane when it is buckled. In this inspection, a defect with a depth of 3 μm–5 μm and a width of 3 mm–5 mm was counted as one. Based on the detection results, granular defects were evaluated according to the following criteria.

[0202] "A": Total number of defects is 0.1 / m 2 the following.

[0203] "B": Total number of defects greater than 0.1 / m 2 And it is 1.0 per m 2 the following.

[0204] "C": Total number of defects greater than 1.0 / m 2 .

[0205] (Evaluation method for end defects of long strip membranes contained in a membrane roll)

[0206] Using the same method as described above (evaluation method for granular defects in long strip membranes contained in membrane rolls), the membrane roll is stored, and the membrane is wound out. For the wound-out membrane, the total number of defects is counted using a defect detector. To distinguish this from granular defects, defects detected within a 50mm width range at each end of the membrane in the width direction are designated as "end defects." In this inspection, a defect with a depth of 3μm to 5μm and a width of 3mm to 5mm is counted as one. Based on the detection results, end defects are evaluated according to the following criteria.

[0207] "A": Total number of defects is 0.1 / m 2 the following.

[0208] "B": Total number of defects greater than 0.1 / m 2 And it is 1.0 per m 2 the following.

[0209] "C": Total number of defects greater than 1.0 / m 2 .

[0210] <Example 1>

[0211] (1) Fabrication of the substrate layer:

[0212] Particles of an alicyclic polymer resin (ZEONOR 1215, manufactured by Zeon Corporation, Japan) were dried at 100°C for 5 hours. The particles were then fed into an extruder, where they were melted and extruded in sheet form from a T-die through a polymer tube and a polymer filter onto a casting drum. After cooling, a strip of substrate layer with a thickness of 80 μm and a width of 1600 mm was obtained.

[0213] (2) Formation of an easily adhesive layer:

[0214] By combining 100 parts by weight of an aqueous dispersion of polyether-based polyurethane (SUPERFLEX 870 manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd.), 15 parts by weight of an epoxy compound as a crosslinking agent (Denacol EX313 manufactured by Nagase ChemteX Co., Ltd.), 8 parts by weight of an aqueous dispersion of silica particles as a lubricant (SNOWTEX MP1040 manufactured by Nissan Chemical Co., Ltd.; average particle size 120 nm), 8 parts by weight of an aqueous dispersion of silica particles (SNOWTEX XL manufactured by Nissan Chemical Co., Ltd.; average particle size 50 nm), 0.5% by weight of an acetylene-based surfactant as a wetting agent (Surfynol 440 manufactured by Air Products and Chemicals Co., Ltd.), and water, a liquid aqueous dispersion of a polyurethane resin with a solids concentration of 2% was obtained.

[0215] An aqueous dispersion of the aforementioned water-based polyurethane resin is coated onto one side of the substrate layer and dried to form an easy-to-adhere layer with a thickness of 45 nm. This yields a long strip of pre-stretch film having a substrate layer and an easy-to-adhere layer.

[0216] (3) Membrane stretching:

[0217] The pre-stretched strip film was subjected to simultaneous biaxial stretching in both the length and width directions at a stretching temperature of 135°C. The stretching ratio in the length direction was 1.15 times, and the stretching ratio in the width direction was 1.44 times. Through the above simultaneous biaxial stretching, a strip of stretched film with a thickness of 52 μm and a width of 1490 mm was obtained.

[0218] (4) Formation of the knurled part:

[0219] On the easily bonded layer sides at both ends of the elongated stretch film, a CO2 laser is irradiated using a 9.4 μm laser oscillator to form knurled sections with raised areas. Specifically, the knurling is applied to a region (knurled area) within 10 mm of the edge in the film width direction. Figure 4 The laser is irradiated in the manner shown, forming a textured surface containing raised portions (3 μm high) of resin protrusions that are fluidized by the laser and recessed portions where the resin is removed by thermal melting or ablation caused by the laser. The textured surface has... Figure 4 The polygonal planar shape shown has a length dimension (corresponding to the length of the knurled portion) of 1.9 mm and a width dimension (corresponding to the width of the knurled portion) of 9.4 mm. The aforementioned protrusions and concave portions are formed side-by-side along the length of the film at 50 mm intervals. Thus, in the knurled regions at both ends of the stretched film, the knurled portions with protrusions are alternately formed side-by-side with the spacers along the length of the film at 50 mm intervals.

[0220] (5) Membrane winding:

[0221] A 6000m long strip of stretch film with knurled sections is wound around a contact roller, and then wound onto a cylindrical core at a winding speed of 50m / min to obtain a film roll. This winding is performed in a manner where the contact roller contacts the knurled area of ​​the stretch film wound on the core, but does not contact the flat area of ​​the stretch film wound on the core (knurled contact winding method). The initial winding tension is 120N / m, and the winding tension is gradually reduced by a tension taper ratio of 20% as winding progresses. Furthermore, the contact roller applies a load (contact pressure) of 100N / m to the film roll during manufacturing.

[0222] The obtained membrane rolls were evaluated using the methods described above.

[0223] <Example 2>

[0224] In step (4), the output power of the CO2 laser was changed, the height of the protrusions included in the concave-convex part was changed to 1 μm, and the spacing between the concave-convex parts (i.e., the spacing between the knurled parts) was changed to 30 mm. Otherwise, the film roll was manufactured and evaluated by the same method as in Example 1.

[0225] <Example 3>

[0226] In step (4), the output power of the CO2 laser was changed, the height of the protrusions included in the concave-convex portion was changed to 7 μm, and the spacing between the concave-convex portions (i.e., the spacing between the knurled portions) was changed to 80 mm. Otherwise, the film roll was manufactured and evaluated by the same method as in Example 1.

[0227] <Example 4>

[0228] In step (5), the winding speed was changed to 80 m / min and the load (contact pressure) of the contact roller pressing the film roll during manufacturing was changed to 200 N / m. Otherwise, the film roll was manufactured and evaluated using the same method as in Example 1.

[0229] <Example 5>

[0230] In step (4), the output power of the CO2 laser was changed, and the height of the protrusion included in the concave-convex portion was changed to 7 μm. In addition, in step (5), the load (contact pressure) of the contact roller pressing the film roll during manufacturing was changed to 50 N / m. Apart from the above, the film roll was manufactured and evaluated using the same method as in Example 1.

[0231] <Example 6>

[0232] In step (3), the stretch ratio along the length of the film was changed, and the thickness of the stretched film was changed to 23 μm. Furthermore, in step (4), the spacing between the raised and recessed portions (i.e., the spacing between the knurled portions) was changed to 30 mm. Then, in step (5), the length of the stretched film to be wound was changed to 9000 m, and the winding tension at the start of winding was changed to 100 N / m. Apart from the above, the film roll was manufactured and evaluated using the same method as in Example 1.

[0233] <Example 7>

[0234] In step (4), the output power of the CO2 laser was changed, the height of the protrusions included in the uneven portion was changed to 9 μm, and the spacing between the uneven portions (i.e., the spacing of the knurled portions) was changed to 100 mm. In addition, in step (5), the winding speed was changed to 100 m / min, and the load (contact pressure) of the contact roller pressing the film roll during manufacturing was changed to 150 N / m. Apart from the above, the film roll was manufactured and evaluated using the same method as in Example 1.

[0235] <Example 8>

[0236] In step (4), the output power of the CO2 laser was changed, and the height of the protrusion included in the uneven portion was changed to 7 μm. Furthermore, at both ends in the film width direction, the laser irradiation position was oscillated in the film width direction with an oscillation amount of 10 mm and a period of 1000 mm. Then, in step (5), the load (contact pressure) of the contact roller pressing the film roll during manufacturing was changed to 50 N / m. Apart from the above, the film roll was manufactured and evaluated using the same method as in Example 1.

[0237] <Comparative Example 1>

[0238] In step (4), the spacing between the raised and recessed portions (i.e., the spacing between the knurled portions) is changed to 10 mm. Furthermore, in step (5), the length of the stretch film to be wound is changed to 5200 m. Apart from the above, the film roll is manufactured and evaluated using the same method as in Example 1.

[0239] <Comparative Example 2>

[0240] In step (4), the output power of the CO2 laser was changed, the height of the protrusions included in the uneven portion was changed to 5 μm, and the spacing between the uneven portions (i.e., the spacing of the knurled portions) was changed to 200 mm. In addition, in step (5), the length of the stretch film to be wound was changed to 5200 m. Apart from the above, the film roll was manufactured and evaluated by the same method as in Example 1.

[0241] <Comparative Example 3>

[0242] In step (4), the output power of the CO2 laser is changed, the height of the protrusions in the uneven portion is changed to 7 μm, and the spacing between the uneven portions (i.e., the spacing of the knurled portions) is changed to 3 mm. Furthermore, the winding method of the stretch film in step (5) is changed to a gap winding method. The gap winding method in step (5) is implemented as follows.

[0243] A 3900m long strip of stretch film with knurled sections is wound around a gap roller, and then the stretch film is wound onto a cylindrical core at a winding speed of 50m / min to obtain a film roll. This winding is performed in a manner where the gap roller does not contact the stretch film wound on the core (gap winding method). The initial winding tension is 160N / m, and the winding tension is gradually reduced by a tension taper ratio of 30% as winding progresses.

[0244] The obtained membrane rolls were evaluated using the methods described above.

[0245] <Comparative Example 4>

[0246] In step (4), the output power of the CO2 laser was changed, the height of the protrusions included in the uneven portion was changed to 7 μm, and the spacing between the uneven portions (i.e., the spacing of the knurled portions) was changed to 5 mm. In addition, in step (5), the length of the wound stretch film was changed to 5200 m, the tension taper ratio was changed to 30%, and the load (contact pressure) of the contact roller pressing the film roll during manufacturing was changed to 20 N / m. Apart from the above, the film roll was manufactured and evaluated using the same method as in Example 1.

[0247] <Comparative Example 5>

[0248] In step (4), the output power of the CO2 laser was changed, the height of the protrusions included in the uneven portion was changed to 7 μm, and the spacing between the uneven portions (i.e., the spacing of the knurled portions) was changed to 5 mm. Furthermore, in step (5), the length of the wound stretch film was changed to 5200 m, the winding speed was changed to 80 m / min, the tension taper ratio was changed to 30%, and the load (contact pressure) of the contact roller pressing the film roll during manufacturing was changed to 20 N / m. Apart from the above, the film roll was manufactured and evaluated using the same method as in Example 1.

[0249] <Comparative Example 6>

[0250] In step (4), the output power of the CO2 laser was changed, the height of the protrusions included in the uneven portion was changed to 13 μm, and the spacing between the uneven portions (i.e., the spacing of the knurled portions) was changed to 3 mm. Furthermore, in step (5), the length of the wound stretch film was changed to 5200 m, the tension taper ratio was changed to 30%, and the load (contact pressure) of the contact roller pressing the film roll during manufacturing was changed to 20 N / m. Apart from the above, the film roll was manufactured and evaluated using the same method as in Example 1.

[0251] <Comparative Example 7>

[0252] In step (4), the method for forming the uneven portion was changed from laser processing using a CO2 laser to hot embossing using a heated mold. The height of the protrusions included in the formed uneven portion was 1.5 μm, the length dimension (equivalent to the length of the knurled portion) was 0.1 mm, the width dimension (equivalent to the width of the knurled portion) was 10 mm, and the spacing between the uneven portions (i.e., the spacing between the knurled portions) was 1 mm. Furthermore, in step (5), the length of the wound stretch film was changed to 5200 m, and the load (contact pressure) of the contact roller pressing the film roll during manufacturing was changed to 115 N / m. Apart from the above, the film roll was manufactured and evaluated using the same method as in Example 1.

[0253] <Results>

[0254] The results of the above embodiments and comparative examples are shown in the following table. In the table below, the abbreviations have the following meanings.

[0255] The "Contact" option in the "Wrapping Method" column is: Knurled contact winding method.

[0256] The "Gap" option in the "Wrapping Method" column is: gap winding method.

[0257] The "L" in the "Knurling Processing Method" column indicates laser processing.

[0258] The "Hot" option in the "Knurling Processing Method" column indicates hot embossing.

[0259] "Knurling height": The height of the raised portion of the knurled part.

[0260] "Knurling spacing": The spacing between the knurled parts.

[0261] "Oscillation amount": The amount of oscillation in the width direction of the knurled part.

[0262] [Table 1]

[0263]

[0264] [Table 2]

[0265]

[0266] Explanation of reference numerals in the attached figures

[0267] 1: Membrane roll;

[0268] 2: Membrane roll;

[0269] 10: Roll core;

[0270] 10A: The central axis of the winding core;

[0271] 10S: The circumference of the core;

[0272] 100: Long strip film;

[0273] 100U: The side of the long strip film;

[0274] 110L, 110R: Knurled area;

[0275] 111L, 111R: Knurled part;

[0276] 112L, 112R: Spacing section;

[0277] 120: Flat area;

[0278] 130: Concave and convex parts;

[0279] 131: concave part;

[0280] 132: convex part;

[0281] 133: Corner;

[0282] 134, 135: Straight sections;

[0283] 140L, 140R: Edges;

[0284] 210L: The first large diameter part;

[0285] 210R: The second largest diameter part;

[0286] 220: Small diameter portion;

[0287] 221L, 221R: Measurement range within the small diameter section;

[0288] 230: Boundary section;

[0289] 300L, 300R: Laser displacement gauges;

[0290] 310L, 310R: The optical axes of the laser;

[0291] 400: Pre-processing film;

[0292] 410: Processing equipment;

[0293] 411: Laser;

[0294] 420: Conveyor roller;

[0295] 430: Contact roller;

[0296] 500: Long strip film.

Claims

1. A film roll having a core and a strip of film wound around the core, The elongated film includes two knurled regions with multiple protrusions at both ends in the width direction and a flat region between the two knurled regions. The film roll includes two large-diameter portions on which the knurled region of the strip film is wound, and a small-diameter portion disposed between the two large-diameter portions and on which the strip film is wound. Both the first roll diameter difference ΔD1, represented by equation (1) below, and the second roll diameter difference ΔD2, represented by equation (2) below, are less than 0.3 mm. At least one of the first roll diameter difference ΔD1 and the second roll diameter difference ΔD2 is 0.05 mm or more. At the center of the winding axis of the film roll, the air layer thickness between the wound strips of film is 0.9 μm or more and 2.0 μm or less. In equation (1), D N1(MAX) D represents the maximum diameter of one of the two large-diameter portions of the membrane roll. F1(AVE) This represents the average diameter of the small diameter portion on the large diameter side of one of the film rolls. In equation (2), D N2(MAX) D represents the maximum diameter of the other of the two major diameter portions of the membrane roll. F2(AVE) This represents the average diameter of the minor diameter portion on the major diameter side of the other of the film rolls.

2. The membrane roll according to claim 1, wherein, The knurled region of the elongated film alternately includes knurled portions with the protrusions and spaced portions without the protrusions along the length of the film. The spacing of the knurled portions along the length of the film is 20 mm or more and 100 mm or less.

3. The membrane roll according to claim 1, wherein, The height of the protrusion is more than 1 μm and less than 10 μm.

4. The membrane roll according to claim 1, wherein, The elongated membrane contains a cyclic olefin polymer.

5. The membrane roll according to claim 1, wherein, The length of the elongated membrane is more than 2000m and less than 10000m.

6. A method for manufacturing a membrane roll, the membrane roll having a core and a strip of film wound around the core, The elongated film includes two knurled regions with multiple protrusions at both ends in the width direction and a flat region between the two knurled regions. The knurled region of the elongated film alternately includes knurled portions with the protrusions and spaced portions without the protrusions along the length of the film. The spacing between the knurled portions along the length of the film is 20 mm or more and 100 mm or less. The manufacturing method includes: The process of winding the long strip of film onto the contact roller; and The process of winding the long strip of film, which is wound around the contact roller, onto the core while the contact roller is brought into contact with the knurled area of ​​the long strip of film.

7. The method for manufacturing a film roll according to claim 6, wherein, The method for manufacturing the film roll includes a step of forming the knurled portion of the film before processing to obtain the strip film.

8. The method for manufacturing a film roll according to claim 7, wherein, The method for manufacturing the film roll includes forming the knurled portion by irradiating it with a laser.

9. The method for manufacturing a film roll according to claim 7, wherein, The process of forming the knurled portion on the film before processing includes swinging the formation position of the knurled portion in the film width direction. The ratio of the oscillation amount of the knurled portion to the width of one of the knurled portions is 0.5 or more and 1.0 or less.

10. The method for manufacturing a film roll according to claim 6, wherein, The height of the protrusion is more than 1 μm and less than 10 μm.

11. The method for manufacturing a film roll according to claim 6, wherein, The elongated membrane contains a cyclic olefin polymer.

12. The method for manufacturing a film roll according to claim 6, wherein, The length of the wound strip film is more than 2000m and less than 10000m.

13. The method for manufacturing a film roll according to claim 6, wherein, The axial length of the contact roller is greater than or equal to the width of the elongated film. In the process of winding the long strip film onto the core, the contact roller presses the film roll during manufacturing toward the center of the core with a load of 50 N / m to 200 N / m.

14. The method for manufacturing a film roll according to claim 6, wherein, The winding speed of the long strip film is above 10m / min and below 150m / min.

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