Roll body and manufacturing method for roll body

Abstract

To provide a roll body and a manufacturing method for the roll body which can reduce step marks.SOLUTION: A roll body 1 includes: a winding core 2; a long first film 10 wound around the winding core 2: and a joining member 3 that joins one longitudinal end part of the first film 10 to the winding core 2. The joining member 3 is disposed between the winding core 2 and one longitudinal end part of the first film 10 in a thickness direction of the first film 10. In a radial direction of the roll body 1, the distance from the outer peripheral surface of the winding core 2 to a radial inner surface of one longitudinal end part of the first film 10, at least at one end part in a width direction, is shortest compared to the distance over the entire width direction.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a roll body and a method for manufacturing a roll body. [Background technology]

[0002] Conventionally, roll bodies have been known in which a sheet such as a long film is wound around a core. When manufacturing such roll bodies, first, the sheet is fixed at its end (the winding start end) to the outer peripheral surface of the core using a fixing member such as double-sided tape. However, when the sheet is fixed to the outer peripheral surface of the core using the fixing member, a step occurs due to the thickness of the sheet and the fixing member, and if the roll body is manufactured in this state, a step mark may occur.

[0003] In order to prevent such step marks, it has been proposed to fill in the steps caused by the thickness of the sheet and the thickness of the fixing member (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-107286 Summary of the Invention [Problem to be solved by the invention]

[0005] However, the roll body described in Patent Document 1 cannot suppress the formation of step marks caused by deformation of the sheet due to heating. Specifically, when the sheet is heated in the manufacturing process, the sheet stretched by heating shrinks over time after being wound up. This shrinkage causes a difference in stress in the radial direction of the roll body across the width of the roll body, which can result in the formation of step marks.

[0006] The present invention provides a roll body and a method for manufacturing a roll body that can reduce step marks. [Means for solving the problem]

[0007] The present invention [1] is a roll body comprising a winding core, a long first film wound around the winding core, and a joining member joining one longitudinal end of the first film and the winding core, wherein the joining member is arranged between the winding core and the one end in the thickness direction of the first film, and the distance from the outer peripheral surface of the winding core to the radially inner surface of the one end in the radial direction of the roll body, the distance at at least one end in the width direction perpendicular to both the longitudinal direction and the thickness direction, is shortest compared to the distance across the entire width direction.

[0008] The present invention [2] is a roll body on which a film is wound, the film comprising a long first film, a long second film, and a joining member joining one longitudinal end of the first film and the other longitudinal end of the second film, the first film being positioned radially outside the roll body and the second film being positioned radially inside the roll body, the joining member being positioned between the one end and the other end in the thickness direction of the first film, and the roll body having a distance from the radially outer surface of the other end to the radially inner surface of the one end in the radial direction of the roll body, the distance at at least one end in a width direction perpendicular to both the longitudinal direction and the thickness direction being shortest compared to the distance across the entire width direction.

[0009] The present invention [3] includes a roll body according to the above [1] or [2], wherein the joining member is further arranged over the entire width of the one end, and the thickness of the joining member at least at one end in the width direction of the one end is thinner than the thickness of the joining member at the center of the one end in the width direction.

[0010] The present invention [4] includes the roll body described in [3] above, in which the thickness of the joining member at both ends of the one end in the width direction is thinner than the thickness of the joining member at the center of the one end in the width direction.

[0011] The present invention [5] includes the roll body according to the above [1] or [2], in which the joining member is not disposed on at least one end of the one end in the width direction.

[0012] The present invention [6] includes the roll body according to the above [5], in which the joining members are not disposed at both ends of the one end in the width direction.

[0013] The present invention [7] includes a method for manufacturing a roll body described in [1] or [2] above, which includes a step of winding up a work film including at least the first film under a vacuum atmosphere.

[0014] The present invention [8] includes the method for manufacturing a roll body described in [7] above, which further includes a step of heating the work film. [Effects of the Invention]

[0015] In the roll of the present invention, the distance in the radial direction of the roll from the outer peripheral surface of the core to the radially inner surface of one longitudinal end of the first film at at least one end in the width direction is shortest compared to the distance across the entire width direction, thereby reducing step marks.

[0016] Furthermore, in the roll body of the present invention, the distance in the radial direction of the roll body from the radially outer surface of the other longitudinal end of the second film to the radially inner surface of one longitudinal end of the first film, at least at one end in the width direction, is shortest compared to the distance over the entire width direction, thereby reducing step marks.

[0017] Furthermore, the method for manufacturing the roll body of the present invention is a method for manufacturing the above-mentioned roll body, and includes a step of winding up the workpiece film including at least the first film in a vacuum atmosphere, so that a roll body with reduced step marks can be manufactured even in a vacuum atmosphere. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a cross-sectional view taken along the radial direction of a joint between a core and a first film in a first embodiment of a roll body of the present invention. [Figure 2] FIG. 2 is a cross-sectional view taken along the width direction of the joining portion between the core and the first film in the first embodiment of the roll body shown in FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along the radial direction of the joining portion between the first film and the second film in a second embodiment of the roll body of the present invention. [Figure 4] FIG. 4 is a cross-sectional view of the joining portion between the first film and the second film in the width direction in the second embodiment of the roll body shown in FIG. [Figure 5] FIG. 5 is a schematic diagram of one embodiment of a roll body manufacturing apparatus used in the roll body manufacturing method of the present invention. [Figure 6] FIG. 6 is a cross-sectional view taken along the width direction of the joining portion between the core and the first film in a first modified example of the roll body of the present invention. [Figure 7] FIG. 7 is a cross-sectional view taken along the width direction of the joining portion between the core and the first film in a second modified example of the roll body of the present invention. [Figure 8] FIG. 8 is a cross-sectional view taken along the width direction of the joining portion between the core and the first film in a third modified example of the roll body of the present invention. [Figure 9] FIG. 9 is a cross-sectional view taken along the width direction of the joining portion between the core and the first film in a fourth modified example of the roll body of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] 1. Roll body (First embodiment) A first embodiment of a roll body 1 of the present invention will be described with reference to FIGS.

[0020] The roll body 1 includes a core 2 and a long first film 10 wound around the core 2. The first film 10 is wound around the core 2 multiple times.

[0021] There are no particular limitations on the shape of the winding core 2. From the viewpoint of facilitating winding of the first film 10, the shape of the winding core 2 can be, for example, a columnar or cylindrical shape. A columnar shape is preferred.

[0022] There are no particular limitations on the material of the winding core 2. Examples of materials for the winding core 2 include polymer materials, paper materials, and metal materials. Metal materials are preferred.

[0023] Examples of polymeric materials for the core 2 include acrylonitrile-butadiene-styrene copolymer (ABS), polyethylene, polypropylene, polyvinyl chloride, polystyrene, ethylene-propylene copolymer, and ethylene-vinyl acetate copolymer.

[0024] Examples of metal materials for the winding core 2 include iron, stainless steel, and aluminum, with aluminum being preferred.

[0025] The diameter of the winding core 2 is not particularly limited. The diameter of the winding core 2 is, for example, 5 cm or more, preferably 10 cm or more, and for example, 100 cm or less, preferably 50 cm or less. The diameter of the winding core 2 is the average diameter in the width direction of the winding core 2. It is also the outer diameter when the winding core 2 is cylindrical.

[0026] In the first embodiment, as shown in FIG. 2, the diameter of the winding core 2 is substantially uniform throughout the width direction, which is perpendicular to the radial direction.

[0027] The widthwise length of the winding core 2 is not particularly limited as long as it is equal to or greater than the widthwise length of the first film 10 described below. The widthwise length of the winding core 2 is, for example, 300 mm or more, preferably 500 mm or more, and for example, 10,000 mm or less, preferably 8,000 mm or less. The widthwise length of the winding core 2 is the average length of the winding core 2 in the widthwise direction.

[0028] The first film 10 has a shape that extends in a plane direction perpendicular to the thickness direction. In the plane direction, the first film 10 is a film that is long in the longitudinal direction and short in the width direction perpendicular to the longitudinal direction. In other words, the width direction is perpendicular to both the longitudinal direction and the thickness direction.

[0029] An example of the first film 10 is a base film.

[0030] The base film includes, for example, a resin film and a functional layer.

[0031] The resin film supports the first film 10. The resin film has a film shape (including a sheet shape). The resin film has flexibility.

[0032] Examples of resin film materials include cellulose resin, polyester resin, (meth)acrylic resin (acrylic resin and / or methacrylic resin), olefin resin, polycarbonate resin, polyethersulfone resin, polyarylate resin, melamine resin, polyamide resin, polyimide resin, polystyrene resin, norbornene resin, and polyvinyl alcohol resin. Examples of polyester resins include polyethylene terephthalate (PET), polybutylene terephthalate, and polyethylene naphthalate. Examples of polyolefin resins include polyethylene, polypropylene, and cycloolefin polymer (COP). Examples of cellulose resins include triacetyl cellulose (TAC). The resin film materials can be used alone or in combination of two or more.

[0033] From the viewpoints of transparency, heat resistance, mechanical strength, etc., the resin film is preferably a polyolefin resin film formed from a polyolefin resin, more preferably a COP film.

[0034] The thickness of the resin film is not particularly limited, but from the viewpoints of strength and handleability, it is, for example, 10 μm or more, preferably 30 μm or more, more preferably 50 μm or more, and for example, 500 μm or less, preferably 300 μm or less, more preferably 200 μm or less. The thickness of the resin film can be measured, for example, using a film thickness meter.

[0035] The functional layer improves mechanical properties and optical properties. The functional layer may be disposed on only one surface of the resin film in the thickness direction, or on both surfaces of the resin film in the thickness direction. The functional layer is preferably disposed on the other surface of the resin film in the thickness direction.

[0036] The functional layer is not particularly limited. Examples of the functional layer include a hard coat layer, an optical adjustment layer, and an anti-blocking layer. The hard coat layer, for example, makes the exposed surface of the resin film less susceptible to scratches. The optical adjustment layer, for example, adjusts the optical properties (e.g., refractive index) of the laminated film. The anti-blocking layer imparts anti-blocking properties to the surfaces of multiple laminated films that come into contact with each other, for example, when the laminated films are stacked in the thickness direction.

[0037] The functional layer may be composed of a single layer or multiple layers. Preferably, it is composed of multiple layers. Furthermore, when the functional layer is composed of multiple layers, it may be composed of multiple layers having different functions. Preferably, the functional layer has a hard coat layer and an optical adjustment layer in this order toward the other side in the thickness direction.

[0038] The functional layer is, for example, a cured product of a curable resin composition. That is, the functional layer is a cured resin layer. Specifically, the functional layer can be formed by applying a curable resin composition to one or both surfaces of a resin film in the thickness direction, drying the composition as necessary, and then curing the composition. The functional layer can contain particles as necessary.

[0039] The curable resin composition contains a curable resin. Examples of the curable resin include polyester resin, acrylic urethane resin, acrylic resin (excluding acrylic urethane resin), urethane resin (excluding acrylic urethane resin), amide resin, silicone resin, epoxy resin, and melamine resin. Preferably, acrylic urethane resin is used. The curable resin can be used alone or in combination of two or more kinds.

[0040] Examples of the curable resin composition include an ultraviolet-curable resin composition and a thermosetting resin composition. From the viewpoint of production efficiency, an ultraviolet-curable resin composition is preferably used as the curable resin composition. A specific example of the ultraviolet-curable resin composition is the ultraviolet-absorbing resin composition described in JP 2020-066153 A.

[0041] The curable resin composition preferably contains particles from the viewpoint of adjusting the hardness, surface roughness, refractive index, and anti-glare properties of the functional layer. Examples of the particles include organic particles and inorganic particles. Preferably, organic particles are used.

[0042] Examples of organic particles include acrylic resin particles, urethane resin particles, melamine resin particles, polystyrene resin particles, acrylic-styrene copolymer resin particles, and polycarbonate resin particles. Acrylic resin particles are preferred.

[0043] Examples of inorganic particles include inorganic oxide particles such as silica, alumina, titania, zirconia, calcium oxide, tin oxide, indium oxide, cadmium oxide, and antimony oxide, and inorganic carbonate particles such as calcium carbonate. Preferably, inorganic oxide particles are used. More preferably, zirconia particles are used.

[0044] The average particle size of the particles is, for example, 0.1 μm or more, preferably 0.5 μm or more, more preferably 1.0 μm or more, and for example, 5.0 μm or less, preferably 4.0 μm or less, more preferably 3.0 μm or less.

[0045] In the curable resin composition, the amount of particles per 100 parts by mass of the curable resin (solid content) is, for example, 0.01 parts by mass or more, preferably 0.10 parts by mass or more, and for example, 5 parts by mass or less, preferably 3 parts by mass or less.

[0046] The curable resin composition may contain additives such as a photopolymerization initiator, a solvent, a leveling agent, a thixotropic agent, and an antistatic agent. The curable resin composition may also contain additives for improving durability, as described in JP 2020-066153 A.

[0047] The thickness (total thickness) of the functional layer is, for example, 0.1 μm or more, preferably 0.5 μm or more, more preferably 1 μm or more, and for example, 10 μm or less, preferably 5 μm or less, more preferably 3 μm or less.

[0048] The width direction length of the base film is not particularly limited as long as it is equal to or less than the width direction length of the winding core 2. The width direction length of the base film is, for example, 300 mm or more, preferably 500 mm or more, and for example, 4000 mm or less, preferably 3000 mm. The width direction length of the base film is the width direction length W of the first film 10. In other words, the width direction length W of the first film 10 is equal to or less than the width direction length of the winding core 2.

[0049] The thickness of the substrate film is, for example, 10 μm or more, preferably 30 μm or more, more preferably 50 μm or more, and for example, 500 μm or less, preferably 300 μm or less, more preferably 200 μm or less.

[0050] The first film 10 may also be a laminated film in which an inorganic layer is laminated on one or both sides in the thickness direction of a base film.

[0051] The inorganic layer is preferably disposed on the other surface in the thickness direction of the substrate film (functional layer).

[0052] Examples of materials for the inorganic layer include metals, metal oxides, and metal nitrides.

[0053] Examples of metals include nickel, chromium, indium, aluminum, tin, gold, silver, copper, platinum, zinc, titanium, tungsten, zirconium, palladium, and alloys of two or more of these metals. Copper is preferred.

[0054] Examples of metal oxides include indium-containing conductive oxides, antimony-containing conductive oxides, and zinc-containing conductive oxides, with indium-containing conductive oxides being preferred.

[0055] Examples of indium-containing conductive oxides include indium tin oxide (ITO), indium zinc oxide (IZO), indium gallium oxide (IGO), and indium gallium zinc oxide (IGZO). ITO is preferred. Examples of antimony-containing conductive oxides include antimony tin oxide (ATO). Examples of zinc-containing conductive oxides include zinc aluminum oxide (AZO).

[0056] Examples of metal nitrides include aluminum nitride, titanium nitride, tantalum nitride, chromium nitride, gallium nitride, and composite nitrides of these.

[0057] The inorganic layer may consist of a single layer or multiple layers.

[0058] The inorganic layer has a thickness (total thickness) of, for example, 10 nm or more, preferably 30 nm or more, and for example, 300 nm or less, preferably 200 nm or less.

[0059] The thickness of the laminated film is, for example, 10 μm or more, preferably 30 μm or more, more preferably 50 μm or more, and for example, 500 μm or less, preferably 300 μm or less, more preferably 200 μm or less.

[0060] In the roll body 1, one longitudinal end of the first film 10 is joined to the winding core 2. More specifically, one longitudinal end of the first film 10 is joined to the winding core 2 so that the center of the width of the first film 10 and the center of the width of the winding core 2 are approximately aligned. Furthermore, the first film 10 is joined so that the width direction of the winding core 2 and the width direction of the first film 10 are approximately parallel.

[0061] The roll body 1 includes a joining member 3 between the core 2 and one longitudinal end of the first film 10. The joining member 3 joins the core 2 and one longitudinal end of the first film 10 together.

[0062] There are no particular limitations on the joining member 3, as long as it can join the core 2 and the first film 10. Examples of the joining member 3 include adhesives and double-sided tape. Preferably, double-sided tape is used.

[0063] The adhesive is not particularly limited as long as it is an adhesive that is normally used to join the winding core 2 and the first film 10, or to join the first film 10 and the second film 20. In addition, the double-sided tape is not particularly limited as long as it is an adhesive that is normally used to join the winding core 2 and the first film 10, or to join the first film 10 and the second film 20.

[0064] The joining member 3 may be used alone or in combination of two or more kinds.

[0065] The bonding member 3 is arranged so that, for example, in a cross section along the longitudinal direction, one end of the bonding member 3 in the longitudinal direction does not protrude from one end of the first film 10 in the longitudinal direction. Preferably, in a cross section along the longitudinal direction, one end face of the first film 10 in the longitudinal direction and one end face of the bonding member 3 in the longitudinal direction are arranged to be substantially flush with each other.

[0066] 2, in the first embodiment, the bonding member 3 is disposed across the entire width of the first film 10. Furthermore, the bonding member 3 is disposed so that, for example, in a cross section along the longitudinal direction, both ends of the bonding member 3 in the width direction do not protrude beyond both ends of the first film 10 in the width direction. Preferably, in a cross section along the longitudinal direction, one end face of the bonding member 3 in the width direction is disposed so as to be substantially flush with one end face of the bonding member 3 in the width direction, and the other end face of the first film 10 in the width direction is disposed so as to be substantially flush with the other end face of the bonding member 3 in the width direction.

[0067] In the first embodiment, two or more types of double-sided tapes with different thicknesses are used in combination for the joining member 3. Specifically, two first double-sided tapes 31 are used in a fixed area including both end portions in the width direction, and one second double-sided tape 32 is used in a fixed area including the center portion in the width direction.

[0068] In the first embodiment, two first double-sided tapes 31 are attached to one end and the other end of the first film 10 in the width direction. The two attached first double-sided tapes 31 are spaced apart in the width direction so as to avoid the center portion of the first film 10 in the width direction. One end of the first double-sided tape 31 attached to one end of the first film 10 in the width direction substantially coincides with one end of the first film 10 in the width direction, and the other end of the first double-sided tape 31 attached to the other end of the first film 10 in the width direction substantially coincides with the other end of the first film 10 in the width direction. In addition, the center portion of the second double-sided tape 32 in the width direction is arranged so as to substantially coincide with the center portion of the first film 10 in the width direction. Furthermore, the other widthwise end of the first double-sided tape attached to one widthwise end of the first film 10 and one widthwise end of the second double-sided tape 32 are in contact without overlapping, and one widthwise end of the first double-sided tape 31 attached to the other widthwise end of the first film 10 and the other widthwise end of the second double-sided tape 32 are in contact without overlapping.

[0069] The thickness 31 of the first double-sided tape is, for example, more than 0 μm, preferably 1 μm or more, more preferably 2 μm or more, and for example, less than 10 μm, preferably 8 μm or less.

[0070] The thickness 32 of the second double-sided tape is, for example, 10 μm or more, preferably 15 μm or more, more preferably 20 μm or more, and for example, 100 μm or less, preferably 80 μm or less, more preferably 50 μm or less.

[0071] The thickness 31 of the first double-sided tape is preferably thinner than the thickness of the second double-sided tape 32. In other words, the thickness of the joining member 3 at both ends in the width direction is thinner than the thickness of the joining member 3 at the center in the width direction.

[0072] If the thickness of the joining member 3 at both ends in the width direction is thinner than the thickness of the joining member 3 at the center in the width direction, step marks on the roll body 1 can be suppressed.

[0073] The ranges of the certain region including the center in the width direction and the certain region including both end portions in the width direction are not particularly limited, and can be set appropriately based on the stress applied to the roll body 1 in the radial direction.

[0074] Specifically, in the first embodiment, the certain region including both ends in the width direction is, for example, a region that combines the range from one end in the width direction to a position W×1 / 6 inward in the width direction from the one end in the width direction, and the range from the other end in the width direction to a position W×1 / 6 inward in the width direction from the other end in the width direction. For example, if the widthwise length W of the first film 10 is 1500 mm, the fixed region including both widthwise ends is the combined region of the range from one widthwise end to a position 250 mm inward from the one widthwise end (a range of 0 mm to 250 mm when one widthwise end is at 0 mm and the other widthwise end is at 1500 mm), and the range from the other widthwise end to a position 250 mm inward from the other widthwise end (a range of 1250 mm to 1500 mm when one widthwise end is at 0 mm and the other widthwise end is at 1500 mm).

[0075] In the first embodiment, the fixed region including the widthwise center is a region excluding the fixed regions including both widthwise ends, and is a region ranging from a position W×1 / 6 inward in the widthwise direction from one widthwise end to a position W×1 / 6 inward in the widthwise direction from the other widthwise end. For example, when the widthwise length W of the first film 10 is 1500 mm, the fixed region including the widthwise center is a region ranging from a position 250 mm inward in the widthwise direction from one widthwise end to a position 250 mm inward in the widthwise direction from the other widthwise end (a range of 250 mm to 1250 mm when one widthwise end is at 0 mm and the other widthwise end is at 1500 mm).

[0076] When a joining member 3 having a constant thickness across the entire width direction is used to join the core 2 and one longitudinal end of the first film 10, differences in radial stress of the roll 1 occur across the width at one longitudinal end of the first film 10, depending on the roll manufacturing process and the shape of the core 2. Specifically, when the core 2 and one longitudinal end of the first film 10, which have substantially the same diameter across the entire width direction, are joined using a joining member 3 having a constant thickness across the entire width direction, and the first film 10 is heated by sputtering or the like during the roll manufacturing process, the first film 10 stretched by heating after winding shrinks (enters a heat-shrunk state), and radial stress of the roll 1 increases at one longitudinal end of the first film 10 from the center in the width direction toward both ends in the width direction. That is, when the core 2, which has approximately the same diameter across the entire width direction, and one longitudinal end of the first film 10 are joined together using a joining member 3 of a constant thickness across the entire width direction, and the first film is heated and shrunk after being wound, the radial stress of the roll 1 is smallest at the center in the width direction at one longitudinal end of the first film 10, and largest at both ends in the width direction. In this way, the difference in stress across the width direction at one longitudinal end of the first film 10 can cause step marks.

[0077] The length of the joining member 3 in the longitudinal direction is not particularly limited as long as it is long enough to join the winding core 2 and the first film 10. The length of the joining member 3 in the longitudinal direction is, for example, 10 mm or more, preferably 30 mm or more, and for example, 500 mm or less, preferably 300 mm or less.

[0078] The length (total length) of the joining member 3 in the width direction is not particularly limited as long as it is long enough to join the core 2 and the first film 10 together.

[0079] Furthermore, the distance T in the radial direction of the roll 1 is from the outer peripheral surface of the core 2 to the radially inner surface of one longitudinal end of the first film 10. In this case, at least one widthwise end of one longitudinal end of the first film 10 has the shortest distance T compared to the distance T across the entire width. If the portion of one longitudinal end of the first film 10 that has the shortest distance T1 compared to the distance T across the entire width is defined as the shortest portion, then at least one widthwise end of one longitudinal end of the first film 10 is the shortest portion.

[0080] If the distance T1 at least at one end in the width direction of the first film 10 at one end in the longitudinal direction is the shortest with respect to the distance T over the entire width direction, the formation of step marks on the roll 1 can be suppressed.

[0081] In the first embodiment, at one longitudinal end of the first film 10, the distance T1 in a certain region that includes both widthwise ends is the shortest relative to the distance T in the entire width direction. That is, at one longitudinal end of the first film 10, the certain region that includes both widthwise ends is the shortest part. Also, at one longitudinal end of the first film 10, the distance T2 in a certain region that includes the widthwise center is the longest relative to the distance T in the entire width direction. That is, if the part at one longitudinal end of the first film 10 that has the longest distance T2 relative to the distance T in the entire width direction is defined as the longest part, then at one longitudinal end of the first film 10, the certain region that includes the widthwise center is the longest part.

[0082] At one end of the first film 10 in the longitudinal direction, the distance T1 at the shortest part (at least one end in the width direction at one end of the first film 10 in the longitudinal direction) is, for example, 0 μm or more, and, for example, less than 10 μm, preferably 8 μm or less.

[0083] At one end of the first film 10 in the longitudinal direction, the distance T2 at the longest part is, for example, 10 μm or more, preferably 15 μm or more, more preferably 20 μm or more, and for example, 100 μm or less, preferably 80 μm or less, more preferably 50 μm or less.

[0084] The ratio (T1 / T2) of the distance T1 at the shortest part at one end of the longitudinal direction of the first film 10 to the distance T2 at the longest part at one end of the longitudinal direction of the first film 10 is, for example, 0 or more, and, for example, less than 1, preferably 0.8 or less, more preferably 0.5 or less, and even more preferably 0.3 or less.

[0085] [Action and effect] In the roll 1 of the first embodiment of the present invention, the distance T in the radial direction of the roll 1 from the outer peripheral surface of the core 2 to the radially inner surface of one longitudinal end of the first film 10, the distance T1 at at least one end in the width direction, is shortest compared to the distance T over the entire width direction. This reduces step marks.

[0086] Specifically, when the first film 10 is heated during the formation of the roll 1, the heated and stretched first film 10 shrinks after being wound around the winding core 2. At this time, both widthwise ends of the first film 10 are more affected than the widthwise center portion and shrink more. Therefore, if a joining member 3 having a uniform thickness across the entire widthwise region is used to join the winding core 2 to one longitudinal end of the first film 10, and the roll manufacturing process includes a step of heating the first film 10, stress in the radial direction of the roll 1 increases at one longitudinal end of the first film 10 from the widthwise center portion toward both widthwise ends. However, the thickness of the first double-sided tape 31 attached to both widthwise ends is thinner than the thickness of the second double-sided tape 32 attached to the widthwise center portion. In other words, in the radial direction of the roll 1, the distance T from the outer peripheral surface of the core 2 to the radially inner surface of one longitudinal end of the first film 10 is the distance T1 at least at one end in the width direction, and this distance T1 is the shortest compared to the distance T over the entire width direction. Therefore, the stress in the radial direction of the roll 1 can be alleviated by the difference in thickness (distance), and as a result, step marks can be reduced.

[0087] (Second embodiment) A second embodiment of the roll body of the present invention will be described with reference to FIGS.

[0088] In the second embodiment, the same reference numerals are used to designate the same members as those in the first embodiment of the roll body 1, and detailed descriptions thereof will be omitted. Furthermore, the second embodiment can be appropriately combined with the first embodiment of the roll body 1 and the modified examples described below.

[0089] As shown in Fig. 3, a film including a long first film 10 and a long second film 20 joined to one longitudinal end of the first film 10 is wound around the roll 1. In addition, in the roll 1, the first film 10 is positioned on the radially outer side of the roll 1, and the second film 20 is positioned on the radially inner side of the roll 1. More specifically, in the roll 1, the second film 20 is first wound around the winding core 2, and then the first film 10 is wound around it.

[0090] The first film 10 may be the same as the first film 10 described in the first embodiment of the roll body 1. The description of the first film 10 in the second embodiment is the same as the description of the first film 10 described in the first embodiment of the roll body 1.

[0091] The second film 20 may be the same as the first film 10 described in the first embodiment of the roll body 1. The description of the first film 10 in the second embodiment is the same as the description of the first film 10 described in the first embodiment of the roll body 1.

[0092] In the second embodiment, the first film 10 and the second film 20 may be the same or different. Preferably, the first film 10 and the second film 20 are the same.

[0093] In the roll body 1, one longitudinal end of the first film 10 is joined to the second film 20. More specifically, one longitudinal end of the first film 10 is joined to the other longitudinal end of the second film 20 so that the center of the width of the first film 10 and the center of the width of the second film 20 are approximately aligned. Furthermore, the first film 10 and the second film 20 are joined so that their width directions are approximately parallel to each other.

[0094] The roll body 1 includes a joining member 3 between one longitudinal end of the first film 10 and the other longitudinal end of the second film 20. The joining member 3 joins the one longitudinal end of the first film 10 and the other longitudinal end of the second film 20.

[0095] The joining member 3 of the second embodiment may be the same as the joining member 3 described in the first embodiment of the roll body 1. The description of the joining member 3 in the second embodiment is the same as the description of the joining member 3 described in the first embodiment of the roll body 1.

[0096] The joining member 3 is arranged so that, for example, in a cross section along the longitudinal direction, one end of the joining member 3 in the longitudinal direction does not protrude from one end of the first film 10 in the longitudinal direction. Preferably, in a cross section along the longitudinal direction, one end face of the first film 10 in the longitudinal direction and one end face of the joining member 3 in the longitudinal direction are arranged to be approximately flush with each other.

[0097] Furthermore, the joining member 3 is arranged so that, for example, in a cross section along the longitudinal direction, the other end of the joining member 3 in the longitudinal direction does not protrude from the other end of the second film 20 in the longitudinal direction. Preferably, in a cross section along the longitudinal direction, the other end surface of the second film 20 in the longitudinal direction and the other end surface of the joining member 3 in the longitudinal direction are arranged so as to be substantially flush with each other.

[0098] 4, in the second embodiment, the bonding member 3 is disposed across the entire width of the first film 10. Furthermore, the bonding member 3 is disposed so that, for example, both ends of the bonding member 3 in the width direction do not protrude beyond both ends of the first film 10 in the width direction in a cross section along the longitudinal direction. Preferably, in a cross section along the longitudinal direction, one end face of the bonding member 3 in the width direction is disposed so as to be substantially flush with one end face of the bonding member 3 in the width direction, and the other end face of the first film 10 in the width direction is disposed so as to be substantially flush with the other end face of the bonding member 3 in the width direction.

[0099] In the second embodiment, two or more types of double-sided tapes with different thicknesses are used in combination for the joining member 3. Specifically, two first double-sided tapes 31 are used in a fixed area including both end portions in the width direction, and one second double-sided tape 32 is used in a fixed area including the center portion in the width direction.

[0100] In the second embodiment, two first double-sided tapes 31 are attached to one end and the other end of the first film 10 in the width direction. The two attached first double-sided tapes 31 are spaced apart in the width direction so as to avoid the center portion of the first film 10 in the width direction. One end of the first double-sided tape 31 attached to one end of the first film 10 in the width direction substantially coincides with one end of the first film 10 in the width direction, and the other end of the first double-sided tape 31 attached to the other end of the first film 10 in the width direction substantially coincides with the other end of the first film 10 in the width direction. In addition, the center portion of the second double-sided tape 32 in the width direction is arranged so as to substantially coincide with the center portion of the first film 10 in the width direction. Furthermore, the other widthwise end of the first double-sided tape attached to one widthwise end of the first film 10 and one widthwise end of the second double-sided tape 32 are in contact without overlapping, and one widthwise end of the first double-sided tape 31 attached to the other widthwise end of the first film 10 and the other widthwise end of the second double-sided tape 32 are in contact without overlapping.

[0101] The thickness 31 of the first double-sided tape and the thickness 32 of the second double-sided tape are the same as the thickness 31 of the first double-sided tape and the thickness 32 of the second double-sided tape described in the first embodiment of the roll body 1.

[0102] The thickness of the first double-sided tape is preferably thinner than the thickness of the second double-sided tape. That is, the thickness of the joining member 3 at both ends in the width direction is thinner than the thickness of the joining member 3 at the center in the width direction.

[0103] If the thickness of the joining member 3 at both ends in the width direction is thinner than the thickness of the joining member 3 at the center in the width direction, step marks on the roll body 1 can be suppressed.

[0104] The range of the fixed region including both end portions in the width direction and the fixed region including the center portion in the width direction is the same as the range of the fixed region including both end portions in the width direction and the fixed region including the center portion in the width direction described in the first embodiment of the roll body 1.

[0105] When a joining member 3 having a uniform thickness across the entire width direction is used to join one longitudinal end of the first film 10 to the other longitudinal end of the second film 20, a difference in radial stress of the roll 1 occurs across the width direction at one longitudinal end of the first film 10, depending on the roll manufacturing process, the shape of the winding core 2, etc. Specifically, when one longitudinal end of the first film 10 and the other longitudinal end of the second film 20 are joined using a joining member 3 having a uniform thickness across the entire width direction and the roll manufacturing process involves heating a film including at least one selected from the group consisting of the first film 10 and the second film 20, the film including at least one selected from the group consisting of the first film 10 and the second film 20 stretched by heating after winding shrinks (enters a heat-shrinkage state), and therefore radial stress of the roll 1 increases at one longitudinal end of the first film 10 from the center in the width direction toward both ends in the width direction. That is, when one longitudinal end of the first film 10 and the other longitudinal end of the second film are joined across the entire width using a joining member 3 of a constant thickness, and the wound film including at least one selected from the group consisting of the first film 10 and the second film 20 enters a heat-shrunk state, the radial stress of the roll body 1 is smallest at the center in the width direction at one longitudinal end of the first film 10, and largest at both width ends. In this way, the difference in stress in the width direction at one longitudinal end of the first film 10 can cause a step mark.

[0106] The length in the longitudinal direction and the length in the width direction (total length) of the joining member 3 are the same as the length in the longitudinal direction and the length in the width direction (total length) of the joining member 3 described in the first embodiment of the roll body 1.

[0107] Furthermore, the distance T' in the radial direction of the roll 1 is from the radially outer surface of the other longitudinal end of the second film to the radially inner surface of one longitudinal end of the first film 10. In this case, at least one widthwise end of one longitudinal end of the first film 10 has the shortest distance T'1 relative to the distance T' across the entire width. If the portion of one longitudinal end of the first film 10 having the shortest distance T'1 relative to the distance T' across the entire width is defined as the shortest part, then at least one widthwise end of one longitudinal end of the first film 10 is the shortest part.

[0108] If the distance T'1 at at least one end in the width direction at one end in the longitudinal direction of the first film 10 is the shortest with respect to the distance T' across the entire width direction, the formation of step marks on the roll 1 can be suppressed.

[0109] In the second embodiment, at one longitudinal end of the first film 10, the distance T'1 in a certain region that includes both widthwise ends is the shortest compared to the distance T' across the entire width direction. That is, at one longitudinal end of the first film 10, the certain region that includes both widthwise ends is the shortest part. Also, at one longitudinal end of the first film 10, the distance T'2 in a certain region that includes the widthwise center is the longest compared to the distance T' across the entire width direction. That is, if the portion at one longitudinal end of the first film 10 that has the longest distance T'2 compared to the distance T' across the entire width direction is defined as the longest part, then at one longitudinal end of the first film 10, the certain region that includes the widthwise center is the longest part.

[0110] At one end of the first film 10 in the longitudinal direction, the distance T'1 at the shortest part (at least one end in the width direction at one end of the first film 10 in the longitudinal direction) is, for example, 0 μm or more, and, for example, less than 10 μm, preferably 8 μm or less.

[0111] At one end of the first film 10 in the longitudinal direction, the distance T'2 at the longest part is, for example, 10 μm or more, preferably 15 μm or more, more preferably 20 μm or more, and for example, 100 μm or less, preferably 80 μm or less, more preferably 50 μm or less.

[0112] The ratio (T1 / T2) of the distance T'1 at the shortest part at one end of the longitudinal direction of the first film 10 to the distance T'2 at the longest part at one end of the longitudinal direction of the first film 10 is, for example, 0 or more, and, for example, less than 1, preferably 0.8 or less, more preferably 0.5 or less, and even more preferably 0.3 or less.

[0113] [Action and effect] In the roll 1 of the second embodiment of the present invention, the distance T' in the radial direction of the roll 1 from the radially outer surface of the other longitudinal end of the second film 20 to the radially inner surface of one longitudinal end of the first film 10 is such that the distance T'1 at least at one end in the width direction is shortest compared to the distance T' over the entire width direction. This reduces step marks.

[0114] 2. Roll body manufacturing equipment An embodiment of a roll body manufacturing apparatus 100 used in the roll body manufacturing method of the present invention will be described with reference to FIG.

[0115] In Figure 5, the left-right direction of the paper is the longitudinal direction, with the right side of the paper being one side in the longitudinal direction and the left side of the paper being the other side in the longitudinal direction. The paper thickness direction is the width direction, with the front side of the paper being one side in the width direction and the back side of the paper being the other side in the width direction. The up-down direction of the paper is the up-down direction, with the top side of the paper being the top side and the bottom side of the paper being the bottom side.

[0116] The roll manufacturing apparatus 100 is an apparatus that manufactures a roll 1 by a roll-to-roll method, for example, under a vacuum atmosphere. The roll manufacturing apparatus 100 includes, for example, a delivery chamber R1, a film-forming chamber R2, and a winding chamber R3, in that order toward one side in the longitudinal direction. Note that the roll manufacturing apparatus 100 does not necessarily have to include the film-forming chamber R2.

[0117] The delivery chamber R1 is disposed adjacent to the film formation chamber R2 on the other longitudinal side thereof. The delivery chamber R1 includes, for example, a delivery roll 51 and a first guide roll 52.

[0118] The feed roll 51 feeds, for example, a base film as a work film. The feed roll 51 is a cylindrical member (winding core) having a rotation axis. A first drive source (not shown) for rotating the feed roll 51 is connected to the feed roll 51. The feed roll 51 can be rotated by a predetermined drive force from the first drive source.

[0119] The workpiece film includes at least the first film 10. The workpiece film may further include the second film 20. In FIG.

[0120] The first guide roll 52 is a rotating member that guides the workpiece film fed from the feed roll 51 into the film-forming chamber R2. The first guide roll 52 is disposed above the feed roll 51 and on the other longitudinal side of the second guide roll 61 (described later).

[0121] The delivery chamber R1 is a casing that houses the delivery roll 51 and the first guide roll 52. The delivery chamber R1 is provided with a vacuum unit (not shown) that can evacuate the interior thereof.

[0122] The film-forming chamber R2 is disposed adjacent to the delivery chamber R1 on one longitudinal side and the take-up chamber R3 on the other longitudinal side. The film-forming chamber R2 includes a second guide roll 61, a third guide roll 62, a film-forming roll 63, a target 64, a fourth guide roll 65, and a fifth guide roll 66.

[0123] The second guide roll 61 is a rotating member that guides the workpiece film transported from the delivery chamber R1 (first guide roll 52) to the third guide roll 62. The second guide roll 61 is disposed on one side of the first guide roll 52 in the longitudinal direction and on the other side of the third guide roll 62 in the longitudinal direction.

[0124] The third guide roll 62 is a rotating member that guides the workpiece film transported from the second guide roll 61 to the film-forming roll 63. The third guide roll 62 is disposed on one side of the second guide roll 61 in the longitudinal direction and above the film-forming roll 63.

[0125] The film-forming roll 63 forms an inorganic layer on the other surface (lower side) in the thickness direction of the base film serving as the workpiece film. The film-forming roll 63 is a cylindrical member having a rotation axis. The film-forming roll 63 transports the workpiece film along the circumferential surface of the film-forming roll 63. The film-forming roll 63 is disposed below the third guide roll 62 and below the fourth guide roll 65.

[0126] The target 64 is disposed below the film-forming roll 63, facing the film-forming roll 63 at an interval. When forming multiple inorganic layers, multiple targets 64 may be disposed. When multiple targets 64 are disposed, the targets 64 are disposed in order along the circumferential direction of the film-forming roll 63 at intervals from each other. The targets 64 are formed from the material of the inorganic layer.

[0127] The fourth guide roll 65 is a rotating member that guides the laminated film as the work film transported from the film-forming roll 63 to the fifth guide roll 66. The fourth guide roll 65 is disposed above the film-forming roll 63 and on the other side of the fifth guide roll 66 in the longitudinal direction.

[0128] The fifth guide roll 66 is a rotating member that guides the laminated film as the work film transported from the fourth guide roll 65 to the sixth guide roll 71. The fifth guide roll 66 is disposed on one side of the fourth guide roll 65 in the longitudinal direction and on the other side of the sixth guide roll 71 in the longitudinal direction.

[0129] The film formation chamber R2 is a casing that houses a second guide roll 61, a third guide roll 62, a film formation roll 63, a target 64, a fourth guide roll 65, and a fifth guide roll 66. The film formation chamber R2 is equipped with a vacuum unit (not shown) that can evacuate the interior.

[0130] The winding chamber R3 is disposed adjacent to the film forming chamber R2 on one side in the longitudinal direction thereof. The winding chamber R3 includes, for example, a sixth guide roll 71 and a winding roll 72.

[0131] The sixth guide roll 71 is a rotating member that guides the workpiece film transported from the fifth guide roll 66 to the winding chamber R3. The sixth guide roll 71 is disposed on one side of the fifth guide roll 66 in the longitudinal direction and above the winding roll 72.

[0132] The take-up roll 72 takes up the workpiece film. The take-up roll 72 is a cylindrical member (winding core) having a rotation axis. A second drive source (not shown) for rotating the take-up roll 72 is connected to the take-up roll 72. The take-up roll 72 can be rotated by a predetermined drive force from the second drive source.

[0133] The winding chamber R3 is a casing that houses the sixth guide roll 71 and the winding roll 72. The winding chamber R3 is equipped with a vacuum unit (not shown) that can evacuate the interior thereof.

[0134] 3. Roll body manufacturing method (First embodiment) A first embodiment of the method for manufacturing a roll body of the present invention will be described using the above-described roll body manufacturing apparatus 100. The method for manufacturing the above-described first embodiment of the roll body 1 is the first embodiment of the method for manufacturing a roll body.

[0135] The method for manufacturing a roll body manufactures the roll body 1 in a vacuum atmosphere. Specifically, the method for manufacturing a roll body manufactures the roll body 1 by a roll-to-roll method in a vacuum atmosphere. The method for manufacturing a roll body includes a step of winding up a workpiece film including the first film 10 in a vacuum atmosphere (winding step). The method for manufacturing a roll body preferably includes a step of heating the workpiece film including the first film 10 (heating step).

[0136] To manufacture the roll body 1, first, a base film is placed on a delivery roll 51. Specifically, a roll body (base roll) in which a long base film is wound into a roll is attached to the delivery roll 51.

[0137] The base film includes the first film 10, and is a film fed from the feed roll 51 in the feed chamber R1.

[0138] Next, one end of the first film 10 (base film) in the longitudinal direction is joined to the winding roll 72 (winding core 2).

[0139] Specifically, first, a core 2 is prepared as the winding roll 72. Then, the first film 10 and the core 2 are joined by a joining member 3 at one end of the first film 10 in the longitudinal direction.

[0140] Specifically, at one longitudinal end of the first film 10, the first double-sided tape 31 is attached to a certain region including both widthwise ends, and the second double-sided tape 32 is attached to a certain region including the widthwise center. The first double-sided tape 31 and the second double-sided tape 32 are each attached to the radially inner side of the first film 10. Then, the surfaces of the first double-sided tape 31 and the second double-sided tape 32 opposite to the surface attached to the first film 10 are attached to the winding core 2.

[0141] At this time, the center of the width direction of the first film 10 substantially coincides with the center of the width direction of the winding core 2. The first film 10 and the winding core 2 are joined so that their width directions are substantially parallel to each other.

[0142] As a result, first film 10 and core 2 are joined by joining member 3 at one end of first film 10 in the longitudinal direction.

[0143] Next, the base film as the first film 10 (workpiece film) is transported (transportation step).

[0144] Specifically, by driving the first drive source and the second drive source and rotating the feed roll 51 and the take-up roll 72 (core 2), the first film 10 is fed from the feed roll 51, transported in order through the first guide roll 52, the second guide roll 61, the third guide roll 62, the film forming roll 63, the fourth guide roll 65, the fifth guide roll 66, and the sixth guide roll 71, and wound up by the take-up roll 72 (core 2).

[0145] As a result, the first film 10 (work film) is transported from the delivery roll 51 to the take-up roll 72 in a roll-to-roll manner.

[0146] The workpiece film conveying speed is, for example, 3 m / min or more and, for example, 20 m / min or less, and the workpiece film conveying tension is, for example, 50 N or more and, for example, 1000 N or less.

[0147] The conveying process may include a heating process. The heating process is not particularly limited as long as it is a process in which the workpiece film including the first film 10 is heated. An example of the heating process is a film forming process.

[0148] The film forming step is a step of forming an inorganic layer on the other surface in the thickness direction of the base film as the first film 10 (workpiece film) while the base film is being transported.

[0149] Specifically, a film is formed in the film-forming chamber R2 while a substrate film serving as the first film 10 is being transported. The film-forming method is not particularly limited as long as it is a method that can form a film under a vacuum atmosphere while heating. Examples of the film-forming method include a dry coating method. Examples of the dry coating method include a vacuum deposition method and a sputtering method. Preferably, a sputtering method is used.

[0150] Examples of sputtering methods include dipole sputtering, ECR (electron cyclotron resonance) sputtering, magnetron sputtering, and ion beam sputtering, with magnetron sputtering being preferred.

[0151] In the sputtering method, gas (an inert gas such as argon) is supplied to the interior of the deposition chamber R2 under a vacuum atmosphere, and a negative voltage is applied to a target 64 placed on a cathode in the deposition chamber R2. This generates a glow discharge, ionizing the gas atoms, and these gas ions collide with the target surface at high speed, ejecting the target material from the target surface. As a result, the target material ejected from the target 64 adheres to the other surface (bottom surface) in the thickness direction of the substrate film below the deposition roll 63, forming an inorganic layer.

[0152] In the sputtering method, the inorganic layer is formed by sputtering while the substrate film is transported along the circumferential surface of the film-forming roll 63. In other words, the inorganic layer is a sputtered layer.

[0153] At this time, the substrate film is in close contact with the film-forming roll 63 along the circumferential direction, preferably at an angle of 180° or more.

[0154] Examples of sputtering gases include argon, krypton, xenon, and mixtures thereof. Argon is preferred. A reactive gas (e.g., oxygen) can also be used in combination. When a reactive gas is used in combination, the amount of the gas introduced is set to satisfy the partial pressure of the reactive gas described below.

[0155] The pressure in the film formation chamber R2 during film formation by sputtering (sputter film formation) (the pressure in the film formation chamber R2 when the sputtering gas, or the sputtering gas and reactive gas are introduced) is, for example, 0.02 Pa to 1 Pa, preferably 0.1 Pa to 0.6 Pa.

[0156] When a reactive gas is used in combination, the partial pressure of the reactive gas in the film formation chamber R2 is, for example, 1.0×10 -4 Pa~1.0×10 -2 It is Pa.

[0157] Examples of power sources for applying a voltage to the target include DC power sources, AC power sources, MF power sources, and RF power sources, with a DC power source being preferred.

[0158] The film formation temperature during sputtering (temperature of the film formation roll during film formation) is, for example, 0°C or higher, preferably 10°C or higher, more preferably 20°C or higher, and for example, 150°C or lower, preferably 80°C or lower.

[0159] The material of the target 64, that is, the material of the inorganic layer, may be the metals, metal oxides, and metal nitrides described above.

[0160] As a result, a laminated film is obtained as a first film below the film-forming roll 63, which includes the base film and the inorganic layer laminated on the other surface (lower surface) in the thickness direction of the base film in that order.

[0161] The laminated film as first film 10 manufactured as described above is transported by film forming roll 63, fourth guide roll 65, and fifth guide roll 66 toward take-up roll 72 (core 2) on the other side in the longitudinal direction.

[0162] Then, in a vacuum atmosphere, the workpiece film including the first film 10 is wound around the winding roll 72 (winding core 2) (winding process), thereby producing the roll body 1.

[0163] The roll body 1 manufactured in this manner can also be attached to the delivery roll 51. That is, the core 2 may be the take-up roll 72 or the delivery roll 51.

[0164] The winding diameter of the roll body is, for example, 0.1 m or more, or preferably 0.3 m or more, and for example, 0.7 m or less, or preferably 1.0 m or less.

[0165] [Action and effect] The method for manufacturing a roll body according to the first embodiment of the present invention is a method for manufacturing the roll body 1 described above, and includes a step of winding up, in a vacuum atmosphere, a workpiece film including at least the first film 10. Therefore, even in a vacuum atmosphere, it is possible to manufacture a roll body 1 with reduced step marks.

[0166] (Second embodiment) A second embodiment of the method for manufacturing a roll body of the present invention will be described below using the above-described roll body manufacturing apparatus 100. The method for manufacturing the second embodiment of the above-described roll body 1 is the second embodiment of the method for manufacturing a roll body.

[0167] In the second embodiment, the same components and steps as those in the first embodiment of the method for manufacturing a roll body are denoted by the same reference numerals, and detailed descriptions thereof will be omitted. Furthermore, the second embodiment can be appropriately combined with the first embodiment of the method for manufacturing a roll body and the modified examples described below.

[0168] The method for manufacturing a roll body manufactures the roll body in a vacuum atmosphere. Specifically, the method for manufacturing a roll body manufactures the roll body 1 by a roll-to-roll method in a vacuum atmosphere. The method for manufacturing a roll body includes a step of winding a workpiece film including a first film 10 and a second film 20 in a vacuum atmosphere (winding step). The method for manufacturing a roll body preferably includes a step of heating the workpiece film including the first film 10 and the second film 20 (heating step).

[0169] To manufacture the roll body 1, first, a base film as the first film 10 and a base film as the second film 20 are prepared.

[0170] Next, one end of the first film 10 in the longitudinal direction is joined to the other end of the second film 20 in the longitudinal direction.

[0171] Specifically, at one longitudinal end of the first film 10, the first double-sided tape 31 is attached to a certain region including both widthwise ends, and the second double-sided tape 32 is attached to a certain region including the widthwise center. The first double-sided tape 31 and the second double-sided tape 32 are each attached to the radially inner side of the first film 10. Then, the surfaces of the first double-sided tape 31 and the second double-sided tape 32 opposite to the surfaces attached to the first film 10 are attached to the radially outer side of the second film 20.

[0172] At this time, the center of the width direction of the first film 10 substantially coincides with the center of the width direction of the second film 20. Furthermore, the width directions of the first film 10 and the second film 20 are joined so as to be substantially parallel to each other.

[0173] As a result, first film 10 and second film 20 are joined by joining member 3 at one end of first film 10 in the longitudinal direction.

[0174] Next, a base roll is prepared, which includes a first film 10 and a second film 20 joined by a joining member 3. In this base roll, the first film 10 is disposed radially inward, and the second film 20 is disposed radially outward. The base roll including the first film 10 and the second film 20 is attached to a feed roll 51, and the work film including the first film 10 and the second film 20 is transported (transportation process). The transport process is the same as the transport process described in the first embodiment of the method for manufacturing a roll body.

[0175] As in the first embodiment of the method for manufacturing a roll body, the transporting step may include a heating step.

[0176] The heating process is not particularly limited as long as it is a process in which a workpiece film including the first film 10 is heated. Alternatively, a workpiece film including the first film 10 and the second film 20 may be heated. An example of the heating process is a film forming process.

[0177] The film forming process is the same as the film forming process described in the first embodiment of the method for manufacturing a roll body.

[0178] After the film-forming step, the first film 10 and the laminated film serving as the second film are transported by the film-forming roll 63, the fourth guide roll 65, and the fifth guide roll 66 toward the take-up roll 72 (core 2).

[0179] Then, in a vacuum atmosphere, the work film including the first film 10 and the second film 20 is wound around the winding roll 72 (winding core 2) (winding process), thereby producing the roll body 1.

[0180] [Action and effect] The method for manufacturing a roll body according to the second embodiment of the present invention is a method for manufacturing the roll body 1 described above, and includes a step of winding up, in a vacuum atmosphere, a workpiece film including at least the first film 10. Therefore, even in a vacuum atmosphere, it is possible to manufacture a roll body 1 with reduced step marks.

[0181] 4. Variations Modified examples of the roll body of the present invention will be described with reference to Figures 6 to 9. Note that the fifth modified example is not shown.

[0182] In the modified examples, the same reference numerals are used to designate the same members as those in the first embodiment of the roll body 1, and detailed descriptions thereof will be omitted. Furthermore, the first embodiment of the roll body 1, the second embodiment of the roll body 1, and the modified examples can be combined as appropriate.

[0183] (First Modification) In the first embodiment of the roll body 1 described above, the joining member 3 is arranged across the entire width of the first film 10, and the joining member 3 uses two or more types of double-sided tape with different thicknesses in combination, but is not limited to this.

[0184] Specifically, in the first modified example, as shown in Fig. 6, the first double-sided tape 31 (bonding member 3) is not arranged in a certain region including both end portions in the width direction, and one second double-sided tape 32 is arranged only in a certain region including the center portion in the width direction. In the first modified example, the center portion in the width direction of the second double-sided tape 32 is arranged so that it substantially coincides with the center portion in the width direction of the first film 10.

[0185] In the first modification, at one longitudinal end of the first film 10, the distance T1 in a certain region that includes both widthwise ends is the shortest relative to the distance T across the entire width direction. In other words, if the portion at one longitudinal end of the first film 10 that has the shortest distance T1 relative to the distance T across the entire width direction is defined as the shortest part, then the certain region at one longitudinal end of the first film 10 that includes both widthwise ends is the shortest part. Furthermore, the distance T2 in a certain region at one longitudinal end of the first film 10 that includes the center in the width direction is the longest relative to the distance T across the entire width direction. In other words, if the portion at one longitudinal end of the first film 10 that has the longest distance T2 relative to the distance T across the entire width direction is defined as the longest part, then the certain region at one longitudinal end of the first film 10 that includes the center in the width direction is the longest part.

[0186] At one end of the first film 10 in the longitudinal direction, the distance T1 at the shortest part is 0 μm. That is, the outer peripheral surface of the winding core 2 and the radially inner surface of the shortest part are in contact with each other.

[0187] That is, at one end of the first film 10 in the longitudinal direction, the distance T1 at least at one end in the width direction is shortest relative to the distance T over the entire width direction. This makes it possible to suppress step marks on the roll body 1.

[0188] (Second Modification) In the first embodiment of the roll body 1 described above, the shape of the winding core 2 is cylindrical, and the diameter of the winding core 2 is approximately the same across the entire width direction perpendicular to the radial direction, but this is not limiting.

[0189] Specifically, in the second modified example, as shown in Fig. 7, the diameter of the winding core 2 is smallest at the center in the width direction and increases toward both ends in the width direction of the winding core 2. In other words, the diameter of the winding core 2 is largest at both ends in the width direction.

[0190] In the second modified example, the maximum and minimum diameters of the winding core 2 are not particularly limited as long as they are within the range of the diameter of the winding core 2 described in the first embodiment of the roll body 1 above.

[0191] In the second modified example, the bonding members 3 may be disposed across the entire width of the first film 10, or may be disposed only in a certain region including the center in the width direction. In Fig. 7, the bonding members 3 are disposed across the entire width including both ends in the width direction and the center in the width direction.

[0192] In the second modification, at one longitudinal end of the first film 10, the distance T1 in a certain region that includes both widthwise ends is the shortest relative to the distance T across the entire width direction. In other words, if the portion at one longitudinal end of the first film 10 that has the shortest distance T1 relative to the distance T across the entire width direction is defined as the shortest part, then the certain region at one longitudinal end of the first film 10 that includes both widthwise ends is the shortest part. Furthermore, the distance T2 in a certain region at one longitudinal end of the first film 10 that includes the center in the width direction is the longest relative to the distance T across the entire width direction. In other words, if the portion at one longitudinal end of the first film 10 that has the longest distance T2 relative to the distance T across the entire width direction is defined as the longest part, then the certain region at one longitudinal end of the first film 10 that includes the center in the width direction is the longest part.

[0193] (Third Modification) In the first embodiment of the roll body 1 described above, the joining member 3 is arranged across the entire width of the first film 10, specifically, at one longitudinal end of the first film, two first double-sided tapes 31 are arranged at both ends in the width direction, and one second double-sided tape 32 is arranged in the center in the width direction, but this is not limited to this.

[0194] Specifically, the arrangement of the joining member 3 is not particularly limited as long as the distance T1 at at least one end in the width direction at one end of the longitudinal direction of the first film 10 is the shortest relative to the distance T over the entire width direction.

[0195] 8, in the third modified example, the bonding member 3 is disposed across the entire width of the first film 10. The bonding member 3 also uses two or more types of double-sided tape with different thicknesses. Specifically, one first double-sided tape 31 is disposed in a certain region including one end in the width direction, and one second double-sided tape 32 is disposed in a certain region including the other end in the width direction.

[0196] In the third modified example, the first double-sided tape 31 is attached to one widthwise end of the first film 10. One widthwise end of the first double-sided tape 31 substantially coincides with one widthwise end of the first film 10. Furthermore, the second double-sided tape 32 is attached to the other widthwise end of the first film 10. The other widthwise end of the first double-sided tape 31 substantially coincides with the other widthwise end of the first film 10. Furthermore, the other widthwise end of the first double-sided tape and one widthwise end of the second double-sided tape 32 are in contact with each other so as not to overlap.

[0197] The range of the certain region including one end in the width direction and the certain region including the other end in the width direction is not particularly limited, and can be set appropriately based on the stress applied to the roll body 1 in the radial direction.

[0198] In the fourth modification, the fixed region including one widthwise end is, for example, a region from the widthwise center to one widthwise end. Specifically, when the widthwise length W of the first film 10 is 1500 mm, the fixed region including one widthwise end is a region ranging from one widthwise end to a position 750 mm inward in the widthwise direction from the one widthwise end (a range of 0 mm to 750 mm when the one widthwise end is at 0 mm and the other widthwise end is at 1500 mm).

[0199] In the fourth modification, the fixed region including the other widthwise end is the region from the center in the widthwise direction to the other widthwise end. Specifically, when the widthwise length W of the first film 10 is 1500 mm, the fixed region including the other widthwise end is the region ranging from the other widthwise end to a position 750 mm inward in the widthwise direction from the other widthwise end (a range of 750 mm to 1500 mm, assuming that one widthwise end is at 0 mm and the other widthwise end is at 1500 mm).

[0200] In the third modification, at one longitudinal end of the first film 10, the distance T1 in a certain region including the one widthwise end is the shortest relative to the distance T across the entire width direction. In other words, if the portion at one longitudinal end of the first film 10 having the shortest distance T1 relative to the distance T across the entire width direction is defined as the shortest part, then the certain region at one longitudinal end of the first film 10 that includes the one widthwise end is the shortest part. Furthermore, the distance T2 in a certain region at one longitudinal end of the first film 10 that includes the other widthwise end is the longest relative to the distance T across the entire width direction. In other words, if the portion at one longitudinal end of the first film 10 having the longest distance T2 relative to the distance T across the entire width direction is defined as the longest part, then the certain region at one longitudinal end of the first film 10 that includes the other widthwise end is the longest part.

[0201] (Fourth Modification) In the first embodiment of the roll body 1 described above, the joining member 3 is disposed over the entire width of the first film 10, but the present invention is not limited to this.

[0202] Specifically, in the fourth modified example, as shown in FIG. 9, the first double-sided tape 31 is not placed in a certain area including both end portions in the width direction, the second double-sided tape 32 is placed in a certain area including the center portion in the width direction, and further, the first double-sided tape 31 is placed in a certain area between the certain area including both end portions in the width direction and the certain area including the center portion in the width direction.

[0203] In the fourth modified example, the second double-sided tape 32 is disposed so that the center in the width direction substantially coincides with the center in the width direction of the first film 10. Two first double-sided tapes 31 are attached to one end and the other end in the width direction of the second double-sided tape 32, respectively. More specifically, the other end in the width direction of the first double-sided tape 31 attached to one end in the width direction of the second double-sided tape 32 contacts one end in the width direction of the second double-sided tape 32 without overlapping it, and one end in the width direction of the first double-sided tape 31 attached to one end in the width direction of the second double-sided tape 32 is spaced apart in the width direction from one end in the width direction of the first film 10. Furthermore, one end in the width direction of the first double-sided tape 31 that is attached to the other end in the width direction of the second double-sided tape 32 contacts the other end in the width direction of the second double-sided tape 32 without overlapping, and the other end in the width direction of the first double-sided tape 31 that is attached to the other end in the width direction of the second double-sided tape 32 is spaced apart in the width direction from the other end in the width direction of the first film 10.

[0204] The ranges of the fixed region including both end portions in the width direction, the fixed region including the center portion in the width direction, and the fixed region between the fixed region including both end portions in the width direction and the fixed region including the center portion in the width direction are not particularly limited, and can be set appropriately based on the stress applied to the roll body 1 in the radial direction.

[0205] In the fourth variant, the certain region including both ends in the width direction is, for example, a region that combines the range from one end in the width direction to a position W×1 / 10 inward in the width direction from the one end in the width direction, and the range from the other end in the width direction to a position W×1 / 10 inward in the width direction from the other end in the width direction. For example, if the widthwise length W of the first film 10 is 1500 mm, the fixed region including both widthwise ends is the combined region of the range from one widthwise end to a position 150 mm inward from the one widthwise end (a range of 0 mm to 150 mm when one widthwise end is at the 0 mm position and the other widthwise end is at the 1500 mm position) and the range from the other widthwise end to a position 150 mm inward from the other widthwise end (a range of 1350 mm to 1500 mm when one widthwise end is at the 0 mm position and the other widthwise end is at the 1500 mm position).

[0206] In the fourth modification, the fixed region including the center in the width direction is, for example, a region ranging from a position W×1 / 5 inward in the width direction from one end in the width direction to a position W×1 / 5 inward in the width direction from the other end in the width direction. Specifically, when the width direction length W of the first film 10 is 1500 mm, the fixed region including the center in the width direction is a region ranging from a position 300 mm inward in the width direction from one end in the width direction to a position 300 mm inward in the width direction from the other end in the width direction (a range of 300 mm to 1200 mm when one end in the width direction is at 0 mm and the other end in the width direction is at 1500 mm).

[0207] In the fourth modification, the region between the region including both widthwise ends and the region including the widthwise center is a region that does not include both widthwise ends and the widthwise center. For example, the region between the region including both widthwise ends and the region including the widthwise center is a region that combines the range from a position W×1 / 10 inward from one widthwise end to a position W×1 / 5 inward from one widthwise end, and the range from a position W×1 / 10 inward from the other widthwise end to a position W×1 / 5 inward from the other widthwise end. For example, when the widthwise length W of the first film 10 is 1500 mm, the region between the region including both widthwise ends and the region including the widthwise center is the combined region of the range from a position 150 mm inward from one widthwise end to a position 300 mm inward from one widthwise end (a range of 150 mm to 300 mm when one widthwise end is set to the 0 mm position and the other widthwise end is set to the 1500 mm position), and the range from a position 150 mm inward from the other widthwise end to a position 300 mm inward from the other widthwise end (a range of 1200 mm to 1350 mm when one widthwise end is set to the 0 mm position and the other widthwise end is set to the 1500 mm position).

[0208] In the fourth modification, at one longitudinal end of the first film 10, the distance T1 in a certain region including the widthwise end is the shortest relative to the distance T across the entire width. In other words, if the portion at one longitudinal end of the first film 10 having the shortest distance T1 relative to the distance T across the entire width is defined as the shortest part, then the certain region at one longitudinal end of the first film 10 that includes both widthwise ends is the shortest part. Furthermore, the distance T2 in a certain region at one longitudinal end of the first film 10 that includes the widthwise center is the longest relative to the distance T across the entire width. In other words, if the portion at one longitudinal end of the first film 10 having the longest distance T2 relative to the distance T across the entire width is defined as the longest part, then the certain region at one longitudinal end of the first film 10 that includes the widthwise center is the longest part.

[0209] At one end of the first film 10 in the longitudinal direction, the distance T1 at the shortest part is 0 μm. That is, the outer peripheral surface of the core 2 and the radially inner surface of the shortest part are in contact with each other.

[0210] That is, at one longitudinal end of the first film 10, the distance T1 in a certain region including both widthwise ends is shortest relative to the distance T in the entire widthwise region. Specifically, in the radial direction of the roll 1, the distance T from the outer peripheral surface of the winding core 2 to the radially inner surface of one longitudinal end of the first film 10 becomes shorter in stages from both widthwise ends toward the center in the widthwise direction. This further reduces step marks on the roll 1.

[0211] (Fifth Modification) In the first embodiment of the roll body 1 described above, the joining member 3 is arranged so that one end surface of the joining member 3 in the longitudinal direction and one end surface of the first film 10 in the longitudinal direction are approximately flush with each other, but this is not limited to this.

[0212] Specifically, in the fifth modified example, the bonding member 3 is disposed so that one end of the first film 10 in the longitudinal direction protrudes from one end of the bonding member 3 in the longitudinal direction. In other words, the bonding member 3 is disposed inside the first film 10 in the longitudinal direction. [Example]

[0213] The present invention will be described in more detail below with reference to examples, comparative examples, and reference examples. It should be noted that the present invention is not limited to the examples, comparative examples, and reference examples. The specific numerical values ​​of the blending ratios (content ratios), physical property values, parameters, etc. used in the following description can be replaced with the upper limit (a numerical value defined as "equal to or less than") or lower limit (a numerical value defined as "equal to or more than" or "exceeding") of the corresponding blending ratios (content ratios), physical property values, parameters, etc. described in the above "Modes for Carrying Out the Invention."

[0214] Comparative Example 1 First, a cycloolefin polymer (COP) film (product name: Zeonor, thickness 100 μm, width length 1500 mm, manufactured by Zeon Corporation) was prepared as a longitudinally long transparent resin film, and a hard coat layer was formed on the other surface in the thickness direction of the COP film. The hard coat layer was formed using the following procedure. Then, an optical adjustment composition (a zirconia particle-containing ultraviolet-curable composition with a refractive index of 1.64) was applied to the other surface in the thickness direction of the hard coat layer, and cured by ultraviolet irradiation to form an optical adjustment layer with a thickness of 100 nm. In this way, a long substrate film was obtained.

[0215] A UV-absorbing resin composition solution was prepared by mixing 3.3 parts by weight of compound C2 described in JP 2020-066153 A, 24 parts by weight of a UV-curable resin composition solution (a urethane acrylate resin composition solution, a mixed solution of 80% by weight of DIC Corporation's "Unidic ELS-888 (solids content 50% by weight)" and 20% by weight of "Unidic RS-605 (solids content 60% by weight)"), 0.49 parts by weight of hydroxycyclohexyl phenyl ketone (photopolymerization initiator, product name: Irgacure 184, manufactured by Ciba-Geigy), 0.049 parts by weight of monodisperse acrylic particles (product name: MX-180TAN, average particle size 1.8 μm, manufactured by Soken Chemical & Engineering Co., Ltd.), and 75 parts by weight of ethyl acetate (solvent). The UV-absorbing resin composition solution was applied to the other surface in the thickness direction of a COP film, dried at 80°C for 1 minute, and cured by UV irradiation using an ozone-type high-pressure mercury lamp. As a result, a hard coat layer having a thickness of 1.3 μm was formed on each of the substrates.

[0216] Next, this base film was placed on a delivery roll in a roll body manufacturing apparatus (DC magnetron sputtering film forming apparatus) shown in FIG. 5. That is, the base roll on which the base film was wound into a roll was attached to the delivery roll. In this way, a base film was prepared as a long first film. Note that the base film was wound on the delivery roll so that the outer side in the radial direction was on one side in the thickness direction of the base film, and then attached to the delivery roll.

[0217] Next, one end of the first film (substrate film) in the longitudinal direction was joined to a core (winding roll).

[0218] Specifically, first, an aluminum core having a diameter of 15.24 cm was prepared as the winding core. Next, the radially inner surface of one longitudinal end of the first film was joined to the outer peripheral surface of the winding core with double-sided tape (joining member).

[0219] The double-sided tape used was a second double-sided tape (thickness 30 μm, longitudinal length 100 mm). One thickness side of one piece of the second double-sided tape was attached to the entire width of the first film (1500 mm), and the other thickness side of the second double-sided tape was attached to the outer peripheral surface of the winding core, thereby joining the first film and the winding core.

[0220] At this time, the second double-sided tape is positioned so that one longitudinal end face of the second double-sided tape and one longitudinal end face of the first film are approximately flush with each other, and so that one widthwise end face of the second double-sided tape and one widthwise end face of the first film are approximately flush with each other, and so that the other widthwise end face of the second double-sided tape and the other widthwise end face of the first film are approximately flush with each other.

[0221] (Transportation process) In the conveying step, first, a base film serving as a first film (workpiece film) was conveyed in a vacuum atmosphere.

[0222] Specifically, to transport the first film (workpiece film), the first and second drive sources (specifically, motors) were driven to rotate the delivery roll and take-up roll, transporting the first film at a transport speed of 13 m / min.

[0223] Next, while transporting the base film as the first film, sputtering (reactive sputtering) was carried out in a vacuum atmosphere. Specifically, in a film formation chamber, a copper layer (thickness: 60 nm) was formed as an inorganic layer on the other side of the base film in the thickness direction (the other side of the optical adjustment layer in the thickness direction) by magnetron sputtering. Details of the sputtering conditions for the copper layer are shown below.

[0224] In forming the copper layer, the sputtering deposition apparatus was evacuated, and then argon (Ar) was introduced into the deposition chamber as a sputtering gas, and the pressure in the deposition chamber was set to 0.3 Pa. Copper (Cu) (manufactured by Mitsui Kinzoku Co., Ltd.) was used as the target. A DC power supply was used as the power source for applying voltage to the target. The deposition temperature (temperature of the deposition roll during deposition) was set to 40°C.

[0225] After the copper layer was formed, the laminated film as the first film was wound up on a winding roll (core). The work film was wound up to a length of 4000 m in the longitudinal direction.

[0226] The conveying tension of the work film during the conveying process was set to 500N.

[0227] In this manner, a roll body of Comparative Example 1 was produced.

[0228] In the roll of Comparative Example 1, the distance T from the outer peripheral surface of the core 2 to the radially inner surface of one longitudinal end of the first film was constant across the entire width direction of the roll 1. In other words, Comparative Example 1 does not have a portion (shortest part) at one longitudinal end of the first film that has the shortest distance T1 relative to the distance T across the entire width direction.

[0229] Example 1 The roll body of Example 1 was manufactured in the same manner as Comparative Example 1, except that the double-sided tape (joining member) that joins one longitudinal end of the first film (base film) to the winding core (winding roll) was changed as follows.

[0230] Specifically, a first double-sided tape (thickness 5 μm, longitudinal length 100 mm) was used as the double-sided tape, and one thickness side of each of the two first double-sided tapes was attached to the radially inner surfaces of both widthwise ends of the first film. More specifically, the two first double-sided tapes were attached to a region from one widthwise end of the first film to a position 250 mm inward from the one widthwise end (a region of 0 mm to 250 mm when one widthwise end is set to the 0 mm position and the other widthwise end is set to the 1500 mm position), and a region from the other widthwise end of the base film to a position 250 mm inward from the other widthwise end (a region of 1250 mm to 1500 mm when one widthwise end is set to the 0 mm position and the other widthwise end is set to the 1500 mm position). Furthermore, a second double-sided tape (thickness: 30 μm, length in the longitudinal direction: 100 mm) was used as the double-sided tape, and one side of the second double-sided tape in the thickness direction was attached to the center of the first film in the width direction. More specifically, the second double-sided tape was attached to a region of the first film excluding both ends in the width direction (a region from 250 mm to 1250 mm, with one end in the width direction at 0 mm and the other end in the width direction at 1500 mm). Next, the other sides of the two types of double-sided tape in the thickness direction were attached to the outer peripheral surface of the winding core, thereby joining the first film and the winding core.

[0231] In the roll of Example 1, the area where the first double-sided tape was attached (both ends in the width direction) was the shortest part at one end of the longitudinal direction of the first film, and the area where the second double-sided tape was attached (the center part in the width direction) was the longest part. The distance T1 at the shortest part was 5 μm, and the distance T2 at the longest part was 30 μm.

[0232] Example 2 The roll body of Example 2 was manufactured in the same manner as Comparative Example 1, except that the double-sided tape (joining member) that joins one longitudinal end of the first film (base film) to the winding core (winding roll) was changed as follows.

[0233] Specifically, a second double-sided tape (thickness: 30 μm, length in the longitudinal direction: 100 mm) was used, and one thickness-wise side of one piece of the second double-sided tape was attached to the radially inner surface of the width-wise central portion of the first film. More specifically, the second double-sided tape was attached to a region excluding both width-wise ends of the first film described in Example 1 above (a region from 250 mm to 1250 mm, assuming that one width-wise end is at 0 mm and the other width-wise end is at 1500 mm). Next, the other thickness-wise side of the second double-sided tape was attached to the outer peripheral surface of the winding core, thereby joining the first film and the winding core. Note that no double-sided tape was attached to both width-wise ends of the first film.

[0234] In the roll of Example 2, the area (both ends in the width direction) where no double-sided tape (bonding member) was placed at one end of the first film in the longitudinal direction was the shortest part, and the area (center in the width direction) where the second double-sided tape was attached was the longest part. The distance T1 at the shortest part was 0 μm, and the distance T2 at the longest part was 30 μm.

[0235] Example 3 A base film as the first film was prepared using the same procedure as in Comparative Example 1 and placed on a delivery roll in a roll body manufacturing apparatus (DC magnetron sputtering film forming apparatus) shown in Fig. 5. That is, the base roll on which the base film was wound in a roll shape was attached to the delivery roll.

[0236] Furthermore, a polyethylene terephthalate (PET) film having a thickness of 50 μm, a width direction length of 1500 mm, and a length in the longitudinal direction of 150 m was prepared as a second film and placed on a take-up roll in a roll body manufacturing apparatus (DC magnetron sputtering film forming apparatus) shown in Figure 5. That is, the PET roll on which the PET film was wound into a roll shape was attached to the take-up roll.

[0237] Next, the radially inner surface of the first film at one longitudinal end of the first film fed from the feed roll and the radially outer surface of the second film at the other longitudinal end of the second film were joined using double-sided tape (joining member).

[0238] More specifically, two first double-sided tapes (5 μm thick, 100 mm long) were used, and one thickness side of each tape was attached to the radially inner side of both widthwise ends of the first film. Specifically, two first double-sided tapes were attached to a 250 mm region from one widthwise end to the other widthwise end of the first film (a region from 0 mm to 250 mm when one widthwise end is defined as 0 mm and the other widthwise end is defined as 1500 mm), and a 250 mm region from the other widthwise end to one end of the first film (a region from 1250 mm to 1500 mm when one widthwise end is defined as 0 mm and the other widthwise end is defined as 1500 mm). Furthermore, a second double-sided tape (30 μm thick, 100 mm long) was used, and one thickness side of one second double-sided tape was attached to the radially inner side of the widthwise center of the first film. Specifically, the second double-sided tape was attached to a region of the first film excluding both widthwise ends (a region of 250 mm to 1250 mm, assuming that one widthwise end is at 0 mm and the other widthwise end is at 1500 mm). Next, the other thickness-wise surfaces of the two types of double-sided tape were attached to the radially outer surface of the second film at the other longitudinal end of the second film, thereby joining the first film and the second film.

[0239] Next, the first film was transported (transportation step). The transporting step was carried out in the same procedure as in Comparative Example 1, to produce a roll body of Example 3. The roll body of Example 3 was arranged so that the first film was located on the radially outer side of the roll body and the second film was located on the radially inner side.

[0240] In the roll of Example 3, the area where the first double-sided tape was attached (both ends in the width direction) was the shortest part at one end of the longitudinal direction of the first film, and the area where the second double-sided tape was attached (the center part in the width direction) was the longest part. The distance T'1 at the shortest part was 5 μm, and the distance T'2 at the longest part was 30 μm.

[0241] Example 4 The roll body of Example 4 was produced in the same manner as Example 3, except that the double-sided tape joining one longitudinal end of the first film (base film) and the other longitudinal end of the second film was changed as follows.

[0242] Specifically, a second double-sided tape (thickness: 30 μm, length in the longitudinal direction: 100 mm) was used, and one thickness side of one piece of the second double-sided tape was attached to the radially inner surface of the widthwise center portion of the first film. More specifically, the second double-sided tape was attached to a region of the first film described in Example 3 above excluding both widthwise ends (a region from 250 mm to 1250 mm, assuming that one widthwise end is at 0 mm and the other widthwise end is at 1500 mm). Next, the other thickness side of the second double-sided tape was attached to the radially outer surface of the second film at the other longitudinal end of the second film, thereby joining the first film and the second film. Note that no double-sided tape was attached to both widthwise ends of the first film.

[0243] In the roll of Example 4, the area (both ends in the width direction) where no double-sided tape (bonding member) was placed at one end of the first film in the longitudinal direction was the shortest part, and the area (center in the width direction) where the second double-sided tape was attached was the longest part. The distance T'1 at the shortest part was 0 μm, and the distance T'2 at the longest part was 30 μm.

[0244] <Evaluation> [exterior] The first film (laminated film) as the workpiece film was unwound from each roll of each Example and Comparative Example 1, and the appearance of the copper layer surface was visually inspected and evaluated for the presence or absence of step marks according to the following criteria. The results are shown in Tables 1 and 2. {standard} A: There was no change in the color of the copper layer surface. B: There was a change in the color of the copper layer surface.

[0245] [Table 1]

[0246] [Table 2]

[0247] <Consideration> In the roll bodies manufactured by the roll body manufacturing methods of Examples 1 and 2, the distance T in the radial direction of the roll body from the outer peripheral surface of the core to the radially inner surface of one end of the first film, and the distance T1 at at least one end in the width direction (specifically, the distance T1 at both ends in the width direction) is shortest compared to the distance T over the entire width direction. Therefore, it was possible to reduce step marks on the roll body.

[0248] On the other hand, in the roll body manufactured by the roll body manufacturing method of Comparative Example 1, the distance T from the outer peripheral surface of the core to the radially inner surface of one longitudinal end of the first film in the radial direction of the roll body 1 was constant across the entire width direction. In other words, in Comparative Example 1, one longitudinal end of the first film did not have a portion (shortest part) with the shortest distance T1 relative to the distance T across the entire width direction. As a result, step marks were generated on the roll body.

[0249] In the roll bodies manufactured by the roll body manufacturing methods of Examples 3 and 4, the distance T in the radial direction of the roll body from the radially outer surface of the other end of the second film to the radially inner surface of one end of the first film, which is the distance T at least at one end in the width direction, is the shortest compared to the distance T over the entire width direction. Therefore, it was possible to reduce step marks on the roll body. [Explanation of symbols]

[0250] 1 roll body 2 cores 3 Joint materials 10 First Film 20 Second Film

Claims

1. A roll body including a winding core, a long first film wound around the winding core, and a joining member joining one end of the first film in a longitudinal direction to the winding core, the joining member is disposed between the core and the one end portion in a thickness direction of the first film, A roll body in which the distance from the outer peripheral surface of the winding core to the radially inner surface of the one end in the radial direction of the roll body, the distance at at least one end in a width direction perpendicular to both the longitudinal direction and the thickness direction, is shortest compared to the distance over the entire width direction.

2. A roll body on which a film is wound, the film includes a long first film, a long second film, and a joining member that joins one end of the first film in a longitudinal direction and the other end of the second film in the longitudinal direction; the first film is positioned on the radially outer side of the roll body, and the second film is positioned on the radially inner side of the roll body, the joining member is disposed between the one end and the other end in a thickness direction of the first film, A roll body in which the distance from the radial outer surface of the other end to the radial inner surface of the one end in the radial direction of the roll body, at least one end in a width direction perpendicular to both the longitudinal direction and the thickness direction, is shortest compared to the distance across the entire width direction.

3. The joining member is further disposed over the entire width of the one end portion, The roll body according to claim 1 or 2, wherein a thickness of the joining member at least at one end in the width direction of the one end is thinner than a thickness of the joining member at a central portion of the one end in the width direction.

4. The roll body according to claim 3 , wherein the thickness of the joining member at both ends of the one end in the width direction is thinner than the thickness of the joining member at a center part of the one end in the width direction.

5. The roll body according to claim 1 or 2, wherein the joining member is not disposed on at least one end of the one end in the width direction.

6. The roll body according to claim 5 , wherein the joining member is not disposed on either end of the one end in the width direction.

7. A method for producing the roll body according to claim 1 or 2, comprising the steps of: A method for manufacturing a roll body, comprising a step of winding up a work film including at least the first film in a vacuum atmosphere.

8. The method for manufacturing a roll body according to claim 7 , further comprising a step of heating the workpiece film.

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