JP7777664B2 - Touch roll and winding device - Google Patents

Description

The present invention relates to a touch roll and a winding device.

A long length of resin film may be wound around a winding shaft to produce a roll of raw material. This raw material roll may be sold as a product in itself, or may be transported to the next process and used in that process. When winding the resin film around the winding shaft, a touch roll is brought into contact with the resin film and a constant pressure (touch pressure) is applied to the resin film while it is being wound, in order to prevent deformation defects (such as wrinkles) from occurring during winding. Examples of touch rolls include the touch rolls (touch rollers) described in Patent Documents 1 and 2.

The touch roll described in Patent Document 1 is a touch roll used when winding up printed film, paper, etc. This touch roll has a cylindrical core metal that is covered with a sponge-like material. In the touch roll described in Patent Document 1, the sponge-like material comes into contact with the film, paper, etc. being wound up.

The touch roll described in Patent Document 2 is a touch roll used when winding magnetic tape. This touch roll has a circular core member, a thick elastic sponge member attached to the outer periphery of the core member, and a thin elastic rubber member with a rubber hardness of 50 degrees or less attached to the outer periphery of the elastic sponge member. In the touch roll described in Patent Document 2, the elastic rubber member comes into contact with the magnetic tape being wound.

Japanese Utility Model Application Publication No. 62-63248 Japanese Utility Model Application Publication No. 56-165747

The object of the present invention is to provide a touch roll and winding device that can prevent deformation defects when winding a resin film.

A touch roll according to one aspect of the present invention is a touch roll having a contact surface that comes into contact with a long resin film when the resin film is wound around a winding shaft. The touch roll comprises a roll body, a first layer disposed radially outward of the roll body, and a second layer having the contact surface and disposed radially outward of the first layer, wherein the A Shore hardness of the second layer is smaller than the A Shore hardness of the first layer.

In this specification, Shore A hardness refers to the hardness (Shore A) of Durometer Type A specified in JIS K 6253.

The touch roll has, in order from the roll body side, a first layer and a second layer. The A Shore hardness of the second layer is lower than that of the first layer. In other words, the second layer is softer than the first layer. When the touch roll is brought into contact with the resin film, the second layer contacts the resin film. Because the second layer is supported by the first layer, which is harder than the second layer, the reaction force when the touch roll is pressed against the resin film can be absorbed by the first layer. Furthermore, because the second layer is softer than the first layer, it can conform to the irregularities on the surface of the resin film more easily than when the first layer is in direct contact with the resin film. As a result, by winding the resin film while the touch roll is in contact with the resin film, it is easier to apply uniform pressure to the resin film in a direction perpendicular to the longitudinal direction of the resin film, preventing air entrapment. This makes it possible to prevent deformation defects when winding the resin film.

The A Shore hardness of the second layer may be greater than or equal to 0 and less than or equal to 40/50 of the A Shore hardness of the first layer. In this case, it is easier to apply uniform pressure to the resin film in a direction perpendicular to the longitudinal direction of the resin film.

The first layer may have an A Shore hardness of 50 to 80, and the second layer may have an A Shore hardness of 0 to 40. In this case, the reaction force is easily absorbed.

The second layer may be removably attached to the first layer. This makes it easy to replace the second layer if it deteriorates or becomes damaged.

The material of the surface of the roll body that comes into contact with the first layer may be metal.

The second layer may have an outer layer having the contact surface and an inner layer disposed between the first layer and the outer layer, and the A Shore hardness of the inner layer and the outer layer may be less than the A Shore hardness of the first layer, and the A Shore hardness of the outer layer may be greater than the A Shore hardness of the inner layer.

In the above configuration, the second layer has an outer layer that is softer than the first layer but harder than the inner layer, and the outer layer contacts the resin film. The outer layer makes it easier to prevent deterioration and damage to the second layer. Furthermore, the inner layer can conform to the unevenness of the surface of the resin film. This makes it easier to apply a consistent pressure to the resin film.

The inner layer may have a Shore A hardness of 0 to 20. The outer layer may have a Shore A hardness of 20 to 40.

A winding device according to another aspect of the present invention includes a winding shaft around which a long resin film is wound, the touch roll according to one aspect of the present invention, and a position adjustment mechanism that moves one of the winding shaft and the touch roll relative to the other so that the contact surface of the touch roll contacts the resin film with a constant pressing force.

The winding device is equipped with a touch roll according to one aspect of the present invention. This makes it possible to wind the resin film onto the winding shaft while preventing deformation defects when winding the resin film.

The present invention provides a touch roll and winding device that can prevent deformation defects when winding a resin film.

FIG. 1 is a schematic diagram of a winding device using a touch roll according to one embodiment. FIG. 2 is a schematic perspective view of a portion of the winding device shown in FIG. FIG. 3 is a schematic diagram of an example of an optical laminate (resin film). FIG. 4 is a perspective view of an example of a touch roll. FIG. 5 is a diagram for explaining the state of contact between the touch roll and the resin film. FIG. 6 is a diagram for explaining the state of contact between the touch roll and the resin film. FIG. 7 is a diagram illustrating a method for inspecting a raw roll. FIG. 8 is a diagram illustrating another example of the touch roll. FIG. 9 is a diagram illustrating yet another example of the touch roll. FIG. 10 is a diagram for explaining a modified example of the arrangement position of the touch roll.

Embodiments of the present invention will be described below with reference to the drawings. The same or equivalent parts in the drawings will be designated by the same reference numerals, and duplicate explanations will be omitted. Dimensional proportions in the drawings do not necessarily correspond to those in the description.

Figure 1 is a diagram showing the schematic configuration of a winding device using a touch roll according to one embodiment. Figure 2 is a schematic perspective view of a portion of the winding device shown in Figure 1, illustrating the contact area between the touch roll and the resin film.

The winding device 2 is a device for winding up a long resin film 4. The resin film 4 can be manufactured, for example, by extrusion molding. The longitudinal length of the resin film 4 is not particularly limited, but is, for example, in the range of 1,000 m to 10,000 m, preferably 1,000 m to 6,000 m. The widthwise length of the resin film 4 is not particularly limited, but may be, for example, 2.5 m or less.

Examples of resin film 4 include the following optical films. The optical film may be a single layer, or an optical laminate comprising two or more layers. Examples of single-layer optical films include the thermoplastic resin films described below.

Layers that make up the optical laminate include a polarizer, a thermoplastic resin film, an optically functional layer, an adhesive layer, a pressure-sensitive adhesive layer, a separate film, a protective film, and a touch sensor panel.

Figure 3 is a schematic diagram showing an example of an optical laminate. The optical laminate 100 shown in Figure 3 has a polarizing plate 102, a first pressure-sensitive adhesive layer 104, a first optical functional layer 106, an adhesive layer 108, a second optical functional layer 110, a second pressure-sensitive adhesive layer 112, and a separate film 114. The first pressure-sensitive adhesive layer 104, the first optical functional layer 106, the adhesive layer 108, the second optical functional layer 110, the second pressure-sensitive adhesive layer 112, and the separate film 114 are laminated in this order on the polarizing plate 102. Each layer of the optical laminate 100 is described in detail below.

[Polarizing plate]
The polarizing plate 102 has a polarizer 102a and a thermoplastic resin film 102b laminated on one or both sides of the polarizer 102a.

(Polarizer)
The polarizer 102a is a layer having linear polarization properties. The material and manufacturing method of the polarizer 102a may be those known in the art. The thickness of the polarizer 102a is usually 30 μm or less, preferably 18 μm or less, and more preferably 15 μm or less. Reducing the thickness of the polarizer 102a is advantageous for reducing the thickness of the polarizing plate 102. The thickness of the polarizer 102a is usually 1 μm or more, and may be, for example, 5 μm or more.

(Thermoplastic resin film)
Examples of the thermoplastic resin film 102b include films known in the art, such as cyclic polyolefin resin films; cellulose acetate resin films made of resins such as triacetyl cellulose and diacetyl cellulose; polyester resin films made of resins such as polyethylene terephthalate, polyethylene naphthalate, and polybutylene terephthalate; polycarbonate resin films; (meth)acrylic resin films; and polypropylene resin films.

The thickness of the thermoplastic resin film 102b is preferably thin in order to reduce the thickness of the polarizing plate 102, but if it is too thin, the strength tends to decrease and processability tends to be poor. Therefore, the thickness is preferably 5 μm or more and 150 μm or less, more preferably 5 μm or more and 100 μm or less, and even more preferably 10 μm or more and 50 μm or less.

[First adhesive layer]
The first pressure-sensitive adhesive layer 104 is a layer interposed between the polarizing plate 102 and the first optical functional layer 106 to bond them together. The first pressure-sensitive adhesive layer 104 can be composed of a pressure-sensitive adhesive composition whose main component is a (meth)acrylic resin, a rubber resin, a urethane resin, an ester resin, a silicone resin, a polyvinyl ether resin, or the like. Among these, a pressure-sensitive adhesive composition whose base polymer is a (meth)acrylic resin, which has excellent transparency, weather resistance, heat resistance, and the like, is preferred. The pressure-sensitive adhesive composition may be an active energy ray-curable or heat-curable type. The first pressure-sensitive adhesive layer 104 can be formed by a method known in the art.

[First optical functional layer]
The first optical functional layer 106 is a layer having an optical function other than the polarizer 102a to provide a desired optical function. A suitable example of the first optical functional layer 106 is a retardation layer. Examples of the retardation layer include a layer that provides a λ/2 retardation, a layer that provides a λ/4 retardation (positive A plate), and a positive C plate. The retardation layer may include an alignment layer and a substrate, or may have two or more liquid crystal layers, alignment layers, and substrates. The thickness of the retardation layer may be the same as that of the polarizer 102a. The material and manufacturing method of the retardation layer may be known in the art.

Other examples of the first optical function layer 106 include a light collector, a brightness enhancement film, a reflective layer (reflective film), a semi-transmissive reflective layer (semi-transmissive reflective film), a light diffusion layer (light diffusion film), etc. The materials and manufacturing methods for each of the above other examples may be those known in the art.

[Adhesive layer]
The adhesive layer 108 is a layer that is interposed between the first optical functional layer 106 and the second optical functional layer 110 to bond them together. The adhesive layer 108 is composed of a known aqueous composition (including an aqueous adhesive) in which a curable resin component is dissolved or dispersed in water, a known active energy ray-curable composition (including an active energy ray-curable adhesive) containing an active energy ray-curable compound, or the like.

[Second optical functional layer]
The second optical function layer 110 is a layer having an optical function other than the polarizer 102a in order to impart a desired optical function. Examples of the second optical function layer 110 include the examples of the first optical function layer 106. Therefore, the description of the first optical function layer 106 can be cited for the second optical function layer 110. Typically, the second optical function layer 110 has an optical function different from that of the first optical function layer 106. For example, if one of the first optical function layer 106 and the second optical function layer 110 is a layer that imparts a phase difference of λ/2, the other is a layer that imparts a phase difference of λ/4.

The second optical functional layer 110 may be bonded to the first optical functional layer 106 via a pressure-sensitive adhesive layer instead of the adhesive layer 108. The description of the first pressure-sensitive adhesive layer 104 can be cited for the pressure-sensitive adhesive layer used here.

[Second adhesive layer]
The second pressure-sensitive adhesive layer 112 is a layer for bonding the optical laminate 100 to an image display element or other optical member. The pressure-sensitive adhesive, pressure-sensitive adhesive composition, thickness, and production method used for the second pressure-sensitive adhesive layer 112 are the same as those described in the section on the first pressure-sensitive adhesive layer 104.

[Separate film]
The separate film 114 is provided on the second pressure-sensitive adhesive layer 112 (the side opposite to the second optical function layer 110) to prevent dust and the like from adhering to the second pressure-sensitive adhesive layer 112 and to prevent the second pressure-sensitive adhesive layer 112 from being attached to other parts of the optical laminate 100 (resin film 4) during winding. The separate film 114 can be a film made of a polyethylene-based resin such as polyethylene, a polypropylene-based resin such as polypropylene, a polyester-based resin such as polyethylene terephthalate, or the like. Of these, a stretched polyethylene terephthalate film is preferred. The separate film 114 is peeled off and removed when the optical laminate 100 is attached to an image display element or other optical component.

The optical laminate 100 may include a protective film for protecting its surface (typically, the surface of the thermoplastic resin film 102b of the polarizing plate 102). After the polarizing plate 102 is bonded to, for example, an image display element or other optical component, the protective film is peeled off and removed along with its adhesive layer.

The protective film is composed, for example, of a base film and an adhesive layer laminated thereon. The above description of the adhesive layer is cited. The resin constituting the base film can be a thermoplastic resin such as a polyethylene-based resin such as polyethylene; a polypropylene-based resin such as polypropylene; a polyester-based resin such as polyethylene terephthalate or polyethylene naphthalate; a polycarbonate-based resin; or a poly(meth)acrylic resin. A polyester-based resin such as polyethylene terephthalate is preferred.

The thickness of the protective film is not particularly limited, but is preferably in the range of 20 μm or more and 200 μm or less. If the thickness of the protective film is 20 μm or more, it tends to be easier to impart strength to the optical laminate 100.

In the optical laminate 100, for example, the thermoplastic resin film 102b may have the same optical function as the first optical functional layer 106 or the second optical functional layer 110. In this case, the optical laminate 100 does not have a layer in the first optical functional layer 106 or the second optical functional layer 110 that has the same optical function as the thermoplastic resin film 102b. The thermoplastic resin film 102b may function as, for example, a protective film. In this case, the optical laminate 100 does not have a protective film on the side opposite the first pressure-sensitive adhesive layer 104 from the polarizing plate 102.

As shown in Figure 1, the resin film 4 is transported by a transport roll R, which is part of the transport mechanism, and taken up by a winding device 2. The rolled resin film 4 taken up by the winding device 2 is also referred to as a raw roll WR. For convenience of explanation, the rolled resin film 4 being wound may also be referred to as a raw roll WR.

The winding device 2 comprises a winding shaft 6, a touch roll 8, and a position adjustment mechanism 10.

The winding shaft 6 is a core for winding up the resin film 4. In this embodiment, the winding shaft 6 is rotated by a motor or the like, causing the resin film 4 to be wound around the winding shaft 6. Unless otherwise specified, the winding device 2 of this embodiment uses a center-drive winding system in which the resin film 4 is wound by the rotation of the winding shaft 6.

The touch roll 8 is a roll that presses the resin film 4 being wound around the winding shaft 6, applying a certain amount of pressure (hereinafter also referred to as "touch pressure"). The touch pressure on the resin film 4 is, for example, 500 N/m or less, preferably 400 N/m or less, and more preferably 330 N/m or less. The lower limit of the touch pressure is typically 10 N/m, preferably 100 N/m. The touch roll 8 has a contact surface 8a that contacts the resin film 4. The contact surface 8a is the outermost surface of the touch roll 8. The width of the contact surface 8a (the length in the direction of the rotation axis of the touch roll 8) is generally equal to or greater than the width of the resin film 4 (the length in the direction perpendicular to the longitudinal direction of the resin film 4). The diameter of the touch roll 8 is, for example, 30 mm to 300 mm, preferably 50 mm to 200 mm, and more preferably 120 mm to 160 mm. The touch roll 8 is also sometimes called a nip roll, rider roll, press roll, etc.

The touch roll 8 is rotatably supported by a pair of support members 12 (see Figure 2). The support members 12 may be plate-shaped or rod-shaped.

The position adjustment mechanism 10 moves one of the winding shaft 6 and the touch roll 8 relative to the other so that the contact surface 8a of the touch roll 8 comes into contact with the resin film 4 with a pressing force that applies a constant touch pressure, as indicated by the white arrow in Figure 1.

In the embodiment illustrated in FIG. 1, the touch roll 8 is moved relative to the winding shaft 6. In the embodiment illustrated in FIG. 1, the position adjustment mechanism 10 is a cylinder. The position adjustment mechanism 10 has a cylinder body 14 and a cylinder rod 16 that is extendable and retractable relative to the cylinder body 14. The cylinder rod 16 is connected to a support member 12. Examples of cylinders that are the position adjustment mechanism 10 include hydraulic cylinders and air cylinders. The position adjustment mechanism 10 may also be an actuator. The position adjustment mechanism 10 may be, for example, a swing-type mechanism. For example, the end of one of the pair of support members 12 opposite the touch roll 8 may be attached to a support shaft so that it can swing. In this case, the support shaft functions as the position adjustment mechanism 10. The pair of support members 12 may be part of the position adjustment mechanism 10.

The position adjustment mechanism 10 may include, for example, a control unit that controls the cylinder to adjust the position of the touch roll 8 so that a constant touch pressure can be applied to the resin film 4 depending on the amount of resin film 4 wound around the winding shaft 6. The control unit may be included in the cylinder, for example.

The position adjustment mechanism 10 allows the touch roll 8 to retract accordingly, even if the diameter of the raw roll WR changes as the resin film 4 is continuously wound around the winding shaft 6. As a result, a constant touch pressure can be applied to the contact area A (the area surrounded by a dashed line and hatched in Figure 2) between the contact surface 8a and the surface of the resin film 4. The contact area A has a rectangular shape extending in the width direction of the resin film 4.

Next, the touch roll 8 will be described in detail using Figure 4. The touch roll 8 has a roll body 18, a first layer 20, and a second layer 22.

The roll body 18 is the core material of the touch roll 8. The roll body 18 has a cylinder 24, a pair of end walls 25, and a pair of shafts 26. Examples of materials for the cylinder 24 include metal, carbon, and CFRP (carbon fiber reinforced plastic). Examples of metals include iron, stainless steel, and aluminum. The surface of the cylinder 24 is the surface of the roll body 18 that contacts the first layer 20. The pair of end walls 25 close the openings at both ends of the cylinder 24. The cylinder 24 and the pair of end walls 25 form a hollow barrel. The pair of shafts 26 are provided on the pair of end walls 25, concentric with the axis of the cylinder 24. Figure 2 illustrates one end wall 25 and one shaft 26 of the pair of end walls 25 and pair of shafts 26. The pair of shafts 26 are rotatably supported by a pair of support members 12. The roll body 18 may have a single shaft that penetrates the pair of end walls 25.

In this embodiment, the first layer 20 is disposed on the outer side of the roll body 18 in the radial direction of the roll body 18 (specifically, on the outer side of the cylinder 24). The first layer 20 covers the surface of the cylinder 24 of the roll body 18. In this embodiment, the first layer 20 is an elastic layer. The first layer 20 is a base layer for the second layer 22. An example of a material for the first layer 20 is rubber. The first layer 20 may be formed, for example, by wrapping a rubber sheet around the cylinder 24 in the circumferential direction, or by forming a cylindrical portion from the rubber sheet in advance and attaching the cylindrical portion to the roll body 18.

The Shore A hardness of the first layer 20 is typically 50 to 80. The first layer 20 is a layer that absorbs the reaction force (or impact) of the pressing force when the touch roll 8 is pressed against the resin film 4. For example, to prevent the touch roll 8 itself from bending due to its own weight, it is preferable that the first layer 20 is not too thick. Preventing bending of the touch roll 8 itself makes it easier to apply touch pressure uniformly along the width direction of the resin film 4. On the other hand, to make it easier to distribute the reaction force, it is preferable that the first layer 20 is not too thin. Distributing the reaction force makes it easier to apply touch pressure uniformly along the width direction of the resin film 4. Therefore, the thickness of the first layer 20 is typically 2 mm to 15 mm, preferably 3 mm to 15 mm, and more preferably 3 mm to 12 mm.

The Shore A hardness of the first layer 20 is the hardness measured by testing a 6 mm thick test piece made of the same material as the first layer 20 using a durometer type A hardness (Shore A) in accordance with JIS K 6253.

The first layer 20 may be formed, for example, by wrapping the sheet that will become the first layer 20 around the roll body 18, or by inserting the roll body 18 into the cylindrical sheet that will become the first layer 20.

The second layer 22 is disposed radially outward of the first layer 20. The surface of the second layer 22 is the contact surface 8a. The Shore A hardness of the second layer 22 is less than the Shore A hardness of the first layer 20. In other words, the second layer 22 is softer than the first layer 20. The Shore A hardness of the second layer 22 is, for example, between 0 and 40/50 of the Shore A hardness of the first layer 20. For example, if the Shore A hardness of the first layer 20 is between 50 and 80, the Shore A hardness of the second layer 22 is between 0 and 40.

The thickness of the second layer 22 is not particularly limited, but is, for example, 0.5 mm to 10 mm, preferably 1 mm to 10 mm, and more preferably 1 mm to 7 mm.

In this embodiment, the second layer 22 is a porous layer. There are no particular limitations on the porous layer, and examples include foam materials (so-called foams) made from resin. Examples of resins that can be used to make the porous layer include polyethylene and polyurethane.

The second layer 22 may be formed, for example, by wrapping a single sheet of foam material around the first layer 20 in the circumferential direction, or by covering the outer surface of the first layer 20 with multiple rectangular (or strip-shaped) foam materials without leaving any gaps. When covering the outer surface of the first layer 20 with multiple rectangular (or strip-shaped) foam materials, for example, multiple rectangular (or strip-shaped) foam materials may be arranged in the circumferential direction so that their longitudinal directions coincide with the direction of the rotation axis of the touch roll 8, or multiple rectangular (or strip-shaped) foam materials may be wrapped around the first layer 20 so that their longitudinal directions intersect the direction of the rotation axis of the touch roll 8 (or spirally).

The second layer 22 may be removably attached to the first layer 20. For example, the above-mentioned single sheet of foam material or multiple rectangular (or strip) foam materials may be attached to the outer surface of the first layer 20 using double-sided tape, a removable adhesive, or the like.

The second layer 22 may have, for example, a multi-layer structure in the radial direction, as long as it has the above-mentioned A Shore hardness relationship with the first layer 20. If the second layer 22 has a multi-layer structure, the materials of each layer may be different, as long as the multi-layer structure of the second layer 22 satisfies the above-mentioned A Shore hardness range.

The Shore A hardness of the second layer 22 is the hardness measured by preparing a 6 mm thick test piece made of the same material as the second layer 22 and testing it with a Type A durometer in accordance with JIS K6253. Alternatively, if the second layer 22 has a laminated structure including multiple layers, the Shore A hardness of each layer of the second layer 22 may be the Type A durometer hardness (Shore A) specified in JIS K6253 for each 6 mm thick test piece made of the same material as each layer.

For example, in an embodiment in which the first layer 20 is a rubber layer and the second layer 22 is a sponge layer, the touch roll 8 corresponds to a roll in which a rubber layer is provided on the outer surface of the roll body 18 and the surface of the rubber roll is covered with a sponge layer.

The touch roll 8 has a first layer 20 and a second layer 22 arranged in this order from the roll body 18 side. The second layer 22 has a lower A Shore hardness than the first layer 20. In other words, the touch roll 8 has a hard first layer 20 (base layer) and a soft second layer 22 on the outside of the roll body 18. The effects of having a hard first layer 20 and a soft second layer 22 on the outside of the roll body 18 will be explained below in comparison with the case where the second layer 22 is not present and the case where the first layer 20 is not present.

As shown in Figures 1 and 2, the touch roll 8 applies a constant touch pressure to the surface of the resin film 4 wound around the winding shaft 6. As shown in Figure 5, the surface of the resin film 4 against which the touch roll 8 is pressed may be uneven. For the sake of explanation, Figure 5 shows the state before the touch roll 8 and resin film 4 come into contact.

When the touch roll 8 does not have the second layer 22, the first layer 20 contacts the surface of the resin film 4. In this case, if the first layer 20 has, for example, the above-mentioned Shore A hardness, it cannot conform to the irregularities of the resin film 4. As a result, a gap may form between the touch roll 8 and the resin film 4 in the contact area A shown in Figure 2. This causes touch pressure to be applied unevenly to the contact area A, for example, along its width direction (the direction of the rotation axis of the touch roll 8). On the other hand, when the touch roll 8 does not have the first layer 20, i.e., when the second layer 22 is provided directly on the roll body 18, the influence of the roll body 18 on the convex portions on the surface of the resin film 4 tends to generate touch pressure stronger than the designed touch pressure. Therefore, in this case as well, touch pressure is applied unevenly along the width direction to the contact area A shown in Figure 2. As described above, when touch pressure is applied unevenly across the width of the contact area A, air is entrained when the resin film 4 is wound around the winding shaft 6. Resin film 4 is not easily permeable to air, so it is susceptible to air being drawn in. Therefore, when air is drawn in, deformation defects such as wrinkles are likely to occur in the resin film 4.

In contrast, when the roll body 18 has a hard first layer 20 and a soft second layer 22 on the outside, as shown in FIG. 6, the second layer 22 conforms to the irregularities on the surface of the resin film 4, and the first layer 20 is interposed between the roll body 18 and the second layer 22, allowing the hardness (or elasticity) of the first layer 20 to absorb the strong pressure generated by the convex portions of the resin film 4. As a result, touch pressure can be applied uniformly to the contact area A along its width. This prevents the above-mentioned deformation defects in the resin film 4 wound around the winding shaft 6. As a result, when the resin film 4 is re-wound from the raw roll WR obtained by winding the resin film 4 around the winding shaft 6 and products are manufactured using the unwound resin film 4, it is easier to produce good products.

If the Shore A hardness of the second layer 22 is between 0 and 40/50 of the Shore A hardness of the first layer 20, it is easier to uniformize the touch pressure across the width of the contact area A. Similarly, if the Shore A hardness of the first layer 20 is between 50 and 80 and the Shore A hardness of the second layer 22 is between 0 and 40, it is easier to uniformize the touch pressure across the width of the contact area A.

As described above, in the touch roll 8, the first layer 20 absorbs the strong pressure generated by the convex portions of the resin film 4, while the second layer 22 conforms to the unevenness of the surface of the resin film 4. Therefore, the thickness of the second layer 22 can be selected appropriately depending on the Shore A hardness of the first layer 20 and the second layer 22 and the touch pressure of the contact area A. As shown in the example, if the thickness of the second layer 22 is 10 mm or less (or 7 mm or less), the first layer 21 can be used more effectively.

In an embodiment in which the second layer 22 is detachable from the first layer 20, the manufacturing costs of the raw roll WR can be reduced. For example, because the second layer 22 is pressed against the resin film 4, the second layer 22 may deteriorate or be damaged (scraped, worn, etc.). Even in such cases, if the second layer 22 is detachable from the first layer 20, only the second layer 22 needs to be replaced. As a result, costs can be reduced compared to replacing the entire touch roll 8.

Next, a specific example will be described. In this example, three touch rolls were prepared. To distinguish between the three touch rolls, they will be referred to as touch roll TR1, touch roll TR2, and touch roll TR3. Touch roll TR1 is a touch roll for comparative experiments.

For ease of explanation, in the explanation of the specific examples, whether using touch rolls TR2 and TR3 or touch roll TR1 for the comparative example, elements equivalent to those in the explanation of the winding device 2 shown in Figure 1 will be assigned the same reference numerals and redundant explanations will be omitted.

(Touch Roll TR1)
The touch roll TR1 had a roll body 18 and a rubber layer provided on the outer surface of the roll body 18. In the touch roll TR1, the rubber layer corresponded to the first layer 20. The outermost surface of the touch roll TR1 (corresponding to the contact surface 8a) was the surface of the rubber layer. In other words, the touch roll TR1 was a touch roll that did not have the second layer 22. The length in the width direction of the touch roll TR1 was 2 m to 2.5 m. The roll body 18 was made of metal. The thickness of the rubber layer was 10 mm. The Shore A hardness of the rubber layer was 65.

(Touch Roll TR2)
The touch roll TR2 had a configuration in which the surface of the rubber layer (first layer 20) of the touch roll TR1 was further covered with a sponge sheet. Therefore, the touch roll TR2 had a roll body 18, a rubber layer provided on the outer surface of the roll body 18, and a sponge layer provided on the outer surface of the rubber layer. In the touch roll TR2, the sponge layer corresponded to the second layer 22. The thickness of the sponge layer (second layer 22; sponge sheet) was 2 mm, and its width direction length was the same as that of the touch roll TR1. The A Shore hardness of the sponge layer (second layer 22), i.e., the A Shore hardness of the sponge sheet used in the touch roll TR2, was 8.

(Touch Roll TR3)
The touch roll TR3 had a configuration in which the surface of the sponge layer of the touch roll TR2 was further covered with the sponge sheet used in the touch roll TR2. Therefore, the touch roll TR3 had a roll body 18, a rubber layer provided on the outer surface of the roll body, and two sponge layers provided in that order on the outer surface of the rubber layer. The two sponge layers corresponded to the second layer 22. Since each sponge layer was 2 mm thick, if the two sponge layers were considered to be one sponge layer, the touch roll TR3 had a 4 mm thick sponge layer (second layer 22) on the outside of the rubber layer. Because the materials used for the two sponge layers were the same, the Shore A hardness of the second layer 22, which had two sponge layers in the touch roll TR3, was 8, the same as in the case of the touch roll TR2. The width direction lengths of the two sponge layers were the same.

Next, in the winding device 2 shown in Figure 1, the resin film 4 was wound up using touch rolls TR1, TR2, and TR3 as the touch roll 8. The resin film 4 used for winding was a poly(meth)acrylic resin film (thickness 40 μm to 80 μm; winding length 4000 mm). The resin film 4 wound up when touch roll TR1, TR2, and TR3 were used was the same.

When winding up the resin film 4, a center-driven winding machine was used as the winding device 2. The winding speed was 30 m/min to 60 m/min. The winding tension (tension per unit width) when winding up the resin film 4 was 150 N/m to 250 N/m. An air cylinder was used for the position adjustment mechanism 10. The touch pressure when pressing the touch rolls TR1, TR2, and TR3 against the resin film 4 using the position adjustment mechanism 10 was 200 N/m to 300 N/m.

The configurations of the resin film 4 and winding device 2 and the winding conditions were the same, except that touch rolls TR1, TR2, and TR3 were each used as touch rolls 8.

The resin film 4 was wound up using the touch roll TR1, the touch roll TR2, and the touch roll TR3, respectively, and the raw roll WR was subjected to an appearance inspection.
Specifically, as shown in Fig. 7, light was irradiated onto the raw roll WR from a light source 28 arranged on one side of the raw roll WR, and the transmitted light was visually observed from the side of the raw roll WR opposite the light source 28. A Polarion Light (manufactured by C.S.C. Co., Ltd.) was used as the light source 28.

If, for example, air is entrained when winding the resin film 4 using the winding device 2, causing a deformation defect (wrinkle, etc.) in the raw roll WR, the area of the deformation defect will appear dark. Therefore, the presence or absence of a deformation defect was evaluated based on the degree of shadow (darkness) caused by the deformation defect relative to the sample used as the evaluation standard.

When touch roll TR1 was used on the raw roll WR, the above visual inspection confirmed the shadows (darkness) of deformation defects. On the other hand, when touch rolls TR2 and TR3 were used, the above visual inspection confirmed no shadows (darkness) of deformation defects. In other words, when a rubber layer is in direct contact with the resin film 4, air can be entrapped during winding of the resin film 4, causing deformation defects. However, when a sponge layer with a lower A Shore hardness than the rubber layer is in contact with the resin film 4, deformation defects can be prevented.

The present invention is not limited to the various embodiments described above, but is intended to encompass the scope indicated by the claims, as well as all modifications within the meaning and scope of the claims.

For example, the touch roll may be the touch roll 30 shown in Figure 8. The touch roll 30 differs from the touch roll 8 in that it has a second layer 32 instead of the second layer 22. The second layer 32 has an inner layer 34 and an outer layer 36. The inner layer 34 and the outer layer 36 are both porous layers (e.g., sponge layers). The A Shore hardnesses of the inner layer 34 and the outer layer 36 are lower than the A Shore hardness of the first layer 20, and the A Shore hardness of the inner layer 34 is lower than the A Shore hardness of the outer layer 36. In other words, the inner layer 34 and the outer layer 36 are softer than the first layer 20, and the outer layer 36 is harder than the inner layer 34. For example, the A Shore hardness of the inner layer 34 is, for example, 0 to 20, and the A Shore hardness of the outer layer 36 is 20 to 40. Because the Shore A hardness of the inner layer 34 is lower than the Shore A hardness of the outer layer 36, if one of the illustrated inner layer 34 and outer layer 36 includes a region where the Shore A hardness is 20, the other does not include a region where the Shore A hardness is 20. The inner layer 34 may be detachable from the first layer 20, for example. The outer layer 36 may be detachable from the inner layer 34.

Because the Shore A hardness of the outer layer 36 (or the Shore A hardness of the second layer 32) is lower than that of the first layer 20, the touch roll 30 has the same effect as the touch roll 8. Specifically, the inner layer 34 of the second layer 32 of the touch roll 30 is softer than the outer layer 36, allowing it to conform to the irregularities on the surface of the resin film 4. Because the second layer 32 has an outer layer 36 that is harder than the inner layer 34, deterioration and damage (scratches, wear, etc.) of the second layer 32 can be prevented more effectively than if the inner layer 34 were in direct contact with the resin film 4. Furthermore, the length of the contact area A in the short direction is likely to be shorter. This makes it possible to more reliably press the surface of the resin film 4 with a consistent touch pressure.

The touch roll may be the touch roll 38 shown in Figure 9. The touch roll 38 differs from the touch roll 8 in that it has a second layer 40 instead of the second layer 22. The relationship of the A Shore hardness of the second layer 40 to the first layer 21 is the same as that of the second layer 22, and examples of materials for the second layer 40 are the same as those for the second layer 22. Below, the second layer 40 will be described, focusing on the differences from the second layer 22.

The second layer 40 has a first region 40a, a second region 40b, and a third region 40c, in this order, along the width direction. The first region 40a, the second region 40b, and the third region 40c have the same thickness. The A Shore hardness of at least one of the first region 40a, the second region 40b, and the third region 40c is different from the A Shore hardness of the other regions. For example, the A Shore hardness of the first region 40a and the third region 40c is the same and is smaller (or larger) than the A Shore hardness of the second region 40b. The difference in A Shore hardness can be achieved by using different materials.

Figure 9 illustrates an example in which the second layer 40 has three regions in the width direction, but the number of regions is not limited to three. The A Shore hardness of the multiple regions that the second layer 40 has in the width direction and the width length of each region need only be set so that a uniform touch pressure can be applied to the resin film 4 in the width direction.

The location where the touch roll 8 comes into contact with the resin film 4 is not limited to the contact point (or its vicinity) of the resin film 4 with the winding shaft 6 (or the roll-shaped resin film 4 wound around the winding shaft 6) as shown in Figures 1 and 2. As shown in Figure 10, it is sufficient that the touch roll 8 is positioned so as to come into contact with the roll-shaped resin film 4 wound around the winding shaft 6 in the circumferential direction of the winding shaft 6.

The roll body 18 does not necessarily have to include a pair of shafts 26. In this case, a rotating shaft may be prepared separately from the touch roll 8, and the rotating shaft may be passed through the touch roll, which is the roll body 18 itself, and rotatably supported by a pair of support members 12. The roll body 18 may have, for example, a cylindrical body (solid body) and a pair of shafts 26. In this case, the pair of shafts 26 are provided concentrically with the axis of the body on both end surfaces in the axial direction of the body. An example of a material for the body is metal (e.g., iron, stainless steel, aluminum, etc.). The surface of the body is the surface of the roll body 18 that comes into contact with the first layer 20.

The position adjustment mechanism 10 may also move the winding shaft 6. As a method for winding the resin film 4 onto the winding shaft 6, the winding device 2 may employ a surface-driven winding method in which a drive shaft (or drive roll) separate from the touch roll 8 is pressed against the resin film 4, the drive shaft is driven to rotate, and the frictional force generated in the contact area A between the drive shaft and the resin film 4 rotates the winding shaft 6 around which the resin film 4 is wound, thereby winding the resin film 4 around the winding shaft 6. Alternatively, the winding device 2 may employ a combined drive method that combines the center-driven winding method exemplified in the above embodiment with the surface-driven winding method. In the surface-driven winding method, the touch roll 8 itself may be used instead of the drive shaft.

The second layer 22 is not limited to being a porous layer, and may be made of rubber, as long as its A Shore hardness is less than that of the first layer.

The embodiments and various modifications described above may be combined as appropriate without departing from the spirit of the present invention.

2...winding device, 4...resin film, 6...winding shaft, 8...touch roll, 8a...contact surface, 20...first layer, 22...second layer, 30...touch roll, 32...second layer, 34...inner layer, 36...outer layer.

Claims (8)

A touch roll having a contact surface that comes into contact with a long resin film when the resin film is wound around a winding shaft,
A roll body;
a first layer disposed on the outer side of the roll body in the radial direction of the roll body;
a second layer having the contact surface and disposed radially outward of the first layer;
Equipped with
the second layer has a lower Shore A hardness than the first layer;
The second layer is
an outer layer having the contact surface;
an inner layer disposed between the first layer and the outer layer;
and
the inner layer and the outer layer have a Shore A hardness lower than the Shore A hardness of the first layer;
the outer layer has a Shore A hardness greater than the inner layer's Shore A hardness;
The inner layer and the outer layer are both porous layers.
Touch roll. the A Shore hardness of the second layer is equal to or greater than 0 and equal to or less than 40/50 of the A Shore hardness of the first layer;
The touch roll according to claim 1 . The first layer has a Shore A hardness of 50 to 80,
The second layer has a Shore A hardness of 0 to 40.
The touch roll according to claim 1 or 2. The second layer is removably attached to the first layer.
The touch roll according to any one of claims 1 to 3. a surface of the roll body that comes into contact with the first layer is made of metal;
The touch roll according to any one of claims 1 to 4. The inner layer has a Shore A hardness of 0 to 20.
The touch roll according to any one of claims 1 to 5. The outer layer has a Shore A hardness of 20 to 40.
The touch roll according to any one of claims 1 to 6. a winding shaft on which a long resin film is wound;
The touch roll according to any one of claims 1 to 7,
a position adjustment mechanism that moves one of the winding shaft and the touch roll relative to the other so that the contact surface of the touch roll comes into contact with the resin film with a constant pressing force;
Equipped with
Winding device.