JP5385178B2 - Flexible film transport apparatus and barrier film manufacturing method - Google Patents

Description

  The present invention relates to a flexible film conveying apparatus and a barrier film manufacturing method, and more particularly to a technique for conveying a flexible film with a stepped roller disposed in a vacuum film forming apparatus.

  In various devices such as optical devices, display devices such as liquid crystal displays and organic EL displays, semiconductor devices, and thin film solar cells, barrier films are used for parts and parts that require moisture barrier properties and gas barrier properties such as oxygen. ing. Furthermore, as an example familiar to daily life, in packaging of foods, clothing, electronic parts, etc., the packaging material may be required to have gas barrier properties such as moisture resistance and oxygen, and gas barrier films are used.

  For example, a moisture-proof gas barrier film is formed by depositing a barrier film exhibiting gas barrier properties such as silicon oxide or silicon nitride on the surface of a flexible film such as a plastic film or a metal film by a vacuum film formation method. It is usual to be manufactured with.

  In order to efficiently perform film formation while ensuring high productivity by the vacuum film formation method, it is preferable to continuously form a barrier film on a long flexible film.

  As an apparatus for carrying out such a vacuum film-forming method, a barrier film is formed on a roll-like long flexible film fed from a feed roll, and then the flexible film is rolled again with a take-up roll. There is known a so-called roll-to-roll type film forming apparatus that is wound around a film.

  This roll-to-roll film forming apparatus maintains a predetermined path passing through a film forming chamber (film forming part) for forming a film on a flexible film by a gas phase film forming method such as plasma CVD in a vacuum state. The flexible film is conveyed by a conveyance roller disposed in a vacuum film formation chamber.

  However, if the barrier film surface on which the flexible film is formed, for example, the inorganic film surface is in contact with the roller surface, scratches such as pinholes are likely to occur on the barrier film surface. Thereby, the barrier film manufactured will be inferior goods.

  Therefore, if you do not want to damage the barrier film surface of the flexible film, use a stepped roller with holding parts whose both ends are larger in diameter than the center part, and use the width direction of the flexible film. It is performed that only both ends are wrapped around and supported by a holding unit. In this case, since both ends of the flexible film are cut before the final product, the quality of the barrier film is not affected.

  When the flexible film is transported by such a stepped roller, it may become wrinkles due to looseness that occurs in the central portion in the width direction of the flexible film, or may be damaged by contacting the central portion of the stepped roller. There is.

  Therefore, when the flexible film is conveyed by the stepped roller, the both end portions of the flexible film are securely held at the holding portions at both ends of the stepped roller so that the central portion of the flexible film is not loosened. It becomes important. In the following, when simply referred to as “holding force”, it refers to the holding force of the flexible film by the roller.

  By the way, in the roller conveyance of the flexible film under the atmospheric pressure in the presence of air, the flexible film easily floats due to the entrained air accompanying the conveyance of the flexible film, thereby reducing the holding force. . Therefore, under atmospheric pressure, the holding force is increased by forming minute irregularities on the roller surface to allow the accompanying air to escape. For example, in Patent Document 1, the surface of the pass roller has a fine flat portion and a concave portion, the depth of the concave portion is 5 μm or more and 50 μm or less on average, and the occupied area ratio of the flat portion is 50% or more and 70% or less. It is described to do. Thereby, since the escape place of the accompanying air by high-speed conveyance of a flexible film can be formed, it is said that a flexible film becomes difficult to slip and generation | occurrence | production of the scratch of a flexible film and a pulling-in wrinkle can be prevented.

JP 2003-146505 A

  However, even if the uneven shape of the roller surface formed by the idea of increasing the holding force under atmospheric pressure as in Patent Document 1 is applied to a measure for increasing the holding force under vacuum, the holding force can be increased. On the contrary, there is a problem that the holding force decreases. This is because it is not necessary to release the entrained air under vacuum, and the contact area between the roller surface and the flexible film is reduced by forming many fine irregularities.

  That is, it is said that the holding force under the atmospheric pressure satisfies the relationship of uneven roller> flat roller, and the holding force under vacuum holds the relationship of uneven roller <flat roller.

  For this reason, it is a common practice to increase the holding force by increasing the contact area by making the holding surface holding the flexible film a smooth flat surface under vacuum conditions.

  However, when using a stepped roller with a flat holding part surface and transporting the flexible film under vacuum, the phenomenon that the central part of the flexible film loosens cannot be sufficiently solved, and the holding force It is required to increase.

  The present invention has been made in view of such circumstances, and when a long flexible film is wound around and held by a holding unit of a stepped roller in a vacuum apparatus, Since the holding force can be remarkably improved, an object of the present invention is to provide a flexible film transport device and a barrier film manufacturing method in which the central portion of the flexible film does not loosen.

  In order to achieve the above object, a flexible film conveying apparatus according to claim 1 of the present invention is a conveying apparatus for conveying a long flexible film in an apparatus controlled to a predetermined degree of vacuum, Holding the stepped roller in a transport apparatus having a stepped roller that has a holding part having a diameter larger than that of the central part at both ends and wraps and holds the flexible film around the holding part. The surface of the part is formed with a concavo-convex shape in which the relative value of the contact area defined below is greater than 1 according to the elastic deformation force of the flexible film under vacuum. When the surface of the holding part is a smooth flat surface, the area where the flexible film and the surface of the holding part are in contact is X, and when the surface of the holding part is the uneven surface, When the area where the flexible film and the holding portion surface are in contact with each other is Y, the ratio of Y to X is the relative value of the contact area.

  Here, the predetermined degree of vacuum refers to a degree of vacuum sufficient according to a film forming method of an apparatus, for example, a film forming apparatus. Further, the elastic deformation force means a degree that the flexible film is easily elastically deformed, and can be defined by, for example, Young's modulus.

  As in the present invention, since the entrained air layer accompanying the conveyance of the flexible film is not formed between the flexible film and the holding part surface of the stepped roller in the vacuum apparatus, an uneven shape is formed on the holding part surface. Even if formed, air does not collect in the recess. Thereby, the operation | movement which a flexible film elastically deforms following a recessed part and bends below is not disturbed. Therefore, depending on the elastic deformation force of the flexible film, the flexible film can follow the specific concave / convex shape that can easily enter the concave / convex concave portion, that is, the flexible film and the holding portion surface. If a concave / convex shape having a contact area relative value exceeding 1 is formed on the holding portion surface of the stepped roller, the flexible film and the concave / convex holding portion surface can be brought into full contact with each other without a substantial gap.

  As a result, when a long flexible film is wrapped around and held by the holding part of the stepped roller in the vacuum apparatus and conveyed, the holding force at the holding part can be significantly improved. Sometimes the central part of the flexible film does not sag.

  In the transport device of the present invention, when the elastic deformation force of the flexible film is expressed in Young's modulus, the uneven shape formed on the surface of the holding portion is in the range of 180 to 280 MPa and the following formula 1 It is preferable to satisfy ~ 3. When the taper angle of the side surface of the convex portion is θ, 0 ° <θ <90 °, and when the depth of the concave portion is H and the distance from the convex portion to A is A, ≧ 2H, Formula 3: The ratio (H / D) of the depth H of the recess to the thickness D of the flexible film is 45% or less.

  In the present invention, any concavo-convex shape may be used as long as the contact area relative value can exceed 1, but here, a preferable example of the concavo-convex shape for the contact area relative value exceeding 1 is specifically described. Specified.

  The elastic deformation force of the flexible film used for manufacturing the barrier film can be covered in a range of 180 to 280 MPa when expressed in Young's modulus. And in this range, a contact area relative value can exceed 1 by forming the uneven | corrugated shape which satisfy | fills Formula 1-Formula 3 in the holding | maintenance part surface of a stepped roller.

In this case, when the Young's modulus of the flexible film is in the range of 180 to 220 MPa and the elastic deformation force is large, the relative area of the contact area can be reduced even if the maximum value of the ratio (H / D) of the formula 3 is 50%. The value can be greater than 1.

In addition, when the Young's modulus of the flexible film is 180 MPa and the elastic deformation force is further large, even if the maximum value of the ratio (H / D) of the formula 3 is 90%, the relative value of the contact area is 1. Can be exceeded.

  In the transport device of the present invention, the concavo-convex shape in which the line-shaped convex portions and the line-shaped concave portions are alternately arranged, the concavo-convex shape in which the convex portions and the concave portions are formed in a lattice shape, and the convex portions and the concave portions are irregular. The concavo-convex shape arranged in the can be adopted.

  According to an eighth aspect of the present invention, in order to achieve the above object, a barrier film that suppresses the passage of water vapor or gas to the surface of the flexible film while conveying the flexible film in a vacuum film forming apparatus is provided. In the manufacturing method of the barrier film to form, the manufacturing apparatus of the barrier film characterized by using the conveying apparatus of any one of Claims 1-7 for conveyance of the said flexible film.

  According to the barrier film manufacturing method of the present invention, since the transport device according to any one of claims 1 to 7 is used, the central portion of the stepped roller is bent by bending the central portion of the flexible film. Can be stably conveyed so as not to come into contact with the film or to cause wrinkles on the flexible film. Thereby, since barrier properties, such as water vapor | steam and gas, do not fall, a high quality barrier film can be manufactured.

  According to the flexible film conveying device of the present invention, when a long flexible film is wound around and held on the holding portion of the stepped roller in the vacuum device, the holding force at the holding portion is retained. Can be significantly improved. Thereby, even if a long flexible film is conveyed by a stepped roller in a vacuum apparatus, the flexible film does not loosen and become wrinkles.

  Therefore, in the method for producing a barrier film, the barrier film is formed on the surface of the flexible film while suppressing the ventilation of water vapor or gas while the flexible film is conveyed in a vacuum film forming apparatus. If the transport device of the present invention is used for the transport, the flexible film does not become wrinkles and the barrier layer is not damaged, so that a high-quality barrier film can be produced.

The schematic diagram which incorporated the conveyance apparatus of the flexible film which concerns on embodiment of this invention in the film-forming apparatus which manufactures a barrier film Explanatory drawing explaining the stepped roller provided in a conveying apparatus Explanatory drawing explaining the uneven | corrugated shape formed in the holding part surface of a stepped roller Explanatory drawing explaining taper angle (theta), the recessed part depth H, and the distance A between convex parts in the uneven | corrugated shape whose longitudinal cross-sectional shape is a rectangular shape, a triangular shape, and a semicircle shape. Explanatory drawing explaining the conditions for designing the uneven | corrugated shape where a contact area relative value exceeds 1 Explanatory drawing explaining various aspects of uneven shape Explanatory drawing explaining another various aspect of uneven | corrugated shape Explanatory drawing explaining another various aspect of uneven | corrugated shape Schematic diagram of the test equipment that conducted the examples Table for explaining conditions and results of Examples and Comparative Examples

  Hereinafter, preferred embodiments of the flexible film conveying apparatus and the barrier film manufacturing method of the present invention will be described in detail.

  FIG. 1 is a schematic view in which a flexible film transport apparatus according to an embodiment of the present invention is incorporated in a film forming apparatus 10 used for manufacturing a barrier film.

  In the present embodiment, a so-called roll is formed by forming a barrier film on the long flexible film W fed from the feed roll 20 in the film forming chamber 14 and then winding the roll film again on the take-up roll 30. -An example of a roll-to-roll method will be described.

  As the flexible film W in this Embodiment, various resin films, such as PET film, or various metal sheets, such as an aluminum sheet, can be used, for example. Furthermore, an organic layer may be formed on the surface of the resin film.

  The film forming apparatus 10 is an apparatus for continuously forming a film on a long flexible film W. Basically, the film forming apparatus 10 has a delivery chamber 12 having a delivery roll 20 for delivering the flexible film W, and a flexibility. A film forming chamber (chamber) 14 for forming a barrier film on the film W, a winding chamber 16 having a winding roll 30 for winding the flexible film W on which the barrier film is formed, a vacuum exhaust unit 32, and a control Part 36. The operation of each element in the film forming apparatus 10 is controlled by the control unit 36.

  A partition wall 15 a is provided between the delivery chamber 12 and the film forming chamber 14, and a partition wall 15 b is provided between the film forming chamber 14 and the winding chamber 16. A slit-like opening 15c through which the flexible film W passes is formed in each partition wall 15a, 15b.

  The delivery chamber 12, the film formation chamber 14, and the winding chamber 16 are connected to the vacuum exhaust unit 32 via a pipe 34. The vacuum exhaust unit 32 is provided with a vacuum pump such as a dry pump and a turbo molecular pump. Then, the control unit 36 controls the vacuum exhaust unit 32 to control the inside of the delivery chamber 12, the film forming chamber 14, and the winding chamber 16 to a predetermined degree of vacuum.

  In addition, each of the delivery chamber 12, the film formation chamber 14, and the winding chamber 16 is provided with a pressure sensor (not shown) for measuring the internal pressure, and the measured value of the pressure sensor is sent to the control unit 36 to be vacuumed. The exhaust unit 32 is feedback-controlled. The ultimate vacuum in the delivery chamber 12, the film formation chamber 14, and the take-up chamber 16 is not particularly limited, and a sufficient degree of vacuum may be maintained depending on the film formation method to be performed.

  In the film forming chamber 14, a barrier film is continuously formed on the surface of the flexible film while the flexible film is conveyed. In the film forming chamber 14, two guide rollers 24 and 28, a drum 26, and a film forming unit 40 are mainly provided. The guide roller 24 and the guide roller 28 are arranged to face each other at a predetermined interval across the drum 26, and the flexible film W fed from the feed roller 29 is stretched over the guide roller 24, the drum 26, and the guide roller 28 in this order. It is.

  The drum 26 is provided below the space H between the guide roller 24 and the guide roller 28 and is electrically grounded (grounded). The drum 26 is formed in a cylindrical shape and is rotatably supported via a rotation shaft. The drum 26 has a predetermined film formation position with respect to the film forming unit 40 that forms a barrier film on the flexible film W by rotating the flexible film W around the surface (circumferential surface). Hold on. The drum 26 may be provided with a temperature adjusting unit (not shown) for adjusting the temperature.

  As the film forming unit 40, for example, a vapor deposition method that forms a film using plasma CVD can be suitably employed. The film forming unit 40 is mainly configured by a film forming electrode 42, a high frequency power supply 44, a source gas supply unit 46 and a partition unit 48, and the control unit 36 described above controls the high frequency power supply 44 and the source gas supply unit 46 of the film formation unit 40. Is controlled.

  The film forming electrode 42 is disposed with a predetermined gap S with respect to the drum 26 around which the flexible film W is wound, and is connected to the high frequency power supply 44. A high frequency voltage is applied to the film forming electrode 42 by the high frequency power source 44. As the high-frequency power source 44, a known high-frequency power source used for film formation by plasma CVD can be used. Further, the high-frequency power supply 44 is not particularly limited in the maximum output, and can be appropriately selected / set according to the barrier film to be formed.

  The film forming electrode 42 is formed in, for example, a rectangular flat plate shape in plan view, and a plurality of holes (not shown) are formed at equal intervals on a wide surface, and the wide surface is arranged facing the drum 26. The The film forming electrode 42 is generally called a shower electrode. The film formation electrode 42 is not limited to a flat plate shape, and may be any film that can be formed by plasma CVD, such as a configuration in which a plurality of electrodes divided in the axial direction of the drum 26 are arranged. Various electrode configurations are available. However, the film-forming electrode 42 is preferably a flat-plate shower electrode having a rectangular shape in plan view when viewed from the viewpoint of the electric field with respect to the flexible film W and the uniformity of plasma and the like. In addition, the film forming electrode 42 and the high frequency power supply 44 may be connected via a matching box for impedance matching, if necessary.

  The source gas supply unit 46 supplies source gas for forming a barrier film in the plasma generation space, that is, the gap S between the drum 26 and the film forming electrode 42, and the source gas supplied through the pipe 47 is supplied. Gas is blown into the gap S from the plurality of holes of the film forming electrode 42.

In the present embodiment, as the source gas, for example, when forming a SiO ₂ film, a TEOS gas and an oxygen gas can be suitably used as the active species gas.

  In the source gas supply unit 46, not only the source gas but also various gases used in plasma CVD, such as an inert gas such as argon gas or nitrogen gas, and an active species gas such as oxygen gas, are used as the source gas. You may supply to the clearance gap S with gas. Thus, when introducing multiple types of gas, each gas may be mixed and supplied by the same piping, or each gas may be supplied by a different piping. Furthermore, the types or introduction amounts of the source gas or other inert gas and active species gas can be selected / set as appropriate according to the type of film to be formed, the target film formation rate, or the like.

The partition part 48 (partition part) partitions the film forming electrode 42 in the film forming chamber 14.
The partition 48 includes, for example, a pair of partition plates 48a, and is disposed so that the film formation electrode 42 is sandwiched between the pair of partition plates 48a.

  Each partition plate 48 a is a plate-like member extending in the length direction of the drum 26, and an end portion on the drum 26 side is bent to the opposite side to the film forming electrode 42. The partition 48 partitions the gap S, that is, the plasma generation space in the film forming chamber 14.

  Next, the conveyance device 50 that conveys the flexible film W in the delivery chamber 12, the film formation chamber 14, and the winding chamber 16 that are under vacuum as described above will be described.

  The transport device 50 mainly includes a plurality of guides that form a transport path for the flexible film W passing through the film forming chamber 14 between the feed roll 20, the take-up roll 30, and the feed roll 20 and the take-up roll 30. It comprises rollers 60, 24, 28, 31. Of the plurality of guide rollers 60, 24, 28, 31, the stepped roller R is used for the guide rollers 28, 31 that come into contact with the barrier film surface after forming the barrier film on at least the flexible film W. It is done. The stepped roller R has holding portions 54 having a larger circular diameter than the central portion at both ends, and the flexible film W can be wound around the holding portions 54 and conveyed.

  The winding roll 30 is formed as a drive roller that conveys the flexible film W. The delivery roll 20 and the guide rollers 60, 24, 28, 31 may be driven to rotate by the conveyance of the flexible film W, or may be synchronized with the rotation of the take-up roll 30 with a driving force. Note that the transport device 50 may be provided with tension adjusting means (for example, a dancer roller) that adjusts the tension during transport of the flexible film W in the middle of the transport path.

  Next, the structure of the stepped roller R will be described.

  As shown in FIGS. 2 (A) and 2 (B), the stepped roller R has a holding part 54 having a larger diameter than the central part 52 at both ends, and the flexible film W is put on the holding part 54. Wrap and hold to transport. Reference numeral 56 denotes a rotating shaft.

  Then, as shown in FIG. 3, the surface of the holding portion 54 of the stepped roller R has the following depending on the elastic deformation force of the flexible film W from the delivery chamber 12 to the winding chamber 16 under vacuum. The concavo-convex shape 58 is formed so that the defined contact area relative value exceeds 1. FIG. 3 shows a case where an uneven shape 58 having a trapezoidal longitudinal cross-sectional shape is formed on the surface of the holding portion 54.

  <Definition of contact area relative value>

  When the surface of the holding portion 54 of the stepped roller R is a smooth flat surface, the area where the flexible film W and the surface of the holding portion 54 come into contact is X, and the surface of the holding portion 54 is the uneven surface. When the area where the flexible film W and the surface of the holding portion 54 are in contact with each other is defined as Y, the ratio of Y to X (Y / X) is defined as the relative value of the contact area.

  The uneven shape 58 formed on the surface of the holding portion 54 of the stepped roller R may be any shape as long as the relative value of the contact area exceeds 1, but for example, the uneven shape 58 so as to satisfy the following conditions. By forming the concavo-convex shape having a contact area relative value exceeding 1, it is possible to easily form.

  That is, when the elastic deformation force of the flexible film W is expressed in terms of Young's modulus, it is in the range of 180 to 280 MPa, and the concavo-convex shape 58 formed on the surface of the holding portion 54 satisfies the following formulas 1 to 3. .

  Formula 1 When the taper angle of the side surface of the convex portion 58A is θ, 0 ° <θ <90 °,

  Formula 2 ... When the depth of the concave portion 58B is H and the distance from the convex portion 58A to the convex portion 58A is A, A ≧ 2H,

  Formula 3: The ratio (H / D) of the depth H of the recess 58B to the thickness D of the flexible film W is 45% or less.

  4A to 4C show the taper angle θ in the case where the longitudinal section of the concavo-convex shape 58 is rectangular (A), the triangular shape (B), and the semicircular case (C). Depth (synonymous with the height of the convex part 58A) H and the distance A from the convex part 58A to the convex part 58A are shown. Moreover, if the Young's modulus of the flexible film W is set in a range of 180 to 280 MPa, the elastic deformation force of the flexible film used for manufacturing the barrier film can be substantially covered.

  FIGS. 5A to 5C schematically show the results of experimental confirmation of the ease of contact between the flexible film W and the surface of the holding portion 54 when the vertical shape of the concavo-convex shape 58 is rectangular. It is shown in.

  FIG. 5A shows a case where the taper angle θ of the concavo-convex shape 58 is 90 °, and the concavo-convex shape 58 has a rectangular shape having a vertical cross section. In this case, even if the flexible film W is elastically deformed and bent downward, it is difficult to enter the recess 58B, and a contact surface between the flexible film W and the inner wall surface of the recess 58B is not formed. As a result, even if the surface area of the holding portion 54 is changed to the concave-convex shape 58 and the surface area becomes larger than that of the flat surface, the concave portion 58B does not contribute to the increase of the contact area, so the contact area relative value becomes smaller than 1. The taper angle θ of 0 ° means that the surface of the holding portion 54 has no uneven shape 58 and is a flat surface.

  As shown in FIG. 5B, when the taper angle θ is smaller than 90 ° and the rectangular shape has a trapezoidal longitudinal section, the concave portion is formed when the flexible film W is elastically deformed and bent downward. It becomes easy to enter the 58B side. Thereby, the ratio which the flexible film W contacts the side wall surface (synonymous with a convex part side wall surface) of the recessed part 58B increases.

  However, even in the case of FIG. 5B, since the relationship between the depth H of the recess 58B and the distance A from the projection 58A to the projection 58A is approximately 1: 1, the flexible film W When the film is bent downward, the flexible film W does not sufficiently enter the recess 58B to reach the bottom surface 58b of the recess 58B.

  On the other hand, the concavo-convex shape 58 of FIG. 5C that satisfies the above-described expression 1 and satisfies A ≧ 2H of expression 2 is bent downward due to the elastic deformation of the flexible film W. As a result, the inside of the recess 58B can be easily bent, and the flexible film W comes into almost full contact with the inner wall surface (side wall surface and bottom surface) of the recess 58B. As a result, the contact area between the flexible film W and the surface of the holding part 54 is increased by the amount by which the surface of the holding part 54 is made uneven and the surface area is larger than that of the flat surface. Can be larger.

  Even if the concave-convex shape 58 on the surface of the holding portion 54 satisfies the formulas 1 and 2 for the flexible film W having a Young's modulus in the range of 180 to 280 MPa, the depth H of the concave portion 58B is If the depth is too deep, the flexible film W cannot reach the bottom surface 58b of the recess 58B, so that the flexible film W cannot be brought into substantially the entire contact with the inner wall surface of the recess 58B. From this, when the depth H of the appropriate recess 58B was experimentally investigated, if the ratio (H / D) of the depth H of the recess 58B to the thickness D of the flexible film W is 50% or less, It was found that the flexible film W can easily reach the bottom surface 58b of the recess 58B. In this case, when the Young's modulus of the flexible film W is 220 MPa or less and the elastic deformation force is large, even if the maximum value of the ratio (H / D) of Formula 3 is 50%, the relative value of the contact area is It can be over 1. In addition, when the Young's modulus of the flexible film W is 180 MPa or less and the elastic deformation force is further large, even if the maximum value of the ratio (H / D) of Formula 3 is 90%, the relative value of the contact area is It can be over 1.

  In a vacuum apparatus such as the film forming apparatus 10 incorporating the transport apparatus 50 of the present invention, the flexible film W is transported between the flexible film W and the surface of the holding portion 54 of the stepped roller R. Since the entrained air layer is not formed, air does not accumulate in the concave portion 58B even if the concave and convex shape 58 is formed on the surface of the holding portion 54. Thereby, the operation | movement which the flexible film W follows the recessed part 58B elastically deforms, and bends below is not disturbed. Therefore, according to the elastic deformation force of the flexible film W under vacuum, the specific uneven shape 58 that can be easily entered into the recess 58B of the uneven shape 58 by the flexible film W, that is, flexible If the concavo-convex shape 58 in which the relative value of the contact area between the conductive film W and the surface of the holding portion 54 exceeds 1 is formed on the surface of the holding portion 54 of the stepped roller R, the flexible film W and the surface of the holding portion 54 are substantially spaced. It is possible to make the entire surface contact.

  Thereby, when the long flexible film W is wound around and held on the holding part 54 of the stepped roller R in the vacuum apparatus, the holding force in the holding part 54 can be remarkably improved. it can. Therefore, the central portion of the flexible film W does not become loose and become wrinkled during conveyance, or it does not come into contact with the central portion 54A of the stepped roller R to be damaged.

  6 to 8 show various forms of the uneven shape formed on the surface of the holding portion of the stepped roller.

  6A to 6D show a case where the concave and convex shape 58 on the surface of the holding portion 54 is configured by alternately arranging linear convex portions 58A and linear concave portions 58B. The black line of FIG. 6 is the convex part 58A, and the white line is the concave part 58B. FIG. 6A shows a case where the lines of the convex portions 58A and the concave portions 58B are formed in parallel to the axis O direction of the stepped roller. FIG. 6B shows a case where the line is formed in a ring shape in the circumferential direction with respect to the axis O of the stepped roller. FIG. 6C shows a case where the line is formed to be inclined to the right with respect to the axis O of the stepped roller, and FIG. 6D is a case formed to be inclined to the left.

  FIGS. 7A to 7B show a case in which the concave and convex shape 58 on the surface of the holding portion 54 is formed in a lattice shape by intersecting linear convex portions 58A that run vertically and horizontally. FIG. 7A shows a case where the line-shaped convex portion 58A runs in the horizontal direction (axis O direction) and the vertical direction (direction perpendicular to the axis O). FIG. 7B shows a case where the line-shaped convex portion 58 </ b> A runs to the right and left with respect to the axis O.

  FIGS. 7C to 7D show the case where the convex portions 58A and the concave portions 58B are arranged in a checkered pattern. FIG. 7C shows a case where the checkered pattern is oriented in the direction of the axis O, and FIG. 7D shows a case where the checkered pattern is inclined with respect to the axis O.

8A to 8B show a case where the convex portions 58A and the concave portions 58B are irregularly arranged.
[Example 1]

  Using the test apparatus 70 shown in FIG. 9, the conveyance test of the flexible film W according to the embodiment of the present invention was performed. In the test apparatus 70, a delivery roll 74 and a take-up roll 76 are arranged at a distance in a vacuum chamber 72 having a transparent observation window (not shown) through which the inside can be seen, and between the feed roll 74 and the take-up roll 76. A stepped roller R is disposed at the center. Then, the flexible film W fed from the feed roll 74 is wound around and held by the holding portion 54 of the stepped roller R, and then wound around the take-up roll 76. The vacuum chamber 72 is connected to a vacuum device (not shown) through an exhaust pipe 78, and the vacuum degree of the vacuum chamber 72 is controlled by the vacuum device.

  When the condition of the concavo-convex shape 58 formed on the surface of the holding portion 54 of the stepped roller R was changed according to the Young's modulus (MPa) of the flexible film W using the test apparatus 70 described above, the relative contact area We tested how the values changed.

  As the stepped roller R, the concave and convex shape 58 on the surface of the holding portion 54 has a rectangular shape shown in FIG. 3, and the step depth (step between the holding portion 54 and the central portion 52) is 4 mm, and the step width (at both ends) The distance between the holding portions 54) was 450 mm. Moreover, the vacuum degree of the vacuum chamber 72 was 5 * 10 <-3> Pa, and the conveyance speed was 3 m / min.

  The conditions of the concavo-convex shape 58 formed on the surface of the holding portion 54 of the stepped roller R in Examples 1 to 8 and Comparative Examples 2 to 6 are as follows.

That is, the example satisfying all the conditions of the following formulas 1 to 3 was used as an example, and the case of not satisfying even one was set as a comparative example. Note that Comparative Example 1 serves as a reference for the relative value of the contact area, and is a case where the surface of the holding portion of the stepped roller R is flat.
<Conditions of Formulas 1 to 3>

  In the range where the Young's modulus of the flexible film is 180 to 280 MPa,

  Formula 1 ... 0 ° <θ <90 °, where θ is the taper angle of the side surface of the convex portion,

  When the depth of the concave portion is H and the distance from the convex portion to the convex portion is A, A ≧ 2H,

Formula 3 ... The ratio (H / D) of the depth H of the recess to the thickness D of the flexible film is 50% or less (provided that the Young's modulus of the flexible film is 180 MPa or less, (H / D) 90 %Less than).
[Uneven shape of Example and Comparative Example]
(1) When a flexible film A having a Young's modulus of 220 (MPa) is conveyed

  Comparative Example 1 The holding part surface is a flat surface (a stepped roller serving as a reference for the relative value of the contact area).

  Example 1 An uneven shape is formed on the surface of the holding portion, H / D is 40%, taper angle θ is 80 °, and A ≧ 2H is satisfied.

  Example 2 ... Same as Example 1 except that H / D was changed from 40% to 50%.

Comparative Example 2 ... Same as Example 1 except that H / D was changed from 40% to 70%.
(2) When a flexible film B having a Young's modulus of 280 (MPa) is conveyed

  Example 3 An uneven shape is formed on the surface of the holding portion, H / D is 35%, the taper angle θ is 60 °, and A ≧ 2H is satisfied.

  Example 4 ... Same as Example 3 except that H / D was changed from 35% to 45%.

  Comparative Example 3 ... Same as Example 3 except that H / D was changed from 35% to 60%.

  Example 8: The same as Example 3 except that the taper angle θ is changed from 60 ° to 45 °.

Comparative Example 6 ... Same as Example 8 except that the condition of A ≧ 2H is not satisfied.
(3) When a flexible film C having a Young's modulus of 180 (MPa) is conveyed

  Example 5: An uneven shape is formed on the surface of the holding portion, H / D is 80%, taper angle θ is 45 °, and A ≧ 2H is satisfied.

  Example 6 ... Same as Example 5 except that H / D was changed from 80% to 90%.

  Comparative Example 4 ... Same as Example 5 except that H / D was changed from 80% to 120%.

  Example 7 This example is the same as Example 5 except that the taper angle θ is changed from 45 ° to 80 °.

Comparative Example 5: Same as Example 5 except that the taper angle θ is changed from 45 ° to 90 °.
[Test results]

As an evaluation of the test results, the contact state between the flexible film and the holding portion surface of the stepped roller was examined. The evaluation method of the contact state is that a colorant is applied to the holding part surface of the stepped roller in advance, and the transfer area of the colorant transferred to the flexible film surface is a flat surface with a smooth holding part surface. When the contact area between the flexible film and the surface of the holding part (referred to as a flat surface contact area) when assumed was larger than the contact area relative value, it was determined that the contact area relative value exceeded 1. That is, as shown in FIG. 5C, when the flexible film enters the concave-convex concave portion on the surface of the holding portion and makes contact with the concave wall surfaces (side wall surface and bottom surface) substantially, The transfer area becomes larger than the flat surface contact area by the total area of the side wall surfaces of the recesses (the total of the side wall areas of the plurality of recesses).
In addition, as an evaluation of the holding force on the surface of the holding part, it is evaluated as ◎, ○, or X depending on the degree to which the flexible film being conveyed loosens in the center part of the stepped roller (the step between the holding part and the center part is 4 mm) did. ◎ indicates no slack and large holding power, ○ indicates slightly slack but no problem with holding power, and × indicates large slack and low holding power.

  The test results are shown in the table of FIG.

  As can be seen from the table of FIG. 10, Examples 1 to 8 satisfying all of the formulas 1 to 3 have a contact area relative value exceeding 1, and good results of 〜 to に お い て were obtained in the slack evaluation. On the other hand, in Comparative Example 1 where the contact area relative value was 1, the slack evaluation was x.

  From this result, when the flexible film is conveyed by a stepped roller under vacuum, it is necessary that the relative value of the contact area exceeds 1, so that the looseness of the flexible film can be effectively suppressed. . Therefore, even if a flexible film is conveyed by a stepped roller under vacuum, it can be stably conveyed without causing defects such as wrinkles in the flexible film.

  Examples 1-2 using a flexible film A having a Young's modulus of 220 MPa, Examples 3, 4, 8 using a flexible film B having a Young's modulus of 280 MPa, and flexibility having a Young's modulus of 180 MPa As can be seen from the comparison with Examples 5 to 6 using the conductive film C, if the Young's modulus of the flexible film decreases, the relative value of the contact area exceeds 1 even if the H / D ratio is increased. it can. That is, when the Young's modulus of the flexible film A is 220 MPa or less and the elastic deformation force is larger than the flexible film A, even if the maximum value of the ratio (H / D) of the formula 3 is 50%, The relative value of the contact area can exceed 1.

  Further, when the Young's modulus of the flexible film is 180 MPa or less and the elastic deformation force is even larger, the relative value of the contact area is 1 even if the maximum value of the ratio (H / D) in Equation 3 is 90%. Can be exceeded.

  DESCRIPTION OF SYMBOLS 10 ... Film-forming apparatus, 12 ... Delivery chamber, 14 ... Film-forming chamber, 16 ... Winding chamber, 20 ... Delivery roll, 24, 28, 31, 60 ... Guide roller, 26 ... Drum, 30 ... Winding roller, 32 DESCRIPTION OF SYMBOLS ... Vacuum exhaust part, 34 ... Pipe, 36 ... Control part, 40 ... Film-forming part, 42 ... Film-forming electrode, 44 ... High frequency power supply, 46 ... Raw material gas supply part, 47 ... Pipe, 48 ... Partition part, 48a ... Partition Plate, 50 ... Conveying device, 52 ... Center part of stepped roller, 54 ... Holding part of stepped roller, 56 ... Rotating shaft, 58 ... Uneven shape, 58A ... Convex part, 58B ... Concave part, 58b ... Bottom face of concavity, 70 ... Test apparatus, 72 ... Vacuum chamber, 74 ... Sending roll, 76 ... Winding roll, W ... Flexible film, R ... Stepped roller

Claims (8)

A transport device that transports a long flexible film in a device controlled to a predetermined degree of vacuum, and has a holding portion having a larger circular diameter than a central portion at both ends, and the holding portion has the above-mentioned In a conveying device provided with a stepped roller that wraps and holds a flexible film,
On the surface of the holding part of the stepped roller, a concavo-convex shape having a contact area relative value defined below corresponding to the elastic deformation force of the flexible film under vacuum exceeding 1 is formed. A flexible film conveyance device.
When the surface of the holding part is a smooth flat surface, the area where the flexible film and the surface of the holding part are in contact is X, and when the surface of the holding part is the uneven surface, When the area where the flexible film and the holding portion surface are in contact with each other is Y, the ratio of Y to X is the relative value of the contact area. When the elastic deformation force of the flexible film is expressed in terms of Young's modulus, it is in the range of 180 to 280 MPa, and the uneven shape formed on the surface of the holding portion satisfies the following formulas 1 to 3. The conveyance apparatus of the flexible film of Claim 1.
Formula 1 ... 0 ° <θ <90 °, where θ is the taper angle of the side surface of the convex portion,
When the depth of the concave portion is H and the distance from the convex portion to the convex portion is A, A ≧ 2H,
Formula 3: The ratio (H / D) of the depth H of the recess to the thickness D of the flexible film is 45% or less. When the elastic deformation force of the flexible film is expressed in terms of Young's modulus, it is in the range of 180 to 220 MPa, and the uneven shape formed on the surface of the holding portion satisfies the following formulas 1 to 3. The conveyance apparatus of the flexible film of Claim 1.
  Formula 1 ... 0 ° <θ <90 °, where θ is the taper angle of the side surface of the convex portion,
  When the depth of the concave portion is H and the distance from the convex portion to the convex portion is A, A ≧ 2H,
  Formula 3 ... The ratio (H / D) of the depth H of the recess to the thickness D of the flexible film is 50% or less. When the elastic deformation force of the flexible film is expressed by Young's modulus, it is 180 MPa, and the concavo-convex shape formed on the surface of the holding portion satisfies the following formulas 1 to 3. 2. A flexible film conveying apparatus according to 1.
  Formula 1 ... 0 ° <θ <90 °, where θ is the taper angle of the side surface of the convex portion,
  When the depth of the concave portion is H and the distance from the convex portion to the convex portion is A, A ≧ 2H,
  Formula 3 The ratio (H / D) of the depth H of the recess to the thickness D of the flexible film is 90% or less.   5. The flexible film transport device according to claim 1, wherein the concave-convex shape on the surface of the holding unit is configured such that line-shaped convex portions and line-shaped concave portions are alternately arranged. .   5. The flexible film transport device according to claim 1, wherein the concave-convex shape on the surface of the holding portion is such that convex portions and concave portions are formed in a lattice shape.   The convex-concave shape of the said holding | maintenance part surface has a convex part and a recessed part arranged irregularly, The conveying apparatus of the flexible film of any one of Claims 1-4 characterized by the above-mentioned. In the method for producing a barrier film, which forms a barrier film that suppresses the passage of water vapor or gas on the surface of the flexible film while conveying the flexible film in a vacuum film forming apparatus,
A method for producing a barrier film, comprising using the transport device according to claim 1 for transporting the flexible film.

Images