Film manufacturing method and manufacturing device

Abstract

To prevent wrinkles from occurring when stretching the raw fabric.SOLUTION: A method for producing a thermoplastic film (F) subjects raw fabric (S) to the following steps in order: bonding single-sided adhesive tapes (T1, T2) to both ends (14, 16) of the transported raw fabric (S); and heating and stretching the raw fabric (S) in the transport direction.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a method and apparatus for producing a film. [Background technology]

[0002] Patent Documents 1 to 4 disclose methods for producing a film that include a step of stretching a raw sheet. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-090650 [Patent Document 2] Japanese Patent Application Laid-Open No. 2007-070514 [Patent Document 3] Japanese Patent Application Publication No. 2019-211787 [Patent Document 4] Japanese Patent Application Laid-Open No. 2017-211580 Summary of the Invention [Problem to be solved by the invention]

[0004] When the raw film is stretched in the conveying direction, the raw film tends to shrink in the width direction, which causes the problem of wrinkling in the film. [Means for solving the problem]

[0005] In order to solve the above problems, a film manufacturing method according to one embodiment of the present disclosure is a method in which the raw material is subjected to the following steps in this order: (1) attaching single-sided adhesive tape to both ends of the raw material being transported; and (2) heating the raw material and stretching it in the transport direction.

[0006] In the film production method according to one embodiment of the present disclosure, the stretching method in the step (2) may be uniaxial stretching using a driving roll.

[0007] In the film manufacturing method according to one embodiment of the present disclosure, the width of the single-sided pressure-sensitive adhesive tape may be 6 mm or more and less than 30 mm.

[0008] In the film manufacturing method according to one embodiment of the present disclosure, the single-sided pressure-sensitive adhesive tape may have an elongation percentage of 65% or more.

[0009] In one embodiment of the film manufacturing method of the present disclosure, the single-sided adhesive tape may be a method in which an adhesive is provided on one side of a substrate, and the substrate includes at least one selected from the group consisting of polyimide, polyethylene terephthalate, polyethylene naphthalate, polypropylene, and polyester.

[0010] In the film manufacturing method according to one aspect of the present disclosure, the pressure-sensitive adhesive may include at least one selected from the group consisting of silicone and acrylic.

[0011] In the film manufacturing method according to one embodiment of the present disclosure, the glass transition temperature of the raw sheet may be 60 degrees Celsius or higher and 370 degrees Celsius or lower.

[0012] In the method for producing a film according to one embodiment of the present disclosure, the raw material may include at least one material selected from the group consisting of polyimide, polyethylene terephthalate, polyethylene naphthalate, polypropylene, and polyester.

[0013] The film manufacturing method according to one embodiment of the present disclosure may be a method in which the surface temperature of the raw web heated in step (2) is in a range from a temperature 30° C. lower than the glass transition temperature of the raw web to a temperature 20° C. higher than the softening temperature of the raw web. Preferably, the surface temperature is in a range from a temperature 20° C. lower than the glass transition temperature of the raw web to the softening temperature of the raw web.

[0014] In the film production method according to one embodiment of the present disclosure, the heating method in the step (2) may be a method using a far-infrared heater.

[0015] In the film manufacturing method according to one embodiment of the present disclosure, the heating method in the step (2) may further include using a reflector provided on the opposite side of the raw web from the far-infrared heater.

[0016] In the film manufacturing method according to one embodiment of the present disclosure, the lamination method in step (1) may be a method using a transport roll that transports the raw sheet and a nip roll that presses the single-sided adhesive tape onto the raw sheet on the transport roll.

[0017] In the film manufacturing method according to one embodiment of the present disclosure, in the step (1), the single-sided adhesive tape may be attached to one side of each of the end portions.

[0018] In the film manufacturing method according to one embodiment of the present disclosure, in the step (1), the single-sided adhesive tape may be attached to both sides of each of the end portions.

[0019] The film manufacturing method according to one embodiment of the present disclosure may be a method of manufacturing a long film by continuously performing the steps (1) and (2) above.

[0020] The film manufacturing method according to one embodiment of the present disclosure may be a method in which (3) the step of removing the single-sided adhesive tape is performed on the raw web after the step (2).

[0021] In the film manufacturing method according to one embodiment of the present disclosure, in the step (3), the single-sided adhesive tape may be removed by cutting off both end portions from the raw web using a blade.

[0022] In the method for producing a film according to one embodiment of the present disclosure, the film may be a transparent polyimide film having a total light transmittance per 50 μm thickness of 80% or more.

[0023] In the method for producing a film according to one aspect of the present disclosure, the film may be a thermoplastic film.

[0024] A film manufacturing apparatus according to one embodiment of the present disclosure is configured to include a pressure-welding unit that bonds single-sided adhesive tape to both ends of a raw sheet being transported, a heater that heats the raw sheet, and a stretching unit that stretches the raw sheet in the transport direction. [Effects of the Invention]

[0025] According to one aspect of the present disclosure, a method and apparatus for producing a film in which a raw sheet is stretched while reducing the occurrence of wrinkles can be realized. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is a schematic diagram illustrating an example of a schematic configuration of a film manufacturing apparatus according to an embodiment of the present disclosure. [Figure 2] 2 is a perspective view showing a part of the schematic configuration shown in FIG. 1 where a single-sided adhesive tape is bonded to an original roll. [Figure 3] 2 is a perspective view showing a part where both end portions are cut off from an original sheet in the schematic configuration shown in FIG. 1. FIG. [Figure 4] FIG. 2 is a cross-sectional view showing an example of the schematic configuration of the single-sided adhesive tape shown in FIG. 1. [Figure 5] FIG. 2 is a plan view showing the raw sheet S before stretching in a comparative example. [Figure 6] FIG. 2 is a plan view showing the raw sheet S after stretching in a comparative example. [Figure 7] FIG. 1 is a plan view showing a raw sheet after stretching in an embodiment of the present disclosure. [Figure 8] FIG. 10 is a schematic diagram illustrating an example of a schematic configuration of a film manufacturing apparatus according to another embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0027] [Embodiment 1] (Manufacturing method) Hereinafter, a method for producing a thermoplastic film F according to one embodiment of the present disclosure will be described with reference to FIGS.

[0028] Fig. 1 is a schematic diagram showing an example of the overall configuration of a film manufacturing apparatus 2 according to this embodiment. Fig. 1 is a view seen from a direction parallel to the length direction of the raw web S and perpendicular to a plane perpendicular to the width direction of the raw web S, with the upstream side of the transport of the raw web S shown on the left and the downstream side on the right. In Fig. 1, the transport direction is the length direction of the raw web S.

[0029] Fig. 2 is a perspective view showing a portion of the schematic configuration shown in Fig. 1 where first and second single-sided adhesive tapes T1, T2 are bonded to a raw web S. In Fig. 2, the upstream side of the transport of the raw web S is shown at the front side, and the downstream side is shown at the back side. Fig. 3 is a perspective view showing a portion of the schematic configuration shown in Fig. 1 where both end portions 14, 16 are cut off from the raw web S. In Fig. 3, the upstream side of the transport of the raw web S is shown at the back side, and the downstream side is shown at the front side.

[0030] First, the single-sided adhesive tapes T1 and T2 are transported to the transport roll R3 via the transport roll R1. At the same time, the raw web S is transported to the transport roll R3 via the transport roll R2. Then, the nip roll N1 presses the single-sided adhesive tapes T1 and T2 onto one side of each of the end portions 14 and 16 of the raw web S on the transport roll R3. As a result, the first single-sided adhesive tape T1 is bonded to one side of the first end portion 14 of the raw web S, and the second single-sided adhesive tape T2 is bonded to one side of the second end portion 16 of the raw web S. The first end portion 14 is the end portion on one side in the width direction of the raw web S, and the second end portion 16 is the end portion on the other side in the width direction of the first end portion 14 of the raw web S. The width direction of the raw web S intersects or is approximately perpendicular to the transport direction.

[0031] Next, the web S is transported to the drive roll R4 together with the single-sided adhesive tapes T1 and T2. The drive roll R4 rotates while gripping the web S together with the single-sided adhesive tapes T1 and T2 between itself and the nip roll N2, thereby driving the transport of the web S. The web S is then transported to another drive roll R5 together with the single-sided adhesive tapes T1 and T2. The drive roll R5 rotates while gripping the web S together with the single-sided adhesive tapes T1 and T2 between itself and the nip roll N3, thereby driving the transport of the web S. The transport speed of the downstream drive roll R5 is faster than the transport speed of the upstream drive roll R4. Due to this speed difference, tension is applied to the web S in the transport direction between the drive rolls R4 and R5. At the same time, the heater 4 heats the web S between the drive rolls R4 and R5. As a result, the drive rolls R4 and R5 uniaxially stretch the web S, with the stretching direction being the transport direction.

[0032] The heater 4 may be a far-infrared heater. The heater 4 heats the raw web S so that the surface temperature of the central portion 18 of the raw web S is in a range from near the glass transition temperature to near the softening temperature of the raw web S. The central portion 18 of the raw web S is located between the two end portions 14, 16 of the raw web S. Under heating, the surface temperature of the central portion 18 of the raw web S may be in a range from 30 degrees Celsius lower than the glass transition temperature of the raw web S to 20 degrees Celsius higher than the softening temperature of the raw web S. Preferably, the surface temperature under heating is in a range from 20 degrees Celsius lower than the glass transition temperature of the raw web S to the softening temperature of the raw web S. Furthermore, a reflector 6 may be provided on the opposite side of the heater 4 from the raw web S. The reflector 6 reflects the heat or heat rays emitted from the heater 4 toward the raw web S.

[0033] Here, the glass transition temperature (Tg) refers to the temperature at the inflection point when the dynamic viscoelasticity of raw fabric S is measured and the correlation between the storage modulus of raw fabric S and the measurement temperature is plotted. The dynamic viscoelasticity of raw fabric S is measured using a DMS-200 manufactured by Seiko Instruments Inc., with a measurement jig spacing of 20 mm and a frequency of 5 Hz. The temperature at which the storage modulus is 1 / 1000 of the storage modulus at the inflection point is defined as the softening temperature (Tm).

[0034] Next, the raw web S is transported to the transport roll R6 together with the single-sided adhesive tapes T1 and T2 while dissipating heat. Then, on the transport roll R6 or between the transport roll R6 and the next transport roll R7, the single-sided adhesive tapes T1 and T2 are removed from the raw web S to obtain a thermoplastic film F. For example, a blade 8 is provided on the transport roll R6 or between the transport roll R6 and the next transport roll R7, and the blade 8 is used to cut off both end portions 14 and 16 from the raw web S together with the single-sided adhesive tapes T1 and T2.

[0035] Next, the thermoplastic film F is further transported via transport roll R7. Meanwhile, the removed single-sided adhesive tapes T1, T2 and both end portions 14, 16 are collected in the collecting section 12. For example, the collecting section 12 may include a winding device that winds up the first end portion 14 together with the first single-sided adhesive tape T1, and a winding device that winds up the second end portion 16 together with the second single-sided adhesive tape T2.

[0036] By continuously carrying out the above process, a long thermoplastic film F can be produced.

[0037] (manufacturing equipment) 1 to 3, the film manufacturing apparatus 2 according to this embodiment is an apparatus for manufacturing a thermoplastic film F, and includes a conveying roll R3 and a nip roll N1 (pressing unit) that bond single-sided adhesive tapes T1, T2 to one side of both end portions 14, 16 of a raw web S being conveyed, a heater 4 that heats the raw web S, and drive rolls R4, R5 and nip rolls N2, N3 (stretching unit) that stretch the raw web S in the conveying direction. The film manufacturing apparatus 2 may further include a blade 8 (removing unit) that removes the single-sided adhesive tapes T1, T2, a support shaft 10 that rotatably supports a wound body of the single-sided adhesive tapes T1, T2, other conveying rolls R1, R2, R6, R7, and a recovery unit 12.

[0038] (single-sided adhesive tape and rolls) The single-sided adhesive tapes T1, T2 and the raw sheet S will be described below with reference to Fig. 4. Fig. 4 is a cross-sectional view showing an example of the schematic configuration of the single-sided adhesive tapes T1, T2 shown in Fig. 1.

[0039] The single-sided adhesive tapes T1 and T2 are selected so as to reinforce both end portions 14 and 16 of the raw roll S and to be stretchable together with the raw roll S. For this reason, the width W1 of each of the single-sided adhesive tapes T1 and T2 is preferably 6 mm or more and 30 mm or less when the width W2 of the raw roll S (see FIG. 5) is 300 mm. In other words, the ratio (W1 / W2) of the width W1 of the single-sided adhesive tapes T1 and T2 to the width W2 of the raw roll S is preferably 2% or more and 10% or less. Furthermore, the cross-sectional area W1*D1 is 0.036 mm 2 Over 4.00mm 2 Preferably, the tensile strength per cross-sectional area is 300 MPa or more in both the length direction and width direction. The elongation and tensile strength are the elongation and applied tension when stretched to the breaking limit, and should be measured in accordance with JIS standard K7127:1999.

[0040] The single-sided adhesive tapes T1 and T2 each have a substrate B1 or B2 with an adhesive A1 or A2 provided on one side thereof. The substrate B1 or B2 may, for example, contain at least one material selected from the group including polyimide, polyethylene terephthalate, polyethylene naphthalate, polypropylene, and polyester. The adhesive A1 or A2 may, for example, contain at least one material selected from the group including a heat-resistant silicone adhesive and an acrylic adhesive. The single-sided adhesive tapes T1 and T2 are preferably the same as each other, but may also be different from each other.

[0041] The glass transition temperature of the raw web S may be, for example, 60°C or higher and 370°C or lower. The raw web S may contain, for example, at least one selected from the group consisting of polyimide, polyethylene terephthalate, polyethylene naphthalate, polypropylene, and polyester. It is preferable that the raw web S contains polyimide so that the thermoplastic film F is a transparent polyimide film having a total light transmittance of 80% or higher per 50 μm thickness. Here, the total light transmittance should be measured in accordance with JIS standard K7361-1:1997.

[0042] By attaching the single-sided adhesive tapes T1, T2 to one side of both end portions 14, 16 of the raw web S, the rigidity of both end portions 14, 16 is improved. Therefore, by applying a large tension to the raw web S to stretch the raw web S, it is possible to reduce the shrinkage of the raw web S in the width direction due to stretching. In addition, breakage of the raw web S in the conveyance direction is prevented. [Example]

[0043] Comparative examples and examples of the present disclosure will be described below with reference to FIGS.

[0044] Comparative Example 1 Fig. 5 is a plan view showing the raw sheet S before stretching in Comparative Example 1. Fig. 6 is a plan view showing the raw sheet S after stretching in Comparative Example 1.

[0045] In Comparative Example 1, the single-sided adhesive tapes T1 and T2 were made of Kapton (registered trademark) adhesive tape. The substrates B1 and B2 of the single-sided adhesive tapes T1 and T2 were colored, transparent polyimide films with a width W1 of 5 mm, a thickness D1 of 0.05 mm, and a tensile strength per width in the longitudinal direction of 4904 N / m. The adhesives A1 and A2 of the single-sided adhesive tapes T1 and T2 were heat-resistant silicone adhesives. The raw sheet S was a colorless, transparent polyimide film with a width W2 of 300 mm, a thickness of 50 μm, a tensile strength per width in the longitudinal direction of 17000 N / m, and a glass transition temperature of 300°C. The width W2 of the raw sheet S at this time was designated the "width W2b before stretching."

[0046] As shown in Figure 5, single-sided adhesive tapes T1 and T2 were attached to both end portions 14 and 16 of the raw sheet S, and marks M1 and M2 were attached to the center portion 18 of the raw sheet S at intervals in the longitudinal direction of the raw sheet S. Then, the distance D2 between the marks M1 and M2 was measured. The distance D2 measured at this time was defined as the "length D2b before stretching."

[0047] Next, the raw web S was sandwiched between the drive roll R4 and nip roll N2, and between the drive roll R5 and nip roll N3. The distance from the raw web S to the heater 4 was 40 mm, and the distance from the raw web S to the reflector 6 was 20 mm. The raw web S was heated by the heater 4 and the reflector 6, and the raw web S was uniaxially stretched by the drive rolls R4 and R5 and the nip rolls N2 and N3. The conveying speed of the raw web S was 0.4 m / min, and the tension applied to the raw web S in the conveying direction was 188 N / m. The heater 4 was a far-infrared heater, and the surface temperature of the central portion 18 of the raw web S reached a temperature range of 300°C to 350°C.

[0048] The stretching of the raw fabric S was completed without breaking the raw fabric S. After the stretching was completed, the raw fabric S was removed from between the drive roll R4 and the nip roll N2 and from between the drive roll R5 and the nip roll N3.

[0049] Next, as shown in Figure 6, the width W2 of the raw web S was measured at the position where the width W2 was smallest, and the measured width W2 was designated the "width W2a after stretching." The distance D2 between the marks M1 and M2 was also measured, and the measured distance D2 was designated the "length D2a after stretching." The stretch ratio (%) in the machine direction of the raw web S and the shrinkage ratio (%) in the width direction of the raw web S were calculated as follows:

[0050] Stretching ratio in the machine direction = (D2a - D2b) / D2b * 100% Width shrinkage rate = (W2b-W2a) / W2b*100% "*" is an operator symbol indicating multiplication.

[0051] The single-sided adhesive tapes T1 and T2 had come off from both end portions 14 and 16 of the stretched portion of the raw sheet S. The stretched portion of the raw sheet S had wrinkles C1 at both end portions 14 and 16 and at the center portion 18. The wrinkles C1 generally extended obliquely relative to the stretching direction and the width direction.

[0052] Comparative Example 2 Comparative Example 2 was carried out in the same manner as Comparative Example 1, except that the width W1 of the single-sided adhesive tapes T1 and T2 was 30 mm. As a result, the raw sheet S was not stretched.

[0053] Example 1 Example 1 was carried out in the same manner as Comparative Example 1, except that the width W1 of the single-sided adhesive tapes T1 and T2 was 20 mm.

[0054] Fig. 7 is a plan view showing the raw sheet S after stretching in Example 1. As shown in Fig. 7, the single-sided adhesive tapes T1 and T2 remained attached to both end portions 14 and 16 of the stretched portion of the raw sheet S. In the stretched portion of the raw sheet S, wrinkles C2 were present only at both end portions 14 and 16, while no wrinkles were present in the central portion 18. The wrinkles C2 extended generally parallel to the stretching direction.

[0055] Example 2 Example 2 was carried out in the same manner as Comparative Example 1, except that the width W1 of the single-sided adhesive tapes T1, T2 was 15 mm. As a result, similar to Example 1, the single-sided adhesive tapes T1, T2 remained attached to both end portions 14, 16 of the stretched portion of the raw roll S, and wrinkles C2 were present only at both end portions 14, 16.

[0056] Example 3 Example 3 was carried out in the same manner as Comparative Example 1, except that the width W1 of the single-sided adhesive tapes T1, T2 was 10 mm. As a result, similar to Example 1, the single-sided adhesive tapes T1, T2 remained attached to both end portions 14, 16 of the stretched portion of the raw roll S, and wrinkles C2 were present only at both end portions 14, 16.

[0057] The stretch ratios in the machine direction of the raw sheet S and the shrinkage ratios in the width direction of the raw sheet S calculated in the above-mentioned Comparative Examples 1 and 2 and Examples 1 to 3 are shown in Table 1 below.

[0058] [Table 1] As shown in Table 1, in the range of widths of the single-sided pressure-sensitive adhesive tapes T1 and T2 greater than 5 mm and less than 30 mm, the stretching rate in the conveying direction of the raw sheet S was greater than 0%, and the shrinkage rate in the width direction of the raw sheet S was 5% or less. Furthermore, in this range, there were no wrinkles in the central portion 18 of the stretched portion of the raw sheet S.

[0059] [Embodiment 2] Other embodiments of the present disclosure will be described below. For ease of explanation, the same reference numerals will be used to designate components having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0060] Fig. 8 is a schematic diagram showing an example of the overall configuration of a film manufacturing apparatus 2 according to this embodiment. Fig. 8 is a view seen from a direction parallel to the length direction of the raw web S and perpendicular to a plane perpendicular to the width direction of the raw web S, with the upstream side of the transport of the raw web S shown on the left and the downstream side on the right. In Fig. 8, the transport direction is the length direction of the raw web S.

[0061] 8, the method for producing a thermoplastic film F according to this embodiment is the same as the method for producing a thermoplastic film F according to the above-described first embodiment, except that single-sided adhesive tapes T1 to T4 are bonded to both surfaces of each of the end portions 14, 16 of a raw web S. First, a nip roll N3 presses single-sided adhesive tapes T3, T4 onto one surface of each of the end portions 14, 16 of the raw web S on a transport roll R8. Next, another nip roll N1 presses single-sided adhesive tapes T1, T2 onto one surface of each of the end portions 14, 16 of the raw web S on a transport roll R3. The one surface of each end portion 14, 16 onto which the nip roll N3 presses the single-sided adhesive tapes T3, T4 is opposite the one surface of each end portion 14, 16 onto which the other nip roll N1 presses the single-sided adhesive tapes T1, T2. As a result, the first and third single-sided adhesive tapes T1, T3 are bonded to both sides of the first end 14 of the raw roll S, and the second and fourth adhesive tapes T2, T4 are bonded to both sides of the second end 16 of the raw roll S.

[0062] By laminating the single-sided adhesive tapes T1 to T4 on both sides of the end portions 14, 16, the rigidity of the end portions 14, 16 is further improved, and therefore shrinkage of the raw sheet S in the width direction due to stretching can be further reduced.

[0063] In addition to the components of the film manufacturing apparatus 2 according to the first embodiment, the film manufacturing apparatus 2 according to the present embodiment further includes a conveying roll R8 and a nip roll N4 (pressure contact portion) that bond the single-sided adhesive tapes T3, T4 to one side of the raw web S opposite both end portions 14, 16. The film manufacturing apparatus 2 may further include a support shaft 20 that rotatably supports the wound body of the single-sided adhesive tapes T3, T4.

[0064] The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present disclosure. [Explanation of symbols]

[0065] 2 Manufacturing equipment 4 heater 6 Reflector 8 blades 14,16 End A1, A2 adhesive B1,B2 Base material F Thermoplastic film (film) N1, N2, N3, N4 nip rolls R1, R2, R3, R6, R7 transport rolls R4, R5 drive roll S Original fabric T1, T2, T3, T4 single-sided adhesive tape W1, W2 width

Claims

1. A method for producing a film, comprising: (1) a step of attaching a single-sided adhesive tape to each of both end portions of a raw web being conveyed; (2) a step of heating the raw web and stretching it together with the single-sided adhesive tape in the transport direction, in this order.

2. 2. The method for producing a film according to claim 1, wherein the stretching method in the step (2) is uniaxial stretching using a driving roll.

3. 3. The method for producing a film according to claim 1, wherein the width of the single-sided adhesive tape is 6 mm or more and less than 30 mm.

4. 4. The method for producing a film according to claim 1, wherein the single-sided adhesive tape has an elongation percentage of 65% or more.

5. The single-sided adhesive tape has an adhesive provided on one side of a substrate, 5. The method for producing a film according to claim 1, wherein the substrate comprises at least one selected from the group consisting of polyimide, polyethylene terephthalate, polyethylene naphthalate, polypropylene, and polyester.

6. 6. The method for producing a film according to claim 5, wherein the adhesive contains at least one selected from the group consisting of silicone and acrylic.

7. 7. The method for producing a film according to claim 1, wherein the glass transition temperature of the raw sheet is 60 degrees Celsius or higher and 370 degrees Celsius or lower.

8. The method for producing a film according to any one of claims 1 to 7, wherein the raw material comprises at least one selected from the group consisting of polyimide, polyethylene terephthalate, polyethylene naphthalate, polypropylene, and polyester.

9. 9. The method for producing a film according to claim 1, wherein the surface temperature of the raw web heated in step (2) is in a range from a temperature 30° C. lower than the glass transition temperature of the raw web to a temperature 20° C. higher than the softening temperature of the raw web.

10. 10. The method for producing a film according to claim 1, wherein the surface temperature of the raw web heated in step (2) is in a range from a temperature 20 degrees Celsius lower than the glass transition temperature of the raw web to a softening temperature of the raw web.

11. The method for producing a film according to any one of claims 1 to 10, wherein the heating method in the step (2) uses a far-infrared heater.

12. The method for producing a film according to claim 11, wherein the heating method in the step (2) further comprises using a reflector provided on the opposite side of the raw web from the far-infrared heater.

13. The method for producing a film according to any one of claims 1 to 12, characterized in that the lamination method in the step (1) uses a transport roll that transports the raw roll and a nip roll that presses the single-sided adhesive tape onto the raw roll on the transport roll.

14. 14. The method for producing a film according to claim 1, wherein in the step (1), the single-sided adhesive tape is attached to one side of each of the two end portions.

15. 14. The method for producing a film according to claim 1, wherein in the step (1), the single-sided adhesive tape is attached to both sides of each of the end portions.

16. The method for producing a film according to any one of claims 1 to 15, wherein steps (1) and (2) are carried out continuously to produce a long film.

17. (3) The method for producing a film according to any one of claims 1 to 16, characterized in that a step of removing the single-sided adhesive tape is performed on the raw web after the step (2).

18. 18. The method for producing a film according to claim 17, wherein in the step (3), the single-sided adhesive tape is removed by cutting off both end portions from the raw web using a blade.

19. 19. The method for producing a film according to claim 1, wherein the film is a transparent polyimide film having a total light transmittance of 80% or more per 50 μm thickness.

20. The method for producing a film according to any one of claims 1 to 19, wherein the film is a thermoplastic film.

21. A film manufacturing apparatus comprising: a pressure-welding section that bonds single-sided adhesive tape to both ends of the raw web being conveyed; a heater for heating the raw sheet; a stretching unit that stretches the raw web together with the single-sided adhesive tape in a transport direction.

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