JP-7856491-B2 - Film stretching apparatus and film manufacturing method

Inventors

• 増田 友昭

Assignees

• 株式会社カネカ

Dates

Publication Date

20260511

Application Date

20220603

Claims (7)

1. A pair of guide rollers are arranged spaced apart in the conveying direction of a film that is conveyed under tension in the conveying direction, and each extends in the width direction of the film, A first heating unit that heats the surface of the film between the pair of guide rollers by thermal radiation, The system comprises an inert box filled with inert gas that covers at least the first heating unit and the heating region in the film between the pair of guide rollers that is heated by the first heating unit , The first guide roller on the upstream side of the pair of guide rollers guides the film being conveyed from the opposite side of the first heating unit with respect to a first virtual plane that extends the main surface of the film between the pair of guide rollers, The second guide roller, the downstream of the pair of guide rollers, guides the conveyed film toward the opposite side of the first heating section relative to the first virtual plane. The pair of guide rollers each contact the back surface of the film, A third guide roller is positioned upstream of the first guide roller and extends in the width direction of the film, A fourth guide roller is positioned downstream of the second guide roller and extends in the width direction of the film, A second heating unit that heats the surface of the film between the third guide roller and the first guide roller by thermal radiation, The device further includes a third heating unit that heats the surface of the film between the second guide roller and the fourth guide roller by thermal radiation, The third guide roller guides the film being conveyed from the opposite side of the second guide roller with respect to a second virtual plane that extends the main surface of the film between the first guide roller and the third guide roller, The fourth guide roller guides the conveyed film on the opposite side from the second guide roller with respect to a third virtual plane extending the main surface of the film between the second guide roller and the fourth guide roller. A film stretching apparatus in which the third guide roller and the fourth guide roller each contact the surface of the film .
2. The film stretching apparatus according to claim 1, wherein the inert box further covers the second heating section, the third heating section, the heating region in the film between the third guide roller and the first guide roller that is heated by the second heating section, and the heating region in the film between the second guide roller and the fourth guide roller that is heated by the third heating section.
3. The film stretching apparatus according to claim 1, wherein the angle at which the film is gripped by the second guide roller is 90° ± 10°.
4. The distance between the film between the pair of guide rollers and the radiating surface of the first heating section is 20 to 100 mm. The film stretching apparatus according to claim 1, wherein, in a plan view from a direction perpendicular to the main surface of the film between the pair of guide rollers, the downstream end of the radiating surface of the first heating unit is located downstream of a first position 20 mm upstream from the rotation axis of the second guide roller.
5. The film stretching apparatus according to claim 1, wherein the film is stretched by tension applied in the transport direction within the heating region.
6. A method for manufacturing a film using a film stretching apparatus according to any one of claims 1 to 5.
7. The method for manufacturing a film according to claim 6 , wherein the glass transition temperature of the film is 200 to 350°C.

Description

This invention relates to a film stretching apparatus and a method for manufacturing a film. Patent documents 1 to 6 disclose a film stretching apparatus that stretches a film in the transport direction by applying tension in the transport direction of the film and heating the film with a heating element such as a hot air oven or infrared heater. Japanese Patent Publication No. 2017-177766Japanese Patent Publication No. 2012-254544Japanese Patent Publication No. 2009-233918Japanese Patent Publication No. 2011-162588Japanese Patent Publication No. 2019-177766Japanese Patent Publication No. 2014-083703 This is a schematic diagram showing an example of the general configuration of a film stretching apparatus according to one embodiment of the present invention.This is a perspective view showing an example of the schematic configuration of the film stretching apparatus described above.This is a schematic diagram showing the positional relationship between the heater and the guide roller in the film stretching apparatus described above.This is a schematic diagram showing yet another example of the schematic configuration of a film stretching apparatus according to one embodiment of the present invention. [Embodiment 1] (Outline configuration of a film stretching apparatus) Figure 1 is a schematic diagram showing an example of the schematic configuration of a film stretching apparatus 100 according to one embodiment of the present invention. Figure 2 is a perspective view showing an example of the schematic configuration of the film stretching apparatus 100. Figure 1 is a view taken from a direction perpendicular to a plane that is parallel to the length direction of the film F and perpendicular to the width direction of the film F. In Figures 1 and 2, the transport direction is the length direction of the film F. As shown in Figures 1 and 2, the film stretching device 100 comprises a first guide roller R1, a second guide roller R2, and a heater 4 (first heating unit). Note that the heater 4 is not shown in Figure 2. The film stretching device 100 further includes drive rollers (not shown) upstream of the first guide roller R1 and downstream of the second guide roller R2. The film stretching device 100 stretches the film F in the transport direction by the difference in peripheral speed of these spaced-apart drive rollers. Film F is, for example, a thermoplastic film. In this embodiment, film F may have a relatively high glass transition temperature (e.g., 200 to 350°C). Film F is, for example, a PI (polyimide) film. The first guide roller R1 and the second guide roller R2 are a pair of guide rollers R1 and R2 that are spaced apart (for example, by about 300 mm) in the direction of transport of the film F, which is being transported under tension in the transport direction, and each extends in the width direction of the film F. The tension applied to the film F is, for example, 100 to 400 N/m. The first guide roller R1 is the upstream guide roller of the pair. The second guide roller R2 is the downstream guide roller of the pair. The heater 4 heats the surface of the film F between the pair of guide rollers R1 and R2 (hereinafter referred to as the inter-roller film F12) by thermal radiation. The heater 4 heats the surface temperature of the film F to a temperature higher than the glass transition temperature (for example, approximately 255-275°C). This allows the film F to be stretched in the transport direction by tension. Hereinafter, the region of the transported film F where the surface temperature is heated to a temperature higher than the glass transition temperature by thermal radiation from the heater 4 (making it stretchable) will be referred to as the heated region H1. In a plan view from a direction perpendicular to the main surface of the inter-roller film F12 (hereinafter referred to as "the above plan view"), the end of the heated region H1 in the transport direction approximately coincides with the end of the radiating surface 4S of the heater 4 in the transport direction. The heater 4 may comprise at least one far-infrared heater. The radiating surface of each far-infrared heater is approximately rectangular in shape. The heater 4 may comprise multiple far-infrared heaters arranged side-by-side along the width direction of the film F. For example, five far-infrared heaters, each approximately 120 mm x 120 mm in size, may be installed with a spacing of approximately 5 mm in the width direction to uniformly heat the surface of the film F along its width direction. This configuration allows the radiating area of the heater 4 to be wider than the width of the film F, and the surface temperature of the film F heated by the heater 4 to be maintained uniformly across the width direction of the film F. Note that the configuration of the heater 4 is not limited to the above configuration. For example, the number of far-infrared heaters provided in the width direction may be selected to match the length of