Process for producing polymer film
The present invention provides a process for producing a polymer film at high productivity: during a process for drying gripped portions of both edges of a gel film, a first heat treatment is performed by blowing hot air in the film width direction and a second heat treatment is performed by blowing hot air at gripped portions of both edges of the gel film in a direction parallel to the film running direction.
1. A process for producing a polymer film, the process comprising:
preparing a solution comprising a polymer, a precursor of the polymer, or a curing agent and the precursor of the polymer;
flow-casting the solution on a support body to mold the solution into a film;
heating the film such that a gel film is formed;
peeling the gel film from the support body: and
applying a heat treatment to the gel film while gripping the gel film at both edge portions in a film width direction,
wherein the heat treatment comprises a first heat treatment from a first heat treatment section that uniformly blows hot air in the width direction of the gel film and a second heat treatment from a second heat treatment section that continuously blows hot air to gripped edge portions in a direction parallel to a running direction of the gel film,
wherein the second heat treatment section is arranged between the first heat treatment section and the gel film; and wherein the first heat treatment is performed at a higher temperature than the second heat treatment.
2. The process of claim 1 , wherein the first heat treatment is performed at a temperature T 1 , and the second heat treatment is performed at a temperature T 2 , and wherein T 1 -T 2 is from 0.1° C. to 30° C.
3. The process of claim 2 , wherein the first heat treatment is performed in the first heat treatment section positioned at a distance D 1 from the gel film, and the second heat treatment is performed in the second heat treatment section positioned at a distance D 2 from the gel film, and wherein a ratio of D 2 /D 1 is 0.30 or less.
4. The process of claim 3 , wherein the distance D 2 is from 3 mm to 100 mm.
5. The process of claim 2 , wherein the polymer film is a polyimide film.
6. The process of claim 2 , wherein the first and second heat treatments are performed simultaneously.
7. The process of claim 2 , wherein the first heat treatment is performed before the second heat treatment.
8. The process of claim 2 , wherein the temperature T 1 is from 200° C. to 600° C.
9. The process of claim 2 , wherein the temperature T 1 is from 250° C. to 500° C.
10. The process of claim 1 , wherein the first heat treatment is performed in the first heat treatment section positioned at a distance D 1 from the gel film, and the second heat treatment is performed in the second heat treatment section positioned at a distance D 2 from the gel film, and wherein a ratio of D 2 /D 1 is 0.30 or less.
11. The process of claim 10 , wherein the polymer film is a polyimide film.
12. The process of claim 10 , wherein the first and second heat treatments are performed simultaneously.
13. The process of claim 10 , wherein the first heat treatment is performed before the second heat treatment.
14. The process of claim 10 , wherein the distance D 2 is from 3 mm to 100 mm.
15. The process of claim 10 , wherein the distance D 2 is from 5 mm to 50 mm.
16. The process of claim 1 , wherein the polymer film is a polyimide film.
17. The process of claim 16 , wherein the first and second heat treatments are performed simultaneously.
18. The process of claim 16 , wherein the first heat treatment is performed before the second heat treatment.
19. The process of claim 1 , wherein the first and second heat treatments are performed simultaneously.
20. The process of claim 1 , wherein the first heat treatment is performed before the second heat treatment.