Method for manufacturing polyimide-based film and polyimide-based film manufactured thereby

Patent metadata

Field	Value
Publication number	US-11577449-B2
Application number	US-201816762376-A
Country	US
Kind code	B2
Filing date	Dec 4, 2018
Priority date	Dec 4, 2017
Publication date	Feb 14, 2023
Grant date	Feb 14, 2023

Abstract

The present invention relates to a method for manufacturing a polyimide-based film and a polyimide-based film manufactured thereby and, particularly, to a method for manufacturing a polyimide-based film and a polyimide-based film manufactured thereby, wherein the polyimide-based film is useful as a cover substrate for a flexible electronic device since flexure characteristics thereof, represented by yield elongation, are excellent.

First claim

The invention claimed is:

1. A method of manufacturing a polyimide-based film in a roll-to-roll manner comprising:
conducting first heat treatment (S1) on a polyimide-based film obtained as a gel state formed by being cast on a support while elongating the polyimide-based film at an elongation percentage of more than 100% and less than 135% in a machine direction (MID) and shrinking the polyimide-based film at a shrinkage percentage of more than 75% and less than 100% in a transverse direction (TD); and
conducting second heat treatment (S2) on the first heat-treated polyimide-based film while further elongating the polyimide-based film in the machine direction (MD) at a tension not less than 30 N/mm 2 and less than 160 N/mm 2 ,
wherein a maximum heating temperature during the first heat treatment is 250° C. to 330° C., and
the second heat treatment is performed for 200 seconds or longer at a temperature within −10° C. to +30° C. of the maximum heating temperature reached during the first heat treatment.

2. The method according to claim 1 , wherein, in step (S1), the elongation percentage in the machine direction is 105% to 130%.

3. The method according to claim 1 , wherein, in step (S1), the elongation percentage in the machine direction is 115% to 130%.

4. The method according to claim 1 , wherein, in step (S1), the shrinkage percentage in the traverse direction is 80% to 100%.

5. The method according to claim 4 , wherein, in step (S1), the shrinkage percentage in the transverse direction is 80% to 95%.

6. The method according to claim 1 , wherein, in step (S2), the time for second heat treatment is not less than 200 seconds and less than 1,500 seconds.

7. The method according to claim 1 , wherein, in step (S2), the tension is 30 N/mm 2 to 150 N/mm 2 .

Assignees

• Kolon Inc

Inventors

• Hong Ki Ii
• Jung Hak-Gee

Classifications

• Y02E10/549

  Organic PV cells · CPC title

• B29K2995/0053

  bi-axially · CPC title

• B29C71/02

  Thermal after-treatment {(B29C71/0063 and B29C71/0072 take precedence)} · CPC title

• C08G73/1042

  Copolyimides derived from at least two different tetracarboxylic compounds or two different diamino compounds · CPC title

• B29C55/005 Primary

  characterised by the choice of materials · CPC title