Patent ID: 11945912
Assignee: PI ADVANCED MATERIALS CO., LTD.
Field: Macromolecular chemistry, polymers (Chemistry)
Classification: CPC C | IPC C

Claim 7:
8. The method of claim 1, wherein the imidizing comprises first imidization and second imidization,
wherein the first imidization is performed at a variable temperature in a range from 60° C. or less to 200° C. and
the second imidization comprises first heat treatment at a variable temperature in a range from 200° C. to 450° C. and second heat treatment at a variable temperature in a range of 550° C. or less but exceeding 450° C., and
a processing condition (b) below is further satisfied in addition to the processing condition (a):

1.0 μm/° C.≤(C2*T)/1.25 μm/° C.  (b)

wherein C is a sum of a molar amount of the imidization accelerator that is added and a molar amount of the dehydration agent that is added relative to 1 mol of an amic acid group of the polyamic acid, T is a thickness of the polyimide film and is 30 μm or more to 75 μm or less, and K is an average value of a highest temperature and two temperatures closest thereto among temperatures formed in the second heat treatment.