PURPOSE: To provide a double-layer MCF that remains warp-free even after processed with a metal foil, by forming a warp-free and twist-free polyimide layer, by heat treatment and curing at temperatures lower than a drying temperature for many hours, after applying and drying an organic solvent solution of a polyimide.
CONSTITUTION: A product which has gone through a drying process is taken up in the form of a roll before introduced into a curing process, and then is introduced into a long heat treatment process at low temperature as it is. This additional process helps reduce the distribution of a residual solvent in a film, and prevents a polyimide layer 2, 4, 5 from being distorted after curing or baking. An ideal heat treatment condition is a temperature 60 to 90°C lower than the drying temperature. The duration of treatment is several hours to 24 hours. Many hours are needed to move the residual solvent content near the boundary face of a metal foil 1 in the film.
| JPH11227080 | HEAT INSULATION COVER |
| JPS5674444 | COLLAPSIBLE DISTRIBUTING VESSEL |
| JP2003100266 | PACKAGING MATERIAL FOR BATTERY |
IMAIZUMI JUNICHI
SUZUKI MASAKATSU
OCHI TAKAHITO
SHIOGAI SUSUMU
