PURPOSE: To prepare a polyimide film by a casting method without tearing and injuring the same during release, by casting a polymer solution containing polyamic acid or polyimide to the surface of a metal substrate, which is preliminarily coated with a solvent and heat-treated at 60W250°C, in a film form.
CONSTITUTION: A solvent such as water or methanol is preliminarily applied to a metal plate such as a stainless steel plate and the coated metal plate is heat- treated at 60W250°C, pref., 80W200°C. Subsequently, an aromatic polyamic acid solution composition is filtered and defoamed to be cast onto the metal plate in a uniform thickness and heated to about 60W170°C by hot air or infrared rays to remove the solvent and pre-dried to form a self-supporting film which is, in turn, released from the metal plate. The wt. reduction of the self-supporting film under heating at this time is pref. about 5W40wt%.
INOUE HIROSHI
HIRANO TETSUHARU
| JPS57109613A | 1982-07-08 |
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