| 摘要 |
PURPOSE:To reduce the curling of the heat-resistant polymer film remaining by removing a metal foil by lowering the amount of the residual solvent present in the heat-resistant polymer film. CONSTITUTION:The heat-resistant polymer film layer of a flexible metal foil laminated sheet is composed of a heat-resistant polymer containing an imide bond and/or having a heterocyclic ring other than the imide bond. This heat- resistant polymer is applied to a metal foil in a state dissolved in a solvent or in such a state that the precursor of the heat-resistant polymer is dissolved in a solvent and the coating layer is dried under heating using hot nitrogen, far infrared rays or high frequency waves to perform the removal of the solvent and/or dehydration. At this time, it is necessary to control the residual amount of the solvent to at least 0.02% or less and, by gradually raising temp. from room temp. at the time of heating, the solvent is prevented from remaining in the vicinity of the metal foil of the heat-resistant polymer. |
