PREPARATION OF POLYIMIDE SHEET MOLDING

摘要

PURPOSE:To prepare a concaved container having high heat resistance and excellent chemical resistance without using any adhesive by using a polyimide sheet having a specific second order transition temp. and rate of elongation. CONSTITUTION:This aromatic polyimide sheet has a second order transition temp. of 250-400 deg.C and a rate of elongation of larger than 120% at 100 deg.C. A sheet molding body 10 having a concave part 11 consisting or double curved surfaces is prepared by applying an outer force from the one side of the sheet 12 to deform the sheet while it is being elongated at a molding temp. which is higher than 100 deg.C and lower than the second order transition temp. plus 100 deg.C. In the state, this molding body is kept above the second order transition temp. for 5-30sec. It is finally cooled to about ordinary temp. to prepare an aromatic polyimide sheet molding body. This molding body has good appearance and its heat resistance, chemical resistance and mechanical properties are as excellent as those of the original polyimide sheet.