| 摘要 |
PROBLEM TO BE SOLVED: To obtain an aromatic polycarbodiimide improved in solubility, adhesive properties, low-temperature processability, and humidity resistance by polymerizing a specified diisocyanate monomer in the presence of a phosphorus- based catalyst. SOLUTION: A diisocyanate monomer of formula I is polymerized with at most 30 mol.% organic diisocyanate such as 4,4'-diphenylmethane diisocyanate or 2,6-tolylene diisocyanate at 40-150 deg.C, desirably, 50-140 deg.C in the presence of a phosphorus-based catalyst to obtain an aromatic polycarbodiimide comprising structural units represented by formula II (wherein (n) is 2-200) and having a number-average molecular weight of 900-90,000, desirably, 3,500-18,000. A polycarbodiimide solution obtained by dissolving the polycarbodiimide in an organic solvent is formed into a film by means of e.g. spin coating or roll coating, and the film is dried by heating to 20-350 deg.C, desirably, 50-250 deg.C to obtain a polycarbodiimide film having a thickness of 1-200μm.
|
