| 摘要 |
PURPOSE:To obtain the titled board having excellent heat-resistance, cold- resistance, electrical characteristics, abrasion resistance, etc., and free from curl, by casting a specific polyamic acid solution on a metal foil and curing the solution using a specific heating method. CONSTITUTION:An acid component consisting of (A) 50-80mol% 3,3',4,4'- biphenyltetracarboxylic acid dianhydride, (B) 50-20mol% pyromellitic acid dianhydride and a diamine component consisting of (C) 50-80mol% p- phenylenediamine and (D) 50-20mol% 4,4'-diaminodiphenyl ether are prepared beforehand in a manner to give a molar ratio of the acid component to the diamine component of 0.9-1 and a ladder ratio of 56-62%. A reaction product of the component A and the component C is mixed with a reaction product of the component B and the component D and the mixture is made to react at 0-100 deg.C for 0.5-30hr to obtain a polyamic acid. The acid is cast on a metal foil and heated from 100 deg.C-300 deg.C spending >=0.5hr. The foil is wrapped around a cylinder having a diameter of 50-100mm facing the metal foil inward and heated from 300 deg.C-350 deg.C spending >=0.5hr. |
