Patent ID: 6805967
Filing Date: 2004-10-19
Classification: C08K,C09D,H05K,Y10T

Abstract:
A flexible printed board comprising a polyimide insulating layer furnished on a metal foil, the polyimide insulating layer being formed by forming a film of a polyamic acid varnish composition on the metal foil, and subsequently imidizing the polyamic acid varnish composition;wherein: the polyamic acid varnish composition comprises a polyamic acid obtained by addition polymerization of an aromatic diamine and an aromatic acid dianhydride, a solvent, and an imidazolyl-diaminoazine; the imidazolyl-diaminoazine is present at a ratio of 0.1 to 10 wt parts per 100 wt parts polyamic acid; and the imidazolyl-diaminoazine is selected from the group consisting of: 2,4-diamino-6-(2-(2-ethyl-1-imidazolyl)ethyl)-s-triazine; 2,4-diamino-6-(2-(2-imidazolyl)ethyl)-s-triazine; 2,4-diamino-6-(2-(1-imidazolyl)ethyl)-s-triazine; 2,4-diamino-6-(2-ethyl-4-imidazolyl)-s-triazine; 2,4-diamino-6-(2-(4-methyl-1-imidazolyl)ethyl)-s-triazine; 2,4-diamino-6-(2-ethyl-5-methyl-4-imidazolyl)-s-triazine; 2,4 -diamino-6-(4-ethyl-2-methyl-1-imidazolyl)-s-triazine; 2,4-diamino-6-(3-(2-methyl-1-imidazolyl)propyl)-s-triazine; 2,4-diamino-6-(4-(2-imidazolyl)butyl)-s-triazine; 2,4-diamino-6-(2-(2-methyl-1-imidazolyl)propyl)-s-triazine; 2,4-diamino-6-(1-methyl-2-(2-methyl-1-imidazolyl)ethyl)-s-triazine; 2,4-diamino-6-(2-(2,5-dimethyl-1-imidazolyl)ethyl)-s-triazine; and 2,4-diamino-6-(2-(2,4-dimethyl-1-imidazolyl)ethyl)-s-triazine.