| 摘要 |
PROBLEM TO BE SOLVED: To industrially prepare a polyamide imide film having high heat resistance and mechanical strengths, causing very little coloring and available singly as a film for a variety of base materials. SOLUTION: The film is formed continuously by continuously applying a solution of a polyamide imide having a logarithmic viscosity equal to or higher than a specified value, which is constituted of trimellitic type aromatic acid residues and cyclohexanedicarboxylic type alicyclic acid residues and drying the applied solution and winding the dried material. The resultant film has high heat resistance and mechanical strengths, good colorless transparency: it has a glass transition temperature of 150°C or higher, a logarithmic viscosity of 0.5 dl/g or higher, an average light transmittance of 80% or higher in the range of wavelengths from 400 to 500 nm and a color difference, (b) value, of below 1. COPYRIGHT: (C)2003,JPO |
