PURPOSE: To make it possible to prevent nonuniformity of mixing and to obtain an excellent filling effect, by defining a mean particle diameter and a particle size distribution of a polyimide powder in a specified range and adjusting a logarithmic viscosity in a specified range by reducing the MW of the polyimide powder.
CONSTITUTION: This polyimide powder has a mean particle diameter of 1-20μm, a particle size distribution of 0.1-50μm and a logarithmic viscosity of 0.1-0.5 (at 30°C, 0.5g/100ml conc. sulfuric acid). This polyimide powder is obtd. by reacting an arom. tetracarboxylic acid dianhydride and an arom. diamine in an org. polar solvent to prepare a polyamic acid and then imidating it. In this instance, it is especially important to adjust the logarithmic viscosity of the polyamic acid obtd. before imidation to 0.1-1.2 (at 30°C, 0.5g/100ml dimethyl- acetamide) and it is thereby possible to adjust the logarithmic viscosity of the obtd. polyimide powder to said value.
MIZOBE KEIZO
INOUE TEI
HONDO MAMORU
| JPS61241326A | 1986-10-27 | |||
| JPS5887129A | 1983-05-24 | |||
| JPS57200452A | 1982-12-08 | |||
| JPS57200453A | 1982-12-08 | |||
| JPS6051722A | 1985-03-23 | |||
| JP39030060A |
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