| 摘要 |
<p>PURPOSE:The titled composition that is obtained by adding particles of specific polyimide as a filler to a specific polyamidic acid solution modified with diaminosiloxane, thus showing excellent thixotropic properties and forming pinhole-free coating films of high heat resistance on the metal wire. CONSTITUTION:(A) A precursor of siloxane-modified polyimide obtained by reaction between (i) a diaminosiloxane of formula I (R1 is divalent organic group; R' is monovalent organic group; n is 1-1,000) in such an amount as it occupies 1-4mol% in the total diamine components and the silicon content becomes less than 0.5wt%, (ii) a silicon-free diamine of the formula: H2N-R2-NH2 (R2 is free from silicon atoms) and (iii) a tetracarboxylic dianhydride or formula II (Ar is tetravalent organic group) is combined with (B) a slurry of spherical porous particles of nonfusing and nonsoluble polyimide whose particle sizes are less than 40mu at maximum and less than 10mu on the average as a filler to give the objective composition.</p> |
