| 摘要 |
PURPOSE:To produce the subject product excellent in the surface slippage without impairing its physical properties or its visual appearance by dispersing tribasic calcium phosphate in film according to a specified method and forming fine projections on the film surface. CONSTITUTION:A suspension of tribasic calcium phosphate dispersed in water is initially dispersed in an organic polar solvent (preferably N,N- dimethylformamide, etc.) and the resultant dispersion is subsequently dehydrated preferably using zeolite as a dehydrating agent. An aromatic tetracarboxylic acid dianhdride (e.g. pyromellitic acid dianhydride) is then reacted with an aromatic diamine (e.g. 4,4'-diaminodiphenyl ether) in the organic polar solvent containing the dispersed tribasic calcium phosphate and the resultant polyamic acid solution containing tribasic calcium phosphate is subjected to film-forming imidation. The film-forming imidation is carried out generally by casting the polyamic acid solution on a glass plate, preliminarily drying it, then releasing it and subsequently carrying out desolvation at 150 to 250 deg.C and then imidating it at 300 to 450 deg.C. |
