| 摘要 |
Linear polycarbonate resin virtually free of surface defects that impair the suitability of the resin for demanding optical application is disclosed. Also disclosed is a process for the manufacture of the resin. The surface defects included in the resin are in the form of transparent fluorescing particles, the particle count of which portion that are 15 and 250 mum in size, is up to 1.8 counts/g, said count being determined by exciting the residue remaining after filtering a solution of said polycarbonate in methylene chloride through a Teflon filter of 5 mum pore size at a wavelength of 400-440 nm, 25x overall magnification and illumination time of 40 millisec. The polycarbonate is suitable for making films of improved optical properties.
|
