| 摘要 |
1283335 Polycarbonate recovery MOBAY CHEMICAL CO 20 Jan 1970 [21 Jan 1969] 2723/70 Heading C3R A method of recovering a polycarbonate from a solution thereof in an inert first solvent comprises dispersing the solution into a spray of fine droplets by means of an atomizing fluid containing at least 80% of the vapour of at least one second solvent for the polycarbonate, removing the solvent from the droplets by introducing them into a countercurrent of heated inert gas, and separating the resulting solids from the heterogeneous stream thus produced to obtain the polycarbonate as a powder. The first and second solvents may be identical. In the examples, a polycarbonate prepared by phosgenation of 2,2-(4,41-dihydroxydiphenyl)propane is dissolved in methylene chloride or a mixture thereof with monochlorobenzene and is atomized with methylene chloride vapour. |
