Patent ID: 7148312

Claim:
A method for the preparation of a high molecular weight polycarbonate resin, which comprises the steps of: a) preparing a crystalline polycarbonate in the form of particles having an average diameter of 80 to 3,000 μm and a variation for the average particle diameter distribution of less than 20%, which comprises the steps of dissolving an amorphous polycarbonate having a weight average molecular weight of 1,500 to 30,000 g/mol in a solvent; transferring the polycarbonate solution into a drying chamber and spraying the transferred solution using a nozzle in the drying chamber; and contacting the sprayed solution with a high temperature gas to evaporate the solvent; and b) conducting a solid state polymertizaon of the crystalline polycarbonate prepared in step a) to prepare a high molecular weight polycarbonate resin having a weight average molecular weight of 35,000 to 200,000 g/mol.