Abstract: In a flash-drying process which comprises flashing a solvent solution of a polymer or copolymer maintained at an elevated temperature and pressure into a flashing zone maintained at a lower pressure than the pressure of the solvent solution through a means for releasing said elevated pressure, thereby evaporating and separating the solvent from the solvent solution, the improvement wherein an inert stripping agent is fed into a flow of the solvent solution at any point between said pressure-releasing means and said flashing zone.

Abstract: An improved process for preparing an impact-resistant chemically blended propylene polymer or copolymer, which comprises the following three steps:(1) a first step of polymerizing propylene containing 0 to 1 mole% of another olefin in the presence of a catalyst composed of (a) a carrier-supported titanium catalyst component containing at least magnesium, halogen and titanium on the surface of the carrier and (b) an organo aluminum compound to form specific crystalline polypropylene;(2) a second step of copolymerizing propylene and ethylene in the presence of the reaction product of the first step and the same catalyst while maintaining the content of propylene in the gaseous phase of the polymerization zone at 65 to 90 mole% thereby to form specific low-crystalline propylene/ethylene copolymer; and(3) a third step of polymerizing ethlene, or both ethylene and propylene in the presence of the reaction product of the second step and the same catalyst while maintaining the content of propylene in the gaseous pha