Abstract: A method for transporting particles such as polyolefin particles from a first container to a second container. The particles are transported from the first container to the second container through a transportation pipe by means of a pressure difference between the first container and the second container. A valve is provided in the transportation pipe near the second container, and the valve is closed and opened to transmit particles intermittently. Cleaning gas is fed into the transportation pipe at a position on the inlet side near the valve. The cleaning gas is gas consisting essentially of olefin monomer. The cleaning gas is fed into the transportation pipe while the valve of the transportation pipe is closed, and the particles remaining in the transportation pipe are sent back to the first container thereby to clean the transportation pipe. Therefore, the inside of the transportation pipe is kept clean all the time.

Abstract: A process for producing ethylene-propylene block copolymer which comprises(1) The first step of reacting propylene or a mixture of propylene and ethylene in the presence of a catalyst composed essentially of(A) a solid catalyst component containing magnesium, titanium and a halogen as the indispensable ingredients,(B) an organoaluminum compound, and(C) a silicon compound (1) represented by the formula R.sup.1 R.sup.2 Si(OR.sup.3).sub.2, wherein R.sup.1 is an alicyclic hydrocarbon group of 5-20 carbon atoms and R.sup.2 and R.sup.

Abstract: The present invention relates to a process for producing ethylene propylene block copolymers excellent in appearance, elongation and impact resistance when molded by a gas phase polymerization which can be conducted in a stable manner.The process of the present invention comprises the first step of polymerizing propylene by using a catalyst system composed essentially of(A) a solid catalyst component containing magnesium, titanium, and a halogen as the indispensable ingredients,(B) an organoaluminum compound, and(C) a silicon compound represented by the formula R.sup.1 R.sup.2 Si(OR.sup.3).sub.2, wherein R.sup.1 is an alicyclic hydrocarbon group and R.sup.2 and R.sup.3 are each a hydrocarbon group, to form a propylene homopolymer, and the second step of then polymerizing ethylene and propylene with further addition of a silicon compound represented by the formula R.sup.4 R.sup.5.sub.a Si(OR.sup.6).sub.3-a, wherein R.sup.4 is an aromatic hydrocarbon group, R.sup.

Abstract: A fluidized bed-type polymerization apparatus has an upper blowing equipment installed at a definite height in the fluidized bed area. Through the equipment, a part of the circulating gas and a part, or the whole, of the fresh feed material is blown, thereby to prevent the formation of lumps of polymer in the fluidized bed portion, owing to improved intermixing at the upper portion of the fluidized bed, as well as efficient heat-removal at that portion.

Abstract: For use in gas phase polymerization apparatus having an agitator in a fluidized bed polymerization reactor, the present invention provides a gas distributor which has holes, and caps covering the respective holes from above and each having an opening oriented in a substantially horizontal direction at an angle of about 90 to about 135 deg with, and outwardly of, a tangent to a circle centered about the center of the reactor whereby an increase in the gas solid ratio can be prevented in the region above the distributor to ensure efficient discharge of the polymer produced, and the polymer particles can be prevented from falling into a gas room thereunder.

Abstract: A fluidized bed-type polymerization apparatus has an upper blowing equipment installed at a definite height in the fluidized bed area. Through the equipment, a part of the circulating gas and a part, or the whole, of the fresh feed material is blown, thereby to prevent the formation of lumps of polymer in the fluidized bed portion, owing to improved intermixing at the upper portion of the fluidized bed, as well as efficient heat-removal at that portion.