Abstract: The invention relates to a method for removing solvent from polymer solution generated by solution polymerization and an apparatus for removing solvent from such polymer solution. The method for removing solvent from polymer solution in accordance with the invention is a method for removing solvent by putting polymer solution and steam in contact with each other to remove the solvent by steam stripping, including a step of feeding a part of the steam into tube 2 for transferring polymer solution to tank 1 for removing solvent, and a step of feeding the remaining part of the steam into the inside of the tank for removing solvent. Particularly, the amount of the steam to be fed into the tube is preferably at 10 to 90% by mass, when the whole amount of the steam is defined as 100% by mass. The polymer contained in the polymer solution includes various polymers such as butadiene rubbers styrene.butadiene rubber, and ethylene.?-olefin.non-conjugated diene copolymer rubber.

Abstract: A method for recovering a polymer efficiently from a polymer solution obtained by a solution polymerization is provided. By means of a method for recovering a polymer comprising heating a polymer solution obtained by a solution polymerization indirectly in a pipe to evaporate a solvent while forming a gas-liquid mixed phase flow or a gas-liquid-solid mixed phase flow followed by supplying the mixture to a recovery tank under pressure or under reduced pressure to separate the polymer from the solvent, the polymer can efficiently be separated from the solvent without changing the physical characteristics or the chemical characteristics of the polymer. When recovering a polymer from a polymer solution having a high viscosity, an infusion of water or steam serves to reduce the viscosity of the polymer solution and also to increase the linear velocity of a gas, whereby preventing the occlusion of a pipe and facilitating the operation.

Abstract: A method for recovering a polymer efficiently from a polymer solution obtained by a solution polymerization is provided. By means of a method for recovering a polymer comprising heating a polymer solution obtained by a solution polymerization indirectly in a pipe to evaporate a solvent while forming a gas-liquid mixed phase flow or a gas-liquid-solid mixed phase flow followed by supplying the mixture to a recovery tank under pressure or under reduced pressure to separate the polymer from the solvent, the polymer can efficiently be separated from the solvent without changing the physical characteristics or the chemical characteristics of the polymer. When recovering a polymer from a polymer solution having a high viscosity, an infusion of water or steam serves to reduce the viscosity of the polymer solution and also to increase the linear velocity of a gas, whereby preventing the occlusion of a pipe and facilitating the operation.

Abstract: A process for producing an olefin copolymer rubber by slurry-polymerizing ethylene, at least one .alpha.-olefin and at least one non-conjugated diene in a poor solvent for the copolymer in the presence of a catalyst consisting of an organometallic compound (the first component) and a transition metal compound (the second component), characterized by using, an organoaluminum compound as the first component of the catalyst, and using, as the second component, a modified vanadium compound obtained by contacting a vanadium compound with at least one compound selected from the group consisting of the compounds represented by the following formulas: ##STR1## wherein R is a hydrocarbon group of 1 to 20 carbon atoms and X.sub.1, X.sub.2 and X.sub.3 are independently halogen atoms or alkoxyl groups. This process can prevent a gel from being formed during polymerization.

Abstract: A process for producing an olefin copolymer rubber by slurry-polymerizing ethylene, at least one .alpha.-olefin and at least one non-conjugated diene in a poor solvent for the copolymer in the presence of a catalyst consisting of an organometallic compound (the first component) and a transition metal compound (the second component), characterized by using, an organoaluminum compound as the first component of the catalyst, and using, as the second component, a modified vanadium compound obtained by contacting a vanadium compound with at least one compound selected from the group consisting of the compounds represented by the following formulas: ##STR1## wherein R is a hydrocarbon group of 1 to 20 carbon atoms and X.sub.1, X.sub.2 and X.sub.3 are independently halogen atoms or alkoxyl groups. This process can prevent a gel from being formed during polymerization.

Abstract: A process for purifying a rubbery polymer by removing a catalyst residue from a rubbery polymer containing the catalyst residue obtained by polymerizing in slurry ethylene and an .alpha.-olefin or ethylene, an .alpha.-olefin and a non-conjugated diene in a poor solvent with a catalyst consisting of an organoaluminum compound and a transition metal compound, characterized in that the removal of the catalyst residue is conducted by water extraction consisting of(1) adding a good solvent and a surface active agent to the polymer slurry in the first step, and(2) adding water to the slurry obtained in above (1) in second step.This process enables the catalyst residue to be removed from EPDM in a very high efficiency.