Abstract: There is disclosed a process for producing an ?-olefin oligomer by subjecting an ?-olefin to oligomerization reaction in the presence of a catalyst and an organic solvent which comprises the step of spraying a solvent containing the organic solvent in the form of a linear or bar-like pressure fluid toward a wall surface of a vapor phase portion of a reactor from a nozzle fitted within a space of the vapor phase portion of the reactor to conduct the oligomerization reaction while cleaning the wall surface of the vapor phase portion of the reactor. In the production process of the present invention, it is possible to effectively prevent deposition of polymers onto the wall surface of the vapor phase portion of the reactor and stably operate the reactor for a long period of time.

Abstract: A process for producing an ?-olefin oligomer by oligomerization of an ?-olefin in a presence of a Ziegler-based catalyst, the process comprising introducing at least a portion of a reaction product which is taken out of a reactor and has a temperature of 115° C. or higher into an external heat exchanger, cooling the introduced reaction product, maintaining an oligomerization solution taken out of the external heat exchanger at a temperature of 110° C. or higher and returning at least a portion of the oligomerization solution to the reactor. In the production of an ?-olefin oligomer, precipitation and adhesion of polymers at the inside of manufacturing apparatuses such as the external heat exchanger and troubles caused thereby can be prevented and a stable continuous operation can be continued for a long time.

Abstract: There is disclosed a process for producing an ?-olefin oligomer by subjecting an ?-olefin to oligomerization reaction in the presence of a catalyst and an organic solvent which comprises the step of spraying a solvent containing the organic solvent in the form of a linear or bar-like pressure fluid toward a wall surface of a vapor phase portion of a reactor from a nozzle fitted within a space of the vapor phase portion of the reactor to conduct the oligomerization reaction while cleaning the wall surface of the vapor phase portion of the reactor. In the production process of the present invention, it is possible to effectively prevent deposition of polymers onto the wall surface of the vapor phase portion of the reactor and stably operate the reactor for a long period of time.

Abstract: A process for producing an &agr;-olefin oligomer by oligomerization of an &agr;-olefin in a presence of a Ziegler-based catalyst, the process comprising introducing at least a portion of a reaction product which is taken out of a reactor and has a temperature of 115° C. or higher into an external heat exchanger, cooling the introduced reaction product, maintaining an oligomerization solution taken out of the external heat exchanger at a temperature of 110° C. or higher and returning at least a portion of the oligomerization solution to the reactor. In the production of an &agr;-olefin oligomer, precipitation and adhesion of polymers at the inside of manufacturing apparatuses such as the external heat exchanger and troubles caused thereby can be prevented and a stable continuous operation can be continued for a long time.

Abstract: There is disclosed a process for producing an &agr;-olefin oligomer which comprises subjecting an &agr;-olefin to oligomerization reaction in an organic solvent in the presence of a Ziegler based catalyst, wherein the oligomerization reaction is carried out through multi-stage reaction steps, and the &agr;-olefin is supplied to each of the reaction steps. It is made possible by the above production process to produce highly pure &agr;-olefin oligomer free from an impurity.

Abstract: There is disclosed a process for producing an ethylenic oligomer which comprises subjecting ethylene to oligomerization reaction in an organic solvent in the presence of a Ziegler based catalyst, and recyclingly using for the oligomerization reaction, the organic solvent separated by distilling the resultant oligomerization reaction product, wherein the water concentration in the oligomerization reaction system is at most 8 ppm by weight, or the concentration of olefins which have at least 3 carbon atoms and which are contained in the organic solvent to be recycled in the oligomerization reaction system is at most 2% by weight. The process of the present invention can maintain the catalytic activity of the catalyst at a high level.

Abstract: There is disclosed a process for producing an ethylenic oligomer which comprises subjecting ethylene to oligomerization reaction in an organic solvent in the presence of a Ziegler based catalyst, and recyclingly using for the oligomerization reaction, the organic solvent separated by distillng the resultant oligomerization reaction product, wherein the water concentration in the oligomerization reaction system is at most 8 ppm by weight, or the concentration of olefins which have at least 3 carbon atoms and which are contained in the organic solvent to be recycled in the oligomerization reaction system is at most 2% by weight. The process of the present invention can maintain the catalytic activity of the catalyst at a high level.