Abstract: An efficient dehalogenation can be carried out by a method which comprises treating an organic compound containing a compound of halogen, such as fluorine or chlorine, as an impurity and having non-conjugated carbon-carbon double bonds, for example, butene polymer produced with a boron trifluoride catalyst, with an inorganic solid treating agent containing aluminum atoms. When the dehalogenation is conducted in the presence of a basic substance such as ammonia or an amine, it can be continued over long while inhibiting the isomerization of the non-conjugated carbon-carbon double bonds.

Abstract: Boron trifluoride can be recovered in a reusable state by a method that is economical and does not cause environmental pollution, which method comprises the steps of bringing a fluid containing boron trifluoride or its complex into contact with metal fluoride so as to selectively adsorb and remove boron trifluoride in the complex and heating the resultant metal tetrafluoroborate at a temperature in the range of 100 to 600° C. to separate it into boron trifluoride and metal fluoride. By applying the method to a process for producing polybutene or olefin oligomer using boron trifluoride complex catalyst, the catalyst can be recovered with retaining its activity and reused effectively.

Abstract: It is possible to produce butene polymer at high yield, which polymer contains 80 mol % or more of polymer molecules having terminal vinylidene structure and being low in the content of residual organic fluorine by a process comprising Step (I) to polymerize in liquid phase by adding complex catalyst composed of boron trifluoride, ether and alcohol and/or water in specified ratios to C4 fractions and Step (II) to reduce the content of trimer and lighter components contained in the obtained polymer to 0.2% by weight or less by distillation.

Abstract: A boron trifluoride complex can be recovered without changing its molar coordination ratio, by applying a direct and/or alternating voltage to an electrically-nonconductive fluid in which at least a part of boron trifluoride complex is dispersed and/or dissolved, and separating the boron trifluoride complex by settling from the electrically-nonconductive fluid. By utilizing this method for the preparation of olefin oligomer using a boron trifluoride complex catalyst, it is possible to reuse the recovered catalyst as it stands for the reaction.

Abstract: A method for effectively separating and removing or recovering BF.sub.3 existing in a liquid hydrocarbon which is characterized in that an organic liquid mixture containing suspended or dissolved BF.sub.3 is brought into liquid phase contact with a synthetic polymer fiber containing nitrile groups at a temperature of 50.degree. C. or lower, so that the BF.sub.3 is adsorbed by the synthetic polymer fiber and it is then heated to 80.degree. C. or higher to recover the BF.sub.3.

Abstract: This invention provides a process for producing copper phthalocyanine pigments which comprises reacting either phthalic anhydride or its derivatives with urea and a copper-containing substance, or either phthalonitrile or its derivative with a copper-containing substance in a reaction solvent by heating characterized in that an alkylxylene ingredient having a branched C4 side-chain represented by the following formula (1) is used as the reaction solvent: ##STR1##