| 摘要 |
PURPOSE:To obtain an ester with a slight catalytic residue, by hydrolyzing a tetraalkyl titanate as an esterification catalyst before neutralizing the reaction system, separating the hydrolyzed catalyst from the reaction system, and recovering the hydrolyzed catalyst in a reusable state having the retained activity. CONSTITUTION:A carboxylic acid (anhydride) is reacted with an alcohol in the presence of a tetraalkyl titanate having 1-14C alkyl groups, preferably tetrapropyl or tetrabutyl titanate, or a polymer thereof, and 6wt% or less, preferably 0.5wt% or above, water is added to the reaction system containing the ester after the reaction. The reaction system is then heated at 60-98 deg.C for 30min or longer to hydrolyze the catalyst. The resultant hydrolytic product is then mechanically separated and recovered from the reaction system (e.g. centrifugation or filtration, etc.), and an alkal is added to neutralize the reaction system and separate the aimed ester. The hydrolytic product will not become a viscous gelatinous substance, and is suspended in the reaction system. Thus, the mechanical separation thereof can be easily carried out. |
