| 摘要 |
This invention relates to an activated titanium catalyst used in an esterification reaction and/or a transesterification reaction, and a method of manufacturing esters having a low acid value and narrow molecular weight distribution by making effective use of the excellent dehydration esterification reaction properties and transesterification ability of this catalyst. Specifically, this invention is a catalyst for an esterification reaction and/or a transesterification reaction, which is a gel-like substance comprising a mixture of an alkoxytitanium, water-soluble polyol and water, or the reaction product thereof, wherein the number of moles of said water-soluble polyol and said water relative to 1 mole of titanium, is respectively 1-50 moles and 1-60 moles. For example, an objective polyester can be produced in a method of producing an ester comprising, a first step wherein a diol is reacted with an ester produced beforehand from a dibasic acid and a monofunctional alcohol, or an ester produced beforehand from a monofunctional alcohol and diol, a second step wherein unreacted ester is separated from the product produced in the first step to obtain another ester, and a third step wherein unreacted ester separated in the second step is recycled to the first step, 0.05-5 millimoles of the catalyst relative to one mole of acid being used in said first step. |
