| 摘要 |
Continuous preparation of sorbic acid Ketene is reacted at 60-102 degrees with an excess of crotonaldehyde, containing as stabilising agent 0.01-1% sterically hindered phenol, in the presence of a catalyst. The catalyst consists of tetra-alkyl titanates and a co-catalyst comprised of one or several acid compounds. The polyester formed is hydrolysed with mineral acid, after removal of excess aldehyde, to form sorbic acid. The crude acid undergoes a complementary heating for 1-5 hours at 70-90 degrees followed by washing out of the mineral acid and neutralising of the last traces of the acid. |
