PREPARATION OF 1, 6-HEXANEDIOL AND 6-HYDROXYCAPROIC ACID AND ESTERS THEREOF

摘要

A PROCESS FOR THE PREPARATION OF L, 6-HEXANEDIOL AND 6-HYDROXYCAPROIC ACID OR ESTERS THEREOF BY CATALYTIC HYDROGENATION OF ADIPIC ACID, ADIPIC ACID MONOESTERS OR ADIPIC ACID DIESTERS OR STREAMS OF STARTING MATERIAL WHICH CONTAIN ADIPIC ACID OR ESTERS THEREOF AS ESSENTIAL CONSTITUENTS, IN WHICH THE BOTTOM PRODUCT OBTAINED IN THE DISTILLATION OF THE HYDROGENATION PRODUCT, FOLLOWING REMOVAL OF THE HEXANEDIOL AND HYDROXYCAPROIC ACID OR ESTERS THEREOF, AND ESSENTIALLY COMPRISES OLIGOMERIC ESTERS OF 6-HYDROXYCAPROIC ACID, IS RECYCLED TO THE HYDROGENATION, AND THE RESULTING ''MIXTURE OF STARTING MATERIAL AND RECYCLE STREAM IS REACTED AT FROM 100 TO 300°C, AT FROM 10 TO 300 BAR IN THE LIQUID PHASE AND AT A MOLAR RATIO OF CARBOXYL GROUPS TO BE HYDROGENATED TO HYDROGEN IN THE REACTOR OF FROM 1 : 5 TO 1 : 100 ON HYDROGENATION CATALYSTS IS DESCRIBED.