Dicarboxylic acids or esters thereof are recovered from solid phase polyester materials, such as post-consumer products and factory scrap, by subjecting the polyester to at least two hydrolysis stages in at least the first of which the amount of water used is substantially less than needed to effect total conversion of the polyester to the dicarboxylic acid. Also the diol content is controlled in the course of carrying out the hydrolysis. The hydrolysis reactions may be preceded by reaction of the polyester with a diol, the resulting depolymerisation products then being hydrolysed.
申请公布号
WO9501953(A1)
申请公布日期
1995.01.19
申请号
WO1994GB01410
申请日期
1994.06.29
申请人
IMPERIAL CHEMICAL INDUSTRIES PLC;HARVIE, JAMES, LUMSDEN;HEPPELL, STUART, MICHAEL