| 摘要 |
A process for the preparation of cyclic esters of the general formula: in which m is an integer from 6-14 and n is an integer from 2-6, which comprises heating a dicarboxylic acid bis(glycol) ester of the general formula:HO-(CH2)n-O-CO-(CH2)m-CO-O-(CH2)n-OH,formula IIin which m and n are as defined above, (b) optionally, up to 100% by weight, based on the weight of ester II, of esters of the general formula:H[O-(CH2)n-O-CO-(CH2)m-CO-]x-O-(CH2)n-OH,formula IIIH[O-(CH2)n-O-CO-(CH2)mCO-]X-OH and/orformula IVHO-CO-(CH2)m-CO-[-O-(CH2)nO-CO-(CH2)m-CO-]x-OH,formula Vin which m and n are as defined previously and x is an integer >1, and (c) a glycol of the general formula:HO-(CH2)n-OH,formula VIin which n has the same numerical value as in formula I-V, (d) an inert high-boiling reaction medium, and (e) a catalyst.
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