Process for the preparation of polyesters with imp

专利名称：Process for the preparation of polyesters

with improved degree of whiteness

发明人：UEBERDIEK, RALF,HUESING, ECKHARD申请号：EP94112372.1申请日：19940808公开号：EP0639602A2公开日：19950222

摘要：The invention relates to a process for the preparation of linear polyestershaving improved whiteness and a low yellowness index by esterification of aromaticdicarboxylic acids or transesterification of bis(lower alkyl) esters thereof, and optionallyaliphatic dicarboxylic acids by means of diols to give bis diol esters and oligomersthereof, and further condensation of these precursors to give spinnable polyesters,which is characterised in that from 0.5 to 15 % by weight of phosphorus-containingmodifiers are added to the esterification, transesterification or polycondensation batch,and in that the polycondensation is carried out first in the melt to an IV of from 0.4 to0.55 dl/g and then in the solid phase to an IV of 0.62 to 0.72 dl/g, where the IV valuesgiven relate to measurement at 25 DEG C in dichloroacetic acid. The phosphorus-containing modifiers condensed in are preferably those of the formula V or VI in whichR<6> is alkylene or polymethylene having 2 to 6 carbon atoms or phenyl, and R<5> isalkyl having 1 to 6 carbon atoms, aryl or aralkyl. The invention also describes thepolyesters obtained by the process and fibre materials made from these polyesters.

申请人：HOECHST AKTIENGESELLSCHAFT

地址：Brüningstrasse 50 D-65929 Frankfurt am Main DE

国籍：DE

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