More rapid mixed acid polyesters prodn. - by reacting aromatic acid with only a portion of the polyol in a first stage, then adding remainder and aliphatic acid
申请公布号:NL7705205(A)
申请号:NL19770005205
申请日期:1977.05.11
申请公布日期:1978.11.14
分类号:C07C67/08;C08G63/12;C08G63/54;C08G63/78;(IPC1-7):07C69/80;07C67/08;08G63/22
主分类号:C07C67/08
摘要:<p>A 2-stage process for making polyesters (I) comprises reacting in a first stage isophthalic or terephthalic acid with sufficient of the polyol (II) to form an agitatable mixt but slightly less than the theoretical amt. needed to react with aromatic acid and the (subsequently added) (un)satd. aliphatic polycarboxylic acid (III). The mixt. is heated at >=190-230 degrees C, than the rest of (II) is added such that the temp. does not fall below 190 degrees C to give a Y2-ester mixt. This mixt. is than reacted in a second stage with (III) to produce (I). Processing time in the first stage, and thus in the overall process, is reduced, e.g. from 11 1/4 to 7 1/2 in the examples.</p>
CIRCUIT FOR SEQUENTIALLY CALCULATING MOVING AVERAGE BY USING AN ANALOG DELAY ELEMENT
SYNCHRONIZED SIGNAL SYSTEM FOR THE STROBO OR FLASH
SEMICONDUCTOR SWITCHING DEVICE
A NEW ANTIBIOTIC AND ITS PREPARATION
4-(2-Benzothiazolyl)-1,2,4-triazole - useful as fungicide
NUEVAS SALES DE CALCIO APROPIADAS COMO ADITIVOS PARA ALIMEN TOS PARA RUMIANTES
VORRICHTUNG ZUR OPTISCHEN MESSUNG VON BLUTGASEN
STEUERSCHALTUNG FUER ELEKTRISCH BETRIEBENES FAHRZEUG
ANORDNUNG ZUR AUTARKEN STROMVERSORGUNG
ANORDNUNG ZUR ERFASSUNG, UEBERTRAGUNG UND UEBERWACHUNG VON MESSWERTEN
ELEKTRISCHE ANLAGE, INSBESONDERE FUER KRAFTFAHRZEUGE
VERFAHREN ZUR HERSTELLUNG VON OXYMETHYLENPOLYMEREN IN KOERNIGER FORM