公开(公告)号：US3845100A

公开(公告)日：1974-10-29

申请号：US1132470

申请日：1970-02-13

Applicant: STANDARD OIL CO

Inventor： KUSAK M

IPC: C07C51/265 ,  C07C51/487 ,  C07C69/82

CPC classification number: C07C51/265 ,  C07C51/487 ,  C07C67/08 ,  C07C67/52 ,  C07C63/26 ,  C07C69/82

Abstract: 1. A PREPARATIVE PROCESS FOR HIGH PURITY DIMETHYL TEREPHTHALATE HAVING AN ACID NUMBER IN THE RANGE OF 0.01 TO 0.03 AND FREEZING POINT IN THE RANGE OF 140.62 TO 140.63*C BY THE OPERATING SEQUENCE: ESTERIFYING TEREPHTHALIC ACID HAVING 50 P.P.M. 4-CARBPXYBENXALDEHYDE OR LESS AND 160-600 P.P.M. P-TOLUIC ACID WITH METHANOL HAVING 0-5% WATER IN THE RESPECTIVE REACTANT WEIGHT RATIO OF 1.0:3.0 TO 10.0 AT A TEMPERATURE IN THE RANGE OF 200 TO 300*C. AND A PRESSURE IN THE RANGE OF OF 500 TO 50000 P.S.I.G.; PRECIPITATING DIMETHYL TEREPHTHALATE AT A FINAL TEMPERATURE OF 25-40:C. AND A PRESSURE OF 130-250 MM. HG.; SEPARATING DIMETHYL TEREPHTHALATE PRECIPITATE FROM METHANNOL MOTHER LIQOUR; WASHING THE SEPARATED PRECIPIATE WITH METHANOL HAVING 0.5% WATER AND DISTILLING THE WASHED PRECIPITATE TO REMOVE AS OVERHEAD FRACTIONS RESIDUAL METHANOL AND METHYL ESTERS OF P-TOLUIC ACID AND4CARBOXYBENZALDEHYDE LEAVING AS RESIDUAL PRODUCT HIGH PURITY DIMETHYL TEREPHTHALATE.