REMOVAL OF AL-SALTS, HCL, NACL AND ORGANIC BY-PRODUCT FROM STRONG ALKALINE DIOPAT SUSPENSION BY MEANS OF ALKALINE STABLE NANOFILTRATION FOLLOWED BY SEPARATION OF SALTS AND BYPRODUCTS AFTER NEUTRALIZATION OF DIOPAT SOLUTION BY MEANS OF ULTRAFILTRATION

摘要

The present invention provides an improved process for isolating 2,4-bis-(2,4-dihydroxyphenyl)-6-(4-methoxyphenyl)-1,3,5-triazine (DIOPAT)from an aqueous alkaline mixture M having a pH of 10 or more and comprising the 2,4-bis-(2,4-dihydroxyphenyl)-6-(4- methoxyphenyl)-1,3,5-triazine, 2,4-dihydroxybenzophenone, and aluminum salts, wherein the process comprises a nanofiltration step, a precipitation step, and a further filtration step.