PROCESS FOR THE PRODUCTION OF SULPHONIC ACID GROUP-CONTAINING CONDENSATION PRODUCTS WITH A LOW CONTENT OF FREE FORMALDEHYDE

摘要

A process for the production of sulphonic acid group-containing condensation products based on amino-s-triazines with at least two amino groups and formaldehyde with a low content of free formaldehyde, wherein a) an amino-s-triazine, formaldehyde and sulphite is condensed in a mole ratio of 1:1.3 to 6:0.3 to 1.5 in aqueous solution at a pH value of 9.0 to 12.0 and at a temperature of 50 DEG to 90 DEG C. until sulphite is no longer detectable. b) subsequently, further condensation is carried out at a pH value of 2.0 to 7.0 and at a temperature of 50 DEG to 90 DEG C. until the viscosity of the solution is 4 to 1000 mm2/s at 80 DEG C. and c) thereafter the condensation product is subjected to an after-treatment in a strongly alkaline range of pH 2ROOT 11.0 and at an elevated temperature.