Basf Se Corporation

Dieter Weilacher

Guenter Scherr

Evelyn Fuchs

Klaus Menzel

Günter Scherr

Martin Reif

Miran Yu

Stephan Weinkoetz

Andreas Eichfelder

Rainer Erhardt

Daniel Flojhar

Benedikt Crone

Gabor Boerzsoenyi

Jörg Schneider

Chunhong Yin

Gabor Börzsönyi

Eva Ruba

Jens Steinbeck

Ralf Strohmeier

Rainer Ehrhardt

Eva Rüba

The present invention relates to a process for preparing liquid compositions of etherified melamine formaldehyde resins, namely melamine formaldehyde resins etherified with a primary C-C-alkanol, which have low formaldehyde contents. The invention also relates to such liquid compositions of etherified melamine formaldehyde resins having a content of free formaldehyde of less than 0.3% by weight. The liquid compositions of etherified melamine formaldehyde resins are useful as crosslinking agents in coating compositions.

Process for preparing liquid compositions of etherified melamine formaldehyde resins

The present invention relates to new uses of condensation resins made from urea, formaldehyde, and CH-acidic aldehydes.

Uses of condensation resins

Process for the preparation of etherified melamine/formaldehyde condensates, in which first a methylolation of melamine with a formaldehyde component in the molar ratio of from 1:6 to 1:15, preferably at a pH of &#x3e;7, is carried out. This is followed by an etherification of the resulting hydroxymethylation intermediate in the presence of a C-C-alkyl, preferably of a C-C-alcohol, particularly preferably of a C-C-alcohol, at a pH of &#x3c;4.5, and subsequently by at least one distillation step in order to remove in particular methanol from the system, the pH of &#x3e;9.5 being established before, during and/or after the distillation. According to the invention, a plurality of hydroxymethylation, etherification and distillation steps follow in order to achieve an etherified melamine/formaldehyde condensate which is distinguished by a high degree of hydroxymethylation, a high solids content and a low viscosity.

Etherified melamine/formaldehyde condensates having a high solid content and low viscosity

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Hassloch, Germany

Dieter Weilacher