摘要 |
The invention relates to a process for the continuous production of an aqueous amino formaldehyde resin solution, preferably melamine formaldehyde resin (MF) or urea formaldehyde resin (UF), comprising the steps of a) preparing a reaction mixture of an amino compound and an aqueous formaldehyde, b) adding a catalyst to the reaction mixture, and c) condensation reacting the reaction mixture in the presence of the catalyst, wherein in step a) the amino compound and the formaldehyde are added as a concentrated aqueous solution or as a solid to a total solid content in the reaction mixture of 40-85 wt % (dry weight relative to the total weight of the reaction mixture), wherein in step c) the condensation reaction takes place in a continuous plug flow of the reaction mixture and wherein in step b) the catalyst is continuously added and finely dispersed into the reaction mixture through one or more addition points. The invention further relates to a continuous plug flow condensation polymerisation reactor and to the use of such reactor for preparing resin solutions. The invention also relates to the use of a specific continuous mixing device for continuous mixing of catalyst into a reaction mixture.
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