| 摘要 |
The present invention relates to processes for producing melamine-formaldehyde foams, said processes comprising the steps of:
a) producing an aqueous mixture M1) comprising
100 parts by weight of at least one melamine-formaldehyde precondensate,2 to 4 parts by weight of at least one curative,0.2 to 5 parts by weight of a surfactant mixture,0.1 to 5 parts by weight of at least one salt of an inorganic acid or one salt of an organic carboxylic acid,1 to 40 parts by weight of at least one blowing agent,0 to 5 parts by weight of at least one dye and/or optical brightener,0 to 20 parts by weight of one or more further additives, and25 to 60 parts by weight of water,b) heating and foaming said mixture M1) using microwave radiation,c) crosslinking and curing the resulting foam using the curative and microwave radiation,d) drying the foam using microwave radiation, ande) annealing the dried foam using hot air,
wherein as essential feature of the present invention said mixture M1) comprises a surfactant mixture comprising a mixture of 50 to 90 wt % of an anionic surfactant and 10 to 50 wt % of a nonionic surfactant, wherein the weight percentages are each based on the total weight of the surfactant mixture,
and also to melamine-formaldehyde foams obtainable by the processes of the present invention and also to uses of said foams. |
