Abstract:
The invention relates to processes for producing melamine-formaldehyde foams comprising the consecutive steps a) and b): a) heating a mixture comprising a melamine-formaldehyde precondensate, a curative and a blowing agent to foam up and crosslink said mixture, and b) tempering the foam obtained in step a), wherein it is essential to the present invention that - step a) utilizes a precondensate which has a melamine:formaldehyde molar ratio in the range from 1:2.1 to 1:3.9, and - which has a sulfite group content, based on the total weight of the melamine-formaldehyde precondensate, in the range from 0% to 1% by weight, and - said tempering in step b) is effected at a temperature in the range from 230 to 290°C, and also to melamine-formaldehyde foams obtainable according to the processes of the invention, and to uses thereof.
Abstract:
The invention relates to a method for the production of an abrasive foam on the basis of a melamine-formaldehyde-condensation product comprising inorganic nanoparticles, with the following steps: (1) Producing a solution or dispersion comprising a precondensate of the foam to be produced and inorganic nanoparticles, (2) foaming the precondensate by heating the solution or dispersion from step (1), in order to obtain a foam comprising inorganic nanoparticles, and if applicable (3) tempering the foam obtained in step (2), which leads to an increased abrasion when polishing delicate surfaces.
Abstract:
A cushion, comprising A) one or more layers of an open-cell foam on the basis of a melamine resin having a fire retardant impregnation and B) a non-flammable or flame-retardant cover material, and C) a non-flammable, carrying substructure, wherein the layers A), B) and C) are having a form- or material connection, and use for furniture, mattresses, mats and seats in motor vehicles, rail vehicles, ships or airplanes.
Abstract:
The present invention relates to melamine-formaldehyde foams comprising hollow microspheres wherein said hollow microspheres have a median particle diameter (D 50 , volume averaged, Malvern, Fraunhofer diffraction) in the range from 260 µm to 490 µm, and also processes for producing these melamine-formaldehyde foams and their uses.