Porous materials and process for their production

A porous material comprising

• (a) an aminoplastic foam with a density in the range from 5 to 1, 000 kg/m3 and with an average pore diameter in the range from 1 μm to 1 mm,
• (b) a polymer matrix which is water-soluble or water-swellable or readily erodible, wherein
• water soluble polymer matrices are selected from polymer matrices whose solubility at a pH-value of 7 and a temperature of 25° C. is more than 1.5 g/l, water-swellable polymer matrices have a water uptake at 20° C. of at least 10% by weight, and
• wherein readily erodible polymers are selected from petroleum wax, microcrystalline wax, polyethylene wax, and polypropylene wax, and
• (c) an active ingredient selected from the group of surfactants, organic solvents, complexing agents, and bleaching agents,
• wherein said active ingredient (c) is absorbed by or dissolved in said polymer matrix (b) or chemically linked to said polymer matrix (b).