Chemical products, not containing amorphous networks of polymeric aluminosilicates for the foundry industry, in particular additives for the use in foundries for the production of moulds, cores and/or feeders; binding agents, not containing amorphous networks of polymeric aluminosilicates, for the use in foundries for the production of moulds, cores and/or feeders; polyurethane-based artificial resin binders, not containing amorphous networks of polymeric aluminosilicates, for the use in foun...