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Method of preparation of aqueous solutions concentrated condensation products of melamine / phenol / formaldehyde anionic, solutions obtained and their use as additives for materials of construction.
Method of preparation of aqueous solutions concentrated condensation products of melamine / phenol / formaldehyde anionic, solutions obtained and their use as additives for materials of construction.
Anionic products of melamine/phenol/formaldehyde condensation, containing sulphonic acid groups. The invention relates particularly to a process for the preparation of stable concentrated aqueous solutions of such condensation products, which have a solids content of at least 50 % by weight, which involves a number of successive condensation stages under varied temperature, duration, proportions and pH conditions. The solutions obtained are used especially as additives for mortars.
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