Patent ID: 8460453

Claim:
A process for preparing clear aqueous solutions of silicates (water glasses) which contain: from 20 to 40% by weight of SiO 2 , from 10 to 20% by weight of M 2 O, where M is a cation selected from the group consisting of Li + , Na + , K + , and NY 4 + , wherein Y is an alkyl or alkenyl radical having from 1 to 6 carbon atoms, from 0.5 to 6% by weight of Al 2 O 3 and water and are stable in storage at 20° C. for at least six months, the method comprising placing an aqueous solution of a silicate (water glass) of the general formula M 2 O x nSiO 2 , where M is a cation selected from the group consisting of Li + , Na + , K + , and NY 4 + , wherein Y is an alkyl or alkenyl radical having from 1 to 6 carbon atoms and n is in the range from 1 to 5, into a reaction vessel to provide a reaction mixture; introducing an aluminum compound into the reaction mixture in such a way that the viscosity of the reaction mixture remains below 10 000 mPas; reacting the aqueous solution of a silicate and aluminum at a temperature range of from 20 to 140° C.; and cooling the reaction mixture after introduction of the total amount of the aluminum compound to room temperature as soon as the reaction mixture is clear.