abstract |
Finely divided, stable, partly aggregated silica sol having a BET surface area of from 100 to 1000 m2/g and a content of from 0.05 to 15 by weight of guanidine carbonate, a process for its preparation by reacting a fresh sol with guanidine carbonate, preferably in the presence of a further base, and the use of the silica sol in paper retention. |