Silica sols, a process for the production of silica sols and use of the sols

摘要

PCT No. PCT/SE90/00690 Sec. 371 Date May 8, 1992 Sec. 102(e) Date May 8, 1992 PCT Filed Oct. 24, 1990 PCT Pub. No. WO91/07351 PCT Pub. Date May 30, 1991.Silica sols which have a large alkali excess, i.e. a low molar ratio SiO2 to M2O, and which contain silica particles with a high specific surface area. The silica sols can be prepared through acidification of a water glass solution and subsequent alkalization of the acid sol to the molar ratio in question. The sols are particularly suitable for use as additives, in combination with cationic polymers, in papermaking.