| 主权项 |
1. An additive for hydraulically setting compositions, comprising a colloidally disperse preparation of at least one salt of a mono- or polyvalent metal cation, of at least one compound which is able to release an anion which forms a low-solubility salt with the metal cation, and of a dispersant comprising 70 to 100% by weight, optionally 80 to 100% by weight, further optionally 90 to 100% by weight, of the total dispersant of a polymeric sulfonated dispersant having anionic and/or anionogenic groups which is selected from sulfonated ketone-formaldehyde condensates, sulfonated melaminesulfonate-formaldehyde condensates, naphthalenesulfonate-formaldehyde condensates, lignosulfonates and sulfonated copolymers obtained by radical copolymerization and
where the metal cation is selected from Ca2+, Al3+, Fe3+, Fe2+, Zn2+, Mn2+, Cu2+, Mg2+, Sr2+, Ba2+, Li+, and mixtures thereof, and where the metal cation is present in a quantity such that the following condition (a) is met:0.1<∑izK,i*nK,i∑jzS,j*nS,j<30(a) where zK,i is the amount of the charge number of the metal cation, nK,i is the number of mols of the weighed-in metal cation, zS,j is the amount of the charge number of the anionic and anionogenic groups present in the polymeric dispersant, nS,j is the number of mols of the anionic and anionogenic groups present in the weighed-in polymeric sulfonated dispersant, the indices i and j are independent of one another and are an integer greater than 0, where i is the number of different kinds of metal cations and j is the number of different kinds of anionic and anionogenic groups present in the polymeric dispersant. |
