Patent ID: 9567262
Date: 2017-02-14
CPC Classifications: C04B,Y02W

Claim:
1. Process for the preparation of a hardening accelerator composition comprising an aqueous hardening accelerator suspension, in the absence of cement, by reacting a water-soluble calcium compound with a water-soluble silicate compound, wherein the water-soluble calcium compound is not a calcium silicate, the reaction of the water-soluble calcium compound with the water-soluble silicate compound occurring in the presence of an aqueous solution which contains a water-soluble dispersant comprising at least one polyalkyleneglycol structural unit with a functional group at one end of the polyalkyleneglycol, said functional group capable of interacting as an anchor group with the surface of cement particles, wherein the functional group comprises anionic radicals, silane radicals and/or polyhydroxy radicals, and the water-soluble dispersant does not contain polymeric structures other than the polyalkyleneglycol structural unit, wherein the aqueous hardening accelerator suspension is a hardening accelerator in building material mixtures containing cement, gypsum, anhydrite, slag, optionally ground granulated blast furnace slag, fly ash, silica dust, metakaolin, natural pozzolans, calcined oil shale, calcium sulpho aluminate cement and/or calcium aluminate cement; wherein the functional group capable of interacting as an anchor group with the surface of cement particles, contains two phosphonate radicals, and is represented by the following general structure (I), wherein A is the same or different and independently from each other an alkylene with two to 18 carbon atoms, optionally ethylene and/or propylene, further optionally ethylene, n is an integer from 10 to less than 100 and M is H, an alkali metal, ½ earth alkali metal and/or an amine, and R is H or a saturated or unsaturated hydrocarbon residue, optionally a C1 to C15 alkyl radical.