The invention relates to a composition comprising at least one binder based on calcium sulfate and at least one polymer obtainable by polymerization of monomers based on alkoxylates of S-vinylthioalkanols. Furthermore a molding, in particular a gypsum plasterboard, a gypsum wallboard, a screed or a knifing filler, obtained by setting of the composition of the invention is disclosed.

The invention relates to a composition comprising at least one binder based on calcium sulfate and at least one polymer obtainable by polymerization of monomers based on alkoxylates of S-vinylthioalkanols. Furthermore a molding, in particular a gypsum plasterboard, a gypsum wallboard, a screed or a knifing filler, obtained by setting of the composition of the invention is disclosed.

Methods for plasticizing cementitious mixtures having relatively high water/cement ratio (at least 0.40 or higher) are surprisingly improved in terms of dosage efficiency, compared to conventional superplasticizer polycarboxylate polymers, when the polycarboxylate polymer is formed from particularly small-sized, specifically selected monomer constituents: (A) polyoxyalkylene monomer represented by the structural formula (R.sup.1)(R.sup.3)CC(R.sup.2)((CH.sub.2).sub.m(CO).sub.nO(CH.sub.2).sub.o(AO).sub.pR.sup.4) wherein (AO).sub.p represents linear ethylene oxide groups and p is 5-23 and more preferably 5-15; (B) unsaturated carboxylic acid represented by (R.sup.5)(R.sup.7)CC(R.sup.6)(C(O)OM) wherein M represents an alkali metal, the ratio of component A to component B being 20:80 to 50:50; and, optionally, (C) a hydrophilic monomer represented by (R.sup.8)(R.sup.9)CC(R.sup.10)(CX) wherein R.sup.8, R.sup.9, and R.sup.10 each represent hydrogen or methyl group, and X represents C(O)NH.sub.2, C(O)NHR.sup.11, C(O)NR.sup.12R.sup.13, SO.sub.3H, C.sub.6H.sub.4SO.sub.3H, or C(O)NHC(CH.sub.3).sub.2CH.sub.2SO.sub.3H, or mixture thereof, wherein R.sup.11, R.sup.12, and R.sup.13 each represent a C.sub.1 to C.sub.5 alkyl group.

The invention relates to a method for producing a dispersant, comprising the steps of a) providing at least one water-soluble polymer comprising polyether groups, b) providing an inorganic component comprising at least one phyllosilicate which has an integral sheet charge of 0, 1 or 2, c) producing an aqueous suspension comprising the at least one water-soluble polymer comprising polyether groups and the inorganic component comprising the at least one phyllosilicate, and d) spray-drying the aqueous suspension to give a solid. Additionally disclosed is the use of the dispersant of the invention in an inorganic binder composition.

The invention relates to a method for producing a dispersant, comprising the steps of a) providing at least one water-soluble polymer comprising polyether groups, b) providing an inorganic component comprising at least one phyllosilicate which has an integral sheet charge of 0, 1 or 2, c) producing an aqueous suspension comprising the at least one water-soluble polymer comprising polyether groups and the inorganic component comprising the at least one phyllosilicate, and d) spray-drying the aqueous suspension to give a solid. Additionally disclosed is the use of the dispersant of the invention in an inorganic binder composition.

A formulation for use as a lost circulation preventive material is a cement-forming aqueous fluid comprising water, a viscoelastic surfactant (VES), a monovalent or multivalent salt, a magnesium powder, a retarder, a weighting material, and a dispersant. The formulation is used in a method of drilling into a subterranean formation that includes introducing into a wellbore passing at least partially through the subterranean formation the cement-forming aqueous fluid, and further increasing the viscosity of the aqueous fluid with the VES; where the monovalent salt is present in an amount effective to pseudo-crosslink the elongated VES micelles to further increase the viscosity of fluid. The formulation further forms a cement by reacting the magnesium powder and the water which reaction is retarded by the retarder. The water may be saline water. When the fluid density is greater than 14 pounds per gallon, a dispersant is required, such as a sulfonated copolymer.

A formulation for use as a lost circulation preventive material is a cement-forming aqueous fluid comprising water, a viscoelastic surfactant (VES), a monovalent or multivalent salt, a magnesium powder, a retarder, a weighting material, and a dispersant. The formulation is used in a method of drilling into a subterranean formation that includes introducing into a wellbore passing at least partially through the subterranean formation the cement-forming aqueous fluid, and further increasing the viscosity of the aqueous fluid with the VES; where the monovalent salt is present in an amount effective to pseudo-crosslink the elongated VES micelles to further increase the viscosity of fluid. The formulation further forms a cement by reacting the magnesium powder and the water which reaction is retarded by the retarder. The water may be saline water. When the fluid density is greater than 14 pounds per gallon, a dispersant is required, such as a sulfonated copolymer.

A formulation for use as a lost circulation preventive material is a cement-forming aqueous fluid comprising water, a viscoelastic surfactant (VES), a monovalent or multivalent salt, a magnesium powder, a retarder, a weighting material, and a dispersant. The formulation is used in a method of drilling into a subterranean formation that includes introducing into a wellbore passing at least partially through the subterranean formation the cement-forming aqueous fluid, and further increasing the viscosity of the aqueous fluid with the VES, where the monovalent salt is present in an amount effective to pseudo-crosslink the elongated VES micelles to further increase the viscosity of fluid. The formulation further forms a cement by reacting the magnesium powder and the water which reaction is retarded by the retarder. The water may be saline water. When the fluid density is greater than 14 pounds per gallon, a dispersant is required, such as a sulfonated copolymer.

The invention relates to a composition comprising 5-50 wt % of calcium silicate hydrate, 10-60 wt % of at least one water-soluble, acid group-containing polymer comprising polyether groups, and 5-40 wt % of at least one polyalkylene glycol ether. Further disclosed is a process for preparing this composition, and cementitious mixtures comprising the composition. A further aspect of the present invention is the use of the composition of the invention in cementitious mixtures for accelerating the development over time of the dispersing action of the acid group-containing polymer after addition of the mixing water and a subsequently accelerated curing of the mixture.

The invention relates to a composition comprising 5-50 wt % of calcium silicate hydrate, 10-60 wt % of at least one water-soluble, acid group-containing polymer comprising polyether groups, and 5-40 wt % of at least one polyalkylene glycol ether. Further disclosed is a process for preparing this composition, and cementitious mixtures comprising the composition. A further aspect of the present invention is the use of the composition of the invention in cementitious mixtures for accelerating the development over time of the dispersing action of the acid group-containing polymer after addition of the mixing water and a subsequently accelerated curing of the mixture.