The present invention relates to a copolymer, especially for use as a dispersant for solid particles, in particular for use as dispersant for mineral binder compositions, having a polymer backbone and side chains bonded thereto, comprising at least one ionizable monomer unit M1 and at least one side chain-bearing monomer unit M2, wherein the copolymer has a gradient structure in at least one section A in a direction along the polymer backbone with regard to the ionizable monomer unit M1 and/or with regard to the side chain-bearing monomer unit M2.

The present invention relates to processes for preparing a copolymer, especially a dispersant for solid particles, in particular a dispersant for mineral binder compositions, wherein ionizable monomers m1 and side chain-bearing monomers m2 are polymerized by nitroxide-mediated solution polymerization to give a copolymer, wherein the polymerization is conducted in the presence of an agent comprising a carboxyl group-bearing and phosphated alkoxy amine.

The present invention relates to processes for preparing a copolymer, especially a dispersant for solid particles, in particular a dispersant for mineral binder compositions, wherein ionizable monomers m1 and side chain-bearing monomers m2 are polymerized by nitroxide-mediated solution polymerization to give a copolymer, wherein the polymerization is conducted in the presence of an agent comprising a carboxyl group-bearing and phosphated alkoxy amine.

The present invention relates to an additive for hydraulically setting compositions comprising a colloidally disperse preparation comprising at least one salt of a polyvalent metal cation with at least one organic phosphonate and/or phosphate compound as anion and at least one polymeric dispersant comprising anionic and/or anionogenic groups and polyether side chains. The additive is especially suitable as slump retainer and for improving early strength.

The present invention relates to an additive for hydraulically setting compositions comprising a colloidally disperse preparation comprising at least one salt of a polyvalent metal cation with at least one organic phosphonate and/or phosphate compound as anion and at least one polymeric dispersant comprising anionic and/or anionogenic groups and polyether side chains. The additive is especially suitable as slump retainer and for improving early strength.

An admixture for a hydraulic composition includes a polycondensation product P containing a copolymer prepared by polycondensation of a monomer mixture containing compounds A to C of the following Formulae (A) to (C); and a polycarboxylic acid-based polymer Q including a structural unit having an amino and an imino group, and/or a structural unit having an amino, imino, and amido group:

##STR00001## (wherein R.sub.1 is a hydrogen atom, alkyl, or alkenyl group; A.sub.1O is a C.sub.2-4 alkylene oxide group; p is a number of 1 to 300; and X is a hydrogen atom, an alkyl, or acyl group; R.sub.2 is an alkyl or alkenyl group; A.sub.2O is a C.sub.2-4 alkylene oxide group; q is a number of 1 to 300; and Y.sub.1 is a phosphate ester group; and R.sub.3 is a hydrogen atom, carboxy, alkyl, alkenyl, phenyl, naphthyl, or heterocyclic group; and r is a number of 1 to 100).

An admixture for a hydraulic composition includes a polycondensation product P containing a copolymer prepared by polycondensation of a monomer mixture containing compounds A to C of the following Formulae (A) to (C); and a polycarboxylic acid-based polymer Q including a structural unit having an amino and an imino group, and/or a structural unit having an amino, imino, and amido group:

##STR00001## (wherein R.sub.1 is a hydrogen atom, alkyl, or alkenyl group; A.sub.1O is a C.sub.2-4 alkylene oxide group; p is a number of 1 to 300; and X is a hydrogen atom, an alkyl, or acyl group; R.sub.2 is an alkyl or alkenyl group; A.sub.2O is a C.sub.2-4 alkylene oxide group; q is a number of 1 to 300; and Y.sub.1 is a phosphate ester group; and R.sub.3 is a hydrogen atom, carboxy, alkyl, alkenyl, phenyl, naphthyl, or heterocyclic group; and r is a number of 1 to 100).

The present invention relates to copolymers that comprise salicylic acid derivative structural units and structural units having free polyether side chains. The copolymers are suitable to plasticize inorganic binder systems, construction chemical compositions comprising said copolymers and the use of said copolymers as a plasticizer for inorganic binder systems. Binder systems with a reduced amount of Portland cement comprising at least one copolymer of the invention provide a better liquefaction and processability as compared to said binder systems without a copolymer of the invention.

The present invention relates to a copolymer, especially for use as a dispersant for solid particles, in particular for use as dispersant for mineral binder compositions, having a polymer backbone and side chains bonded thereto, comprising at least one ionizable monomer unit M1 and at least one side chain-bearing monomer unit M2, wherein the copolymer has a gradient structure in at least one section A in a direction along the polymer backbone with regard to the ionizable monomer unit M1 and/or with regard to the side chain-bearing monomer unit M2.

The invention relates to a process for producing a pulverulent composition comprising at least one polymeric dispersant (PD) which comprises structural units having anionic and/or anionogenic groups and structural units having polyether side chains, and at least one polysaccharide (PS). The process here comprises the process steps: a) production of an aqueous dispersion having a viscosity of the dispersion of less than 10 000 mPa.Math.s, comprising the at least one polymeric dispersant (PD) and the at least one polysaccharide (PS) and b) spray drying of the aqueous dispersion produced in process step a). Furthermore, the use of the pulverulent composition according to the invention in inorganic binder compositions, especially as a rheological additive, is disclosed.