Copolymers having a gradient structure as dispersant for alkalinically activated binding agents

A binder composition comprising:

• an organic binder and/or a mineral binder,
• an alkaline activating agent, and
• a copolymer, as dispersant, having a polymer backbone and side chains bonded thereto and 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 copolymer has a further section B, where there is essentially a constant local concentration of monomers and/or a statistical or random distribution of monomers over the entire section B,
• the ionizable monomer unit M1 has a structure represented by formula I:
• and the side chain-bearing monomer unit M2 includes a structure represented by formula II:
• where:
• R1, in each case independently, is —COOM, —SO2—OM, —OPO(OM)2, or —PO(OM)2,
• R2, R3, R5, and R6, in each case independently, are H or an alkyl group having 1 to 5 carbon atoms,
• R4 and R7, in each case independently, are H, —COOM, or an alkyl group having 1 to 5 carbon atoms, or R1 forms a ring together with R4 to give —CO—O—CO—,
• M, independently of one another, represents H+, an alkali metal ion, an alkaline earth metal ion, a di- or trivalent metal ion, an ammonium ion, or an organic ammonium group,
• m=0, 1, or 2,
• p=0 or 1,
• X, in each case independently, is —O— or —NH—,
• R8 is a group represented by formula -[AO]n—Ra, where A is a C2- to C4-alkylene, Ra is H, a C1- to C20-alkyl group, a cycloalkyl group, or an alkylaryl group, and
• n=2-250.