Spray drying aid for a re-dispersible dispersion powder

A pyrrolidone-containing polymer (PP) comprising at least one monomeric unit of the general formulae (I) to (II)

• wherein R is independently hydrogen or C1-C2-alkyl;
• X is —NR;
• A is independently selected from the group consisting of C1-C20-alkanediyl, which carries at least one functional group C(═O)R2, wherein
• R2 is selected from the group consisting of Cl, Br and OR3, wherein
• R3 is selected from the group consisting of H, C1-C10-alkyl, C3-C10-cycloalkyl and C2-C15-alkenyl;
• Z is a group of formula (IV)
• in which B is C1-C20-alkylene, which carries at least one functional group —COOH, or a mixture of the group of formula (IV) with group A.

A process of manufacturing a re-dispersible dispersion powder (RDP), the process comprising the steps of

• i) mixing a pyrrolidone-containing polymer (PP) comprising at least one unit of the general formulae (I) to (III)
• wherein R is independently hydrogen, C1-C4-alkyl, or two radicals R are linked to one another to form a six-membered ring;
• X is —O— or —NR;
• A is independently selected from the group consisting of C1-C20-alkanediyl, C3-C20-cycloalkanediyl, and C6-C20-arylene,
• wherein the C1-C20-alkanediyl can be optionally interrupted by one or more non-adjacent oxygen atoms, sulfur atoms, or functional groups —NR— where the nitrogen atom can be optionally protonated or quarternized, —CO—, —CO—O—, —CO—NR—, —SO—, or —SO2—,
• wherein the C1-C20-alkanediyl and the C3-C20-cycloalkanediyl can optionally carry at least one functional group selected from the group consisting of C(═O)R2 and SO3H, wherein
• R2 is selected from the group consisting of Cl, Br and OR3, wherein
• R3 is selected from the group consisting of H, C1-C10 alkyl, C3-C10 cycloalkyl and C2-C15 alkenyl,
• wherein the C6-C20-arylene can be optionally interrupted by oxygen, sulfur, —NR—, —SO—, or —SO2— and can be optionally substituted by —COOH or —SO3H, or a mixture of such groups;
• Z is a group of formula (IV)
• in which B is C1-C20-alkanediyl, which can be optionally interrupted by one or more non-adjacent oxygen atoms, sulfur atoms or functional groups —NR— where the nitrogen atom can be optionally protonated or quaternized, —CO—, —CO—O—, —CO—NR—, —SO— or —SO2—, and can optionally carry additional functional groups —COOH or —SO3H, C6-C20-cycloalkanediyl or a mixture of such groups
• or a mixture of the group of formula (IV) with group A
• with an aqueous polymer dispersion;
• and
• ii) spray drying the mixture obtained in step i).

A process for producing a pyrrolidone-containing polymer (PP), wherein the process comprises polymerization of a reactive mixture (rM2), wherein the reactive mixture (rM2) comprises at least the following components

• (A) at least one itaconic acid derivative, and
• (B) at least one amino acid of the general formula (1)
• wherein
• R1 is selected from the group consisting of at least monosubstituted C2-C20 alkanediyl and at least monosubstituted C3-C20 cycloalkanediyl, wherein the substituent is NH2, with the NH2 substituent optionally being located on the most distal carbon atom;
• R2 is selected from the group consisting of Cl, Br and OR3, wherein
• R3 is selected from the group consisting of H, C1-C10 alkyl, C3-C10 cycloalkyl and C2-C15 alkenyl.