Waterborne crosslinker composition

A multi-aziridine crosslinker composition, wherein the multi-aziridine crosslinker composition is an aqueous dispersion having a pH ranging from to 14 and comprises a multi-aziridine compound in dispersed form, wherein said multi-aziridine compound has:

• a. from 2 to 6 of the following structural units A:
• whereby
• R1 is H,
• R2 and R4 are independently chosen from H or an aliphatic hydrocarbon group containing from 1 to 4 carbon atoms,
• R3 is an aliphatic hydrocarbon group containing from 1 to 4 carbon atoms,
• m is 1,
• R′ and R″ are according to (1) or (2):
• (1) R′═H or an aliphatic hydrocarbon group containing from 1 to 14 carbon atoms, and
• R″=an aliphatic hydrocarbon group containing from 1 to 14 carbon atoms, a cycloaliphatic hydrocarbon group containing from 5 to 12 carbon atoms, an aromatic hydrocarbon group containing from 6 to 12 carbon atoms, CH2—O—(C═O)—R′″, CH2—O—R″″, or CH2—(OCR′″″HCR′″″H)n—OR″″″, whereby R″′ is an aliphatic hydrocarbon group containing from 1 to 14 carbon atoms and R″″ is an aliphatic hydrocarbon group containing from 1 to 14 carbon atoms or an aromatic hydrocarbon group containing from 6 to 12 carbon atoms, n being from 1 to 35, R′″″ independently being H or an aliphatic hydrocarbon group containing from 1 to 14 carbon atoms and R″″″ being an aliphatic hydrocarbon group containing from 1 to 4 carbon atoms,
• (2) R′ and R″ form together a saturated cycloaliphatic hydrocarbon group containing from 5 to 8 carbon atoms;
• b. one or more linking chains wherein each one of these linking chains links two of the structural units A, whereby a linking chain is the shortest chain of consecutive atoms that links two structural units A;
• and
• c. a molecular weight in the range from 500 to 10000 Daltons wherein the molecular weight is determined using MALDI-TOF mass spectrometry.