Storage-stable Polyisocyanates based on aliphatic and/or cycloaliphatic diisocyanates including from 1 to 20% by weight of alkylamino groups of the formula R1R2N as a constituent of biuret groups, wherein R1 and R2 independently of one another are aliphatic or cycloaliphatic C1-C12 alkyl radicals, and where at least 95 mol % of the isocyanate groups are blocked with at least one blocking agent, and the polyisocyanates contain from 4.0 to 21.0% by weight of blocked and free NCO groups (calculated as NCO, molecular weight=42). The polyisocyanates are used to produce coating compositions, coatings, and coated substrates.