Blocked polyisocyanate composition, one-component coating composition, coating film, and coated article

A blocked polyisocyanate composition comprising a blocked polyisocyanate formed through blocking at least a part of isocyanate groups possessed by a polyisocyanate derived from one or two or more diisocyanates selected from the group consisting of an aliphatic diisocyanate and an alicyclic diisocyanate with an active methylene-based compound comprising a malonic acid diester, wherein

• a specific molar ratio represented by formula (1) is 0.05 or more and 0.60 or less:
• specific molar ratio=(B+C+D)/(A+B+C+D) (1)
• wherein A represents a content (mol %) of isocyanurate groups represented by formula (I);
• B represents a content (mol %) of iminooxadiazinedione groups represented by formula (II);
• C represents a content (mol %) of uretdione groups represented by formula (III);
• and D represents a content (mol %) of allophanate groups represented by formula (IV),
• and
• a monohydric alcohol selected from the group consisting of methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, 2-butanol, t-butanol, n-amyl alcohol, isoamyl alcohol, 2-methyl-1-butanol, n-hexanol, 2-methyl-1-pentanol, 2-ethyl-1-butanol, n-heptanol, n-octanol, and 2-ethyl-1-hexanol, and
• wherein the monohydric alcohol is in an amount of 10 eq % or more and 500 eq % or less of blocked isocyanate groups.