Film production method

An ink storage method comprising

• an ink preparation step of preparing an ink comprising a metal complex represented by the formula (1-B), a compound represented by the formula (H-2), and an organic solvent, and
• a storage step of storing the ink prepared in the ink preparation step for 3 days or more,
• wherein the content of the metal complex represented by the formula (1-B) in the ink immediately after preparation of the ink preparation step is defined as Cb[M], the total content of metal complexes having a molecular weight larger by 16, 32 or 48 than that of the metal complex represented by the formula (1-B) in the ink immediately after the preparation is defined as Cb[M+16n], the content of the metal complex represented by the formula (1-B) in the ink immediately after storage of the storage step is defined as Ca[M], and the total content of metal complexes having a molecular weight larger by 16, 32 or 48 than that of the metal complex represented by the formula (1-B) in the ink immediately after the storage is defined as Ca[M+16n], satisfying the formulae (1) and (2):
• 0.1≤(Ca[M+16n]/Ca[M])/(Cb[M+16n]/Cb[M])≤20 (1)
• 0.0001≤Ca[M+16n]/Ca[M]≤0.006 (2):
• wherein
• M represents an iridium atom or a platinum atom,
• n1 represents an integer of 1 or more, n2 represents an integer of 0 or more, and n1+n2 is 2 or 3, and n1+n2 is 3 when M is an iridium atom, while n1+n2 is 2 when M is a platinum atom,
• E11B, E12B, E13B, E14B, E21B, E22B, E23B and E24B each independently represent a nitrogen atom or a carbon atom, and when a plurality of E11B, E12B, E13B, E14B, E21B, E22B, E23B and E24B are present, they may be the same or different at each occurrence, and when E11B is a nitrogen atom, R11B is not present, when E12B is a nitrogen atom, R12B is not present, when E13B is a nitrogen atom, R13B is not present, when E14B is a nitrogen atom, R14B is not present, when E21B is a nitrogen atom, R21B is not present, when E22B is a nitrogen atom, R22B is not present, when E23B is a nitrogen atom, R23B is not present, and when E24B is a nitrogen atom, R24B is not present,
• R11B, R12B, R13B, R14B, R21B, R22B, R23B and R24B each independently represent a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxy group, a cycloalkoxy group, an aryl group, an aryloxy group, a monovalent heterocyclic group, a halogen atom or a substituted amino group, or R11B and R12B, R12B and R13B, R13B and R14B, R11B and R21B, R21B and R22B, R22B and R23B, and R23B and R24B each are combined together to form an aromatic ring together with the atoms to which they are attached, and the group represented by R11B, R12B, R13B, R14B, R21B, R22B, R23B and R24B optionally has a substituent, and when a plurality of R11B, R12B, R13B, R14B, R21B, R22B, R23B and R24B are present, they may be the same or different at each occurrence, and R11B and R12B, R12B and R13B, R13B and R14B, R11B and R21B, R21B and R22B, R22B and R23B, and R23B and R24B each may be combined together to form a ring together with the atoms to which they are attached,
• the ring R1B represents a pyridine ring or a diazine ring constituted of a nitrogen atom, a carbon atom, E11B, E12B, E13B and E14B,
• the ring R2B represents a benzene ring, a pyridine ring or a diazine ring constituted of two carbon atoms, E21B, E22B, E23B and E24B, and
• A1-G1-A2 represents an anionic bidentate ligand, A1 and A2 each independently represent a carbon atom, an oxygen atom or a nitrogen atom, and these atoms each may be an atom constituting a ring, G1 represents a single bond or an atomic group constituting the bidentate ligand together with A1 and A2, and when a plurality of A1-G1-A2 are present, they may be the same or different:
• wherein,
• ArH1 and ArH2 each independently represent an aryl group or a monovalent heterocyclic group, and these groups each optionally have a substituent,
• nH3 represents an integer of 1, and
• LH1 represents a group represented by the formula (AA-4) or the formula (AA-14), and these groups each optionally have a substituent:
• wherein,
• R represents a hydrogen atom, an alkyl group, a cycloalkyl group, an aryl group or a monovalent heterocyclic group, and the plurality of R each may be the same or different.