Dispersion liquid, composition, sealing member, light-emitting device, illumination tool, display device, method for producing dispersion solution, and method for modifying surfaces of metal oxide particles

A dispersion liquid comprising:

• metal oxide particles which have been surface-modified by at least one kind of silane compound and at least one kind of silicone compound;
• and
• a solvent,
• wherein the silane compound contains a methyl group,
• the silicone compound contains a hydrocarbon group having 2 or more carbon atoms,
• a mole ratio (methyl group/hydrocarbon group) of the methyl group to the hydrocarbon group in the metal oxide particles is 0.01 or more and 10 or less,
• wherein the metal oxide particles which have been surface-modified by the at least one kind of silane compound and the at least one kind of silicone compound are secondarily modified metal oxide particles obtained by
• primarily modifying metal oxide particles by a first surface-modifying material composed of a silane compound containing a methyl group and not containing a hydrocarbon group having 2 or more carbon atoms, and
• secondarily modifying the primarily-modified metal oxide particles by
• a second surface-modifying material composed of at least one of a silicone compound containing a methyl group and a hydrocarbon group having 2 or more carbon atoms and a silicone compound not containing a methyl group and containing a hydrocarbon group having 2 or more carbon atoms,
• in a case where a transmission spectrum of the metal oxide particles that are obtained by drying the dispersion liquid by vacuum drying is measured in a wavenumber range of 800 cm−1 or higher and 3,800 cm−1 or lower with a Fourier transform infrared spectrophotometer, and values of the transmission spectrum are standardized such that a maximum value of the transmission spectrum in the range is 100 and a minimum value is 0, the following expression (1) is satisfied,
• IA/IB≤3.5 (1)
• (in the expression, “IA” represents a spectrum value standardized at 3,500 cm−1, and “IB” represents a spectrum value standardized at 1,100 cm−1).