Phosphor particles
Provided are phosphor particles comprising Mn-doped complex fluoride red phosphor particles and inorganic fine particles which are affixed to the surface of each red phosphor particle. The Mn-doped complex fluoride red phosphor-containing phosphor particles are suppressed in mutual adhesion and agglomeration, flow well during mixing with a silicone or epoxy resin, and have excellent humidity resistance.
1. Phosphor particles comprising 100 parts by weight of Mn-doped complex fluoride red phosphor particles having the following formula (1):
A 2 MF 6 :Mn (1)
wherein A is at least one alkali metal selected from Na, K, Rb, and Cs and M is at least one tetravalent element selected from Si, Ge, and Ti, and 0.1 to 10 parts by weight of inorganic fine particles different from the Mn-doped complex fluoride,
the Mn-doped complex fluoride red phosphor particles having an average particle diameter D 50 of at least 5 μm, the inorganic fine particles having an average particle diameter D 50 of 1 nm to 2 μm, both as measured by the laser diffraction scattering method, and the inorganic fine particles being affixed to at least some parts on the surface of each Mn-doped complex fluoride red phosphor particle, wherein
the inorganic fine particles are hydrophobic silica fine particles which are formed by introducing R 1 SiO 3/2 units and R 2 3 SiO 1/2 units to the surface of hydrophilic silica fine particles composed of SiO 2 units, wherein R 1 is a substituted or unsubstituted monovalent hydrocarbon group of 1 to 20 carbon atoms, R 2 is a substituted or unsubstituted monovalent hydrocarbon group of 1 to 6 carbon atoms, and the silicon-bonded hydrocarbon groups R 2 are the same or different each other.
2. The phosphor particles of claim 1 wherein the inorganic fine particles are distributed over and affixed to the surface of each Mn-doped complex fluoride red phosphor particle.
3. The phosphor particles of claim 1 wherein in formula (1), A is an alkali metal which is K and M is a tetravalent element which is Si.
4. The phosphor particles of claim 1 wherein the inorganic fine particles in the form of hydrophobic silica fine particles have an average particle diameter D 50 of 5 nm to 1 μm as measured by the laser diffraction scattering method, a D 90 /D 10 value of up to 3, provided that particle size distributions D 10 and D 90 are measured by the laser diffraction scattering method, and an average circularity of 0.8 to 1.