The green fluorescent substances for three wavelength area luminous forma fluorescent lamp and three wavelength area luminous forma fluorescent lamps null which use

摘要

PURPOSE:To provide a green-emitting phosphor which is high in luminance and dispersibility and gives a uniform phosphor coating by coating the surfaces of particles of a Tb-activated green-emitting phosphor having a specific composition with a given amount of a water-soluble hydroxyalkylcellulose. CONSTITUTION:The surfaces of particles of a terbium-activated green emitting phosphor represented by formula I or II (wherein R1 is Y, La or Gd; a0; b0; 0.1=a+b=0.7; e=0; f=0; g0; 0.8=e+f+g=1.3; x=0; y0; 5X10-6=z=6X10-3; 0.8=x+y+z=1.3) are coated with 0.005 - 0.5wt.% water-soluble hydroxyalkylcellulose (e.g. hydroxypropylcellulose) based on 100wt.% particles of the phosphor. The resulting particles have good dispersibility in slurries and hence are capable of forming a phosphor coating.