Patent ID: 6153001
Filing Date: 2000-11-28
Classification: C09D

Abstract:
An ink jet recording ink comprising water, an aqueous organic solvent, a surfactant and a self-dispersible pigment, wherein:(a) the number average particle diameter of dispersed particles of said pigment is from 15 to 100 nm;(b) given that mv is the volumetric average particle diameter of the dispersed particles of said pigment and mn is the number average diameter of the dispersed particles of said pigment, mv/mn is less than or equal to 3;(c) the number of particles having a particle diameter greater than or equal to 0.5 .mu.m among the dispersed particles of said pigment contained in one liter of said ink is less than or equal to 7.5.times.10.sup.10 ;(d) the surface tension of said ink is less than or equal to 60 mN/m as measured at 23.degree. C.;(e) the electroconductivity of said ink is from 0.05 to 0.4 S/m;(f) the pH of said ink is from 6 to 11: and(g) a content of said surfactant is from 0.001 to 4.0% by weight based on the total amount of said ink.