Title:
AQUEOUS DISPERSION OF OXIDIZED CARBON BLACK
Document Type and Number:
Japanese Patent JP3862255
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To provide an aqueous dispersion of oxidized carbon black useful for aqueous black ink for use in a inkjet printer and aqueous ink.
SOLUTION: This aqueous dispersion of the oxidized carbon black is made by liquid-phase oxidation of carbon black with a peroxo diacid or peroxo diacid salt so as to be 2-5 μmol/m2 of a carboxyl group, neutralization of some or all of the carboxyl groups of the carbon black with an alkali solution of a dissociation constant (pKa) of 5 or less, and then a removal of a residual salt and purification, wherein the aqueous dispersion of the oxidized carbon black is classified so that, in the carbon black particle aggregate, an average particle diameter Dupa 50% is 50-130 nm, a maximum particle diameter Dupa 99% is 150-320 nm, and value of ΔDupa (mode)/Dupa (mode), the ratio of a half-band width in a particle size distribution ΔDupa (mode) to a mode diameter Dupa (mode), is 1.20 or less, and it is made by adjusting pH of the aqueous dispersion 4-6 and adding 1-6 wt.% (based on the carbon black) of a polyethyleneimine having a molecular weight of 200-1,000.
Inventors:
Keisuke Arai
Application Number:
JP2001387803A
Publication Date:
December 27, 2006
Filing Date:
December 20, 2001
Export Citation:
Assignee:
Tokai Carbon Co., Ltd.
International Classes:
C09C1/56; C09D11/00; C09D11/324; C09D11/38; C09D17/00; (IPC1-7): C09C1/56; C09D17/00; //C09D11/00
Domestic Patent References:
| JP2001081355A | ||||
| JP2001294776A | ||||
| JP2000230134A | ||||
| JP2001164147A | ||||
| JP10237367A | ||||
| JP10023726A |
Attorney, Agent or Firm:
Yasuo Fukuda
Kenji Akatsuka
Kenji Akatsuka