US 7,553,365 B2
Water-based pigment dispersions, inkjet recording inks, and color filters
Shigeru Sakamoto, Tokyo (Japan); Yoshimasa Tsuchiya, Tokyo (Japan); Masanori Takakamo, Tokyo (Japan); Tohru Hosoda, Tokyo (Japan); Akio Yoshida, Tokyo (Japan); Michiei Nakamura, Tokyo (Japan); Naoyuki Sakai, Tokyo (Japan); Dai Watanabe, Tokyo (Japan); Hideyuki Koiso, Tokyo (Japan); and Kenji Ogawa, Tokyo (Japan)
Assigned to Dainichiseika Color & Chemicals Mfg. Co., Ltd., Tokyo (Japan)
Filed on Jan. 25, 2005, as Appl. No. 11/41,293.
Claims priority of application No. 2004-017443 (JP), filed on Jan. 26, 2004; and application No. 2004-018437 (JP), filed on Jan. 27, 2004.
Prior Publication US 2005/0164101 A1, Jul. 28, 2005
Int. Cl. C09B 67/04 (2006.01); C09D 7/14 (2006.01); B02C 17/00 (2006.01)
U.S. Cl. 106—499  [106/401; 106/413; 106/447; 106/460; 106/476; 106/493; 106/496; 106/497; 106/498; 241/15; 241/16; 241/29] 3 Claims
 
1. A production process for an aqueous pigment dispersion, which comprises (A) and (B):
(A) finely dispersing a pigment in a pigment dispersion mixture of at least said pigment and a dispersant in an aqueous medium with beads having diameters of from 0.5 mm to 2 mm such that said pigment is formed into fine particles having an average particle size of from 100 to 500 nm; and
(B) ultrafinely dispersing said pigment dispersion mixture, which has been obtained in step (A), with microbeads having diameters of not smaller than 0.02 mm but smaller than 0.2 mm.