US 11,851,571 B2
Ink set, inkjet printing apparatus, and inkjet printing method
Yuusuke Koizuka, Kanagawa (JP); Naoto Shimura, Tokyo (JP); Nozomi Terai, Tokyo (JP); and Tatsuya Takarada, Kanagawa (JP)
Assigned to Ricoh Company, Ltd., Tokyo (JP)
Filed by Yuusuke Koizuka, Kanagawa (JP); Naoto Shimura, Tokyo (JP); Nozomi Terai, Tokyo (JP); and Tatsuya Takarada, Kanagawa (JP)
Filed on Sep. 23, 2021, as Appl. No. 17/482,556.
Claims priority of application No. 2020-176543 (JP), filed on Oct. 21, 2020; and application No. 2021-122305 (JP), filed on Jul. 27, 2021.
Prior Publication US 2022/0119664 A1, Apr. 21, 2022
Int. Cl. C09D 11/40 (2014.01); B41J 2/14 (2006.01); B41M 5/00 (2006.01); C09D 11/033 (2014.01); C09D 11/037 (2014.01); C09D 11/104 (2014.01); C09D 11/322 (2014.01)
CPC C09D 11/40 (2013.01) [B41J 2/1433 (2013.01); B41M 5/0023 (2013.01); C09D 11/033 (2013.01); C09D 11/037 (2013.01); C09D 11/104 (2013.01); C09D 11/322 (2013.01)] 8 Claims
OG exemplary drawing
 
1. An ink set comprising:
a standard ink; and
a light ink,
wherein the standard ink comprises at least a cyan ink, a magenta ink, and a yellow ink,
the light ink comprises a light cyan ink or a light magenta ink, or both,
a content of a cyan pigment in the cyan ink is 1.9% by mass or greater but 3.6% by mass or less,
a content of a cyan pigment in the light cyan ink is 0.4% by mass or greater but 1.4% by mass or less,
a content of a magenta pigment in the magenta ink is 1.9% by mass or greater but 3.6% by mass or less,
a content of a magenta pigment in the light magenta ink is 0.4% by mass or greater but 1.4% by mass or less,
the light ink contains water, an organic solvent, and a resin, and
the organic solvent contains an amide compound represented by General formula (1) below,

OG Complex Work Unit Chemistry
where in the General formula (1), R1, R2, and R3 each independently represent a hydrocarbon group containing from 1 through 8 carbon atoms.