US 12,378,428 B2
Water-based ink for ink-jet recording
Yuki Okumura, Iwakura (JP)
Assigned to BROTHER KOGYO KABUSHIKI KAISHA, Nagoya (JP)
Filed by BROTHER KOGYO KABUSHIKI KAISHA, Nagoya (JP)
Filed on Nov. 11, 2021, as Appl. No. 17/524,278.
Application 17/524,278 is a continuation of application No. PCT/JP2020/018542, filed on May 7, 2020.
Claims priority of application No. 2019-102064 (JP), filed on May 31, 2019.
Prior Publication US 2022/0119661 A1, Apr. 21, 2022
Int. Cl. C09D 11/326 (2014.01); B41M 5/00 (2006.01); C09D 11/107 (2014.01); C09D 11/38 (2014.01)
CPC C09D 11/326 (2013.01) [C09D 11/107 (2013.01); C09D 11/38 (2013.01); B41M 5/0023 (2013.01)] 7 Claims
OG exemplary drawing
 
1. A water-based ink for ink-jet recording comprising:
a resin-dispersed pigment;
resin fine particles;
a humectant including a humectant component of which vapor pressure at 20° C. is not less than 0.02 hPa; and
water,
wherein the resin fine particles are formed of a resin which is at least one selected from the group consisting of: a resin based on acrylic acid, a resin based on maleate ester, a resin based on vinyl acetate, a resin based on carbonate, a resin based on styrene, a resin based on ethylene, a resin based on propylene, a resin based on urethane, and a resin of copolymer of those listed above;
the water-based ink satisfies the following conditions (A) and (B):
11.1≤β/α≤17.8  condition (A):
2.5≤β/γ≤3.0  condition (B):
in the conditions (A) and (B),
α: a viscosity (mPa·s) at 25° C. of the water-based ink in a case that an evaporation rate, of the water-based ink, obtained by the following formula (1) is 0%,
β: a viscosity (mPa·s) at 25° C. of the water-based ink in a case that the evaporation rate, of the water-based ink, obtained by the following formula (1) is 50%, and
γ: a viscosity (mPa·s) at 25° C. of the water-based ink in a case that the evaporation rate, of the water-based ink, obtained by the following formula (1) is 40%;
Evaporation rate(%)={(a mass of the water-based ink before evaporation)−(a mass of the water-based ink after the evaporation)}/(the mass of the water-based ink before the evaporation)×100  (1);
wherein a ratio (H/R) of a content amount (H) of the humectant to a content amount (R) of the resin fine particles in an entire amount of the water-based ink is not less than 2.9 and not more than 6.0; and
wherein a glass transition temperature of the resin fine particles is in a range of 40° C. to 71° C.