AQUEOUS INKJET INKS CONTAINING SILANIZED SILICA PARTICLES
The present disclosure pertains an aqueous inkjet ink having self-dispersing pigment or pigment dispersed by polyurethane or acrylic dispersant polymer with alkaline neutralized carboxyl functional group, polyurethane or acrylic binder particles, and less than 3 wt % of surface modified silanized colloid silica particles with particle size smaller than 30 nm as an additive.
1 . An aqueous inkjet ink comprising an aqueous vehicle, a pigment dispersion, a polymeric binder, and an additive; wherein said pigment dispersion comprising a self-dispersing pigment or a pigment dispersed by a polyurethane dispersant polymer or an acrylic dispersant polymer with alkaline neutralized carboxyl functional group, said polymeric binder is a polyurethane polymer or an acrylic polymer, and said additive comprising a surface modified silanized colloidal silica particle, and is present at less than 3 wt %, based on the total weight of the ink; and wherein the average particle size of said silica particle is smaller than 30 nm.
2 . The ink of claim 1 , wherein said surface modified silanized colloidal silica particle is the reaction product of a colloidal silica particle with an epoxy silane.
3 . The ink of claim 2 , wherein said pigment dispersion comprising a pigment dispersed by a polyurethane dispersant polymer with alkaline neutralized carboxyl functional group.
4 . The ink of claim 3 , wherein said polymeric binder is a polyurethane polymer.
5 . The ink of claim 3 , wherein said polymeric binder is an acrylic polymer.
6 . The ink of claim 2 , wherein said pigment dispersion comprising a pigment dispersed by an acrylic dispersant polymer with alkaline neutralized carboxyl functional group.
7 . The ink of claim 6 , wherein said polymeric binder is a polyurethane polymer.
8 . The ink of claim 6 , wherein said polymeric binder is an acrylic polymer.
9 . The ink of claim 2 , wherein said pigment dispersion comprising a self-dispersing pigment.
10 . The ink of claim 9 , wherein said polymeric binder is a polyurethane polymer.
11 . The ink of claim 9 , wherein said polymeric binder is an acrylic polymer.
12 . The ink of claim 1 , wherein said ink does not comprise any free, surface un-modified, colloidal silica particles.
13 . The ink of claim 1 , wherein said polyurethane dispersant polymer and acrylic dispersant polymer are different from said polymeric binder.
14 . The ink of claim 1 , wherein said silanized colloidal silica particle has the structure of Formula (I):
wherein X is O or a straight bond; le and R 2 are independently linear or branched C 1 -C 5 alkylene; and R 3 is H, C 1 -C 5 alkyl or C 1 -C 5 alkyl substituted by C 1 -C 3 alkyl.
15 . The ink of claim 14 , wherein Xis O.
16 . The ink of claim 15 , wherein R 1 is —(CH 2 ) 3 —.
17 . The ink of claim 16 , wherein R 2 is —(CH 2 )—, and R 3 is H.
18 . The ink of claim 14 , wherein X is a straight bond.