| 主权项 |
1. A process for preparing self-binding pigment particles comprising the following steps:
a) providing a suspension comprising at least one calcium carbonate containing material, b) providing an anionic polymeric binder that comprises at least one modified polysaccharide, c) providing at least one cationic polymer selected from the group consisting of one or more polyamines, polyethyleneimines, polyacrylamides, cationic epichlorohydrin resins, polydiallyldimethylammonium chlorides, cationic starches, cationic guars, and any mixture thereof, d) mixing the suspension of step a) and the binder of step b), and e) grinding the mixed suspension of step d) so that the particle size of the calcium carbonate material is reduced and self-binding pigment particles are obtained, wherein the at least one cationic polymer of step c): i) is mixed in step d) with the suspension of step a) and the binder of step b), and/or ii) is mixed with the suspension obtained after grinding step e), and the obtained mixture is deagglomerated, wherein the binder of step b) is added in an amount from 0.001 to 20 wt.-% based on the total weight of the dry calcium carbonate containing material, and wherein the at least one cationic polymer of step c) is added in an amount from 0.001 to 20 wt.-% based on the total weight of the dry calcium carbonate containing material, and wherein the grinding step e) is carried out until the fraction of self-binding pigment particles having a particle size of less than 2 μm is greater than 20 wt.-% based on the total weight of the pigment particles, as measured with a Mastersizer 2000. |
