US 12,391,839 B2
Coating formulation for a digital print medium
Jan Philipp Weihs, Dudingen (CH); and Georg Häusler, Alberswil (CH)
Assigned to OMYA INTERNATIONAL AG, Oftringen (CH)
Appl. No. 17/310,056
Filed by OMYA INTERNATIONAL AG, Oftringen (CH)
PCT Filed Jan. 24, 2020, PCT No. PCT/EP2020/051744
§ 371(c)(1), (2) Date Jul. 14, 2021,
PCT Pub. No. WO2020/152328, PCT Pub. Date Jul. 30, 2020.
Claims priority of application No. 19153693 (EP), filed on Jan. 25, 2019.
Prior Publication US 2022/0049117 A1, Feb. 17, 2022
Int. Cl. C09D 11/38 (2014.01); B41M 5/00 (2006.01); C09D 11/033 (2014.01); C09D 11/037 (2014.01); C09D 11/106 (2014.01); C09D 11/322 (2014.01); B41M 5/52 (2006.01)
CPC C09D 11/322 (2013.01) [B41M 5/0023 (2013.01); C09D 11/033 (2013.01); C09D 11/037 (2013.01); C09D 11/106 (2013.01); C09D 11/38 (2013.01); B41M 5/52 (2013.01); B41M 5/5218 (2013.01)] 24 Claims
OG exemplary drawing
 
1. A cationic coating formulation consisting of:
water,
at least one anionic ultrafine ground calcium carbonate,
at least one non-ionic polyvinyl alcohol,
at least one water-soluble salt of a divalent metal ion,
at least one dispersing agent, and
at least one cationic polymer,
wherein the at least one anionic ultrafine ground calcium carbonate, when in the form of a compacted bed, has
a monomodal pore size distribution,
a volume defined pore size polydispersity expressed as full width at half maximum (FWHM) from 40 to 80 nm, and
a volume defined median pore diameter from 30 to 80 nm;
wherein
the cationic coating formulation has a solid content in the range from 10 to 80 wt.-%, based on the total weight of the cationic coating formulation,
the at least one water-soluble salt of a divalent metal ion is selected from the group consisting of CaCl2, CaBr2, CaI2, Ca(NO3)2, MgCl2, MgBr2, MgI2, and Mg(NO3)2, and
the at least one dispersing agent is selected from a polyacrylate-based dispersing agent, phosphates, a polyphosphate-based dispersing agent, carboxymethyl cellulose or a salt thereof, or a mixture thereof.