Inkjet recording medium
View Patent ↗An inkjet recording medium including: a coated paper substrate; and an inkjet-receptive coating applied to at least one side of the coated paper wherein the inkjet-receptive coating includes inorganic oxide particles, a multivalent metal salt and a binder; wherein said inorganic oxide particles includes a cationic porous silica having an average particle size less than 0.5 microns and a pore volume of at least 0.70 ml/g and a surface area less than 200 m 2 /g, and said inkjet recording medium has a 75° gloss of at least 60.
1. An inkjet recording medium comprising:
a coated paper substrate; and
an inkjet-receptive coating applied to at least one side of said coated paper wherein said inkjet-receptive coating comprises inorganic oxide particles, a multivalent metal salt and a binder; wherein said inorganic oxide particles comprise a cationic porous silica having an average particle size less than 0.5 microns and a pore volume (N 2 ) of at least 0.70 ml/g and a surface area less than 200 m 2 /g, and said inkjet recording medium has a 75° gloss of at least 60.
2. The inkjet recording medium of claim 1 wherein the silica particles have a median particle size of about 0.2 to 0.5 microns.
3. The inkjet recording medium of claim 1 wherein said medium has a mottle value of less than 3.0 when printed with an inkjet printer containing pigmented inks.
4. The inkjet recording medium of claim 1 wherein said binder comprises a polyvinyl alcohol.
5. The inkjet recording medium of claim 1 wherein said coating further comprises a crosslinker.
6. The inkjet recording medium of claim 1 wherein said binder is present in an amount of about 3 to 50 parts based on 100 parts total pigments.
7. The inkjet recording medium of claim 1 wherein said inorganic oxide particles account for substantially all of the pigments in the coating.
8. The inkjet recording medium of claim 1 wherein said inkjet receptive coating is present at a coat weight of about 0.15 to 1.0 lbs./ream (3,300 ft. 2 ).
9. The inkjet recording medium of claim 1 wherein the multivalent metal salt is present in an amount of about 35 to 133 parts based on 100 parts total pigments.
10. The inkjet recording medium of claim 1 wherein the multivalent metal salt comprises a cation selected from the group consisting of Mg +2 , Ca +2 , Zn +2 , Ba +2 , Al +3 and combinations thereof that forms a salt with an inorganic or organic counter ion.
11. The inkjet recording medium of claim 10 wherein the multivalent metal salt is selected from the group consisting of CaCl 2 , MgCl 2 , MgSO 4 , Ca(NO 3 ) 2 , Mg(NO 3 ) 2 , ZnCl 2 , Zn(NO 3 ) 2 , AlCl 3 , Al 2 (OH) 5 Cl, BaCl 2 , and Ba(NO 3 ) 2 and combinations thereof.
12. The inkjet recording medium of claim 11 wherein the multivalent metal salt comprises calcium chloride.
13. The inkjet recording medium of claim 1 wherein the inkjet-receptive coating comprises a first layer and a second layer wherein the second layer is disposed as a topcoat on the first layer.
14. The inkjet recording medium of claim 13 wherein the second layer comprises the multivalent metal salt.
15. The inkjet recording medium of claim 1 wherein the coating comprises cationic silica particles having a median particle size of about 0.2 to 0.5 microns, a calcium salt and polyvinyl alcohol.
16. The inkjet recording medium of claim 1 wherein the inkjet recording medium exhibits a gloss/mottle ratio of at least 100 when printed with an inkjet printer containing pigmented inks.
17. The inkjet recording medium of claim 16 wherein the inkjet recording medium exhibits a mottle of not over 1.0.
18. The inkjet recording medium of claim 1 wherein the gloss of the inkjet recording medium is at least 70.
19. The inkjet recording medium of claim 1 wherein the coated paper substrate comprises a fine particle size clay having a particle size distribution where at least 90% of the particles by weight have a particle size less than 2 μ.
20. The inkjet recording medium of claim 19 wherein the coated paper substrate comprises a carboxylated styrene butadiene copolymer latex binder.
21. The inkjet recording medium of claim 2 wherein the total pore volume of the particles as measured on a dry basis is about 0.7 to about 2.0 ml/g.
22. The inkjet recording medium of claim 21 wherein the total pore volume of the particles as measured on a dry basis is about 0.7 to about 1.5 ml/g.
23. The inkjet recording medium of claim 1 wherein the cationic porous silica is surface treated with aluminum chloride.