Recording sheet with improved image waterfastness, surface strength, and runnability
The present invention relates to a sizing or coating composition that, when applied to paper substrate, creates a substrate having improved waterfastness, surface strength, and surface strength as measured by resistance to abrasion. In addition, the present invention relates to paper substrates containing the composition, as well as methods of using and making the paper substrate and composition.
1. A paper substrate comprising a web of cellulosic fibers and having applied thereto a composition in an amount effective to impart to the substrate a waterfastness as measured by DL % of from −10 to 15, a surface strength that is less than 75 mg/1000 revolutions as measured by the Taber Abrasion test, and a runnability of such that the substrate, when in a roll that is 36 inches wide, 50 inches in diameter, and having a 3 inch core, runs continuously for greater than half of a total length of the roll, the composition comprising
at least one binder which has hydroxyl groups;
at least one dye fixative containing one or more quaternary ammonium functional groups; and
at least one crosslinking agent which is capable of crosslinking with the hydroxyl groups of the binder and the functional groups of the dye fixative.
2. The paper substrate according to claim 1 , wherein the composition further comprises at least one pigment.
3. The paper substrate according to claim 1 , wherein the composition further comprises at least one organic salt.
4. The paper substrate according to claim 1 , wherein the at least one binder is present at an amount ranging from 85 to 98 wt % based upon the total weight of solids in the composition.
5. The paper substrate according to claim 1 , wherein the at least one binder comprises starch, and wherein the at least one dye fixative is present at an amount ranging from 0.5 to 10 wt % based upon the total weight of starch in of the composition.
6. The paper substrate according to claim 1 , wherein the at least one binder comprises starch, and wherein the at least one crosslinking agent is present at an amount ranging from 0.5 to 5 wt % based upon the total weight of starch in of the composition.
7. The paper substrate according to claim 1 , wherein the at least one binder is at least one member selected from the group consisting of starch, modified starch, and polyvinyl alcohol.
8. The paper substrate according to claim 1 , wherein the at least one dye fixative is at least one member selected from the group consisting of a polyamine, a polyeneimine, and an optical brightening agent:nitrogen-containing compound complex.
9. The paper substrate according to claim 1 , wherein the at least one crosslinking agent is at least one member selected from the group consisting of glyoxal and blocked glyoxal.
10. The paper substrate according to claim 1 , comprising
at least one binder comprising starch at an amount of 85 to 98 wt % based upon the total weight of solids in of the composition;
at least one dye fixative at an amount ranging from 0.5 to 10 wt % based upon the total weight of solids in of the composition; and
at least one crosslinking agent at an amount ranging from 0.25 to 5 wt % based upon the total weight of solids in of the composition.
11. The paper substrate according to claim 1 , wherein:
the at least one binder is selected from the group consisting of starch and polyvinyl alcohol;
the at least one dye fixative is selected from the group consisting of a polyamine, a polyeneimine, and an optical brightening agent:nitrogen-containing compound complex; and
the at least one crosslinking agent is selected from the group consisting of glyoxal and blocked glyoxal.
12. The paper substrate according to claim 1 , wherein the amount of the composition applied is effective to impart to the substrate has a waterfastness as measured by DL % of from −5 to 15.
13. The paper substrate according to claim 1 , wherein the amount of the composition applied is effective to impart to the substrate a surface strength that is less than 60 mg/1000 revolutions as measured by the Taber Abrasion test.
14. The paper substrate according to claim 1 , wherein the amount of the composition applied is effective to impart to the substrate a surface strength that is less than 50 mg/1000 revolutions as measured by the Taber Abrasion test.
15. The paper substrate according to claim 1 , wherein the amount of the composition applied is effective to impart to the substrate a surface strength that is less than 40 mg/1000 revolutions as measured by the Taber Abrasion test.
16. The paper substrate according to claim 1 , wherein the amount of the composition applied to the substrate is such that the substrate, when in a roll that is 36 inches wide, 50 inches in diameter, and having a 3 inch core, runs continuously for at least two lengths of the roll.
17. A method of making the paper substrate according to claim 1 , comprising contacting the web of fibers with the composition at a size press or a coater.
18. The paper substrate according to claim 1 , where the composition further comprises at least one inorganic salt comprising at least one cation selected from the group consisting essentially of calcium and magnesium.
19. The paper substrate according to claim 1 , wherein:
the at least one binder comprises starch;
the at least one dye fixative comprises a cationic optical brightening agent; and
the at least one crosslinking agent is selected from the group consisting of glyoxal and blocked glyoxal.
20. The paper substrate according to claim 19 , wherein the cationic optical brightening agent is a cationic stilbene-based optical brightening agent.
21. The paper substrate according to claim 1 , wherein the crosslinking agent is selected from the group consisting of glyoxal, blocked glyoxal, borates, and acid anhydrides.