Papers having borate-based complexing and method of making same
The present invention relates to paper substrates containing either an internal starch or a size press applied starch and a boron-containing compound and having improved physical and mechanical properties, as well as methods of making and using the same.
1. A paper or paperboard, comprising
cellulosic fibers, and
a sizing or coating composition comprising
starch; and
a boron-containing compound, wherein
the amount of boron-containing compound is equal to or less than about 7% by weight of the starch; and
greater than 50% of the starch and boron-containing compound is located at least one surface of the web;
and wherein at least a portion of the starch and boron-containing compound penetrates the surface of the web.
2. The paper or paperboard of claim 1 wherein the amount of starch is equal to or less than about 200 lbs per ton of fiber.
3. The paper or paperboard of claim 1 wherein the boron-containing compound is selected from the group consisting of boric acid and borate metal salts.
4. The paper or paperboard of claim 1 , wherein the boron-containing compound is selected from the group consisting of boric acid, borax, and zinc borate.
5. The paper or paperboard of claim 1 wherein the boron-containing compound and the starch form a complex.
6. The paper or paperboard according to claim 1 , wherein the amount of boron-containing compound is from about 0.2% to about 7% by weight of the starch.
7. The paper or paperboard according to claim 1 , wherein the amount of boron-containing compound is less than 5% by weight of the starch.
8. The paper or paperboard according to claim 1 , wherein the amount of boron-containing compound is from about 0.2 to less than 5% by weight of the starch.
9. The paper or paperboard according to claim 1 , further comprising hollow microspheres.
10. The paper or paperboard according to claim 1 , wherein the paper or paperboard is at least one member selected from the group consisting of office paper, form paper, envelope paper, label stock paper, bristol paper, printing paper, publication paper, bleached board, and linerboard.
11. The paper or paperboard of claim 1 wherein the starch is selected from the group consisting of corn starch, wheat starch, potato starch, rice starch, tapioca starch, and sago starch.
12. The paper or paperboard of claim 1 wherein the starch is selected from the group consisting of anionic starch, cationic starch and amphipathic starch.
13. A method for making the paper or paperboard according to claim 1 , comprising:
providing a papermaking furnish comprising cellulosic fibers;
forming a fibrous web from the papermaking furnish;
drying the web; and
sizing or coating the web with the composition to form a sized or coated web.
14. The method of claim 13 further comprising calendering the sized or coated web to provide a finished paper or paperboard.
15. The method according to claim 13 , wherein the papermaking furnish further comprises hollow microspheres.
16. The method according to claim 13 , wherein the amount of boron-containing compound is from about 0.2% to about 7% by weight of the starch.
17. The method according to claim 13 , wherein the amount of boron-containing compound is less than 5% by weight of the starch.
18. The method according to claim 13 , wherein the amount of boron-containing compound is from about 0.2 to less than 5% by weight of the starch.