Claims
- 1. A method of making paper or paperboard comprising:a) introducing at least one acidic aqueous alumina sol and at least one synthetic hectorite microparticle additive to a papermaking pulp to form a treated pulp; and b) forming the treated pulp into paper or paperboard; wherein said acidic aqueous alumina sol contains elongated secondary particles that are elongated from about 50 nm to about 300 nm in only one plane and are formed by edge-to-edge coagulation of rectangular plate-like primary particles having a length on one side of from about 10 nm to about 30 nm when observed through an electron microscope, and wherein said acidic aqueous alumina sol is made of particles having an alumina hydrate boehmite structure and said acidic aqueous alumina sol is added in amounts of from about 0.01% to about 0.5% by weight based on dried solids weight of both said sol and said pulp.
- 2. The method of claim 1, wherein said sol has a pH of from about 3 to about 6.
- 3. The method of claim 1, wherein said acidic aqueous alumina sol is added to said pulp in an amount of at least about 0.05 pound based on the dried solids weight of both the sol and the pulp.
- 4. The method of claim 1, wherein said acidic aqueous alumina sol is added to said pulp in an amount of from about 0.3 pound per ton of paperstock to about 5.0 pounds per ton of paperstock based on the dried solids weight of both the sol and the pulp.
- 5. The method of claim 1, further comprising introducing at least one anionic polyacrylamide to the pulp.
- 6. The method of claim 1, further comprising combining at least one cationic starch with said papermaking pulp prior to introducing said at least one acidic aqueous alumina sol to said pulp.
- 7. The method of claim 1, wherein said pulp comprises a sulfite pulp.
- 8. The method of claim 1, further comprising introducing at least one polymer composition to the pulp or treated pulp.
- 9. The method of claim 8, wherein said at least one cationic polymer composition comprises a cationic polyacrylamide polymer.
- 10. The method of claim 8, wherein said at least one cationic polymer composition is a synthetic, water-soluble cationic polymer containing acrylamide units and cationic monomeric units.
- 11. The method of claim 1, further comprising adding a high molecular weight cationic polymer to said papermaking pulp, followed by subjecting the suspension to high shear conditions, before adding said acidic aqueous alumina sol.
- 12. The method of claim 1, further comprising adding at least one cellulytic enzyme to said pulp or treated pulp.
- 13. The method of claim 1, further comprising adding at least one cellulytic enzyme to said pulp before introducing said acidic aqueous alumina sol to said pulp.
- 14. A paper or paperboard made according to the method of claim 1.
- 15. The method of claim 1, wherein said synthetic hectorite microparticle additive is introduced in an amount of from about 0.1 pounds to about 2.0 pounds per ton of pulp, based on dried solids weight of both said additive and said pulp.
- 16. A paper or paperboard made from a drained paperweb, said paperweb comprising cellulosic fibers, and at least one synthetic hectorite microparticle additive, and from about 0.01% to about 0.5% by weight of an acidic aqueous alumina sol based on dried solids weight of both said sol and said paperweb, wherein said acidic aqueous alumina sol contains elongated secondary particles that are elongated from about 50 nm to about 300 nm in only one plane and are formed by edge-to-edge coagulation of rectangular plate-like primary particles having a length on one side of from about 10 nm to about 30 nm when observed through an electron microscope, and wherein said acidic aqueous alumina sol is made of particles having an alumina hydrate boehmite structure.
- 17. The paper or paperboard of claim 16, wherein said sol has a pH of from about 3 to about 6.
- 18. The paper or paperboard of claim 16, wherein said acidic aqueous alumina sol contains elongated secondary particles that are elongated from about 50 nm to about 300 nm in only one plane and are formed by edge-to-edge coagulation of rectangular plate-like primary particles having a length on one side of from about 10 nm to about 30 nm when observed through an electron microscope.
- 19. The paper or paperboard of claim 16, wherein said synthetic hectorite microparticle additive is present in an amount of from about 0.1 pounds to about 2.0 pounds per tan of paperweb, based on dried solids weight of both said additive and said paperweb.
- 20. A paper or paperboard made from a drained and dried paperweb formed from a papermaking pulp comprising cellulosic fibers, and at least one synthetic microparticle additive, and from about 0.01% to about 0.5% by weight of an acidic aqueous alumina sol based on dried solids weight of both said sol and said pulp, wherein said acidic aqueous alumina sol contains elongated secondary particles that are elongated from about 50 nm to about 300 nm in only one plane and are formed by edge-to-edge coagulation of rectangular plate-like primary particles having a length on one side of from about 10 nm to about 30 nm when observed through an electron microscope, and wherein said acidic aqueous alumina sol is made of particles having an alumina hydrate boehmite structure.
- 21. The paper or paperboard of claim 20, wherein said synthetic hectorite microparticle additive is present in an amount of from about 0.1 pounds to about 2.0 pounds per ton of pulp, based on dried solids weight of both said additive and said pulp.
Parent Case Info
This application claims the benefit under 35 U.S.C. § 119(c) of prior U.S. Provisional Patent Application No. 60/205,012 filed May 17, 2000, which is incorporated in its entirety by reference herein.
US Referenced Citations (15)
Foreign Referenced Citations (3)
Number |
Date |
Country |
WO 9741063 |
Nov 1997 |
WO |
WO 9943780 |
Sep 1999 |
WO |
WO 0053532 |
Sep 2000 |
WO |
Non-Patent Literature Citations (4)
Entry |
Smook, G. A.; “Handbook for Pulp and Paper Technologists”, 1982, TAPPI, Atlanta, USA pp. 208-243. |
Copy of International Search Report PCT/US01/16075, dated Jan. 30, 2002. |
Copy of U.S. patent application No. 09/803,225, filed Mar. 9, 2001. |
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Provisional Applications (1)
|
Number |
Date |
Country |
|
60/205012 |
May 2000 |
US |