Paper making and fiber liberation – Processes and products – Non-fiber additive
Reexamination Certificate
1999-04-06
2001-09-11
Fortuna, Jose (Department: 1731)
Paper making and fiber liberation
Processes and products
Non-fiber additive
C162S175000, C162S158000, C162S168600, C162S181100
Reexamination Certificate
active
06287423
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to novel polymer compositions which contain amide, sulfonate and/or phosphonate groups and method of use, including, but not limited to, paper making methods, particularly as retention or strength aids.
BACKGROUND OF THE INVENTION
Currently, filler levels in paper are limited, in part, by paper strength losses as filler levels increase. Minimum strength requirements prohibit the paper maker from adding more filler which is desirable because fillers are generally less expensive than the wood fiber that they replace. The ability to add more filler would allow the paper maker to reduce paper production costs by replacing the more expensive fiber. In order to achieve higher filler levels, the paper maker needs fillers, additives or processes which increase paper strength. Historically, the paper maker has used filler modification, wet end additives and fiber modifications to achieve higher strength levels in paper. Filler modifications have included changing filler type, changing filler particle size and surface treatments of fillers. Wet end additives have included synthetic and natural polymers such as polyacrylamides and starches. Fiber modifications have included changing fiber type and fiber processing.
In general, the paper industry is trending toward higher filler levels to reduce costs and as a result is continually looking for ways to improve paper strength. To achieve this, a new generation of strength aids is required for the paper industry.
In U.S. Pat. No. 3,709,780, there is disclosed paper products having improved strength properties by adding to the cellulose paper dispersion a chitin-based compound of a graft copolymer of 2-acrylamide-2-methylpropanesulfonic acid (AMPS) onto a chitosan substrate.
In U.S. Pat. No. 3,692,673, there is disclosed polymers of acrylamido sulfonic acids, and their salts, which are useful as flocculants or aqueous systems.
In U.S. Pat. No. 4,555,558, there is disclosed water soluble terpolymers of AMPS; N,N-dimethylacrylamide; and acrylonitrile. These terpolymers are reported to provide high temperature fluid loss additives and rheology stabilizers for high calcium-containing, brine clay drilling fluids.
In U.S. Pat. No. 3,926,718, there is disclosed the use of water-soluble block polymers having blocks derived from a water-soluble monomer and blocks derived from N-vinyl pyrrolidone. These polymers are reported to perform as drainage and retention aids for paper webs where the polymer is added to a pulp slurry.
In U.S. Pat. No. 5,075,401, there is disclosed a graft copolymer made by a free radical reaction mechanism. The copolymer uses polymeric units of acrylamide, acrylic acid and/or AMPS.
REFERENCES:
patent: 3692673 (1972-09-01), Hoke
patent: 3709780 (1973-01-01), Slagel et al.
patent: 3926718 (1975-12-01), Guilbault et al.
patent: 4555558 (1985-11-01), Giddings et al.
patent: 5028271 (1991-07-01), Huddleston et al.
patent: 5064730 (1991-11-01), Takano et al.
patent: 5075401 (1991-12-01), Zhang
patent: 5336316 (1994-08-01), Dawson et al.
patent: 5368690 (1994-11-01), Solarek et al.
patent: 5538596 (1996-07-01), Satterfield et al.
patent: 5627145 (1997-05-01), Thevissen
patent: 5880236 (1999-03-01), Konrad et al.
patent: 5942086 (1999-08-01), Owen
patent: 5985992 (1999-11-01), Chen
patent: 5988279 (1999-11-01), Udarbe et al.
patent: 5989391 (1999-11-01), Watanabe et al.
Drummond Donald Kendall
Wernett Patrick Clinton
Fortuna Jose
Minerals Technologies Inc.
Powell Marvin J.
LandOfFree
Paper composition for improved sheet properties does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Paper composition for improved sheet properties, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Paper composition for improved sheet properties will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2547960