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US 5,281,307 AGranted
Crosslinked vinyl alcohol/vinylamine copolymers for dry end paper addition
AssigneeAir Products and Chemicals, Inc.
InventorsJohn G. Smigo, Lloyd M. Robeson, George Davidowich, Gerald D. Miller, William E. Carroll
Life of this patent
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Abstract
An improved papermaking process has been developed to enhance the properties of the resultant paper or paper-type products. The process involves adding a polyvinyl alcohol/vinylamine copolymer along with a crosslinking agent at the dry end step of a conventional papermaking process. Improvements in the properties of the resultant paper products are observed, especially at low levels of copolymer addition.
Claims10
In a papermaking process, the improvement for producing paper having improved strength properties, said improvement comprising:
- adding a polyvinyl alcohol/vinylamine copolymer containing between 0.5 and 25 mole% vinylamine units to the paper stock in the papermaking process in an amount from about 0.1 to 8 wt% of dry copolymer based on dry pulp, and also adding to said paper stock a crosslinking agent capable of crosslinking said copolymer, which crosslinking agent is added to the dry end of the papermaking process.
Dependencies are inferred from the claim text.