Air Products and Chemicals, Inc.

John G Smigo

Robert K Pinschmidt, Jr

Andrew Francis Nordquist

Lloyd Mahlon Robeson

George Davidowich

Gerald D Miller

William Eamon Carroll

Thomas P McAndrew

Timothy L Pickering

Poly(vinylamine) homopolymers and copolymers are hydrophobically modified by reaction of amine units present in the polymer with a saturated aliphatic or aromatic glycidyl ether compound. The resulting polymers are useful as flocculants in separating water from suspended solids and are especially effective in improving fines retention in papermaking. Poly(vinylamine hydrochloride) modified in this manner with butyl glycidyl ether is shown to be very efficient in retaining the paper product fines present in recycle paper pulps.

Modification of poly (vinylamine)

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.

Crosslinked vinyl alcohol/vinylamine copolymers for dry end paper

Polyvinylaminals, optionally as the formed copolymer with polyvinyl hemiaminals, and polyvinyl acetals are added to a papermaking pulp slurry to improve the retention of fines in the final paper product. This polymer is provided by reacting a poly(vinylamine) which can be a homopolymer or a copolymer containing vinyl alcohol and vinyl amine units with a monoaldehyde. The aldehyde, such as butyraldehyde, modifies the structure of the polymer and increases its hydrophobicity. The use of these polymers in papermaking involving the recycle of waste papers provides notable advantages in fines retention because of the high level of fines which normally accompany such recycle paper waste.

Fines retention in papermaking with amine functional polymers

Polyvinylaminals, optionally as the formed copolymer with polyvinylhemiaminals and polyvinylacetals are useful as separating agents and are provided by reacting a poly(vinylamine) or a copolymer containing vinyl alcohol and vinylamine units with a monoaldehyde. The aldehyde, such as butyraldehyde, can be introduced into the polymer aminalization as a liquid or gas, generally in a proportion of about 0.02 to 0.5 mol per mol of alcohol and amine units in the polymer chain. These polymers, especially as the cationic salt, perform very well in the flocculation, settling, clarification and dewatering of wastewater.

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Macungie, PA, United States of America

John G Smigo