Abstract: This invention relates to a process for preparing polyamine-epihalohydrin resins having reduced levels of residuals. The process comprises (a) charging a membrane separation apparatus with an aqueous composition comprising at least one polyamine-epihalohydrin resin, and (b) separating the aqueous composition into a permeate and a retentate by passing the aqueous composition through the membrane of the membrane separation apparatus. The retentate comprises at least one polyamine-epihalohydrin resin having lower levels of residuals on an equal active component basis than the aqueous composition of (a). The permeate comprises residuals removed from the aqueous composition of (a) and less than 5% by weight of the active component of said at least one polyamine-epihalohydrin resin. The polyamine-epihalohydrin resins having reduced levels of residuals can be used to make wet strength agents, dry strength agents, creping adhesives for paper products, curing agents for wood product adhesives, and other products.
Abstract: The invention relates to hybrid dispersions comprising nitrocellulose-polyurethanepolyurea particles (NC-PU dispersions) with accelerated drying behavior as compared with the known systems, and also to their use in coating materials.
Type:
Grant
Filed:
August 18, 2008
Date of Patent:
July 13, 2010
Assignee:
Bayer MaterialScience AG
Inventors:
Jörg Tillack, Sebastian Dörr, Rainer Trinks, Maria Almato