| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for reducing residuals in a product from a standpoint of environment conservation and the like when preparing polyamine-epihalohydrin resins.SOLUTION: A method comprises (a) charging a membrane separation apparatus with a produced aqueous composition comprising a 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 polyamine-epihalohydrin resin having low levels of residuals can be obtained as the retentate. The polyamine-epihalohydrin resins having residuals removed therefrom as the permeate can be used to produce wet strength agents, dry paper strength agents, creping adhesives for paper products, and curing agents for wood product adhesives. The membrane is a polyamide filtration membrane having a nominal molecular weight cut off range of 150-1,000 Daltons. |
