Strengthening fibrous material, useful for paper or cardboard for packaging

摘要

A method of strengthening fibrous materials comprises: (i) (partial) impregnation with a solvent-free impregnant containing (A) 5-95 wt.% oligomer(s) and/or polymer(s) based on epoxy (meth)acrylates, urethane acrylates, polyester acrylates, polyether acrylates and/or acrylated polyacrylates, which become highly cross-linked when exposed to actinic radiation, (B) 5-95 wt.% di- and/or poly- functional monomer(s) cross-linked by actinic radiation, (C) 0-10 wt.% photoinitiator(s) and (D) 0-10 wt.% co-initiator(s); followed by (ii) curing with actinic radiation. An Independent claim is also included for the use of the impregnant composition for strengthening fibrous materials.