Method and composition for the sizing of paper using azetidinium and/or guanidine polymers

A printed paper product prepared by a method, comprising the steps of:

• (A) applying to an exposed surface of a paper substrate a sizing composition comprised of
• (1) a sizing agent selected from the group consisting of
• (a) an acidic salt of a guanidine polymer comprised of monomer units having the structural formula (IV)
• wherein R3 is hydrogen or lower alkyl and R4 is hydrogen, alkyl, alkoxy, or hydroxyl-substituted alkoxy, and n is an integer in the range of 1 to 10 inclusive,
• (b) a mixture of an azetidinium polymer and an acidic salt of a guanidine polymer comprised of monomer units having the structural formula (IV) as defined above, and
• (c) a copolymer of an azetidinium monomer and a guanidine monomer,
• (2) up to 40 wt. % of an optional film-forming binder, and
• (3) a liquid vehicle, wherein the sizing agent is admixed with the liquid vehicle prior to direct application of the sizing composition to the substrate surface, and
• (B) applying to the sized paper substrate a dye composition containing a reactive dye having ionizable and/or nucleophilic groups capable of reacting with the sizing agent thereby providing a sized substrate,
• wherein if the sizing agent is (a) or (c), then film-forming binder is present and the sizing agent represents approximately 5 wt. % to 95 wt. % of the sizing composition, based upon total solids weights of the sizing composition after drying.