Method of making sized paper

Abstract From the Canadian patent

A method of making sized paper comprises treating an aqueous pulp slurry containing a cationic neutral sizing agent or a wet sheet prepared with an oxidizing agent. The cationic neutral sizing agent may comprise an acid salt or a quarternary ammonium salt of a diamine derivative of a copolymer formed by reaction of a C6-40 .alpha.-olefin-maleic anhydride copolymer with a diamine having at least one primary amino group. The oxidizing agent may be a halogen e.g. chlorine, bromine or iodine an, oxyacid of a halogen, a salt of an oxyacid of a halogen e.g. sodium hypochlorite, an oxide of a heavy metal or ozone.