GREASEPROOF PAPER WITH LOWER CONTENT OF FLUOROCHEMICALS

Methods for making and using aqueous dispersions for imparting grease/oil resistance to paper, paperboard and cellulose fiber products generally are provided. In particular, there are provided aqueous colloidal dispersions comprising nanoparticles of at least one colloidal clay and an aqueous fluorochemical, which can be applied to, on, or in paper, paperboard and cellulose fiber products. The paper and products that have been modified using these aqueous dispersions have good resistance to oil and grease penetration with lower overall amounts of aqueous fluorochemicals being required. Additional methods for imparting grease/oil resistance to paper, paperboard and cellulose fiber products generally are provided. In particular, there is provided a process for improving the oil and grease resistance of a cellulose fiber material, the process comprising: a) applying a pretreatment composition comprising a cationic polymer to a cellulose fiber material in a size press to form a pretreated cellulose substrate; b) drying the pretreated cellulose substrate; and c) applying a fluorochemical composition to the dry pretreated cellulose substrate to form an oil-repellent cellulose fiber material.