Color preservation of wax-coated paperboard

A process for preparing an improved wax-coated cellulosic product which comprises the steps of:

• (1) providing a paper or paperboard substrate:
• (2) coating the substrate with a mixture consisting essentially of (A) a fluorinated organic phosphate having the formula
• (R.sub.f L).sub.3-y Z
• wherein
• R.sub.f is R.sub.2 (CF.sub.2).sub.a where R.sub.2 is F or H and a is an integer from 1 to 20, (CF.sub.3).sub.2 CR.sub.3 (CF.sub.2).sub.b where R.sub.3 is F or H when b is O and R.sub.3 is F when b is an integer from 1 to 18, or R.sub.4 (c-C.sub.6 F.sub.10) where R.sub.4 is F or C.sub.n F.sub.2n+1 in which n is an integer from 1 to 4 and c-designates an alicyclic structure,
• L is ##STR6## where R.sub.5 is an alkyl group having from 1 to 10 carbon atoms, or the group
• --(CH.sub.2).sub.n O--
• where n is an integer 1 or 2, y is an integer 1 or 1, and
• Z is P(O)(OM).sub.x where x is the integer 1 or 2, and M is a water-solubilizing cation selected from the group consisting of alkali metal, ammonium and substituted ammonium when x is 1, and each M is independently selected from the group consisting of hydrogen, alkali metal, ammonium and substituted ammonium when x is 2, in an amount of between about 0.01 and about 0.2 pounds, per thousand square feet, and (B) a poly(oxypropylene)poly(oxethylene)block copolymer surfactant in an amount of between about 0.015 and about 0.18 pounds per thousand square feet of said intermediate layer and drying the resulting coated substrate;
• and (3) coating said coated substrate with molten wax.