Patent ID: 6669816
Filing Date: 2003-12-30
Classification: D21H

Abstract:
A process for the manufacture of coated liquid packaging board having improved long term resistance to edge penetration by lactic acid or hot hydrogen peroxide, which process comprises: (a) forming a sized board of cellulose fibers using a sizing dispersion containing an aqueous dispersion of rosin material, a ketene dimer (AKD) of formula wherein R1, and R2 are C6-C30 hydrocarbon groups as a sizing agent and from 20 to 60 wt % of an aluminum compound calculated as aluminum on rosin material in the sizing dispersion, wherein said aluminum compound is chosen from the group consisting of (1) aluminum sulfate; (2) aluminum polymers of general formula 1[Al(OH)x(A)(3âˆ’x)]nâ€ƒâ€ƒ(1) where A=Clâˆ’, NO3âˆ’, HCOOâˆ’, or CH3COOâˆ’;(3) aluminum polymers of general formula 2 [Al(OH)x,(H3PO4)y(A)(3âˆ’x)]nâ€ƒâ€ƒ(2) where A=Clâˆ’, NO3âˆ’, HCOOâˆ’, or CH3COOâˆ’;(4) aluminum polymers of general formula 3 [Al(OH)x(H3PO4)y (SO4)(3âˆ’x/2)]nâ€ƒâ€ƒ(3) where â€œxâ€  ranges from 0.03 to 2.7, and â€œyâ€  ranges from 0.01 to 0.8 and n&gE;2; and(5) mixtures thereof, and (b) applying to the sized board a suspension containing at least a binder and a pigment to form a coated board.