US 7,371,796 B2
	Copolymers of vinyl alcohol and itaconic acid for use in paper coatings
Elliott Echt, Wilmington, Del. (US); Peter A. Morken, Wilmington, Del. (US); and G. Michael Collins, League City, Tex. (US)
Assigned to E. I. du Pont de Nemours and Company, Wilmington, Del. (US)
Filed on Dec. 15, 2004, as Appl. No. 11/12,516.
Claims priority of provisional application 60/529855, filed on Dec. 15, 2003.
Prior Publication US 2005/0154120 A1, Jul. 14, 2005
Int. Cl. D21H 19/60 (2006.01); C09D 131/04 (2006.01); C09D 133/02 (2006.01); C09D 133/08 (2006.01)

U.S. Cl. 524—557  [524/561; 524/564; 524/803; 526/318.3; 526/318.4; 526/318.44; 526/318.5; 526/330; 526/329.5]

13 Claims

1. A method for preparing a high solids paper coating composition having an aqueous phase, said aqueous phase comprising a copolymer comprising units of vinyl alcohol, alkyl acrylate, itaconic acid and optionally vinyl acetate, said copolymer comprising i) less than about 5 mol % vinyl acetate units; (ii) about 1 mol % to about 9 mol % itaconic acid units; (iii) at least about 90 mol % vinyl alcohol units and (iv) about 1 mol % to about 9 mol % alkyl acrylate units wherein said copolymer is completely dissolved in said aqueous phase of the coating composition and the amount of water present in said aqueous phase is such that the concentration of water in the paper coating composition is less than 40% by weight, based on the total weight of the paper coating composition, the method comprising the steps of: providing a first aqueous composition and adding said copolymer as a dry solid component to said first aqueous composition.