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US 8,999,111 B2Granted
Method of increasing paper surface strength by using acrylic acid/acrylamide copolymer in a size press formulation containing starch
AssigneeEcolab USA Inc.
InventorsDavid J Castro, Mei Liu, Gary S Furman, Dorota Smoron, Shawnee M Wilson, Zhiyi Zhang
Life of this patent
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Abstract
The invention provides methods and compositions for increasing the strengthening effect of a starch coating on paper. The method involves contacting the starch with a synthetic polymer before the starch is cooked. This changes how the starch gelatinizes and how the polymer gets distributed on the paper resulting in greater paper surface strength.
Claims10
A method of coating a paper substrate, the method comprising the steps of:
- forming a composition by contacting starch and a synthetic polymer during a starch cooking process in a fluid, the fluid being at temperature and conditions such that the starch remains insolubly suspended in the fluid,
- cooking the composition under temperature and conditions sufficient to gelatinize the starch and to open up the starch to water penetration and to form a complex with the synthetic polymer but the temperature and pressure being insufficient to form covalent bonds between the starch and the synthetic polymer, and
- applying the composition to a paper substrate,
- wherein the composition excludes pigment and the synthetic polymer is not a starch,
- and wherein the composition is applied to a paper substrate by one device selected from the list consisting of:
- a size press device, print roll coater device, air-knife coater device, metering bar coater device, blade coater device, under vacuum coater device, cast coating device, and any combination thereof.
3 more elements
Dependencies are inferred from the claim text.