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US 8,592,541 B2Granted
Gypsum wallboard
AssigneeOMNOVA Solutions Inc.
InventorIra John Westerman
Life of this patent
Estimating the term…
Abstract
Gypsum wallboard can be made lighter and less dense, without sacrificing strength, by adding to the gypsum slurry used in making the board a styrene butadiene polymer latex substantially stable against divalent ions in which the styrene butadiene polymer includes at least 0.25 wt. % of an ionic monomer.
Claims6
A latex composition, for use in making gypsum wall board, including a polymer having a styrene block and comprising:
- about 4 to 70 wt. % butadiene;
- about 20 to about 95 wt. % styrene;
- and
- at least 0.25 wt. % of an ionic monomer comprised of 2-acrylamido-2-methyl propanesulfonic acid salt;
- wherein said 2-acrylamido-2-methyl propanesulfonic acid salt is present predominantly within the styrene block of said polymer.
2 more elements
Dependencies are inferred from the claim text.