Gypsum composition with styrene butadiene latex additive
AssigneeOMNOVA Solutions Inc.
InventorsJohn I. Westerman, Paul A. Hardy, Roman Zorska
Life of this patent
Estimating the term…
Abstract
Gypsum wallboard 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 latex substantially stable against divalent ions in which the styrene butadiene polymer includes at least 0.25 wt. % of an ionic monomer.
Claims31
A composition for making gypsum products comprising
- water,
- a foaming agent, paper pulp or both,
- calcium sulfate hemihydrate, and
- an aqueous styrene butadiene polymer latex substantially stable against divalent ions in which the styrene butadiene polymer includes at least 0.25 wt. % of 2-acrylamido-2-methyl propanesulfonic acid salt, said aqueous styrene butadiene polymer present in an amount of about 0.1 to 10 wt. % based on the weight of the calcium sulfate hemihydrate.
A composition comprising gypsum and an aqueous styrene butadiene polymer latex substantially stable against divalent ions, the latex being prepared by aqueous emulsion polymerization of a monomeric mixture comprising styrene and butadiene in the presence of a seed polymer prepared by aqueous emulsion polymerization of styrene and a salt of 2-acrylamido-2-methylpropanesulfonic acid in which least 0.25 wt. % of an ionic monomer.
A composition for making gypsum wallboard comprising
- water,
- a foaming agent, paper pulp or both,
- about 40 to 60 wt. % of calcium sulfate hemihydrate, and
- an aqueous styrene butadiene polymer latex substantially stable against divalent ions in which the styrene butadiene polymer includes at least 0.25 wt. % of 2-acrylamido-2-methyl propanesulfonic acid salt, wherein the amount of styrene butadiene polymer in the composition is 0.1 to 10 wt. %, based on the weight of calcium sulfate hemihydrate in the composition.
A composition for making gypsum products comprising
- water,
- calcium sulfate hemihydrate, and
- an aqueous styrene butadiene polymer latex substantially stable against divalent ions in which the styrene butadiene polymer includes about 0.25 to 20 wt. %, based on the weight of the polymer, of 2-acrylamido-2-methyl propanesulfonic acid salt.
A composition for making gypsum products consisting essentially of water, calcium sulfate hemihydrate, and an aqueous styrene butadiene polymer latex substantially stable against divalent ions in which the styrene butadiene polymer consists of
- (a) styrene,
- (b) butadiene,
- (c) about 0.25 to 20 wt. %, based on the weight of the polymer, of 2-acrylamido-2-methyl propanesulfonic acid salt,
- (d) an optional hydrophilic adjunct comonomer selected from the group consisting of hydroxyethyl methacryalte, acrylonitrile, methacrylonitrile, acrylamide and methacrylamide, and
- (e) an optional additional monomer selected from the group consisting of isoprene, chloroprene, alpha-methylstyrene, 4-methylstyrene, 4-tert-butylstyrene, 4-ethylstyrene, divinylbenzene, vinylidene chloride, 2-vinylpyridine, 4-vinyl pyridine, metal and ammonium salts of acrylic acid and methacrylic acid, substituted and unsubstituted amides of acrylic acid and methacrylic acid other than acrylamide and methacrylamide, nitrites of acrylic and methacrylic acid other than acrylonitrile and methacrylonitrile, and C1 to C12 esters of acrylic acid and methacrylic acid.
Dependencies are inferred from the claim text.