Omnova Solutions Inc.

Gencorp, Inc.

Ira John Westerman

Raymond J Weinert

Satish C Sharma

John P Kovalchin

Roman Zorska

Nick G Triantafillopoulos

Paul A Hardy

David M Lee

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.

Gypsum wallboard

A polymeric latex 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.

Polymeric latexes prepared in the presence of 2-acrylamido-2-methylpropanesulfonate

A polymer latex suitable for use in gypsum wallboard or other applications. The polymer latex is a styrene butadiene latex that is substantially stable against divalent ions. The polymer latex includes styrene, butadiene, and an ionic monomer comprised of a 2-acrylamido-2-methyl propanesulfonic acid salt. The polymer latex may also include hydrophilic adjunct comonomers. The latex includes at least 0.25 wt. % of the ionic monomer.

A cement composition comprising a polymeric latex 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.

Cement composition with polymeric latexes prepared in the presence of amps seed

Process for preparing a polymeric latex

A latex binder composition comprises occluded composite particles containing at least a vinyl ester homopolymer or a copolymer thereof polymerized from acrylate and/or ethylene monomers, and a polymer polymerized from conjugated diene and/or vinyl substituted aromatic monomers and desirably unsaturated carboxylic acid monomers. The occluded composite particles are produced in the absence of crosslinking agents by first polymerizing the vinyl esters and optional acrylate and/or ethylene monomers, and subsequently in situ polymerizing the conjugated diene and/or vinyl substituted aromatic, etc., monomers in the presence of the vinyl ester latex particles. The occluded composite-particle latex contains phase separated domains which are neither a core-shell nor an inverted core-shell particle and provide properties which are superior to physical blends of the two classes of polymers when utilized as binders in paper coating formulations. Such properties include excellent ink receptivity, low mottle, good blister resistance, good coating strength, good brightness, and the like.

Growing community of inventors

Wadsworth, OH, United States of America

Ira John Westerman