The Dow Chemical Company

Dow Global Technolgoies LLC

James P Cosman

Raymond A Plepys

Stanley E Moore

Richard J Elwell

Charles A Martin, Ii

Paul D Bettge

Jack M Pal

Christiaan J Kind

Karen Tan

Geoffrey H Dean

Charles A Ii Martin

Chris J Kind

Rigid polyurethane foams are made using a polyol component that includes toluene diamine-initiated polyols containing specified levels of oxyethylene groups. Foams made from these polyols have low k-factors and excellent demold expansion values.

Rigid polyurethane foam based on toluene diamine-initiated polyols

This invention involves several ways for improving a coalescing process for purifying a crude polyether. In one aspect, particulate zirconium dioxide is selected as a coalescing medium. In a second aspect, alkali metal catalyst is recovered and recycled to make additional polyether product. In a third aspect, a polyether stream obtained from the coalescing step is purified by stripping water in at least two phases, the first of which involves moderate conditions so that water but not allyl alcohol or higher molecular weight impurities are removed from the polyether, and the second of which involves more stringent stripping conditions. In a fourth aspect, crude polyether that is subjected to a holding period before undergoing a coalescing step is mixed with water to minimize the formation of impurities that are believed to compatibilize the aqueous and polyether phases. In a fifth aspect, the coalescing process is conducted under a non-oxidizing atmosphere.

Process for purifying polyethers

Polyurethane and/or polyurea dispersions are prepared by reacting certain coreactants with a polyisocyanate in the presence of a preformed polyurethane and/or polyurea dispersion. The resulting products are epsecially useful to prepare flexible polyurethane foams which exhibit low shrinkage. In addition, polyurethane and/or polyurea dispersions having a bimodal particle size distribution are disclosed.

Polyurethane and/or polyurea dispersions in active hydrogen-containing

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Sarnia, Canada

James P Cosman