Title: PROCESS FOR MAKING A POLYMER POLYOL

 Number/Link: WO2015/165761  (German)

Applicant/Assignee: BASF

Publication date: 5-11-2015

“Gist”: Polymer polyols are prepared by melt-dispersing SAN into a carrier polyol using a specific stabilizer

Why it is interesting: Polymer polyols, or ‘graft polyols’, contain finely dispersed polymeric particles and are especially useful for the production of flexible polyurethane foams.  Usually polymer polyols are produced by in-situ polymerization of styrene-acrylonitrile (SAN)- or polyurea particles in a carrier polyol. In this invention, polymer polyols are prepared by dispersing molten SAN into a carrier polyol using shear mixing and a specific stabilizer.  The stabilizer is a (preferably) comb-shaped polyol-SAN copolymer, and is described in another BASF application: WO2015/165878. The polymer polyols are said to have a fine and uniform particle size distribution, a low viscosity and a high stability against segregation.

SAN