Title: POLYURETHANE BASED ON RENEWABLE RAW MATERIALS

 Number/Link: WO2015/000722

Applicant/Assignee: BASF

Publication date: 8-01-2015

“Gist”: Preparing TPU from polyester diols based on a blend of diacids reduces blooming

Why it is interesting: This application relates to polyester polyols prepared from a diol and a mixture of  diacids of which “at least one is at least partly” produced from a renewable resource. When these polyester diols are reacted with a diisocyanate and a chain extender, the resulting TPU shows a reduced tendency to “bloom” (i.e. form a white exudate on the surface). In the examples TPUs based on polyester polyols prepared from 1,3-propanediol and either azaleic- or sebacid acid (all from renewable resources) show very strong blooming while a TPU based on a polyester polyol prepared from 1,3-propanediol and a 1:1 blend of azeleic- and sebacic acid  shows very little blooming. While this an interesting effect, it is not clear to me why “at least one of the diacids needs to be at least partly” made from a renewable resource is claimed. The claim appears unrelated to the actual invention.

Sebacic Acid