Title: POLYURETHANE

 Number/Link: US2015/0119535

Applicant/Assignee: Nippon Soda

Publication date: 30-04-2015 (priority PCT/JP)

“Gist”: TPU based on a ‘hybrid’ polybutadiene-polyester polyol and an asymmetric isocyanate

Why it is interesting: According to this invention, TPUs with excellent water-resistance can be prepared from a polyol which is made by reacting a polybutadiene diol with a mole weight of a few 1000 with a cyclic ester monomer, up to a mole weight of about 5000 to 15000 (preferred).  The resulting ‘hybdrid’  (polyester-polybutadiene-polyester) polyol is then prepolymerized with a surplus of an assymetric di-isocyanate. Finally the prepolymer is reacted with a chain extender to make the TPU. In the examples polybutadiene diols are reacted with ε-caprolactone and then with IPDI or 2,4-TDI.  The chain extender used is 1,4-butanediol. Interesting materials and (but) relatively soft as would be expected.

Caprolactone