Title: CLEAR HYDROPHOBIC TPU
Number/Link: WO2014/121174
Applicant/Assignee: Lubrizol
Publication date: 7-08-2014
“Gist”: A hydrophobic, clear and low density TPU is prepared from 4,4’MDI, a dimer acid-based polyol and a mixture of “non-stacking” chain extenders.
Why it is interesting: Most commercial TPUs are hydrophilic to a certain extend and because of phase separation and partial crystallization are often transparent but not clear. The current invention teaches a highly hydrophobic and clear TPU made form 4,4′ MDI, a polyester polyol produced by reacting a C36 dimerized fatty acid (“dimer acid”) with 1,6-hexanediol and a chain extender mixture consisting of 1,12-dodecanediol and 2-butyl,2-ethyl propanediol or 1,4-cyclohexanedimethanol (all preferred). Hardblock content in the examples is between 25 and about 45% resulting in a shore A hardness range of about 75 to 95. No thermal data are given.
While this is no doubt an interesting material, I expect this to be a single phase glass with a relatively low Tg and therefore less useful for structural applications.
Example of a C36 dimer acid
Innovation in Polyurethanes 