Patent Title: POLYURETHANES WITH GOOD PERMEABILITY FOR ELECTROMAGNETIC RADIATION
Number/Link: WO2019/002350 (German)
Applicant/Assignee: BASF
Publication Date: 3 January 2019
“Gist”: TPU based on aliphatic polycarbonate diol
Why it is interesting: The invention relates to thermoplastic polyurethanes with a high permeabilty to electromagnetic radiation, especially in the 0.5 to 3 GHz frequency range. (I assume these materials are aimed at mobile phone covers and the like). ‘Surprisingly’ it was found that such TPUs can be prepared from polycarbonate diols which are based on butanediol, pentanediol or hexanediol. In the examples, TPUs based on these diols together with BDO and 1,6-HDI or 4,4′-MDI, show a lower dielectric loss factor at 400 MHz as compared to TPUs based on other polyols.

TPU mobile phone case.