Title: Polyurethane

 Number/Link: US2013/0287982

Applicant/Assignee: Michelin

Publication date: 31-10-2013  (priority PCT/FR)

“Gist”: Use of dithiodiols or dithiodiamines in polyurethane elastomer formulations for improved adhesion to metal.

Why it is interesting: The current invention relates to polyurethane elastomers containing a chain extender mixture consisting of a conventional chain extender (e.g. butandiol) and 1-30% (of the total chain extender) of an S-S bridge containing diol or diamine like 2,2′-dithiodiethanol or 4,4′-dithiodianiline. The resulting polyurethane reportedly shows an increased bonding strength  to metal, which can be even more enhanced by adding elemental sulfur and conventional sulfur-containing rubber-curing accelerators like dithiocarbamates, thiurams, thiazoles etc. (as well known in the art of rubber vulcanization). The resulting polyurethanes are useful for the production of metal strand-reinforced composites like tires and ‘tweels’ (tweel=tire+wheel  see http://michelintweel.com/index.html).

Michelin “tweel”