Photocrosslinkable Polyurethane Coatings and Adhesives

Patent Title: PHOTORESPONSIVE POLYURETHANES

 Number/Link: WO2018/039453

Applicant/Assignee:  Univ of Akron

Publication date: 1-March-2018

Gist”: PU coatings or adhesives with built-in coumarin or phenacyl groups 

Why it is interesting: According to this invention, polyurethane coating- and adhesive systems with two ‘levels of strength’ can be made by incorporating photoresponsive groups like coumarin into the PU backbone.  The coumarin groups will dimerize when irradiated with UV light of about 340nm and can be cleaved again with light of about 250nm. Alkoxyphenacyl groups can also be built into the PU backbone, allowing photocleavage with UV light of 250-350nm. The use of coumarin in (self-healing) coatings is not new and has been discussed before in this blog, so I doubt that this is patentable.

coumarin monomer

Hydroxy functional coumarin monomer

UV Crosslinkable TPU

Title: BREATHABLE AND CROSSLINKABLE THERMOPLASTIC POLYURETHANE

 Number/Link:  WO2015/164695

Applicant/Assignee: Lubrizol

Publication date: 29-10-2015

Gist”: TPU composition containing unsaturated polyester diol and long chain monol

Why it is interesting: A soft, plasticizer-free, TPU with low processing temperature and curable by UV light can be produced by incorporating an unsaturated polyester diol and a linear C20-C65 monol. The unsaturated polyester can e.g. be prepared from butanediol, adipic acid and some trimethylolpropane monallylether.  The TPU is said to be especially useful as UV curable adhesive for fabrics.

Trimethylolpropane monoallyl ether

Trimethylolpropane monoallyl ether