Title: Catalyst for Non-Isocyanate Based Polyurethane
Number/Link:US2015/247004
Applicant/Assignee: Dow; Univ. Northwestern
Publication date: 3-09-2015
“Gist”: The cyclocarbonate-amine reaction is catalysed by a lewis acid/lewis base combination
Why it is interesting: It is well known that polyhydroxyurethanes can be produced from cyclic carbonates and amines. These “nonisocyanate polyurethanes” can have advantages over conventional polyurethanes, e.g. as coatings with improved chemical resistance. The reactivity of (especially 5-ring) cyclocarbonates is however much lower than that of isocyanates making the reaction much less practical. According to this invention that problem can be solved by using a ‘cooperative’ catalyst system consisting of a lewis acid and an organic lewis base. In an example a difunctional cyclocarbonate-capped prepolymer is reacted with 1,3-cyclohexane-bis(methylamine) catalysed by a mixture of lithium trifluoromethanesulfonate and triazabicyclodecene.
It has been noted before in this blog that Dow, as one of the major isocyanate producers, also appears to be interested in non-iso PU.
John Spevacek
/ September 15, 2015I’m always amazed by how patent applications from academics are so different than from industrial researchers. Figures 3, 4 and 5 is this application are a great example as are the activation cycles in Paragraph 0023. They would be needed in a research publication, but are not needed for a patent and will likely hurt them in the future.
Geert Bleys
/ September 15, 2015Yes indeed. Those academics just can’t stop teaching :-)
How’s your teaching going by the way.