Patent Title: REACTIVE POLYURETHANE PLASTICIZERS AND ADHESIVES MADE THEREFROM

 Number/Link: W02016179131

Applicant/Assignee: Dow

Publication date: 10-11-2016

“Gist”: An EO/PO monol is reacted with an excess of 4,4′-MDI

Why it is interesting: The invention is about reactive PU plasticizers which are said to be especially useful for polyurethane moisture curing adhesives used in automotive glass bonding. As opposed to conventional plasticizers they will supposedly not migrate and therefore not degrade adhesive properties over time or cause window fogging. The reactive plasticizers are prepared by reacting a slight excess of 4,4′-MDI with and EO/PO monol of MW between 500 and 2000 Da and an EO:PO ratio of about 1:1, such that the resulting in NCO content is between 0.1 and 1%.  Obviously at such low NCO values most of the MDI will have reacted twice with monol, and the resulting non-reactive plasticizer may (in my opinion) well migrate depending on the composition of both monol and adhesive.

4,4′-MDI