Patent Title: POLYURETHANE BASED GEL COMPOSITION

 Number/Link: W016/036786

Applicant/Assignee: Dow

Publication date: 10-03-2016

“Gist”: PU gels are made from MDI prepolymer, high EO polyol and some diamine at low NCO index.

Why it is interesting: Polyurethane gels are well known and are sometimes used in comfort cushioning as layers or dispersed as particles in e.g. viscoelastic matresses. According to this invention plasticizer-free gels can be made by reacting a slightly branched, low NCO prepolymer ( based on 2,4′ and 4,4′ MDI and a high EO polyol), with a large amount of high EO polyol (triol or higher) and some amine-ended low mole-weight diol.
Although the material is said to be ‘plasticizer-free’not all of the polyol will be reacted at low NCO index.  However, because of its high polarity, the unreacted polyol will probably not leach.

A Polyurethane Gel