Patent Title: Vegetable Oil-Modified, Hydrophobic Polyurethane Dispersions

 Number/Link: US20160009852

Applicant/Assignee: Rust-Oleum

Publication date: 14-01-2016

“Gist”: PUDs containing saturated monoglycerids

Why it is interesting: Aqueous polyurethane dispersions are popular for use in environmentally friendly coating compositions. Because of the inherent presence of hydrophilic (often acid-) groups to stabilise these dispersions, the resulting coatings often lack hydrolytic stability. According to this invention, this can be improved by incorporating monoglycerids, prepared by reacting vegetable oils with glycerol followed by distillation, into the PU backbone.  A prepolymer is prepared by reacting the monoglicerids, together with a non-isocyanate urethane polyol (prepared from polyamines and monocyclic carbonates), a conventional long-chain polyol and dimethylolpropionic acid, with an excess of isocyanate. The prepolymer is then neutralized with an amine and subsequently reacted with a chain extender in water to make the PUD. Coatings made with these dispersions are said to be superhydrophobic and have a low friction coeficient.

Dimethylolpropionic acid