PUDs for Superhydrophobic Coatings

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

Dimethylolpropionic acid

Self-Crosslinking Polyhydroxyurethanes for Imitation Leather

Title: SELF-CROSSLINKABLE POLYHYDROXY POLYURETHANE RESIN, RESINACEOUS MATERIAL THAT CONTAINS THE RESIN, PROCESS FOR PRODUCTION OF THE RESIN, AND IMITATION LEATHER, SURFACING MATERIAL AND WEATHERSTRIP MATERIAL, USING THE RESIN

 Number/Link: US2013/0095715

Applicant/Assignee: UKIMA CHEMICALS & COLOR

Publication date: 18-04-2013 (priority publication PCT/JP)

Gist”: Poly(hydroxyurethanes) prepared form cyclic carbonates and amines are modified by incorporating blocked isocyanate groups.  The latter can be heat-activated resulting in a self-crosslinking system useful for imitation leathers.

Why it is interesting: Poly(hydroxurethanes) can be produced without isocyanates from cyclic carbonates and amines (see previous posts in this blog on the subject of isocyanate-free polyurethanes) but for the production of imitation leathers (both “synthetic” and “articial” leathers) these materials reportedly are inferior to conventional urethanes. In this invention part of the OH groups of the hydroxyurethanes are reacted with “modifiers”  containing at least one isocyanate group and at least one blocked (or “masked”) isocyanate group.  The resulting resin can be used (as such or in a suitable solvent) in an imitation leather production process and can be ‘self’- crosslinked by heat-activating the blocked isocyanate groups, improving properties.

Example of a "modifier" according to the invention. "Y" is the blocking agent.

Example of a “modifier” according to the invention. “Y” is the blocking agent.