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.