Patent Title: POLYURETHANE RESINS HAVING MULTIPLE MECHANISMS OF HARDENING FOR USE IN PRODUCING THREE-DIMENSIONAL OBJECTS

 Number/Link: US2016137839

Applicant/Assignee: Carbon3D

Publication date: 19-05-2016

“Gist”: Isocyanates are blocked with ethylenically unsaturated blocking agents

Why it is interesting: This invention relates to additive manufacturing of 3D objects using photocurable liquids. The liquid consists of a diisocyanate, or a difunctional isocyanate-ended prepolymer, which is blocked with an ethylenically unsaturated blocking agent, for example t-butylaminoethylmethacrylate (TBAEMA). The photocurable liquid further comprises a diol (or diamine), a photoinitiator and a ethylenically unsaturated diluent, for example a methacrylate or a styrene.  The liquid can then be selectively cured into an intermediate solid 3D object by irradiation with UV light using conventional “printing” methods. After an optional washing stage the intermediate object can be finally cured using heat.

TBAEMA