TPU/PU-Acrylate Semi-IPNs


 Number/Link: WO2016/191118

Applicant/Assignee: 3M

Publication date: 1-dec-2016

Gist”:  TPU and PU-acrylate oligomers are blended and radiation-cured

Why it is interesting: According to this invention semi-interpenetrating polymer networks (IPNs) that are prepared from thermoplastic polyurethane (or urethane/urea) and acrylate-functional polyurethane oligomers are highly heat-stable and abrasion resistant and can be used for the production of microstructured surfaces.  Microstructured (‘riblet’) surfaces with dimples or ridges of a few to a few hundred microns deep are used as drag reducing coatings on planes, ships and in aeronautics. In the examples 90% of a commercial TPU is blended and co-extruded with 10% of a commercial aliphatic urethane acrylate oligomer.  The extruded film was then laminated on on a microreplicated liner, radiation cured and removed from the liner to produce the riblet surface.

Microstructured layer according to the invention

Microstructured layer according to the invention

PU-Acrylate/Epoxy IPN for 3D Printing


 Number/Link:  WO 2016/153711

Applicant/Assignee: Dow

Publication date: 29-09-2016

Gist”: Acrylate-capped PU prepolymer is copolymerized with epoxides using UV radiation

Why it is interesting: This case is about UV-curable compositions to make flexible materials using additive manufacturing, especially stereolithography.  A prepolymer of an isocyanate and a ‘flexible’ polyol is capped with a hydroxy-functional acrylate, then mixed with a multifunctional epoxy, a multifunctional acrylate ‘monomer’ (a crosslinker also acting as reactive diluent) and two photoinitiators:  one radical and one cationic.  In the example a 6 to 8000 Mole weight diol is capped with TDI and then with hydroxyethyl acrylate.  The prepolymer is then mixed with 3,4-Epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate, 1,6-hexanedioldiacrylate and two photoinitiators.  After UV curing the materials had a shore A hardness between about 60 and 80 and an elongation at break between about 70 and 200.

3,4-Epoxycyclohexylmethyl-3,4- epoxycyclohexane carboxylate

epoxycyclohexane carboxylate

Polyurethane-Acrylate Plastisol


 Number/Link: US2016/0152857

Applicant/Assignee: Polyone

Publication date: 2-06-2016

Gist”: Plastisols from blocked-iso grafted acrylate in plasticizer

Why it is interesting:
Conventional plastisols are suspensions of PVC particles in a (usuallly phthalate-) plasticizer. The suspension can be cured by heating, which results in a plasticized elastomer.  Plastisols are used for coatings of e.g. car underbodies and for ‘screen printing’ of textiles. According to this invention a non-PVC plastisol can be produced by dispersing core-shell acrylate polymer particles (Mn between 300,000 and 1,000,000) with blocked isocyanate groups grafted to the backbone into a plasticizer, preferably into dioctylphthalate, together with a latent amine crosslinker like adipic dihydrazide. No information is given about the blocking agent but the plastisol is said to cure at 130-170°C and be especially suited for textile printing.

Adipic dihydrazide

Adipic dihydrazide