PU-Acrylate/Epoxy IPN for 3D Printing

Patent Title: PHOTOCURABLE COMPOSITIONS FOR THREE-DIMENSIONAL 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

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

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Toughened Thermoplastic Polyurethane

Title: Method Of Toughening Thermoplastic Polyurethane And Articles Comprising Toughened Thermoplastic Polyurethane

 Number/Link: US2013/0323512

Applicant/Assignee: Nike

Publication date: 5-12-2013

Gist”: TPU is interpenetrated with a thermosetting PU using a solvent

Why it is interesting: According to this invention a conventional TPU can be “toughened” by dipping and  swelling it in a solution containing (about) 20% of a PU-forming composition comprising a polyester polyol, a chain extender, a mixture of pure and polymeric MDI and DBTDL as a catalyst.  The solvent is preferably acetone. The swollen TPU is dried and the PU is cured by heating. It is believed that a TPU-PU interpenetrating polymer network (IPN) is formed.  The invention is targeted at improving the scuff resistance of golf balls. (scuff resistance=resistance against failure of the coating by shear stress).

Nike golf ball.

Nike golf ball.

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