All posts in category Thermoplastics

Supercritically Foamed Thermoplastic Polyurethane

Title: LOW DENSITY FOAM, MIDSOLE, FOOTWEAR, AND METHODS FOR MAKING LOW DENSITY FOAM

Number/Link: WO2015/017088

Applicant/Assignee: Nike

Publication date: 5-02-2015

“Gist”: TPU blown with supercritical CO2 and/or N2

Why it is interesting: This case relates to foamed TPU (or EVA) with densities down to 150 kg/m³. The low density is accomplished by the combination of a conventional physical blowing agent and a supercritical fluid, specifically supercritical CO2 or N2 or a combination of these. The conventional blowing agent is incorporated into the polymer pellets before these are added to the extruder while the supercritical fluid is added to the molten polymer through a port in the extruder barrel. The material is then extruded or injection moulded. Nike have filed two more patents on this technology: WO2015/017089 and WO2015/017090.

Nike shoe with foamed thermoplastic midsole

1 Comment

by Gerhard Bleys on February 9, 2015 • Permalink

Posted in Elastomers, Thermoplastics

Tagged blowing agent, comfort, elastomers, EVA, footwear, nano, TPE, TPU

Posted by Gerhard Bleys on February 9, 2015

https://purpatents.com/2015/02/09/supercritically-foamed-thermoplastic-polyurethane/

Cross-Linked Melt-Spun Polyurethane Fibers

Title: ISOCYANATE PREPOLYMER COMPOSITION AND CROSSLINKED POLYURETHANE PREPARED THEREFROM

Number/Link: WO2015/007731

Applicant/Assignee: BASF

Publication date: 22-01-2015

“Gist”: Melt spinning a TPU – prepolymer blend.

Why it is interesting: Crosslinked polyurethane fibers are produced by melt-spinning a thermoplastic polyurethane which is melt-blended with a specific isocyanate prepolymer composition. The prepolymer composition is a mixture of a polymeric MDI and the reaction product of a polyester polyol and an excess of 4.4′-MDI. The polyester polyol is prepared from adipic acid together with 2-methyl-1,3-propanediol (MPdiol) and/or trimethylolpropane. The prepolymer composition is characterized by its low viscosity (probably due to the use of the branched polyester). The crosslinked fibers show an improved tensile set and temperature resistance.

Polymeric MDI

Polyester TPU with Reduced Blooming

Title: POLYURETHANE BASED ON RENEWABLE RAW MATERIALS

Number/Link: WO2015/000722

Applicant/Assignee: BASF

Publication date: 8-01-2015

“Gist”: Preparing TPU from polyester diols based on a blend of diacids reduces blooming

Why it is interesting: This application relates to polyester polyols prepared from a diol and a mixture of diacids of which “at least one is at least partly” produced from a renewable resource. When these polyester diols are reacted with a diisocyanate and a chain extender, the resulting TPU shows a reduced tendency to “bloom” (i.e. form a white exudate on the surface). In the examples TPUs based on polyester polyols prepared from 1,3-propanediol and either azaleic- or sebacid acid (all from renewable resources) show very strong blooming while a TPU based on a polyester polyol prepared from 1,3-propanediol and a 1:1 blend of azeleic- and sebacic acid shows very little blooming. While this an interesting effect, it is not clear to me why “at least one of the diacids needs to be at least partly” made from a renewable resource is claimed. The claim appears unrelated to the actual invention.

Sebacic Acid

Innovation in Polyurethanes

All posts in category Thermoplastics

Supercritically Foamed Thermoplastic Polyurethane

Cross-Linked Melt-Spun Polyurethane Fibers

Polyester TPU with Reduced Blooming

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