TPU Foams

Title: POLYURETHANE FOAMS AND METHOD FOR PRODUCING SAME

Number/Link: US2017/0174818

Applicant/Assignee: Lubrizol

Publication Date: 22-june-2016 (PCT oct. 2015)

“Gist”: TPUs with specific MW and polydispersity are injection moulded together with cellopener and gas in supercritical state

Why it is interesting: The invention relates to injection moulded “flexible foams”, especially useful for footwear applications. Thermoplastic polyurethanes with a Mw of 120,000 to 500,000 and a dispersity index of 1.85 to 2.51 are foamed using a gaseous blowing agent (CO2 or C1 to C6 hydrocarbons etc. ) together with a cellopener (silicone or EO/PO surfactant), such that at least 50% of cells are open.  In the examples the blowing agent is added in supercritical state to the melt before injection moulding. The type of gas used, nor the densities of the foams are mentioned.  Foaming TPU with gas in supercitical has also been file by Nike as discussed before in this blog.

Nike shoe with foamed thermoplastic midsole

 

TPU from Oleic Acid

Title: RENEWABLY DERIVED THERMOPLASTIC POLYESTER-BASED URETHANES AND METHODS OF MAKING AND USING THE SAME

Number/Link: US2017/0145145

Applicant/Assignee: Trent University

Publication Date: 25-may-2017

“Gist”: Thermoplastic polyurethane made entirely from C9 monomers derived from oleic acid.

Why it is interesting: Azaleic acid can be prepared by oxidative cleavage of the oleic acid double bond.  Azaleic acid in turn can be converted to 1,9-nonanediol and to 1,7-heptamethyldiisocyanate via azides and Curtius rearrangment (see previous blog post). In this invention a polyester diol is prepared from azaleic acid and nonanediol and is then reacted with 1,7-heptamethylenediisocyanate together with nonanediol as chain extender, resulting in a phase-separated TPU. Best properties are obtained when the nonanediol is first prepolymerized with the diisocyanate. The TPU is said to degrade without cytotoxic degradation products, and is therefore useful for medical applications such as resorbable implants and scaffolds.
Related case: US2017/0145146.

Oleic Acid

 

Crystalline High-Hardblock TPU

Title: CRYSTALLINE HIGH MODULUS THERMOPLASTIC POLYURETHANE

Number/LinkWO2017079101  WO2017079188

Applicant/Assignee: Lubrizol

Publication Date: 11 May 2017

“Gist”: High-hardblock TPU using ‘stacking’ chain extenders and MDI

Why it is interesting: Thermoplastic polyurethanes with hardblock levels of 75% and higher were first patented by Upjohn in 1981 in a “classic” patent which has been discussed before in this blog. These materials – often marketed under the ‘ISOPLAST’ tradename- are usually produced from a diol, 4,4′-MDI and a (mixture of) chain extender(s) comprising a ‘non-stacking’ chain extender like cyclohexanedimethylol, neopentylglycol, MPdiol etc. to control crystallinity. In the current invention only ‘stacking’ chain extenders are used in an otherwise identical composition, resulting -unsurprisingly- in a more crystalline material with a higher modulus and melting temperature. It is also said that these materials are easier to compound with e.g. fire retardants.
Even if this idea were formally ‘new’ I doubt its inventiveness and therefore its patentability.

The famous ISOPLAST(TM) nail

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