TPU patent landscape: the polymer that outlived its own patents
Thermoplastic polyurethane is the oldest thermoplastic elastomer in industry: in 2027, the base chemistry of polyurethanes turns ninety. Every foundational patent expired long ago, yet patent activity around TPU has not faded — it has changed both its geography and the subject of the contest. We worked through open patent databases and assembled the key documents from 1937 to 2023 to see who protects what around TPU today, and what follows from that for a processor.
The essentials in 30 seconds Polyurethane chemistry was born in November 1937 (DE728981C, Otto Bayer's group at I.G. Farbenindustrie), and TPU as a class in 1959 (US2871218A, Charles Schollenberger, B.F. Goodrich). Both patents have long been in the public domain, so buying, compounding and processing commercial TPU raises no licensing questions. The patent contest has moved from chemistry to formulations and to the way the material is organized: expanded TPU beads, glass-fiber reinforced grades, materials for 3D printing, non-isocyanate chemistry. In our curated sample of 18 documents, US and Chinese publications are level (6 and 6), and every Chinese document is younger than 2007.
What this landscape illuminates
TPU holds a unique position in materials science: an elastomer that is processed like a thermoplastic. By injection molding, by extrusion, and over the past decade by 3D printing as well. For an engineer it is the material of wear-resistant wheels and rollers, seals, cable jackets, hoses, shoe soles and protective films; a hardness range from soft 60 Shore A to rigid grades beyond 70 Shore D covers a whole spectrum of tasks between rubber and structural plastics.
When a material is nearly ninety years old, its patent landscape answers a different question than it would for a young polymer. Not "can this be done at all," but where exactly the technological contest runs today: in which applications, in which formulation moves, and in which jurisdictions. That map is what tells a compounder and a processor where the industry is heading.
Methodology
This is a review landscape, not a statistical one. We worked with open sources — Google Patents, Espacenet, Justia and the USPTO — using queries around thermoplastic polyurethane (TPU) and adjacent classification headings (isocyanate polymerization, CPC C08G18; polyurethane compositions, C08L75). From the results we assembled a curated sample of 18 patent documents from 1937 to 2023; each one was checked against its primary publication page — number, applicant, dates, substance. Market milestones were verified separately on the web (the commercialization of Estane, the launch of expanded TPU beads, the first TPU on a CO₂-based polyol).
For chemistry this mature, a curated sample is more honest than pseudo-statistics: the databases hold hundreds of thousands of C08G18 documents, and any "complete" sample built without commercial tools would be arbitrary. Eighteen verified documents are enough to reveal the structure: who patented, when, and around what.
Two births: the polymer in 1937, the thermoplastic elastomer in 1959
Polyurethane chemistry has a precise date of birth. In November 1937, Otto Bayer's group at I.G. Farbenindustrie filed an application for a process for producing polyurethanes and polyureas by reacting diisocyanates with compounds bearing mobile hydrogen atoms — later granted as DE728981C, "Verfahren zur Herstellung von Polyurethanen bzw. Polyharnstoffen" (Google Patents). This is the ancestor document of the entire industry: it covers both aromatic and aliphatic diisocyanates — in essence, the chemical foundation beneath today's foams, elastomers, coatings and adhesives was described before the war.
But TPU as a class of materials was born later, and elsewhere. In the late 1950s the chemist Charles Schollenberger at B.F. Goodrich was looking for a replacement for vulcanized rubber — and showed that a linear polyurethane with hard and soft segments behaves like a vulcanizate without vulcanization: the physical bonds of the hard domains act in place of a chemical network, and on heating they "come apart," making the material processable. Patent US2871218A, "Simulated vulcanizates of polyurethane elastomers" (issued in January 1959, Google Patents), became the foundation of the first commercial TPU — Estane®, which started with coated industrial fabrics and is still produced today. The very title of the patent — "simulated vulcanizates" — conveys the essence of the invention precisely: rubber you can mold.
Who patents today: the center of gravity shifts east
The classic TPU era belonged to American and European giants — B.F. Goodrich (today the Lubrizol line), Bayer/Covestro, BASF. But our sample of the past two decades shows a pronounced shift: the most consistent patent line is now Chinese, and in it the strategy of Wanhua Chemical — the world's largest MDI producer, that is, of the key feedstock for TPU — is clearly visible.
That line began with process: application CN101020737A (2007) describes continuous production of a thermoplastic polyurethane elastomer (Google Patents). Then came applied compositions: CN109721701A (filed in 2017) protects a TPU composition for heavily loaded hydraulic seals and for escalator and elevator rollers (Google Patents). And then the move into Western jurisdictions with US grants: US11286328B2 (2022) on TPU for 3D printing and US11613627B2 on a halogen-free flame-retardant TPU composition (Google Patents). The trajectory is textbook: first learn to produce cheaply, then protect the formulations, and finally patent where the high-margin markets live.
| Area | Documents in sample | Examples | Period |
|---|---|---|---|
| Reinforced composites (LGF/GF) | 4 | CN103819891A, CN105086422A, WO2009080281A1, US20140343196A1 | 2008–2015 |
| Non-isocyanate PU (NIPU) | 4 | CN101775137B, EP3199569B1, WO2021247815A1, US11820876B2 | 2010–2023 |
| Base chemistry and process | 3 | DE728981C, US2871218A, CN101020737A | 1937–2007 |
| Compositions and flame retardancy | 3 | EP1112315B1, CN109721701A, US11613627B2 | 1999–2023 |
| Expanded beads (E-TPU) | 2 | WO2007082838A1, CN104974370A | 2006–2015 |
| 3D printing | 1 | US11286328B2 | 2018–2022 |
| Chemical recycling | 1 | US6750260B2 | 2001–2004 |
The geography of the sample illustrates the same shift: American and Chinese documents are equally represented, and all the Chinese ones are younger than 2007.
Technology fronts: four battlegrounds of modern TPU
Expanded TPU beads (E-TPU). The loudest TPU innovation of the century is expanded beads that are steam-welded in a mold, combining the resilience of an elastomer with the lightness of a foam. The base document is BASF's application WO2007082838A1 (2006 priority); more on it below. Alongside it in the sample sits the Chinese application CN104974370A on a method of producing TPU beads and bead molding (Google Patents): confirmation that a queue formed quickly behind the pioneer.
Reinforced composites. Glass fiber turns TPU from an elastomer into a structural material with elastomeric impact toughness. The sample holds a whole group: the process application WO2009080281A1 on producing long-fiber thermoplastic compositions (Google Patents), the Chinese compositions CN103819891A (a high-performance LGF-TPU with 20–60 parts by weight of long glass fiber) and CN105086422A (LGF-TPU for anti-slip soles), and the American US20140343196A1 on fiber-filled TPU blends. This is the very class of materials to which the reinforced TPU in our Exaflex® line belongs.
Sustainability: recycling, CO₂ feedstock, non-isocyanate chemistry. There are three sub-fronts here. Chemical recycling — glycolysis of polyurethane waste back to polyols — was already being protected in the early 2000s (US6750260B2, Google Patents), while a recent review in Materials (2024) analyzes an entire pool of active industrial glycolysis patents (MDPI). The feedstock front is polyether carbonate polyols with chemically bound CO₂: in 2018 Covestro presented the first commercial TPU on such a polyol — Desmopan® 37385A (press release). And the most radical is non-isocyanate polyurethanes (NIPU), where urethane linkages form from cyclic carbonates and amines, without isocyanates at all: the sample includes the waterborne NIPU system CN101775137B, foams EP3199569B1, bio-polyol systems WO2021247815A1, and the recent US grant US11820876B2 (2023, Google Patents). NIPU chemistry is still far from a commercial thermoplastic elastomer, but the density of patenting shows that the industry is seriously preparing an exit route from isocyanate dependence.
3D printing. TPU has become the workhorse of flexible printing, both filament and powder-based (SLS). The patent contest is over grades that print consistently: low shrinkage, predictable crystallization, thermal stability in the print zone.
Two patents in close-up
BASF: the foam that changed the footwear industry. Application WO2007082838A1, "Schaumstoffe auf Basis thermoplastischer Polyurethane" (inventors Frank Prissok and Frank Braun, priority 18 January 2006, Google Patents), describes expanded TPU particles and articles molded from them. Its commercial embodiment is Infinergy®, the first industrial E-TPU: a closed-cell bead foam that holds its resilience across a wide temperature range and returns a significant share of impact energy. This is the material that entered running shoes en masse in 2013 as a cushioning midsole — a rare case where a specific patent document can be touched in every sports store. For an engineer, the architecture of the protection is instructive in itself: what is patented is not the polymer (TPU chemistry has long been open) but the form in which it is organized — the expanded particle and the technology for welding it into an article.
Wanhua: TPU that holds its geometry in 3D printing. Grant US11286328B2, "Thermoplastic polyurethane elastomer, and preparation method, use and product thereof" (issued 29 March 2022, Justia), protects a TPU based on aromatic/alicyclic diisocyanates and polyester polyols for 3D printing. Per the text of the patent, the composition delivers molding shrinkage of up to 0.2% and thermal stability up to 300 °C — this is the applicant's claim, not independently verified data, but the direction itself is telling: the main pain of flexible printing is not elasticity but dimensional stability and repeatability, and it is precisely these properties that formulations now compete on.
What this means for a Ukrainian producer and R&D
The first conclusion is legal, and for a processor it is as comfortable as it gets. The base chemistry of TPU has been open for decades: both Bayer's patent and Schollenberger's have long been in the public domain, so buying, compounding and processing commercial thermoplastic polyurethane raises no licensing questions whatsoever. Care is needed only at the level of reproducing someone else's specific formulations or technologies — bead foaming, for example.
The second conclusion is engineering. The active patent fronts mark the niches where TPU is technologically "hot" today: glass-fiber reinforced structural grades, materials for additive manufacturing, expanded systems. If your part combines requirements for elasticity and stiffness, that is exactly where the industry is looking, and exactly where it is worth seeking a replacement for metal, for rubber, or for the "rubber + bracket" pairing.
The third conclusion is strategic: in mature polymers, value shifts from owning the chemistry to knowing how to compound and process the material for the task. The US/CN parity in our sample is a reminder that the contest is now won not by the discoverers but by whoever converts open chemistry into working grades faster. For a Ukrainian compounder that is good news: the entry ticket is competence, not a license.
For Material Wizard, polyurethanes are a strategic direction: the Exaflex® TPU line covers molding grades with hardness from 80 to 95 Shore A for footwear, automotive components, rollers and seals, as well as glass-fiber reinforced TPU for structural parts. Exact properties of a specific grade are per its TDS; selecting a grade for a part and a processing window is best started with a conversation with a specialist. Broader context on the material is collected in our overview article on what TPU is.
Expert review: 5 questions about patents around TPU
Do you need licenses to compound or process TPU?
No: the base patents on polyurethane chemistry (1937) and on thermoplastic polyurethane itself (1959) expired long ago, so working with commercial TPU — molding, extrusion, compounding — requires no licenses. Active rights concern specific formulations and technologies (E-TPU bead foaming, for instance), and they are worth checking only when you are reproducing someone else's solution one to one.
Why is TPU called the first thermoplastic elastomer?
Charles Schollenberger's 1959 patent was the first to show an industrial elastomer without chemical vulcanization: the hard segments of the chain form physical junctions that act like a rubber network but "come apart" on heating. That is the defining feature of thermoplastic elastomers — rubber-like behavior plus thermoplastic processing — and TPU was the first large-tonnage material to deliver it.
Who patents TPU technologies most actively today?
By our sample, the classic leaders (BASF, Covestro, the Lubrizol line) focus on systemic innovation — expanded TPU, CO₂ feedstock — while the most consistent new line is being built by China's Wanhua: from a continuous synthesis process to US grants on grades for 3D printing and halogen-free flame-retardant compositions. The sample is a review one, so this illustrates a trend rather than a ranking.
What is non-isocyanate polyurethane (NIPU), and will it replace TPU?
NIPU is a polyurethane in which urethane linkages are obtained by reacting cyclic carbonates with amines, without toxic isocyanates. Patent activity here is dense (foams, waterborne systems, bio-polyols), but so far this is the chemistry of coatings, adhesives and foams: there is no commercial thermoplastic elastomer of TPU's level built on NIPU chemistry on the market. Over the next few years NIPU is a complement, not a replacement.
How do you choose a TPU grade for a specific part?
A landscape answers strategic questions; choosing a grade answers engineering ones: you need hardness, service temperatures, the environment (oils, hydrolysis, UV), the processing method and the wear requirements. The rational first step is to outline the task to a specialist and obtain samples for a trial molding run; Exaflex® TPU grades are available with delivery across Ukraine.
Sources: I.G. Farbenindustrie / O. Bayer et al., DE728981C; B.F. Goodrich / C.S. Schollenberger, "Simulated vulcanizates of polyurethane elastomers", US2871218A; BASF, WO2007082838A1; Wanhua Chemical: CN101020737A, CN109721701A, US11286328B2, US11613627B2; reinforced composites: CN103819891A, CN105086422A, WO2009080281A1, US20140343196A1, EP1112315B1; E-TPU beads: CN104974370A; recycling: US6750260B2, glycolysis review Materials 2024; NIPU: CN101775137B, EP3199569B1, WO2021247815A1, US11820876B2; market milestones: Estane at 50 (UTECH), Covestro Desmopan 37385A (press release).
Material Wizard is a producer and supplier of engineering polymers. Locations: Derazhnia and Kharkiv. Exaflex® TPU grades are available with delivery across Ukraine — supply terms and grade selection for your task can be confirmed with a specialist.