Thermoplastic Polyurethane Multifilament Yarn for Textile Products

Applicant: HUNTSMAN

Inventors: Ann - Christin Kiewidt [DE], Olaf Michel [DE], Giacomo Giannini [BE], Hugo Verbeke [BE]

Patent Number: WO2025172128A1

Publication Date: August 20, 2025

Field of Invention: This patent introduces a new type of yarn made from thermoplastic polyurethane (TPU), designed for use in textile products - especially shoe components like uppers. It also covers how the yarn is made and used.

TPUs are widely used in textiles, but they tend to be sticky, which makes it hard to produce multifilament yarns (yarns made from multiple strands). During melt spinning - a process where TPU is melted and shaped into filaments - these sticky filaments often get tangled, making production difficult.

Additionally, textile yarns need protection from sunlight to avoid discoloration. UV absorbers and light stabilizers are added for this purpose, but they can break down under the high temperatures used in melt spinning. This breakdown increases stickiness and worsens the problem.

So, there’s a need for a TPU material that can be spun into multifilament yarns without becoming too sticky, even when UV protection additives are included.

The inventors solved this by adding polystyrene to the TPU mix, along with UV absorbers and light stabilizers. This combination creates a UV - resistant filament with a matte finish that isn’t sticky.

Key components of the TPU material:

• Thermoplastic polyurethane
• 5–20% polystyrene
• UV absorber
• Hindered amine light stabilizer (HALS)

Example: Materials Used

• 10% modified polystyrene (styrene ~30%, molecular weight 140,000)
• 0.16% TINUVIN® 622SF (UV additive from BASF)
• 0.4% TINUVIN® 234 (UV additive from BASF)
• IROGRAN® A92 E 4860 (TPU base)

Process: The mixture was melt - extruded into filaments. These filaments had a matte surface and were successfully spun into multifilament yarn.