Softening thermoplastic polyurethanes using ionomer technology
US11225543B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 26, 2019 |
| Grant date | Jan 18, 2022 |
| Priority date | — |
| Expiry date | May 26, 2039 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08G18/7671
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
In one or more embodiments, the present invention provides a novel approach to the addition of plasticizers for softening TPUs, i.e., lowering the durometer and the melt viscosity. This approach involves incorporating bonded sulfonate groups with quaternary ammonium counterions into the TPU. In one or more embodiments of the present invention, the softening of TPU is achieved by incorporating an ionic diol, such as N,N-bis (2-hydroxyethyl)-2-aminoethane-sulfonic acid (BES), coupled with various bulky alkyl ammonium cations, during the chain extension step of the TPU synthesis. It is believed that that steric hindrance of the bulky quaternary ammonium groups weakens the dipole-dipole interactions of the sulfonate groups and/or lowers the crystallinity of the hard block, thereby creating additional free volume that softens the polymer and lowers the melt viscosity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.