Low density fluoropolymer foam
US11643520B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 5, 2018 |
| Grant date | May 9, 2023 |
| Priority date | — |
| Expiry date | Aug 12, 2039 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2433/08
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
The invention relates to low density fluoropolymer foam, and preferably polyvinylidene fluoride (PVDF) foam, such as that made with KYNAR PVDF resins, and articles made of the foam. The foam is produced by adding microspheres containing blowing agents to the polymer and processing it through an extruder. The microspheres consist of a hard shell containing a physical blowing agent. The shell softens at elevated temperatures and allows the expansion of the blowing agent, and microsphere to create larger voids within the polymer matrix. By proper control of the polymer composition, viscosity, processing temperature, blowing agent selection, loading ratio, and finishing conditions, useful articles such as foamed PVDF pipe, tube, profiles, film, wire jacketing and other articles can be produced. The microspheres may be added to the fluoropolymer matrix by several means, including as part of a masterbatch with a compatible polymer carrier.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.