Extrusion of polypropylenes with organic peroxides
US10457789B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Feb 17, 2016 |
| Grant date | Oct 29, 2019 |
| Priority date | — |
| Expiry date | Feb 17, 2036 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2323/12
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A process to form a polypropylene composition comprising combining at a temperature within a range from 190° C. to 320° C. a polypropylene resin and within the range from 0.01 wt % to 3 wt % of at least one organic peroxide, by weight of the polypropylene composition and within a range from 100 to 4000 ppm each of phosphorous- and hindered phenol antioxidants; the polypropylene resin comprising at least 50 mol % propylene, and having a molecular weight distribution (Mw/Mn) greater than 6, a branching index (g′) of at least 0.97, and a melt strength greater than 10 cN determined using an extensional rheometer at 190° C. The resulting polypropylene composition comprises at least 50 mol % propylene and has a peak extensional viscosity of greater than 500 kPa·s at a strain rate of 0.01 sec−1 (190° C.) and a melt strength of at least 40 determined using an extensional rheometer at 190°.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.