Process for producing a coated pipe
US10899942B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Sep 20, 2017 |
| Grant date | Jan 26, 2021 |
| Priority date | — |
| Expiry date | Sep 20, 2037 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L2308/00
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
The present invention deals with a process for producing a coated pipe. The process comprises (i) homopolymerising ethylene or copolymerising ethylene and an α-olefin comonomer in a first polymerisation step in the presence of a polymerisation catalyst to produce a first ethylene homo- or copolymer having a density of from 940 to 980 kg/m3 and a melt flow rate MFR2 of from 1 to 2000 g/10 min; (ii) homopolymerising ethylene or copolymerising ethylene and an α-olefin comonomer in a second polymerisation step in the presence of a first ethylene homo- or copolymer to produce a first ethylene polymer mixture comprising the first ethylene homo- or copolymer and a second ethylene homo- or copolymer, said first ethylene polymer mixture having a density of from 940 to 980 kg/m3 and a melt flow rate MFR2 of from 10 to 2000 g/10 min; (iii) copolymerising ethylene and an α-olefin comonomer in a third polymerisation step in the presence of the first ethylene polymer mixture to produce a second ethylene polymer mixture comprising the first ethylene polymer mixture and a third ethylene copolymer, said second ethylene polymer mixture having a density of from 915 to 965 kg/m3, preferably from 930 t…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.