# US 2025/0145809 A1 · Polyethylene pipe resin with improved long term hydrostatic strength > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2025/0145809 A1 - Document ID: US20250145809A1 - Status: Published application - Kind: A1 - Application number: 18/727,798 - Filed: 2022-12-13 - Published: 2025-05-08 - Earliest claimed: 2022-01-10 - Assignees: Abu Dhabi Polymers Co. Ltd (Borouge) - Sole Proprietorship L.L.C.; Borealis AG - Applicants: Abu Dhabi Polymers Co. Ltd (Borouge) - Sole Proprietorship L.L.C.; Borealis AG - Inventors: Ashish KUMAR; Nisha ANTONY; Senthil Kumar KALIAPPAN - Web page: https://patentgrep.com/patent/US20250145809A1 ## CPC - C08F 210/16: Copolymers of ethene with alpha-alkenes, e.g. EP rubbers - C08L 23/0815: {with aliphatic 1-olefins containing one carbon-to-carbon double bond} - C08F 2/001: {Multistage polymerisation processes characterised by a change in reactor conditions without deactivating the intermediate polymer (C08F295/00, C08F297/00 take precedence)} - C08F 110/02: Ethene - C08K 3/04: Carbon - C08L 23/12: Polypropene - F16L 9/12: of plastics with or without reinforcement (F16L9/16 - F16L9/22 take precedence) - C08L 2203/18: used for pipes - C08L 2205/025: containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure - C08L 2314/02: Ziegler natta catalyst - C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) - C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09) - F16L: PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL ## Abstract The present invention relates to a polyethylene composition comprising a base resin which comprises (A) a first ethylene homo- or copolymer fraction, and (B) a second ethylene copolymer fraction, wherein fraction (A) has a lower molecular weight than fraction (B), fraction (A) is present in an amount of 45.0 to 55.0 wt. %, preferably 46.0 to 53.0 wt. %, more preferably 46.5 to 52.0 wt. %, based on the total weight of the base resin, fraction (B) is present in an amount of 55.0 to 45.0 wt. %, preferably 54.0 to 47.0 wt. %, more preferably 53.5 to 48.0 wt. %, based on the total weight of the base resin, the base resin has a density of 945 kg/m3 to 958 kg/m3, more preferably of 947 to 956 kg/m3, and most preferably of 948 kg/m3 to 954 kg/m3, the polyethylene composition has a melt flow rate MFR5 of 0.15 to 0.30 g/10 min, preferably of 0.20 to 0.29 g/10 min, and still more preferably of 0.22 to 0.28 g/10 min, the polyethylene composition has a flow rate ratio FRR21/5 of 25 to 35, more preferably of 28 to 34, the polyethylene composition has a molecular weight distribution MWD of 20 to 30, more preferably from 21 to 29, and the polymer composition has an average chain length of 900 carbons or higher, to a process for producing the polyethylene composition, to an article, especially a pipe comprising the polyethylene composition and to the use of the polyethylene composition for the production of an article, especially a pipe. ## Claims ### Claim 1 A polyethylene composition comprising a base resin which comprises (A) a first ethylene homo- or copolymer fraction, and (B) a second ethylene copolymer fraction, wherein fraction (A) has a lower molecular weight than fraction (B), fraction (A) is present in an amount of 45.0 to 55.0 wt. %, based on the total weight of the base resin, fraction (B) is present in an amount of 55.0 to 45.0 wt. %, based on the total weight of the base resin, the base resin has a density measured according to ISO 1183-1:2004 (method A) of 945 kg/m3 to 958 kg/m3, the polyethylene composition has a melt flow rate MFRs determined according to ISO 1133 of 0.15 to 0.30 g/10 min, the polyethylene composition has a flow rate ratio FRR21/5 of 25 to 35, the polyethylene composition has a molecular weight distribution MWD of 20 to 30, and the polymer composition has an average chain length of 900 carbons or higher. ### Claim 2 (depends on 1) Polyethylene composition according to claim 1 wherein the second ethylene copolymer fraction (B) is a copolymer of ethylene and C4-C12 alpha-olefin. ### Claim 3 (depends on 1) Polyethylene composition according to claim 1 wherein fraction (A) has a melt flow rate MFR2 determined according to ISO 1133 of 80 to 250 g/10 min. ### Claim 4 (depends on 1) Polyethylene composition according to claim 1 wherein the base resin has a content of units derived from alpha-olefins other than ethylene, of 0.10 to 0.50 mol %. ### Claim 5 (depends on 1) Polyethylene composition according to claim 1 wherein fraction (B) of the base resin has a content of units derived from alpha-olefins other than ethylene, of from 0.20 to 1.0 mol %. ### Claim 6 (depends on 1) Polyethylene composition according to claim 1 wherein the polymer composition has a degree of polymerization of 450 or higher. ### Claim 7 (depends on 1) Polyethylene composition according to claim 1 having a strain hardening modulus measured at 80° C. and 20 mm/min on preconditioned (120° C./1 h) 300 μm thick specimens according to ISO 18488 of 50 or higher. ### Claim 8 (depends on 1) Polyethylene composition according to claim 1 wherein the polyethylene composition has a weight average molecular weight of from 150,000 to 350,000 g/mol. ### Claim 9 (depends on 1) Polyethylene composition according to claim 1 wherein the composition has critical pressure pc in the rapid crack propagation (S4 test) as described in ISO 13477:2008 of 10 bar or higher. ### Claim 10 (depends on 1) Polyethylene composition according to claim 1 comprising from 1 to 8 wt. % of carbon black based on the total weight of the polyethylene composition. ### Claim 11 (depends on 10) Polyethylene composition according claim 10 wherein the composition has a density measured according to ISO 1183-1:2004 (method A) of 955 kg/m3 to 968 kg/m3. ### Claim 12 (depends on 1) A process for producing a polyethylene composition according to claim 1 wherein the base resin is produced in a multi-stage polymerization process in the presence of a Ziegler-Natta catalyst. ### Claim 13 (depends on 1) A pipe comprising the polyethylene composition according to claim 1. ### Claim 14 (depends on 13) Pipe according to claim 13 having a long term hydrostatic strength of 11.3 MPa or higher at 20° C. and 50 yrs according to EN IS09080. ### Claim 15 (depends on 1) A polyethylene composition according to claim 1 for producing an article.