FIELD: chemical industry.
SUBSTANCE: method for producing a polymodal polyethylene composition includes polymerization of ethylene in a reactor system containing three ethylene reactors and a hydrogen removal unit installed between the first and the second reactors. Polymerization of ethylene in the first reactor is carried out in an inert hydrocarbon medium, as which hexane is used, in the presence of a catalytic system and hydrogen to obtain low-molecular or medium-molecular polyethylene. Then, 98.0-99.8 wt.% of hydrogen contained in a suspension mixture obtained in the first reactor is removed. In the second reactor, polymerization of ethylene is carried out in the presence of residual hydrogen to obtain the first high-molecular polyethylene. In the third reactor, polymerization of ethylene is carried out to obtain the second high-molecular polyethylene. Production of the polymodal polyethylene composition is carried out by separating hexane from a suspension unloaded from the third reactor. A polymodal polyethylene composition for molding is also proposed.
EFFECT: invention provides for improving mechanical properties of obtained polymodal polyethylene composition.
9 cl, 2 tbl, 6 ex
Title | Year | Author | Number |
---|---|---|---|
MULTIMODAL POLYETHYLENE PIPE | 2017 |
|
RU2794125C2 |
MULTIMODAL POLYETHYLENE PIPE | 2017 |
|
RU2722148C1 |
PIPE OF MULTIMODAL POLYETHYLENE | 2017 |
|
RU2761951C2 |
SCREW-ON CAP MADE OF MULTIMODAL POLYETHYLENE | 2017 |
|
RU2758691C2 |
CONTAINER MADE OF MULTIMODAL POLYETHYLENE | 2017 |
|
RU2759667C2 |
HIGH-TECHNOLOGICAL MULTIMODAL ULTRAHIGH MOLECULAR WEIGHT POLYETHYLENE | 2017 |
|
RU2728873C1 |
HIGH-TECHNOLOGICAL MULTIMODAL ULTRAHIGH MOLECULAR WEIGHT POLYETHYLENE | 2017 |
|
RU2740662C2 |
MIXTURES OF POLYOLEFIN RESINS FOR HIGH RESISTANCE TO CRACKING UNDER STRESS AND GOOD RECYCLABILITY | 2019 |
|
RU2784520C2 |
POLYETHYLENE POSSESSING HIGHER RATE OF CRYSTALLISATION AND IMPROVED RESISTANCE TO CRACKING UNDER IMPACT OF ENVIRONMENT | 2009 |
|
RU2513703C2 |
MULTIMODAL POLYETHYLENE COMPOSITION AND FILM INCLUDING IT | 2017 |
|
RU2759997C2 |
Authors
Dates
2021-10-22—Published
2017-09-07—Filed