EP0447035A2
Expired / Lapsed
EP
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Method for the preparation of ethylene polymer compositions
Assignee: Mitsui Chemicals Inc
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Filing: 1991-02-13
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Granted: —
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Expires: 2011-02-13
Abstract
Abstract The present invention provides a method for the preparation of an ethylene polymer composition having a density of 0.86-0.94 g/cm³ and an intrinsic viscosity [η] of 1-6 dl/g using an olefin polymerization catalyst comprising a transition metal compound containing a ligand having a cycloalkadienyl skeleton and an organoaluminium oxy-compound. A method for the preparation of an ethylene polymer composition having density of 0.87-0.93 g/cm³ and an intrinsic viscosity [η] of 0.5-6 dl/g is also provided.
Inventors
- 👤 Toshiyuki C/O Mitsui Petrochem. Ind. Ltd Tsutsui
- 👤 Takashi C/O Mitsui Petrochemical Ind. Ltd. Ueda
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 13:23
CPC Classifications
C; C08; C08L; C08L23/00; C08L23/02; C08L23/04; C08F; C08F297/00; C08F297/06; C08F297/08; C08F10/00; C08F10/02; C08F210/00; C08F210/16; C08L23/08; C08L23/0807; C08L23/0815; C08L2205/00; C08L2205/02; C08L2205/025; Y; Y10; Y10S; Y10S526/00; Y10S526/943
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
223 words
A method for the preparation of an ethylene polymer composition, having a density of 0.86-0.94 g/cm³ and an intrinsic viscosity [η] of 1-6 dl/g, using an olefin polymerization catalyst [I] comprising a transition metal compound [A], which contains a ligand having a cycloalkadienyl skeleton, and an organoaluminum oxy-compound [B], wherein the method comprises carrying out a multi-stage process comprising a polymerization step (a): wherein ethylene is homopolymerized or ethylene and another α-olefin are copolymerized to form an ethylene polymer [I] having a density greater than 0.88 g/cm³ and an intrinsic viscosity [η] of 0.3-3 dl/g, and a polymerization step (b): wherein ethylene and another α-olefin are copolymerized to form an ethylene copolymer [II] having a density no higher than that of the ethylene polymer [I] and having an intrinsic viscosity of at least 1.5 times that of the ethylene polymer [I] and from 1 to 10 dl/g, wherein the polymerization steps (a) and (b) are carried out such that step (a) is carried out first and step (b) is carried out in the presence of the ethylene polymer [I] or step (b) is carried out first and step (a) is carried out in the presence of the ethylene copolymer [II] so that the ethylene copolymer [II] amounts to 10-1000 parts by weight based on 100 parts by weight of the ethylene polymer [I].
Claim 2
Dependent Claim
43 words
A method according to Claim 1, wherein the amount of ethylene copolymer [II] in the polymerization step (b) is 20-500 parts by weight when the amount of ethylene polymer [I] obtained in the polymerization step (a) is taken as 100 parts by weight.
Claim 3
Independent Claim
238 words
A method for the preparation of an ethylene polymer composition having a density of 0.87-0.93 g/cm³ and an intrinsic viscosity [η] of 0.5-6 dl/g, which comprises carrying out a multi-stage process comprising a polymerization step (c): wherein ethylene and another α-olefin are copolymerized using an olefin polymerization catalyst [II], which comprises a transition metal compound [A] containing a ligand having a cycloalkadienyl skeleton and an organoaluminum oxy-compound [B], to form an ethylene copolymer [III] having a density of lower than 0.91 g/cm³ and an intrinsic viscosity [η] of 0.5-6 dl/g, and a polymerization step (d): wherein ethylene is homopolymerized or ethylene and another α-olefin are copolymerized using an olefin polymerization catalyst [III], which comprises a titanium catalyst component [C] containing titanium, magnesium and halogen as its essential ingredients, an organoaluminum compound [D] and/or an organoaluminum oxy-compound [E] to form an ethylene copolymer [IV] having a density greater than that of the ethylene copolymer [III] and an intrinsic viscosity [η] of 0.5-6 dl/g, wherein the polymerization steps (c) and (d) are carried out such that step (c) is carried out first and step (d) is carried out in the presence of the ethylene copolymer [III] or step (d) is carried out first and step (c) is carried out in the presence of the ethylene polymer [IV] so that the ethylene polymer [IV] amounts to 10-1000 parts by weight based on 100 parts by weight of the ethylene copolymer [III].
Claim 4
Dependent Claim
40 words
A method according to claim 3, wherein the polymerization steps (c) and (d) are carried out such that the step (d) is carried out in the presence of the ethylene polymer [III] obtained in the step (c) carried out previously.
Claim 5
Dependent Claim
47 words
A method according to claim 3 or 4, wherein the amount of the ethylene copolymer [IV] in the polymerization step (d) is 20-500 parts by weight when the amount of the ethylene polymer [III] obtained in the polymerization step (c) is taken as 100 parts by weight.
Claim 6
Independent Claim
27 words
A method according to any one of the preceding claims wherein the transition metal of the transition metal compound [A] is zirconium, titanium, hafnium, chromium or vanadium.
References Cited (Backward Citations)
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