CN114222767A - Multimodal polyethylene - Google Patents
Multimodal polyethylene Download PDFInfo
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- CN114222767A CN114222767A CN202080056905.4A CN202080056905A CN114222767A CN 114222767 A CN114222767 A CN 114222767A CN 202080056905 A CN202080056905 A CN 202080056905A CN 114222767 A CN114222767 A CN 114222767A
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- ethylene polymer
- component
- ethylene
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- 229920000573 polyethylene Polymers 0.000 title claims abstract description 180
- -1 polyethylene Polymers 0.000 title description 43
- 239000004698 Polyethylene Substances 0.000 title description 14
- 239000000203 mixture Substances 0.000 claims abstract description 42
- 230000000379 polymerizing effect Effects 0.000 claims abstract description 12
- NNBZCPXTIHJBJL-UHFFFAOYSA-N decalin Chemical compound C1CCCC2CCCCC21 NNBZCPXTIHJBJL-UHFFFAOYSA-N 0.000 claims abstract description 8
- PXXNTAGJWPJAGM-UHFFFAOYSA-N vertaline Natural products C1C2C=3C=C(OC)C(OC)=CC=3OC(C=C3)=CC=C3CCC(=O)OC1CC1N2CCCC1 PXXNTAGJWPJAGM-UHFFFAOYSA-N 0.000 claims abstract description 4
- VXNZUUAINFGPBY-UHFFFAOYSA-N 1-Butene Chemical compound CCC=C VXNZUUAINFGPBY-UHFFFAOYSA-N 0.000 claims description 38
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 claims description 31
- 239000005977 Ethylene Substances 0.000 claims description 31
- 229920001577 copolymer Polymers 0.000 claims description 21
- 238000006116 polymerization reaction Methods 0.000 claims description 21
- 150000002430 hydrocarbons Chemical class 0.000 claims description 20
- 238000000034 method Methods 0.000 claims description 19
- 239000004215 Carbon black (E152) Substances 0.000 claims description 15
- 229930195733 hydrocarbon Natural products 0.000 claims description 15
- 239000011777 magnesium Substances 0.000 claims description 14
- 238000006243 chemical reaction Methods 0.000 claims description 13
- 239000002002 slurry Substances 0.000 claims description 13
- 239000003054 catalyst Substances 0.000 claims description 12
- 229910052749 magnesium Inorganic materials 0.000 claims description 12
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 10
- 239000001301 oxygen Substances 0.000 claims description 10
- 229910052760 oxygen Inorganic materials 0.000 claims description 10
- 239000007787 solid Substances 0.000 claims description 9
- 150000003609 titanium compounds Chemical class 0.000 claims description 9
- 229920001519 homopolymer Polymers 0.000 claims description 8
- 238000005482 strain hardening Methods 0.000 claims description 8
- 150000001875 compounds Chemical class 0.000 claims description 7
- 229910052736 halogen Inorganic materials 0.000 claims description 7
- 150000002681 magnesium compounds Chemical class 0.000 claims description 7
- 125000004432 carbon atom Chemical group C* 0.000 claims description 6
- 150000002367 halogens Chemical class 0.000 claims description 6
- 239000000155 melt Substances 0.000 claims description 6
- 238000002360 preparation method Methods 0.000 claims description 6
- 239000004711 α-olefin Substances 0.000 claims description 6
- 239000000654 additive Substances 0.000 claims description 3
- 239000011954 Ziegler–Natta catalyst Substances 0.000 claims description 2
- 230000000996 additive effect Effects 0.000 claims description 2
- 239000007795 chemical reaction product Substances 0.000 claims description 2
- 238000001595 flow curve Methods 0.000 claims description 2
- 125000005843 halogen group Chemical group 0.000 claims 1
- 230000003534 oscillatory effect Effects 0.000 claims 1
- 229920000642 polymer Polymers 0.000 description 38
- VLKZOEOYAKHREP-UHFFFAOYSA-N n-Hexane Chemical compound CCCCCC VLKZOEOYAKHREP-UHFFFAOYSA-N 0.000 description 33
- 239000010936 titanium Substances 0.000 description 18
- 239000000243 solution Substances 0.000 description 15
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 13
- 229910052782 aluminium Inorganic materials 0.000 description 12
- 239000001257 hydrogen Substances 0.000 description 11
- 229910052739 hydrogen Inorganic materials 0.000 description 10
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 9
- 229910052719 titanium Inorganic materials 0.000 description 9
- LIKMAJRDDDTEIG-UHFFFAOYSA-N 1-hexene Chemical compound CCCCC=C LIKMAJRDDDTEIG-UHFFFAOYSA-N 0.000 description 8
- KWKAKUADMBZCLK-UHFFFAOYSA-N 1-octene Chemical compound CCCCCCC=C KWKAKUADMBZCLK-UHFFFAOYSA-N 0.000 description 8
- 238000000071 blow moulding Methods 0.000 description 8
- 239000003085 diluting agent Substances 0.000 description 8
- 238000005259 measurement Methods 0.000 description 7
- FYYHWMGAXLPEAU-UHFFFAOYSA-N Magnesium Chemical compound [Mg] FYYHWMGAXLPEAU-UHFFFAOYSA-N 0.000 description 6
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 6
- 238000009826 distribution Methods 0.000 description 6
- 239000007788 liquid Substances 0.000 description 6
- 229910052757 nitrogen Inorganic materials 0.000 description 6
- NLZUEZXRPGMBCV-UHFFFAOYSA-N Butylhydroxytoluene Chemical compound CC1=CC(C(C)(C)C)=C(O)C(C(C)(C)C)=C1 NLZUEZXRPGMBCV-UHFFFAOYSA-N 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 5
- UAIZDWNSWGTKFZ-UHFFFAOYSA-L ethylaluminum(2+);dichloride Chemical compound CC[Al](Cl)Cl UAIZDWNSWGTKFZ-UHFFFAOYSA-L 0.000 description 5
- 239000007789 gas Substances 0.000 description 5
- 238000004817 gas chromatography Methods 0.000 description 5
- 239000000178 monomer Substances 0.000 description 5
- 239000000523 sample Substances 0.000 description 5
- 150000004703 alkoxides Chemical class 0.000 description 4
- 235000010354 butylated hydroxytoluene Nutrition 0.000 description 4
- 238000002474 experimental method Methods 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- TVMXDCGIABBOFY-UHFFFAOYSA-N n-Octanol Natural products CCCCCCCC TVMXDCGIABBOFY-UHFFFAOYSA-N 0.000 description 4
- 239000000047 product Substances 0.000 description 4
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 description 4
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 description 4
- 230000008961 swelling Effects 0.000 description 4
- PBKONEOXTCPAFI-UHFFFAOYSA-N 1,2,4-trichlorobenzene Chemical compound ClC1=CC=C(Cl)C(Cl)=C1 PBKONEOXTCPAFI-UHFFFAOYSA-N 0.000 description 3
- 229920001038 ethylene copolymer Polymers 0.000 description 3
- 238000005227 gel permeation chromatography Methods 0.000 description 3
- 239000000395 magnesium oxide Substances 0.000 description 3
- CPLXHLVBOLITMK-UHFFFAOYSA-N magnesium oxide Inorganic materials [Mg]=O CPLXHLVBOLITMK-UHFFFAOYSA-N 0.000 description 3
- 239000002244 precipitate Substances 0.000 description 3
- MCULRUJILOGHCJ-UHFFFAOYSA-N triisobutylaluminium Chemical compound CC(C)C[Al](CC(C)C)CC(C)C MCULRUJILOGHCJ-UHFFFAOYSA-N 0.000 description 3
- 238000005160 1H NMR spectroscopy Methods 0.000 description 2
- NMVXHZSPDTXJSJ-UHFFFAOYSA-L 2-methylpropylaluminum(2+);dichloride Chemical compound CC(C)C[Al](Cl)Cl NMVXHZSPDTXJSJ-UHFFFAOYSA-L 0.000 description 2
- RVDLHGSZWAELAU-UHFFFAOYSA-N 5-tert-butylthiophene-2-carbonyl chloride Chemical compound CC(C)(C)C1=CC=C(C(Cl)=O)S1 RVDLHGSZWAELAU-UHFFFAOYSA-N 0.000 description 2
- IMNFDUFMRHMDMM-UHFFFAOYSA-N N-Heptane Chemical compound CCCCCCC IMNFDUFMRHMDMM-UHFFFAOYSA-N 0.000 description 2
- 239000004411 aluminium Substances 0.000 description 2
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 2
- VSCWAEJMTAWNJL-UHFFFAOYSA-K aluminium trichloride Chemical compound Cl[Al](Cl)Cl VSCWAEJMTAWNJL-UHFFFAOYSA-K 0.000 description 2
- 238000004458 analytical method Methods 0.000 description 2
- 230000002902 bimodal effect Effects 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- HQMRIBYCTLBDAK-UHFFFAOYSA-M bis(2-methylpropyl)alumanylium;chloride Chemical compound CC(C)C[Al](Cl)CC(C)C HQMRIBYCTLBDAK-UHFFFAOYSA-M 0.000 description 2
- 238000009835 boiling Methods 0.000 description 2
- 238000004364 calculation method Methods 0.000 description 2
- 239000000460 chlorine Substances 0.000 description 2
- 230000006835 compression Effects 0.000 description 2
- 238000007906 compression Methods 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 239000011521 glass Substances 0.000 description 2
- AXZKOIWUVFPNLO-UHFFFAOYSA-N magnesium;oxygen(2-) Chemical compound [O-2].[Mg+2] AXZKOIWUVFPNLO-UHFFFAOYSA-N 0.000 description 2
- 238000000465 moulding Methods 0.000 description 2
- 239000012299 nitrogen atmosphere Substances 0.000 description 2
- 239000000843 powder Substances 0.000 description 2
- 238000001556 precipitation Methods 0.000 description 2
- 239000002243 precursor Substances 0.000 description 2
- 238000010992 reflux Methods 0.000 description 2
- 238000001542 size-exclusion chromatography Methods 0.000 description 2
- 239000011949 solid catalyst Substances 0.000 description 2
- 239000011550 stock solution Substances 0.000 description 2
- 239000000725 suspension Substances 0.000 description 2
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 2
- VOITXYVAKOUIBA-UHFFFAOYSA-N triethylaluminium Chemical compound CC[Al](CC)CC VOITXYVAKOUIBA-UHFFFAOYSA-N 0.000 description 2
- QPFMBZIOSGYJDE-QDNHWIQGSA-N 1,1,2,2-tetrachlorethane-d2 Chemical compound [2H]C(Cl)(Cl)C([2H])(Cl)Cl QPFMBZIOSGYJDE-QDNHWIQGSA-N 0.000 description 1
- AEJKOMCKFXSARH-UHFFFAOYSA-N 2,2-dibromoethylaluminum Chemical compound [Al]CC(Br)Br AEJKOMCKFXSARH-UHFFFAOYSA-N 0.000 description 1
- MXRNYNIJHVXZAN-UHFFFAOYSA-N CCO[Mg]CC Chemical compound CCO[Mg]CC MXRNYNIJHVXZAN-UHFFFAOYSA-N 0.000 description 1
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 1
- 241000251730 Chondrichthyes Species 0.000 description 1
- 238000012565 NMR experiment Methods 0.000 description 1
- 238000005481 NMR spectroscopy Methods 0.000 description 1
- ISWSIDIOOBJBQZ-UHFFFAOYSA-N Phenol Chemical class OC1=CC=CC=C1 ISWSIDIOOBJBQZ-UHFFFAOYSA-N 0.000 description 1
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 1
- 150000001338 aliphatic hydrocarbons Chemical class 0.000 description 1
- 238000000137 annealing Methods 0.000 description 1
- 239000003963 antioxidant agent Substances 0.000 description 1
- 239000002216 antistatic agent Substances 0.000 description 1
- 239000012298 atmosphere Substances 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- SHOVVTSKTTYFGP-UHFFFAOYSA-L butylaluminum(2+);dichloride Chemical compound CCCC[Al](Cl)Cl SHOVVTSKTTYFGP-UHFFFAOYSA-L 0.000 description 1
- 150000007942 carboxylates Chemical class 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 229910052801 chlorine Inorganic materials 0.000 description 1
- 238000004587 chromatography analysis Methods 0.000 description 1
- 239000013065 commercial product Substances 0.000 description 1
- 230000001143 conditioned effect Effects 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 238000010908 decantation Methods 0.000 description 1
- 125000004177 diethyl group Chemical group [H]C([H])([H])C([H])([H])* 0.000 description 1
- CQYBWJYIKCZXCN-UHFFFAOYSA-N diethylaluminum Chemical compound CC[Al]CC CQYBWJYIKCZXCN-UHFFFAOYSA-N 0.000 description 1
- 238000010790 dilution Methods 0.000 description 1
- 239000012895 dilution Substances 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 238000004090 dissolution Methods 0.000 description 1
- 239000003480 eluent Substances 0.000 description 1
- 230000006353 environmental stress Effects 0.000 description 1
- 230000005284 excitation Effects 0.000 description 1
- 230000001747 exhibiting effect Effects 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 239000012530 fluid Substances 0.000 description 1
- 230000005484 gravity Effects 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 230000009878 intermolecular interaction Effects 0.000 description 1
- 239000001095 magnesium carbonate Substances 0.000 description 1
- 229910000021 magnesium carbonate Inorganic materials 0.000 description 1
- CRGZYKWWYNQGEC-UHFFFAOYSA-N magnesium;methanolate Chemical compound [Mg+2].[O-]C.[O-]C CRGZYKWWYNQGEC-UHFFFAOYSA-N 0.000 description 1
- ORPJQHHQRCLVIC-UHFFFAOYSA-N magnesium;propan-2-olate Chemical compound CC(C)O[Mg]OC(C)C ORPJQHHQRCLVIC-UHFFFAOYSA-N 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000002667 nucleating agent Substances 0.000 description 1
- 239000002245 particle Substances 0.000 description 1
- 239000008188 pellet Substances 0.000 description 1
- 230000002572 peristaltic effect Effects 0.000 description 1
- 239000000049 pigment Substances 0.000 description 1
- 229920000098 polyolefin Polymers 0.000 description 1
- 108091008777 probable nuclear hormone receptor HR3 Proteins 0.000 description 1
- 238000012545 processing Methods 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 238000010008 shearing Methods 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 230000003595 spectral effect Effects 0.000 description 1
- 238000001228 spectrum Methods 0.000 description 1
- 239000003381 stabilizer Substances 0.000 description 1
- 238000007655 standard test method Methods 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 230000035882 stress Effects 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 238000012360 testing method Methods 0.000 description 1
- ORYGRKHDLWYTKX-UHFFFAOYSA-N trihexylalumane Chemical compound CCCCCC[Al](CCCCCC)CCCCCC ORYGRKHDLWYTKX-UHFFFAOYSA-N 0.000 description 1
- LFXVBWRMVZPLFK-UHFFFAOYSA-N trioctylalumane Chemical compound CCCCCCCC[Al](CCCCCCCC)CCCCCCCC LFXVBWRMVZPLFK-UHFFFAOYSA-N 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F210/00—Copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond
- C08F210/16—Copolymers of ethene with alpha-alkenes, e.g. EP rubbers
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08F—MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08F110/00—Homopolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond
- C08F110/02—Ethene
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
- C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
- C08L23/04—Homopolymers or copolymers of ethene
- C08L23/06—Polyethene
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2205/00—Polymer mixtures characterised by other features
- C08L2205/02—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group
- C08L2205/025—Polymer mixtures characterised by other features containing two or more polymers of the same C08L -group containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2205/00—Polymer mixtures characterised by other features
- C08L2205/03—Polymer mixtures characterised by other features containing three or more polymers in a blend
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Addition Polymer Or Copolymer, Post-Treatments, Or Chemical Modifications (AREA)
- Transition And Organic Metals Composition Catalysts For Addition Polymerization (AREA)
Abstract
The present invention relates to a multimodal ethylene polymer having a density of from 0.955 to 0.960g/cm at 23 ℃3At 190 ℃ and 5kg according to ISO1133-1:2011A measured melt flow index of 0.9 to 1.7dg/min, and a ratio of Mz/Mw of at least 7.0; and which comprises from 40 to 53 wt% of a low molecular weight ethylene polymer component a, from 25 to 40 wt% of a high molecular weight ethylene polymer component B, and from 15 to 28 wt% of an ultra high molecular weight ethylene polymer component C, wherein all values are based on the total weight of the multimodal ethylene polymer; wherein the multimodal ethylene polymer is prepared by polymerizing the component A, followed by polymerizing the component B in the presence of the component A, and followed by polymerizing the component C in the presence of the components A and B, and the ethylene polymer component A has 90 to 110cm3G, e.g. 95 to 105cm3Viscosity number VN/g1The mixture of the ethylene polymer component A and the ethylene polymer component B has a density of 175 to 225cm3G, e.g. 180 to 220cm3Viscosity number VN/g2And the mixture of the ethylene polymer component A, the ethylene polymer component B and the ethylene polymer component C has 240 to 320cm3G, e.g. 250 to 300cm3Viscosity number VN/g3In which VN1、VN2And VN3Measured according to ISO/R1191 in decalin at 135 ℃.
Description
The present invention relates to a multimodal, preferably trimodal polyethylene and to the use of such polyethylene in blow moulding applications.
Compositions comprising ethylene copolymers are used in many fields of application, for example in blow moulding applications. Blow molding is a molding process commonly used to produce containers for, for example, household and industrial use. In the blow molding process, polyethylene is melted and extruded into a mold, and compressed air is used to inflate and shape the polymer into the desired form. An important property of the polymer to be molded is its mechanical properties, which in turn determine the properties of the final molded article.
A key property for blow molding applications is good processability, as characterized by good die swell and high shear thinning index. This, combined with good Environmental Stress Crack Resistance (ESCR) as indicated by a high strain hardening modulus, will enable optimal wall thickness control for the production of hollow articles and facilitate excellent weld line formation, while offering the potential for reduced thickness (down gauging).
EP1576047B1 discloses a polyethylene composition having a multimodal molecular mass distribution having a molecular mass distribution at 23 ℃ of from 0.955 to 0.960g/cm3And an MFI of from 0.8 to 1.6dg/min190/5And it comprises from 45 to 55% by weight of a low molecular mass ethylene homopolymer a, from 20 to 35% by weight of a high molecular mass copolymer B made from ethylene and another 1-olefin having from 4 to 8 carbon atoms, and from 20 to 30% by weight of an ultrahigh molecular mass ethylene copolymer C. According to EP1576047B1, the polyethylene composition is suitable for blow molding.
WO2018/046711 discloses a process for producing a multimodal polyethylene composition by polymerization in three reactors. A hydrogen removal unit is disposed between the first reactor and the second reactor.
There is a continuing need to provide ethylene polymers suitable for use in blow molding that have a combination of good processability and good ESCR.
It is an object of the present invention to provide ethylene polymers which solve the above and/or other problems.
Accordingly, the present invention provides a multimodal ethylene polymer having from 0.955 to 0.960g/cm at 23 ℃3A melt flow index of 0.9 to 1.7dg/min measured according to ISO1133-1:2011 at 190 ℃ and 5kg, and a ratio of Mz/Mw of at least 7.0, and which comprises:
40 to 53% by weight of a low molecular mass ethylene polymer component A,
from 25 to 40% by weight of a high molecular weight ethylene polymer component B, and
15 to 28% by weight of an ultrahigh molecular mass ethylene polymer component C,
wherein all values are based on the total weight of the multimodal ethylene polymer.
The invention provides a multimodal ethylene polymer having at 23 ℃ from 0.955 to 0.960g/cm3A melt flow index of 0.9 to 1.7dg/min measured according to ISO1133-1:2011 at 190 ℃ and 5kg, and a ratio of Mz/Mw of at least 7.0, and which comprises:
40 to 53% by weight of a low molecular mass ethylene polymer component A,
from 25 to 40% by weight of a high molecular weight ethylene polymer component B, and
15 to 28% by weight of an ultrahigh molecular mass ethylene polymer component C,
wherein all values are based on the total weight of the multimodal ethylene polymer, wherein
The multimodal ethylene polymer is prepared by polymerizing component A, subsequently polymerizing component B in the presence of component A, and subsequently polymerizing component C in the presence of components A and B, and
the ethylene polymer component A has a thickness of from 90 to 110cm3G, e.g. 95 to 105cm3Viscosity number VN/g1，
The mixture of ethylene polymer component A and ethylene polymer component B has a density of 175 to 225cm3G, e.g. 180 to 220cm3Viscosity number VN/g2And is and
the mixture of ethylene polymer component A, ethylene polymer component B and ethylene polymer component C has a density of 240 to 320cm3G, e.g. 250 to 300cm3Viscosity number VN/g3，
Wherein VN1、VN2And VN3Measured according to ISO/R1191 at 135 ℃ in decalin.
It has surprisingly been found that the multimodal ethylene polymer according to the present invention has a combination of good processability and good ESCR.
Multimodal ethylene polymer
By ethylene polymer is meant a polymer the majority by weight of which is derived from ethylene monomer units. The ethylene polymer may be an ethylene homopolymer or a copolymer of ethylene and a C3-C20 comonomer. The C3-C20 comonomer is preferably selected from the group consisting of C3-10 alpha-olefins, such as propylene, 1-butene, 1-hexene and 1-octene. Preferably, the ethylene polymer is an ethylene-1-butene copolymer.
The ethylene polymer according to the invention has 955 to 960g/cm3Preferably 956 to 959g/cm3The density of (c).
The ethylene polymers according to the invention have an average molecular weight according to I of from 0.9 to 1.7dg/min, preferably from 1.0 to 1.5dg/minMelt Flow Index (MFI) measured at 190 ℃ and 5kg in SO1133-1:2011190/5)。
Preferably, the ethylene polymer according to the invention has a Melt Flow Index (MFI) measured according to ISO1133-1:2011 at 190 ℃ and 21.6kg of from 10 to 40dg/min, preferably from 20 to 30dg/min190/21.6)。
The melt flow index and the density of the multimodal ethylene polymer according to the present invention are measured for pelletized ethylene polymers.
The ethylene polymer according to the invention has a ratio Mz/Mw of at least 7.0, e.g. from 7.0 to 10.0, from 7.1 to 9.0, from 7.2 to 8.0. Mz/Mw is determined according to size exclusion chromatography as described in the experimental section. It was surprisingly found that such a high Mz/Mw ratio leads to a combination of good processability and good ESCR.
Preferably, the ethylene polymer according to the present invention has a ratio Mw/Mn of at least 22.0, preferably from 23.0 to 33.0, more preferably from 25.0 to 30.0. Mw/Mn is determined according to size exclusion chromatography as described in the experimental section. The advantage of such a high Mw/Mn ratio is good processability.
Preferably, the ethylene polymer according to the invention has a calculated MFI of from 10 to 30, preferably from 15 to 25190/21.6/MFI190/5Flow Rate Ratio (FRR). FRR indicates the rheological width of the material.
The ethylene polymers according to the present invention have a relatively high shear thinning index (SHI), which is the ratio of the viscosity of the polymer at a lower shear rate (e.g., 0.1rad/s or 0.01rad/s) to the viscosity of the polymer at a higher shear rate (e.g., 100 rad/s). A high SHI value is beneficial because it means that the viscosity is low at high shear rates where processability is important, and high at low shear rates where dimensional stability is important.
Viscosity values were calculated according to the method as described in the experimental section.
η100Is the viscosity value in Pa.s at 190 ℃ and a shear rate of 100 rad/s.
η0.1Is the viscosity value in Pa.s at 190 ℃ and a shear rate of 0.1 rad/s.
η0.01Is the viscosity value in Pa.s at 190 ℃ and a shear rate of 0.01 rad/s.
Preferably, the ethylene polymer according to the invention has a shear thinning index SHI (η) of at least 15, more preferably at least 17, for example from 17 to 200.1/η100)。
Preferably, the ethylene polymer according to the invention has a shear thinning index SHI (η) of at least 25, more preferably at least 30, for example 30 to 350.01/η100)。
Preferably, the ethylene polymer according to the present invention has a die swell of at least 1.40, more preferably at least 1.50 to 1.80, determined at 200/s according to ISO11443: 2014.
Preferably, the ethylene polymer according to the present invention has a die swell of at least 1.70, more preferably at least 1.80 to 2.10, determined according to ISO11443:2014 at 400/s.
Preferably, the ethylene polymer according to the present invention has a die swell, determined at 800/s according to ISO11443:2014, of at least 2.10, more preferably of at least 2.20 to 2.50.
Preferably, the ethylene polymer according to the present invention has a die swell, determined according to ISO11443:2014 at 1600/s, of at least 2.60, more preferably of at least 2.80 to 3.00. Advantageously, the ethylene polymers according to the invention give smooth extrudates without melt fracture or shark skinning in the die swell measurement.
Preferably, the ethylene polymer according to the present invention has a strain hardening modulus of at least 15MPa, preferably at least 17MPa, determined according to ISO 18488: 2014.
Ethylene Polymer Components A, B and C
The ethylene polymer according to the present invention comprises an ethylene polymer component a, an ethylene polymer component B and an ethylene polymer component C. The ethylene polymer according to the present invention may comprise a polymer component different from polymer components A, B and C. It is preferred that the ethylene polymer according to the present invention does not comprise a polymer component other than polymer components A, B and C. Preferably, polymers A, B and C sum to at least 80 wt%, preferably at least 90 wt%, at least 95 wt%, at least 98 wt%, at least 99 wt% or 100 wt% of the ethylene polymer according to the invention.
The amount of ethylene polymer component a in the ethylene polymer according to the invention is from 40 to 53 wt%, such as from 43 to 50 wt%.
The amount of ethylene polymer component B in the ethylene polymer according to the invention is from 25 to 40 wt%, such as from 28 to 35 wt%.
The amount of ethylene polymer component C in the ethylene polymer according to the invention is from 15 to 28 wt%, such as from 18 to 25 wt%.
When the ethylene polymer according to the present invention is produced using a cascade reactor using a multi-stage polymerization process, the amount of ethylene fed in each polymerization step may be used herein as the amount of each ethylene polymer component in the ethylene polymer according to the present invention.
The ethylene polymer component A may be an ethylene homopolymer or a copolymer of ethylene and a C3-C20 comonomer. The C3-C20 comonomer is preferably selected from the group consisting of C3-10 alpha-olefins, such as propylene, 1-butene, 1-hexene and 1-octene. If the ethylene polymer component A is a copolymer, the ethylene polymer component A is preferably a copolymer of ethylene and 1-butene. If the ethylene polymer component A is a copolymer, the amount of comonomer units in the ethylene polymer component A is preferably from 0.001 to 1.5 mol%, for example from 0.01 to 0.1 mol%. Preferably, however, the ethylene polymer component A is an ethylene homopolymer.
The ethylene polymer component B may be an ethylene homopolymer or a copolymer of ethylene and a C3-C20 comonomer. The C3-C20 comonomer is preferably selected from the group consisting of C3-10 alpha-olefins, such as propylene, 1-butene, 1-hexene and 1-octene. Preferably, the ethylene polymer component B is a copolymer of ethylene and a C3-C20 comonomer, most preferably a copolymer of ethylene and 1-butene. Preferably, the amount of comonomer units in the ethylene polymer component B is from 0.1 to 0.8 mol%, for example from 0.2 to 0.5 mol%. Ethylene polymer component B has a higher molar amount of comonomer units than ethylene polymer component a. Ethylene polymer component B has a lower density than ethylene polymer component a. The ethylene polymer component B has a lower melt flow index than the ethylene polymer component a.
The ethylene polymer component C may be an ethylene homopolymer or a copolymer of ethylene and a C3-C20 comonomer. The C3-C20 comonomer is preferably selected from the group consisting of C3-10 alpha-olefins, such as propylene, 1-butene, 1-hexene and 1-octene. Preferably, ethylene polymer component C is a copolymer of ethylene and a C3-C20 comonomer, most preferably a copolymer of ethylene and 1-butene. Preferably, the amount of comonomer units in the ethylene polymer component C is from 0.3 to 1.5 mol%, for example from 0.4 to 1.0 mol%. Typically, ethylene polymer component C has a higher molar amount of comonomer units than ethylene polymer component B, although it is possible that ethylene polymer component C has an equal or lower molar amount of comonomer units than ethylene polymer component B. Typically, ethylene polymer component C has a lower density than ethylene polymer component B, although it is possible that ethylene polymer component C has an equal or lower molar amount of comonomer units than ethylene polymer component B. Ethylene polymer component C has a lower melt flow index than ethylene polymer component B.
The amount of comonomer units in each ethylene polymer component can be determined by the methods as described in the experimental section.
The ethylene polymer according to the invention is multimodal, i.e. has a multimodal molecular mass distribution. Preferably, the ethylene polymer according to the present invention is trimodal, i.e. has a trimodal molecular mass distribution.
The trimodality is a measure of the position of the centers of gravity of the three individual molecular mass distributions and can be described by means of the viscosity numbers VN (in accordance with ISO/R1191) of the polymers formed in the successive polymerization stages. The relative bandwidth of the polymer formed in each reaction stage is therefore as follows:
viscosity number VN measured on the polymer after the first polymerization stage1Viscosity number VN to low molecular weight polyethylene AASame, and according to the invention preferably from 90 to 110cm3G, e.g. 95 to 105cm3/g。
Viscosity number VN measured on the polymer after the second polymerization stage2VN not equal to the high-molecular-mass polyethylene B formed in the second polymerization stage, which can only be determined by calculationBBut rather the viscosity number of the mixture of polymer a and polymer B. According to the invention, VN2Preferably 175 to 225cm3G, e.g. 180 to 220cm3/g。
Viscosity number VN measured on the polymer after the third polymerization stage3VN not equal to the ultrahigh molecular mass copolymer C formed in the third polymerization stage, which can only be determined by calculationcBut rather the viscosity number of the mixture of polymer a, polymer B and polymer C. According to the invention, VN3Preferably 240 to 320cm3G, e.g. 250 to 300cm3/g。
Preferably, the ethylene polymer component A has at least 968g/cm3Preferably 969 to 971g/cm3The density of (c).
Preferably, the ethylene polymer component A has a melt flow index, measured according to ISO1133-1:2011 at 190 ℃ and 1.2kg, of from 10 to 60dg/min, preferably from 15 to 35 dg/min.
Preferably, the mixture of ethylene polymer component A and ethylene polymer component B has a density of from 960 to 965g/cm3The density of (c).
Preferably, the mixture of ethylene polymer component A and ethylene polymer component B has a melt flow index, measured according to ISO1133-1:2011 at 190 ℃ and 5kg, of from 5 to 15dg/min, preferably from 7 to 12 dg/min.
Preferably, the mixture of ethylene polymer component A, ethylene polymer component B and ethylene polymer component C has 955 to 960g/cm3The density of (c).
Preferably, the mixture of ethylene polymer component A, ethylene polymer component B and ethylene polymer component C has a melt flow index, measured according to ISO1133-1:2011 at 190 ℃ and 5kg, of from 0.5 to 2.0 dg/min.
A. The density and melt flow index of the mixtures of a and B and of A, B and C are generally measured for the powder obtained after each polymerization step.
Process for preparing ethylene polymers
Preferably, the ethylene polymer according to the present invention is produced in a multistage slurry polymerisation process using a cascade of reactors in the presence of a Ziegler Natta catalyst system.
The ethylene polymer according to the present invention may be prepared by a process comprising producing component a, component B and component C as a trimodal ethylene polymer made by polymerizing component a, subsequently polymerizing component B in the presence of component a and subsequently polymerizing component C in the presence of components a and B. Accordingly, the present invention provides a process for the preparation of an ethylene polymer according to the present invention, wherein the process comprises a sequential polymerization process comprising at least three reactors in series, wherein said process comprises the steps of:
-preparing component A in a first reactor under a first set of conditions,
transferring component A and unreacted monomers of the first reactor to a second reactor,
feeding the monomers to a second reactor,
-preparing component B in a second reactor in the presence of component A under a second set of conditions,
-transferring component A, component B and unreacted monomers of the second reactor to a third reactor,
feeding the monomers to a third reactor,
preparing component C in a third reactor in the presence of component A and component B under a third set of conditions,
wherein the first set of conditions, the second set of conditions, and the third set of conditions are different from each other.
The order of preparing components A, B and C can be different than described above. Accordingly, all possible sequences are considered disclosed herein:
component a in reactor 1, component B in reactor 2, component C in reactor 3 (above embodiment);
component a in reactor 1, component C in reactor 2, component B in reactor 3;
component B in reactor 1, component a in reactor 2, component C in reactor 3;
component B in reactor 1, component C in reactor 2, component a in reactor 3;
component C in reactor 1, component a in reactor 2, component B in reactor 3;
component C in reactor 1, component B in reactor 2, and component A in reactor 3.
The polymerization process can be carried out in suspension at a temperature of, for example, from 70 to 100 ℃, preferably from 75 to 90 ℃ and a pressure of, for example, from 0.15 to 10 bar. The molecular mass of each of components A, B and C can be regulated by a molar mass regulator, preferably by hydrogen.
Multistage slurry polymerization processes using cascade reactors are known per se and the details thereof are further described, for example, in WO2007022908, page 5, line 32 to page 8, line 1, which is incorporated herein by reference.
Preferably, the ethylene polymer according to the present invention is produced using a cascade reactor in a multistage slurry polymerization process of ethylene in the presence of a catalyst system comprising:
(I) a solid reaction product obtained by the reaction of,
a) a hydrocarbon solution containing 1) and 2),
1) an organic magnesium oxyhalide compound or a halogen-containing magnesium compound, and
2) an organic oxygen-containing titanium compound, and
b) having the formula AlRnX3-nWherein R is a hydrocarbon moiety having 1 to 10 carbon atoms, X is halogen and 0<n<3, and
(II) has the formula AlR3Wherein R is a hydrocarbon moiety containing from 1 to 10 carbon atoms.
During the reaction of the hydrocarbon solution containing the organic magnesium oxide-containing compound and the organic titanium oxide-containing compound with the component (I b), the solid catalyst precursor precipitates, and the resulting mixture is heated after the precipitation reaction to terminate the reaction.
The aluminum compound (II) is metered in before or during the polymerization and may be referred to as cocatalyst.
The multi-stage slurry polymerization process may be a three-stage slurry polymerization process.
Preferably, the diluent in the slurry polymerization process is a diluent consisting of aliphatic hydrocarbon compounds exhibiting an atmospheric boiling temperature of at least 35 ℃, more preferably above 55 ℃. Suitable diluents are hexane and heptane. The preferred diluent is hexane.
Suitable organic oxygen-containing magnesium compounds include, for example, magnesium alkoxides such as magnesium methoxide, magnesium ethoxide, and magnesium isopropoxide; and alkyl alkoxides such as ethyl magnesium ethoxide; and so-called magnesium carbide alkoxides such as ethyl magnesium carbonate.
Preferably, the organic magnesium oxide-containing compound is a magnesium alkoxide. The preferred magnesium alkoxide is magnesium ethoxide Mg (OC)2H5)2。
Suitable halogen-containing magnesium compounds include, for example, magnesium dihalides and magnesium dihalide complexes, in which the halogen is preferably chlorine.
Preferably, the hydrocarbon solution comprises an organic magnesium oxide compound as (I) (a) (1).
Suitable organic oxygen-containing titanium compounds can be prepared from the general formula [ TiO ]x(OR)4-2x]nWherein R represents an organic moiety, x is 0 to 1 and n is 1 to 6.
Suitable examples of the organic oxygen-containing titanium compound include alkoxides, phenoxides, oxidized alkoxides, condensed alkoxides, carboxylates, and enolates. Preferably, the organic oxygen-containing titanium compound is a titanium alkoxide. Suitable alkoxides include, for example, Ti (OC)2H5)4、Ti(OC3H7)4、Ti(OC4H9)4And Ti (OC)8H17)4. The preferred organic oxygen-containing titanium compound is Ti (OC)4H9)4。
Preferably, the aluminum halide is of the formula AlRnX3-nWherein R is a hydrocarbon moiety having 1 to 10 carbon atoms, X is halogen and 0.5<n<2. Having the formula AlRnX3-nSuitable examples of the aluminum halide in (I) b include dibromoethylaluminum, dichloroethylaluminum, dichloropropylaluminum, n-butylaluminum dichloride, isobutylaluminum dichloride, diethyl chlorideAluminum, diisobutylaluminum chloride. Preferably, X is Cl. Preferably, the organic aluminum halide of (I) b) is an organic aluminum chloride, more preferably the organic aluminum halide of (I) b) is selected from ethylaluminum dichloride, diethylaluminum dichloride, isobutylaluminum dichloride, diisobutylaluminum chloride or mixtures thereof.
I b) in a molar ratio of Al to I a) of Ti in the range of 3:1 to 16: 1. According to a preferred embodiment of the invention, Al of I b) is used in I a) with a Ti molar ratio of 6:1 to 10: 1.
Having the formula AlR3Suitable examples of cocatalysts of (a) include triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum and trioctylaluminum. Preferably of the formula AlR3The aluminum compound in (II) is triethylaluminum or triisobutylaluminum.
The hydrocarbon solution of the organooxygen-containing magnesium compound and the organooxygen-containing titanium compound can be prepared according to the procedures as disclosed, for example, in US 4178300 and EP 0876318. The solution is typically a clear liquid. If any solid particles are present, these can be removed via filtration before the solution is used in the catalyst synthesis.
Generally, the molar ratio of magnesium to titanium is lower than 3:1, and preferably the molar ratio of magnesium to titanium is between 0, 2:1 and 3: 1.
In general, the molar ratio of titanium of (a) of aluminium of (II) is from 1:1 to 300:1, and preferably the molar ratio of titanium of (A) of aluminium of (II) is from 3:1 to 100: 1.
The catalyst can be obtained by the following steps: a first reaction between magnesium alkoxide and titanium alkoxide, followed by dilution with a hydrocarbon solvent, thereby producing a soluble complex consisting of magnesium alkoxide and titanium alkoxide, and thereafter a hydrocarbon solution of said complex with a compound having the formula AlRnX3-nThe organic aluminum halide of (2).
Optionally, the electron donor may be added during the preparation of the solid catalytic complex (simultaneously with a subsequent step or in another step) or at the polymerization stage. The addition of an electron donor is for example disclosed in WO 2013087167.
Generally, having the formula AlRnX3-nThe aluminum halide of (a) is used as a solution in a hydrocarbon. Any hydrocarbon that does not react with the organoaluminium halide is suitable for use as the hydrocarbon.
The order of addition may be that of adding a hydrocarbon solution containing an organooxygen-containing magnesium compound and an organooxygen-containing titanium compound to a catalyst having the formula AlRnX3-nOr vice versa.
The temperature of the reaction can be any temperature below the boiling point of the hydrocarbon used. In general, the duration of the addition is preferably less than 1 hour.
In the reaction of a hydrocarbon solution of an organic oxygen-containing magnesium compound and an organic oxygen-containing titanium compound with a catalyst of the formula AlRnX3-nIn the reaction of the organic aluminum halide, a solid catalyst precursor precipitates. The resulting mixture was heated for a certain period of time after the precipitation reaction to end the reaction. After the reaction, the precipitate was filtered and washed with hydrocarbon. Other means of separating the solids from the diluent and subsequent washing may also be applied, such as, for example, multiple decantation steps. All steps should be carried out in an inert atmosphere of nitrogen or another suitable inert gas.
Other aspects
The invention further relates to a composition comprising the ethylene polymer according to the invention. The composition may consist of the ethylene polymer according to the invention and additives such as pigments, nucleating agents, antistatic agents, fillers, antioxidants and the like. The amount of additive in the composition is generally at most 10% by weight of the composition, preferably at most 5% by weight.
The invention further relates to an article comprising the ethylene polymer according to the invention or the composition according to the invention. Preferably, the article is a blow molded article.
It is to be noted that the invention relates to all possible combinations of features described herein, preferably in particular those combinations of features presented in the claims. Thus, it is to be understood that all combinations of features relating to the composition according to the invention, all combinations of features relating to the method according to the invention, and all combinations of features relating to the composition according to the invention and features relating to the method according to the invention are described herein.
It is further noted that the terms "comprising," "including," and "containing" do not exclude the presence of other elements. However, it is also to be understood that the description of a product/composition comprising certain components also discloses a product/composition consisting of these components. A product/composition consisting of these components may be advantageous in that it provides a simpler and more economical process for preparing the product/composition. Similarly, it is also to be understood that the description of a method involving certain steps also discloses a method consisting of these steps. A process consisting of these steps may be advantageous as it provides a simpler and more economical process.
When values are mentioned for the lower and upper limits of a parameter, it is also understood that ranges formed by combinations of the values of the lower limit and the values of the upper limit are disclosed.
The invention will now be elucidated by means of the following examples, without being limited thereto.
Catalyst preparation
Experiment I
Preparation of a Hydrocarbon solution comprising an organic magnesium and titanium Oxycoxide Compound
100 g of granulated Mg (OC)2H5)2And 150 ml Ti (OC)4H9)4Into a 2 liter round bottom flask equipped with a reflux condenser and a stirrer. With gentle stirring, the mixture was heated to 180 ℃ and then stirred for 1.5 hours. During which a clear liquid is obtained. The mixture was cooled to 120 ℃ and then diluted with 1480ml of hexane. After the addition of hexane, the mixture was further cooled to 67 ℃. The mixture was held at this temperature for 2 hours and then cooled to room temperature. The resulting clear solution was stored under a nitrogen atmosphere and used as such. Analysis of the solution showed a titanium concentration of 0.25 mol/l.
Experiment II
Preparation of the catalyst
424ml of hexane and 160ml of the complex of experiment I were metered in a 0.8 l glass reactor equipped with baffles, reflux condenser and stirrer. The agitator was set at 1200 RPM. In a separate flask, 100mL of 50% Ethyl Aluminum Dichloride (EADC) solution was added to 55mL of hexane. The resulting EADC solution was metered into the reactor over 15 minutes using a peristaltic pump. Subsequently, the mixture was refluxed for 2 hours. After cooling to ambient temperature, the resulting red/brown suspension was transferred to a glass P4 filter and the solid was isolated. The solid was washed 3 times with 500ml hexane. The solid was taken up in 0.5L hexane and the resulting slurry was stored under nitrogen. The solids content was 64 g/ml.
Analysis result of the catalyst:
10.8 wt% of Ti; mg 11.2 wt%; 5.0 weight percent of Al; cl 65 wt%; OEt 3.2 wt% and OBu 2.6 wt%.
Polymerisation
Copolymers of ethylene and 1-butene are prepared in three reactors R1, R2, R3 connected in series, separated by two flash vessels. All three reactors were the same size (20L) and the liquid level in each reactor was controlled at 75% by the discharge frequency during normal production. Hexane was used as the diluent. The hydrogen and comonomer (1-butene) feeds to each reactor were controlled separately. Hydrogen was used to control molecular weight and 1-butene was used to control density. The composition of the gas cap in each reactor was analyzed by Gas Chromatography (GC). The temperature in R1, R2 and R3 was 84 ℃.
The catalyst prepared by experiment II and a cocatalyst (triisobutylaluminum) were metered into the first reactor R1. The Al concentration in the first reactor was 21.3 ppm.
The ethylene pressure in R1 was controlled by the amount of catalyst metered into the reactor. Hydrogen was metered to R1 to control the MFI of the polymer. Low molecular weight homopolymer a was produced in R1. The gas cap in the reactor was analyzed by GC. About 10-15% nitrogen gas was evolved in the first reactor.
The reason for the presence of nitrogen in R1 is because the container of diluent was kept under 15 bar of nitrogen. The diluent was added to the reactor by pressure difference (no pump). Typical residence time in the first reactor is about 3.6 hours.
The slurry is continuously discharged from the first reactor into a first flash vessel. In the first flash vessel, as much unreacted hydrogen and ethylene gas as possible is removed, after which the slurry is pumped to the second reactor. Typical pressures in the flash vessel are 0.1 bar and temperatures are 32-45 ℃. The pressure in the flash vessel was controlled at 0.1 bar.
In the second reactor R2, fresh hexane was added along with ethylene, hydrogen and 1-butene. The liquid level in R2 was controlled at 75% by discharge to the second flash vessel. The gas cap in the second reactor was analyzed by GC. Manipulation of MFI between 8 and 12 using hydrogen5Within specification, and the density of the polymer is controlled to 960-964g/cm using 1-butene3Within the specification of (a). High molecular weight copolymer B was produced in R2. After an average residence time of about 2 hours, the polymer slurry was discharged to a second flash vessel.
In the second flash vessel, as much unreacted hydrogen, ethylene and 1-butene gas as possible was removed before the slurry was pumped to the third reactor.
In the third reactor R3, fresh hexane was added along with ethylene, hydrogen and 1-butene. The liquid level in R3 was controlled at 75% by discharge to the decanter. The composition in the third reactor was analyzed by GC. To prevent the discharge line from being blocked, the pressure in the third reactor was raised to about 5 bar with nitrogen. The MFI was controlled within the specification of 1.4-1.8 using hydrogen and the density of the final polymer was controlled at 955-959g/cm using 1-butene3Within the specification of (a). In R3, an ultrahigh molecular weight copolymer C was produced. After a residence time of 1.3 hours, the polymer slurry was discharged. The catalyst productivity was 25.2 kg/g.
The weight ratio of ethylene fed to the reactor was 47:32: 21.
The various conditions of the polymerization process are summarized in Table 1. The MFI, VN, density and amount of 1-butene of the polymer obtained from each reactor are also summarized in table 1.
TABLE 1
The resulting ethylene copolymer was pelletized and various properties were measured as shown in table 2, along with the same properties of a typical commercial product used for blow molding.
TABLE 2
| Example 1 | Comparative example 1 | Comparative example 2 | Comparative example 3 | Comparative example 4 | |
| Modality | Three peaks | Three peaks | Bimodal | Bimodal | Singlet |
| Density (g/cm)3) | 0.955 | 0.959 | 0.956 | 0.958 | 0.959 |
| MFI5(dg/min) | 1.37 | 1.21 | 1.21 | 1.76 | 0.88 |
| MFI21.6(dg/min) | 27.1 | 22.3 | 27.2 | 27.4 | 24.1 |
| FRR | 19.8 | 18.4 | 22.5 | 15.6 | 27.4 |
| Mw/Mn | 28.6 | 14.2 | 39.1 | 23.9 | 15.0 |
| Mz/Mw | 7.3 | 4.2 | 6.6 | 5.8 | 6.1 |
| SHI(0.1/100) | 18.7 | 16.6 | 19.4 | ||
| SHI(0.01/100) | 31.2 | 23.8 | 30.9 | ||
| Swelling in 200/s die | 1.53 | 1.34 | 1.43 | 1.58 | 1.76 |
| Swelling in a 400/s die | 1.86 | 1.59 | 1.69 | 1.88 | 2.03 |
| Swell at 800/s die | 2.28 | 1.89 | 1.99 | 2.45 | 2.50 |
| Swelling in 1600/s die | 2.88 | Critical point | 2.46 | Critical point | 2.69 |
| SH modulus (MPa) | 17.4 | 14.6 | 18.2 | 14.0 | 14.0 |
Critical: the extrudate exhibits a rough surface characterized by melt fracture/sharkskin.
It will be appreciated that the polyethylene according to the invention has a combination of good processability as indicated by high SHI and high die swell and good ESCR as indicated by high SH modulus.
When die swell at the highest shear rate (1600/s) was measured, comparative examples 1 and 3 showed some melt fracture, and thus the diameter of the strand could not be accurately measured. The polyethylene according to the invention having the desired processing properties does not show this behavior.
Further, die swell at 72/s was measured for example 1 to be 1.17-1.29.
Further, tan. delta. at 600rad/s was measured to be 0.57 for example 1.
Melt flow index MFI
MFI was measured according to ISO1133-1:2011 at 190 ℃ under loads of 1.2kg, 5kg and 21.6 kg. The measurement was performed on the sample to which the standard stabilizer had been added.
Viscosity number VN
VN was measured in decalin at 135 ℃ according to ISO/R1191.
Density of
The densities in table 1 were determined as follows:
the polymer powder from the reactor was compression molded at 160 ℃ followed by cooling at a rate of 40 ℃/min. The density of the molded plaques was measured directly after molding at 23 ℃ according to ISO 1183-1: 2012. The measured density was converted to an annealed density using the following formula (indicated in table 1):
calculated annealing Density (kg/m)3) Measurement of Density (kg/m)3)+2.7kg/m3
The densities in table 2 were determined as follows:
the polymer pellets were compression molded according to ISO 1872-2. The density of the molded plaques was measured at 23 ℃ according to ISO 1183-1: 2012. The molded plaques were conditioned at 23 ℃ at 50% RH for >16h before the density was measured.
1-butene content
1H-NMR measurements were carried out on samples taken from each reactor, which could be a mixture of polymers A and B (second reactor) or a mixture of polymers A, B and C (third reactor). The comonomer content in polymers B and C was calculated based on the ratio of polymers A, B and C in the sample.
About 15mg of the sample was dissolved in about 0.5ml of 1,1,2, 2-tetrachloroethane-d 2(TCE-d2)/BHT stock solution at about 135 deg.C using a 5mm NMR tube. A stock solution was prepared by dissolving about 2mg of BHT in 25ml of TCE-d 2. The tube was purged with nitrogen for about 1min before dissolution to reduce the oxygen concentration in the tube. The samples were checked periodically for homogeneity and mixed manually if necessary.
All NMR experiments were performed on a Bruker 500Avance III HD spectrometer equipped with a 10mm cryogenically cooled probe running at 125 ℃. 1H NMR measurements were made using a spectral width of 20ppm, an acquisition time of about 3.3s, a 30 excitation pulse and a relaxation delay of 10s between each 512 transients. The spectrum was calibrated by setting the signal of TCE at 5.91 ppm.
Mz/Mw and Mw/Mn
Mw, Mn and Mz are measured according to ASTM D6474-12 (Standard test method for determining Molecular Weight Distribution (MWD) and molecular weight averages for polyolefins by high temperature gel permeation chromatography). Mw represents the weight average molecular weight and Mn represents the number average weight. Mz represents z-average molecular weight.
MWD and SCB as a function of molecular weight were determined at 160 ℃ using a high temperature chromatography Polymer Char GPC-IR system (Polymer Char s.a., spain) equipped with an IR5 MCT detector and a Polymer Char viscometer. Three Polymer Laboratories 13 μm PLgel Olexis 300X 7.5mm columns were used in series for GPC separation. 1,2, 4-trichlorobenzene stabilized with 1g/L of butylhydroxytoluene (also known as 2, 6-di-tert-butyl-4-methylphenol or BHT) was used as eluent at a flow rate of 1 mL/min. The sample concentration was about 0.7mg/mL and the injection volume was 300. mu.L. Molar masses were determined on the basis of the ubiquitous GPC principle using calibrations carried out with narrow and wide standards of PE (0.5-2800kg/mol, Mw/Mn from 4 to 15) in combination with the known Mark Houwink constants (α ═ 0.725 and logK ═ 3.721) of the PE calibrants.
Shear thinning index SHI
The viscosity values were calculated from the fitted flow curves generated by the vibrating rheometer, using a modified Carreau-Yasuda model, according to ISO6721-10, and are represented by the following equation:
wherein
Eta is viscosity in Pa.s
η0Zero shear viscosity (Pa.s)
a is rheological breadth parameter
n is a power law constant, in this case set to 0 (slope defining the high shear rate region)
Gamma is the shear rate (1/s)
λ is relaxation time(s)
η100Is the viscosity value in Pa.s at 190 ℃ and a shear rate of 100 rad/s.
η0.1Is the viscosity value in Pa.s at 190 ℃ and a shear rate of 0.1 rad/s.
η0.01Is the viscosity value in Pa.s at 190 ℃ and a shear rate of 0.01 rad/s.
To facilitate model fitting, the power-law constant is held at a constant value, in this case zero. Details of the significance and interpretation of the Carreau-Yasuda model and derived parameters can be found in the following references each incorporated herein by reference in their entirety: c.a. hieber and h.h. chiang, Rheol Acta, 28, 321 (1989); c.a. hieber and h.h.chiang, polym.eng.sci., 32, 931 (1992); and r.b. bird, r.c. armstrong and o.hasseger, Dynamics of Polymeric Liquids, volume 1, Fluid Mechanics, second edition, John Wiley & Sons (1987).
Die swell
According to ISO11443:2014, in a die equipped with a diameter of 1mm and a length of 10mm, with an entry angle of 30 °
Die swell was measured on a capillary rheometer at different shear rates. The measurement was carried out at 190 ℃. Die swell was calculated from the diameter of the extrudate after crystallization measured with a caliper using the following formula:
die swell ═ diameter of extrudate/die diameter)2-1
Modulus of strain hardening
In the context of the present invention, the strain hardening modulus is used as an indicator of the resistance to slow crack propagation. The slow crack propagation resistance is related to the lifetime of the ethylene polymer. The strain hardening modulus can be considered as a measure of the disentanglement ability of the tie molecules in the ethylene polymer. Tie molecules are those molecules that form intermolecular interactions via physical entanglement, for example, that contribute to the mechanical strength of the ethylene polymer. The strain hardening modulus was determined according to the method described in ISO DIS 18488(2014) using a test specimen 0.30mm thick. The strain hardening modulus was determined as the slope of the Neo-Hookean constitutive model between true strains of 8 and 12.
Tanδ
Tan δ is a parameter representing the elasticity of the molten polymer, which strongly affects the swelling ratio of the polymer. Tan δ was determined by using the controlled stress rheometer model DHR3 from TA instrument. The geometry was 25mm diameter plate-plate under a 1mm measurement gap. The dynamic vibration shearing was carried out at 90 ℃ under a nitrogen atmosphere. Tan (. delta.) 600 is the calculated ratio of loss modulus (G ') to storage modulus (G') at an angular frequency of 600 rad/s.
Claims (15)
1. A multimodal ethylene polymer having from 0.955 to 0.960g/cm at 23 ℃3A melt flow index of 0.9 to 1.7dg/min measured according to ISO1133-1:2011 at 190 ℃ and 5kg, and a ratio of Mz/Mw of at least 7.0, and which comprises:
40 to 53% by weight of a low molecular mass ethylene polymer component A,
from 25 to 40% by weight of a high molecular weight ethylene polymer component B, and
15 to 28% by weight of an ultrahigh molecular mass ethylene polymer component C,
wherein all values are based on the total weight of the multimodal ethylene polymer, wherein
Said multimodal ethylene polymer being prepared by polymerizing said component A, followed by polymerizing said component B in the presence of said component A, and followed by polymerizing said component C in the presence of said components A and B, and
the ethylene polymer component A has a thickness of 90 to 110cm3G, e.g. 95 to 105cm3Viscosity number VN/g1，
The mixture of the ethylene polymer component A and the ethylene polymer component B has a density of 175 to 225cm3G, e.g. 180 to 220cm3Viscosity number VN/g2And is and
the mixture of the ethylene polymer component A, the ethylene polymer component B and the ethylene polymer component C has a density of 240 to 320cm3G, e.g. 250 to 300cm3Viscosity number VN/g3，
Wherein VN1、VN2And VN3Measured according to ISO/R1191 in decalin at 135 ℃.
2. The ethylene polymer of claim 1 wherein the ethylene polymer has from 0.956 to 0.959g/cm at 23 ℃3According to ISO1133-12011 melt flow index of 1.0 to 1.5dg/min measured at 190 ℃ and 5kg, a melt flow index of 10 to 40dg/min, preferably 20 to 30dg/min, measured according to ISO1133-1:2011 at 190 ℃ and 21.6kg, and/or a ratio of Mz/Mw of 7.0 to 10.0, preferably 7.1 to 9.0 or 7.2 to 8.0.
3. An ethylene polymer as claimed in any preceding claim, wherein the amount of the ethylene polymer component a in the ethylene polymer is from 43 to 50 wt%, the amount of the ethylene polymer component B in the ethylene polymer is from 28 to 35 wt%, and/or the amount of the ethylene polymer component C in the ethylene polymer is from 18 to 25 wt%.
4. An ethylene polymer as claimed in any preceding claim wherein
The ethylene polymer component a is an ethylene homopolymer,
the ethylene polymer component B is a copolymer of ethylene and a C3-10 alpha-olefin, preferably a copolymer of ethylene and 1-butene, and wherein the amount of comonomer units in the ethylene polymer component B is from 0.1 to 0.8 mol%, such as from 0.2 to 0.5 mol%, and
the ethylene polymer component C is a copolymer of ethylene and a C3-10 alpha-olefin, preferably a copolymer of ethylene and 1-butene, and wherein the amount of comonomer units in the ethylene polymer component C is from 0.3 to 1.5 mol%, such as from 0.4 to 1.0 mol%.
5. The ethylene polymer of any of the previous claims, wherein the ethylene polymer components A, B and C total at least 80 wt%, at least 90 wt%, at least 95 wt%, at least 98 wt%, at least 99 wt%, or 100 wt% of the ethylene polymer.
6. An ethylene polymer as claimed in any preceding claim wherein the ethylene polymer has a calculated MFI of from 10 to 30, preferably from 15 to 25190/21.6/MFI190/5Flow Rate Ratio (FRR).
7. An ethylene polymer as claimed in any preceding claim, wherein the ethylene polymer has a shear thinning index SHI (η) of at least 15, more preferably at least 17, for example from 17 to 200.1/η100) And/or a shear thinning index SHI (η) of at least 25, more preferably at least 30, e.g., 30 to 350.01/η100) Wherein
η100Is the viscosity value at 190 ℃ and a shear rate of 100rad/s, in Pa.s,
η0.1is the viscosity number in Pa.s at 190 ℃ and a shear rate of 0.1rad/s,
η0.01is the viscosity value in Pa.s at 190 ℃ and a shear rate of 0.01 rad/s; wherein eta0.01、η0.1、η100Calculated from a fitted flow curve generated by an oscillatory rheometer using a modified Carreau-Yasuda model according to ISO6721-10, represented by the following equation:
wherein
Eta is viscosity in Pa.s
η0Zero shear viscosity (Pa.s)
a is rheological breadth parameter
n is a power law constant set to 0
Gamma is the shear rate (1/s)
λ is the relaxation time(s).
8. An ethylene polymer as claimed in any preceding claim wherein said ethylene polymer has the following die swell determined according to ISO11443: 2014:
at least 1.40, preferably at least 1.50 to 1.80, and/or at 200/s
At least 1.70, preferably at least 1.80 to 2.10, and/or at 400/s
At least 2.10, preferably at least 2.20 to 2.50, and/or at 800/s
At least 2.60, preferably at least 2.80 to 3.00 at 1600/s.
9. An ethylene polymer as claimed in any preceding claim wherein the ethylene polymer has a strain hardening modulus of at least 15MPa, preferably at least 17MPa, determined according to ISO 18488: 2014.
10. An ethylene polymer as claimed in any preceding claim wherein the ethylene polymer has a ratio of Mw/Mn of at least 22.0, preferably from 23.0 to 33.0, more preferably from 25.0 to 30.0.
11. A process for the preparation of an ethylene polymer as claimed in any one of the preceding claims which is a multi-stage slurry polymerization process using a cascade reactor in the presence of a Ziegler Natta catalyst system.
12. The process of claim 11, wherein the catalyst system comprises:
(I) a solid reaction product obtained by the reaction of:
a) a hydrocarbon solution containing 1) and 2),
1) an organic magnesium oxy-containing compound or a halogen-containing magnesium compound,
2) an organic oxygen-containing titanium compound, wherein,
b) having the formula AlRnX3-nWherein R is a hydrocarbon moiety containing 1 to 10 carbon atoms, X is halogen and 0 < n < 3, and
(II) has the formula AlR3Wherein R is a hydrocarbon moiety containing from 1 to 10 carbon atoms.
13. Composition consisting of an ethylene polymer according to any one of claims 1-10 and an additive.
14. An article comprising the ethylene polymer of any one of claims 1-10 or the composition of claim 13.
15. The article of claim 14, wherein the article is a blow molded article.
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| US20060155058A1 (en) * | 2002-12-19 | 2006-07-13 | Basell Polyolefine Gmbh | Polyethylene blow molding composition for producing small containers |
| CN108473602A (en) * | 2016-09-12 | 2018-08-31 | 泰国聚乙烯有限公司 | Multimodal polyethylene container |
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| NL7711923A (en) | 1977-10-31 | 1979-05-02 | Stamicarbon | SOLUTIONS OF ORGANIC OXYGEN CONTAINING MAGNESIUM COMPOUNDS IN HYDROCARBONS. |
| DE19545444A1 (en) | 1995-12-06 | 1997-06-12 | Du Pont | Alkoxides with alkaline earths and titanium, zirconium and / or hafnium, their production and use |
| DE102005040390A1 (en) | 2005-08-25 | 2007-03-01 | Basell Polyolefine Gmbh | Multi-modal polyethylene moulding material for production of pipes, e.g. water pipes, comprises low-mol. wt. ethylene homopolymer, high-mol. wt. ethylene copolymer and ultrahigh-mol. wt. ethylene copolymer |
| BR112014013764B1 (en) | 2011-12-12 | 2021-04-27 | Saudi Basic Industries Corporation | PROCESS FOR THE PRODUCTION OF BIMODAL POLYETHYLENE IN THE PRESENCE OF THIS CATALYST SYSTEM |
| US9505161B2 (en) * | 2014-04-10 | 2016-11-29 | Fina Technology, Inc. | Solid-state stretched HDPE |
| WO2016065497A1 (en) * | 2014-10-31 | 2016-05-06 | Abu Dhabi Polymers Co. Ltd (Borouge) Llc | Pipe or pipe system |
| PT3293211T (en) * | 2016-09-12 | 2019-09-12 | Scg Chemicals Co Ltd | Multimodal polyethylene screw cap |
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| US20060155058A1 (en) * | 2002-12-19 | 2006-07-13 | Basell Polyolefine Gmbh | Polyethylene blow molding composition for producing small containers |
| CN108473602A (en) * | 2016-09-12 | 2018-08-31 | 泰国聚乙烯有限公司 | Multimodal polyethylene container |
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