A multi-component external electron donor composition and use

Abstract

The application provides a multi-component external electron donor composition and application. The multi-component external electron donor composition comprises at least one first external electron donor of the following formula (I) and at least one second external electron donor of the following formula (II); and the molar ratio of the first external electron donor and the second external electron donor is (1:99)-(99:1).

Description

Technical Field

[0001] This invention relates to the field of chemical engineering, and more specifically, to a multi-electron donor composition and its application. Background Technology

[0002] Ziegler-Natta propylene polymerization catalysts consist of a main catalyst, an internal electron donor, alkylaluminum, and an external electron donor. Currently, the main catalysts for industrial polypropylene production are MgCl2-supported Zn catalysts with aromatic carboxylic acid diesters as internal electron donors. These catalysts require the addition of external electron donors during polymerization to adjust the isotacticity of polypropylene and the catalyst's hydrogen sensitivity, which also has a certain impact on catalyst activity, the apparent density of polypropylene, and the copolymerization properties of propylene and ethylene.

[0003] Currently, external electron donors are mainly silanes containing 1 to 4 alkoxy groups, with dialkyldimethoxysilanes being the most commonly used. Different structures of external electron donors have varying effects on the isotacticity of polypropylene, the hydrogen sensitivity of the catalyst, and its activity. In polymerization reactions, increased temperature often leads to an increased polymerization rate and further increased heat release, frequently causing temperature runaway and making reactor control difficult. Since siloxane-based external electron donors cannot control temperature regulation during polymerization, researchers have sought to regulate the temperature by adding a second type of external electron donor to ensure stable polymerization.

[0004] A patent published by Dow Chemical Company (US7491670) indicates that the introduction of C 8-20 Fatty acid C 1-20 Alkyl esters can suppress the activity of propylene polymerization catalysts at high temperatures, forming a positive feedback loop in the reaction, stabilizing the polymerization temperature, and simplifying the reaction operation. The introduction of cinnamic acid esters (CN102391397B) and carbonates (CN104403028A) can also suppress the activity of propylene polymerization catalysts at high temperatures, while simultaneously improving the stereoregularity of the polymer to some extent. Summary of the Invention

[0005] One object of the present invention is to provide a multi-electron donor composition;

[0006] Another object of the present invention is to provide the application of the aforementioned multi-electron donor composition;

[0007] Another object of the present invention is to provide a ZN catalyst system;

[0008] Another object of the present invention is to provide a method for preparing polypropylene.

[0009] To achieve the above objectives, in one aspect, the present invention provides a multi-electron donor composition, wherein the multi-electron donor composition comprises at least one first electron donor (a silane-1,3-diether compound of formula (I)) and at least one second electron donor (an acyloxyalkylsilane compound of formula (II)); the molar ratio of the first electron donor to the second electron donor is (1:99)-(99:1).

[0010]

[0011] Whether R1 and R2 are the same or different, each is independently C1-C. 10 Alkyl groups, C3-C 12 cycloalkyl and C6-C 20 Any of the aryl groups;

[0012] R3, R4, R5, R6 may be the same or different, and each is independently hydrogen, halogen, or C1-C. 10 Alkyl groups, C3-C 12 cycloalkyl and C6-C 20 Any of the aryl groups;

[0013] R7 and R8 may be the same or different, and each is independently any one of the C1-C5 chain alkyl groups;

[0014] R9, R 10 R 11 and R 12 Whether they are the same or different, each is independently C. 1-20 Aliphatic groups, C 3-12 Alicyclic groups or C 6-20 Any one of the aromatic groups; the aliphatic group, alicyclic group and aromatic group are substituted or unsubstituted; optionally, the carbon atom of the aliphatic group, the carbon atom of the ring of the alicyclic group and the aromatic group are replaced by a heteroatom selected from one or more Group IV, Group V or Group VI.

[0015] The first and second external electron donors in the multi-electron donor composition of the present invention can be mixed and placed together, or they can be packaged and placed separately and then mixed and put into the reactor when used, or they can be put into the reactor separately.

[0016] According to some specific embodiments of the present invention, wherein,

[0017] R1 and R2 are each independently any one of methyl, ethyl, isopropyl, tert-butyl, isobutyl, cyclopentyl, cyclohexyl, phenyl, 2,6-dimethylphenyl and 2,6-diisopropylphenyl;

[0018] R3, R4, R5 and R6 are each independently any one of hydrogen, fluorine, chlorine, bromine, iodine, methyl, ethyl, isopropyl, tert-butyl, isobutyl, cyclopentyl, cyclohexyl, phenyl, 2,6-dimethylphenyl and 2,6-diisopropylphenyl;

[0019] R7 and R8 are each any one of C1-C3 alkyl groups;

[0020] R9, R 10 R 11 and R 12 Each is independently selected from C 1-20 Aliphatic groups, C 3-12 Alicyclic groups or C 6-20 Aromatic groups; the aliphatic, alicyclic, and aromatic groups may be substituted or unsubstituted; optionally, the carbon atom of the aliphatic group, the carbon atom of the ring of the alicyclic group, and the aromatic group may be replaced by one or more heteroatoms selected from N, O, or S; when substituted, the N on the aliphatic, alicyclic, and aromatic groups is replaced by -R. a Replace, where R a Selected from H or C 1-20 alkyl.

[0021] According to some specific embodiments of the present invention, wherein R9, R 10 R 11 and R 12 Each is independently selected from C atoms containing or without heteroatoms. 1-20 Aliphatic groups, C 3-12 Alicyclic or C 6-20 Aromatic groups.

[0022] According to some specific embodiments of the present invention, wherein,

[0023] R1 and R2 are each independently any one of methyl, isopropyl, cyclohexyl, and phenyl;

[0024] R3, R4, and R5 are hydrogen atoms;

[0025] R6 is any one of hydrogen, methyl, ethyl, and isopropyl;

[0026] R7 and R8 are each any one of methyl, ethyl, n-propyl and isopropyl;

[0027] R9, R 10 R 11 and R 12 Each was independently selected from C 1-20 Alkyl, C 1-20 alkenyl, C 3-12 cycloalkyl or C 6-20Aromatic group; wherein the alkyl, alkenyl, cycloalkyl, and aromatic groups are substituted or unsubstituted; optionally, the carbon atoms of the alkyl, alkenyl, cycloalkyl, and aromatic groups are replaced by one or more heteroatoms selected from N, O, or S; when substituted, the N on the alkyl, alkenyl, cycloalkyl, and aromatic groups is replaced by -R. a Replace, where R a Selected from H or C 1-10 alkyl.

[0028] According to some specific embodiments of the present invention, wherein R9, R 10 R 11 and R 12 Each is independently selected from C atoms that do not contain heteroatoms. 1-20 Alkyl, C 1-20 alkenyl, C 3-12 cycloalkyl or C 6-20 Aromatic group.

[0029] According to some specific embodiments of the present invention, wherein,

[0030] R7 and R8 are methyl groups;

[0031] R9, R 10 R 11 and R 12 Each was independently selected from C 1-10 Alkyl, C 1-10 alkenyl, C 3-10 cycloalkyl or C 6-14 Aromatic group; optionally, the carbon atoms of the alkyl, alkenyl, cycloalkyl and aromatic groups are replaced by one or more heteroatoms selected from O or S.

[0032] According to some specific embodiments of the present invention, the number of heteroatoms on the alkyl, alkenyl, cycloalkyl and aromatic groups is 1, 2, 3, 4 or 5.

[0033] According to some specific embodiments of the present invention, wherein R9, R 10 R 11 and R 12 Each is independently selected from C atoms that do not contain heteroatoms. 1-10 Alkyl, C 1-10 alkenyl, C 3-10 cycloalkyl or C 6-14 Aromatic group.

[0034] According to some specific embodiments of the present invention, the first external electron donor is selected from dicyclopentyl(3-isopropyl-2-methoxyphenyl)methoxysilane, dicyclohexyl(3-isopropyl-2-methoxyphenyl)methoxysilane, dicyclohexyl(2-methoxyphenyl)methoxysilane, dicyclopentyl(2-methoxyphenyl)methoxysilane, dimethyl(3-isopropyl-2-methoxyphenyl)methoxysilane, phenylmethyl(3-isopropyl-2-methoxyphenyl)methoxysilane, cyclohexylmethyl(3-isopropyl-2-methoxyphenyl)methoxysilane, cyclopentylmethyl(3-isopropyl-2-methoxyphenyl)methoxysilane, cyclohexylmethyl(2-methoxyphenyl)methoxysilane, and cyclopentylmethyl(2-methoxyphenyl)methoxysilane. The second external electron donor is selected from one or more combinations of isooctyloxytrimethylsilane, isooctyloxytriethylsilane, benzoyloxytrimethylsilane, benzoyloxytriethylsilane, isooctyloxymethyldiethylsilane, cyclohexanoyloxyethyldimethylsilane, cyclopentanoyloxyethyldimethylsilane, cyclohexanoyloxytrimethylsilane, cyclopentanoyloxytriethylsilane, sec-butanoyloxytriethylsilane, butanoyloxytrimethylsilane, sec-pentanoyloxytriethylsilane, sec-hexanoyloxytrimethylsilane ester, sec-octanoyloxytrimethylsilane, n-octanoyloxytriethylsilane, sec-octanoyloxyethyldimethylsilane, n-octanoyloxyethyldimethylsilane, sec-heptanoyloxytrimethylsilane, and isopropanoyloxytrimethylsilane.

[0035] According to some specific embodiments of the present invention, the first electron donor is selected from one or more combinations of dicyclohexyl(3-isopropyl-2-methoxyphenyl)methoxysilane, dicyclohexyl(2-methoxyphenyl)methoxysilane, dicyclopentyl(2-methoxyphenyl)methoxysilane, phenylmethyl(3-isopropyl-2-methoxyphenyl)methoxysilane, cyclohexylmethyl(3-isopropyl-2-methoxyphenyl)methoxysilane, cyclopentylmethyl(3-isopropyl-2-methoxyphenyl)methoxysilane, cyclohexylmethyl(2-methoxyphenyl)methoxysilane, and cyclopentylmethyl(2-methoxyphenyl)methoxysilane.

[0036] According to some specific embodiments of the present invention, the second electron donor is selected from one or more combinations of isooctanoyloxytrimethylsilane, isooctanoyloxytriethylsilane, benzoyloxytrimethylsilane, benzoyloxytriethylsilane, isooctanoyloxymethyldiethylsilane, cyclohexanoyloxyethyldimethylsilane, cyclopentanoyloxyethyldimethylsilane, cyclohexanoyloxytrimethylsilane, cyclopentanoyloxytriethylsilane, sec-butanoyloxytriethylsilane, butanoyloxytrimethylsilane, sec-pentanoyloxytriethylsilane, sec-hexanoyloxytrimethylsilane ester, sec-octanoyloxytrimethylsilane, n-octanoyloxytriethylsilane, sec-octanoyloxyethyldimethylsilane, n-octanoyloxyethyldimethylsilane, sec-heptanoyloxytrimethylsilane, and isopropanoyloxytrimethylsilane.

[0037] When the external electron donor component is only the first external electron donor, the resulting catalyst system exhibits high isotropic orientation and hydrogen-modulated sensitivity, but it lacks the ability to control polymer agglomeration or excessively high polymerization temperatures during the polymerization reaction. The influence of different electron donors and the active centers of the Ziegler-Natta catalyst varies. The first external electron donor provides stereotactic properties to the catalyst, while the second external electron donor causes partial deactivation of the catalyst and a decrease in catalytic activity above 80°C, making reactor temperature control more difficult.

[0038] According to some specific embodiments of the present invention, the molar ratio of the first external electron donor and the second external electron donor is 1:80 to 80:1.

[0039] According to some specific embodiments of the present invention, the molar ratio of the first external electron donor and the second external electron donor is 5:95 to 95:5.

[0040] According to some specific embodiments of the present invention, the molar ratio of the first external electron donor and the second external electron donor is 10:90 to 90:10.

[0041] According to some specific embodiments of the present invention, the molar ratio of the first external electron donor and the second external electron donor is 15:85 to 85:15.

[0042] According to some specific embodiments of the present invention, the first external electron donor and the second external electron donor may be a combination of two or more.

[0043] On the other hand, the present invention provides the application of the multi-electron donor composition described in any of the preceding claims in the preparation of ZN catalyst systems.

[0044] In another aspect, the present invention provides a ZN catalyst system, wherein the ZN catalyst system further comprises a solid catalyst component and alkyl aluminum; the solid catalyst component comprises a magnesium chloride-supported Ti solid component and an internal electron donor; the internal electron donor is one or more of diester or diether internal electron donors in combination.

[0045] The components of the ZN catalyst system of the present invention can be mixed and placed separately, or they can be packaged and placed separately and then mixed and added to the reactor when used, or they can be added to the reactor separately.

[0046] According to some specific embodiments of the present invention, the internal electron donor is selected from one or more combinations of aromatic carboxylic acid diesters, 1,3-diethers, malonic acid esters, succinates, phthalates, glutarates, and glycol esters.

[0047] According to some specific embodiments of the present invention, the malonate compound is shown in formula (III), the succinate compound is shown in formula (III'), and the phthalate compound is shown in formula (III''):

[0048]

[0049] R 13 R 14 R 15 R 16 R 17 R 18 R 19 R 20 R 21 R 22 R 23 R 24 Each is either hydrogen or a C1-C8 alkyl group.

[0050] According to some specific embodiments of the present invention, the internal electron donor is selected from one or more combinations of diisobutyl phthalate, di-n-butyl phthalate, di-n-butyl 2-isopropylmalonate, diethyl 2-decylmalonate, diethyl 2-methyl-2-isopropylmalonate, diisobutyl diisopropylsuccinate, and 2,3-diisopropylsuccinic acid.

[0051] According to some specific embodiments of the present invention, the solid catalyst component comprises titanium chloride supported on magnesium chloride and an internal electron donor.

[0052] According to some specific embodiments of the present invention, in the ZN catalyst system, the molar ratio of Mg to Ti is 3-9; the molar ratio of Al to Ti is 10-1000; the molar ratio of Si to Ti is 2-50; and the mass content of internal electron donor is 7-20% with the total mass of the ZN catalyst system being 100%.

[0053] According to some specific embodiments of the present invention, the molar ratio of Al to Ti is 40-800.

[0054] According to some specific embodiments of the present invention, the molar ratio of Al to Ti is 60-600.

[0055] According to some specific embodiments of the present invention, the molar ratio of Al to Ti is 300-600.

[0056] According to some specific embodiments of the present invention, the molar ratio of Si to Ti is 5-30.

[0057] According to some specific embodiments of the present invention, the molar ratio of Si to Ti is 15-25.

[0058] According to some specific embodiments of the present invention, the molar ratio of Si to Ti is 20.

[0059] According to some specific embodiments of the present invention, the mass content of the internal electron donor is 7-10%.

[0060] According to some specific embodiments of the present invention, the trialkylaluminum is selected from triethylaluminum or triisobutylaluminum.

[0061] The solid catalyst component can be prepared using existing methods, such as CN1453298, CN1690039, EP1840138, CN101423566, CN101423570, CN101423571, CN101423572, CN1986576, CN1986576, CN101125898, CN1891722, WO2007147864, CN1831017, CN101560273, EP The methods described in 2029637, EP2029642, CN1330086, CN1463990, CN1397568, CN1528793, CN1732671, CN1563112, CN1034548, CN1047302, CN1091748, CN1109067, CN94103454, CN1199056, EP03614941990, EP03614931990, and WO002617.

[0062] According to some specific embodiments of the present invention, the catalytic activity of the ZN catalyst system is 20-40 kgPP / g catalyst.

[0063] According to some specific embodiments of the present invention, the catalytic activity of the ZN catalyst system is 20-36 kgPP / g catalyst.

[0064] This invention employs a composite external electron donor composed of a sterically hindered silane 1,3-diether compound and an acyloxyalkylsilane compound for propylene polymerization. Acyloxyalkylsilane compounds also exhibit the characteristic of suppressing high-temperature catalyst activity, and their effect is no less than that of fatty acid ester compounds in Dow Chemical's patent for temperature control. The silane 1,3-diether compound has good hydrogen sensitivity, which is beneficial for controlling the polymer melt index. Furthermore, the combined use of acyloxyalkylsilane compounds and silane 1,3-diether compounds as external electron donors demonstrates superior improvement in stereoregulation properties and hydrogen sensitivity compared to siloxane-based external electron donors.

[0065] In this invention, "C1-C" 10 "Alkyl group" refers to an alkyl group with a total number of carbon atoms of 1-10, including straight-chain and branched alkyl groups, such as, but not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, pentyl and its various isomers (e.g., n-pentyl, isopentyl, neopentyl, etc.), hexyl and its various isomers (e.g., n-hexyl, isohexyl, etc.), heptyl and its various isomers, octyl and its various isomers, nonyl and its various isomers, and decyl and its various isomers, etc.; the alkyl group also includes those with C atoms bonded to a carbon atom. 1-10 Alkyl or C 6-20 aryl-substituted alkyl groups.

[0066] “C 3-12 "Alicyclic" refers to cyclic alkane groups with a total number of carbon atoms of 3-12 and alkyl-substituted cycloalkyl groups, such as, but not limited to, cyclopropane, cyclobutane, cyclopentane, cyclohexane, methylcyclopropane, methylcyclobutane, methylcyclopentane, methylcyclohexane, etc.

[0067] “C6-C 20 "Aryl" refers to an aryl group with a total number of carbon atoms of 6-20, including unsubstituted aryl groups and substituted aryl groups. Substituted aryl groups include alkylaryl groups (aryl groups substituted with alkyl groups). For example, C6-C 20 The aryl groups include, but are not limited to, phenyl, o-tolyl, m-tolyl, p-tolyl, o-ethylphenyl, m-ethylphenyl, p-ethylphenyl, n-propylphenyl, isopropylphenyl, n-butylphenyl, sec-butylphenyl, isobutylphenyl, tert-butylphenyl, naphthyl, anthracene, phenanthryl, benzyl, etc.

[0068] In another aspect, the present invention also provides a method for preparing polyolefins, wherein the method comprises using the ZN catalyst system described in any of the preceding claims as a catalyst and using an olefin having 3-10 carbon atoms as a polymerization monomer to prepare polyolefins.

[0069] According to some specific embodiments of the present invention, the method includes preparing polyolefins using olefins with 3-10 carbon atoms as polymerizing monomers in the presence of hydrogen.

[0070] According to some specific embodiments of the present invention, the mass ratio of olefins with 3-10 carbon atoms to catalyst is 0.5 kg to 3 kg: 10 mg.

[0071] According to some specific embodiments of the present invention, the mass ratio of hydrogen to olefins having 3-10 carbon atoms is 0-2g:1.2kg.

[0072] According to some specific embodiments of the present invention, the mass ratio of hydrogen to olefins having 3-10 carbon atoms is 0.168-1.4 g: 1.2 kg.

[0073] According to some specific embodiments of the present invention, the olefin having 3-10 carbon atoms is propylene.

[0074] According to some specific embodiments of the present invention, the reaction temperature for preparing polyolefins is 60-120°C.

[0075] According to some specific embodiments of the present invention, the reaction temperature for preparing polyolefins is 60-100°C.

[0076] According to some specific embodiments of the present invention, the reaction temperature for preparing polyolefins is 70-90°C.

[0077] According to some specific embodiments of the present invention, the second external electron donor may be added to the reaction vessel simultaneously with one or more of the first external electron donors of the present invention to achieve a stable polymerization reaction; or the second external electron donor of the present invention may be added to the reaction vessel intermittently to achieve a stable polymerization reaction.

[0078] According to some specific embodiments of the present invention, the method includes directly adding the first external electron donor and the second external electron donor as described in the present invention during the reaction process, or adding the first external electron donor and then intermittently adding one or more of the second external electron donors as described in the present invention.

[0079] According to some specific embodiments of the present invention, the method includes:

[0080] The step of adding the mixture of the first and second external electron donors, the solid catalyst component, alkyl aluminum, hydrogen and propylene into the reactor in any order;

[0081] The steps involved in a polymerization reaction.

[0082] According to some specific embodiments of the present invention, the method further includes a step of extracting polypropylene from the reactor after the polymerization reaction is completed.

[0083] According to some specific embodiments of the present invention, the method includes:

[0084] a) Add the solid catalyst component (Ziegler-Natta main catalyst) to the polymerization reactor;

[0085] b) Add alkylaluminum to the polymerization reactor;

[0086] c) Add a mixture of the first external electron donor and the second external electron donor to the polymerization reactor;

[0087] d) Add propylene to the reactor;

[0088] e) Extract polypropylene from the reactor.

[0089] According to some specific embodiments of the present invention, the first external electron donor is added at the start of the reaction, and the second external electron donor is added when any one or more of the following conditions are met:

[0090] (1) Polymer agglomeration occurs during the polymerization reaction;

[0091] (2) When the polymerization temperature is greater than or equal to 80℃ during the polymerization reaction.

[0092] In the above operation method, if only the first external electron donor formula (Formula I) is used for propylene polymerization, polymer agglomeration or excessively high polymerization temperature may occur during the polymerization reaction. In this case, the compound external electron donor (first / second external electron donor) of the present invention can be formed in situ by timely adding one or more of the second external electron donors of Formula (II) of the present invention into the reactor, wherein the addition time is sufficient to reduce polymer agglomeration, flake peeling or scaling, thereby stabilizing the polymerization.

[0093] In another aspect, the present invention also provides polyolefins prepared by the method described above.

[0094] According to some specific embodiments of the present invention, the melt index of the polyolefin is 5-100 g / 10 min.

[0095] According to some specific embodiments of the present invention, the melt index of the polyolefin is 10-55 g / 10 min.

[0096] According to some specific embodiments of the present invention, the isotacticity of the polyolefin is 95%-97.5%.

[0097] According to some specific embodiments of the present invention, the polyolefin is polypropylene.

[0098] The polymerization reaction of the present invention is preferably a propylene polymerization reaction, which includes homopolymerization or copolymerization.

[0099] The multi-electron donor in the ZN catalyst system of this invention can effectively stabilize the polymerization reaction.

[0100] In summary, this invention provides a multi-electron donor composition and its application. The technical solution of this invention has the following advantages:

[0101] In the external electron donor of Formula I of the present invention, a silicon heterostructure is introduced, which has greater steric hindrance. Its effect is not only to suppress catalyst activity when the polymerization temperature rises, but also to prepare high hydrogen-sensitive polyolefins and stabilize the polymerization reaction. The silicon heterostructure is used to control the melt index of the prepared polypropylene product. The different steric hindrances of the substituents linked to the silicon heterostructure can change the ease of insertion of the chain transfer agent (hydrogen) in the polymerization system, thereby enabling the preparation of polyolefin products with high melt index. Detailed Implementation

[0102] The following detailed embodiments illustrate the implementation process and beneficial effects of the present invention, aiming to help readers better understand the essence and characteristics of the present invention, and are not intended to limit the scope of implementation of this case.

[0103] Test methods

[0104] The isotacticity of polypropylene was determined using a heptane extraction method. Approximately 2g of polypropylene was placed in a Soxhlet extractor and extracted with boiling heptane for 6 hours. The remaining polymer was dried to constant weight, and the ratio of the remaining polymer to the initially added polymer was used as the isotacticity.

[0105] The melt index of polypropylene was determined according to the test standard ASTM D1238, with experimental conditions of 2.16 kg and 230 °C.

[0106] Example 1

[0107] A 5L high-pressure reactor was heated and evacuated to remove air and water. The reactor was then purged with nitrogen and this process was repeated three times. Next, 20 mg of a MgCl2-supported TiCl4 catalyst solid component (with a total catalyst solid component mass of 100%, an internal electron donor mass content of 8.1%, and diisobutyl phthalate) was added. The Ti content in the solid component was 2.50 wt%, the triethylaluminum addition was Al / Ti (molar) = 500, and the molar ratio of Mg to Ti was 3.24. Bicyclopentyl(2-methoxyphenyl)methoxysilane and heptanoyltrimethylsilane were added in a molar ratio of 85:15. The molar ratio of the two external electron donors to Ti was 20 (calculated by molar) before adding 336 mmol of hydrogen and 1.2 kg of propylene. The reactor was shut off, and the temperature was raised to 70°C to start polymerization. After 2 hours of reaction, unreacted propylene was discharged, yielding 680g of polypropylene particles. The catalytic activity of the catalytic system was 34.0 kg PP / g catalyst, the melt index of polypropylene was 46.2 g / 10 min, and the isotacticity was 96.5%.

[0108] Example 2

[0109] A 5L high-pressure reactor was heated and evacuated to remove air and water. The reactor was then purged with nitrogen and the process was repeated three times. Then, 20 mg of a MgCl2-supported TiCl4 catalyst solid component (with a total catalyst solid component mass of 100%, an internal electron donor mass content of 9.1%, and diisobutyl phthalate) was added. The Ti content in the solid component was 2.53 wt%, the triethylaluminum addition was Al / Ti (molar) = 600, and the molar ratio of Mg to Ti was 3.60. Bicyclopentyl(2-methoxyphenyl)methoxysilane and heptanoyltrimethylsilane were added in a molar ratio of 80:20. The molar ratio of the two external electron donors to Ti was 20. Finally, 168 mmol of hydrogen and 1.2 kg of propylene were added. The reactor was shut off, and the temperature was raised to 70°C to start polymerization. After 2 hours of reaction, unreacted propylene was discharged, yielding 680g of polypropylene particles. The catalytic activity of the catalytic system was 34.0 kg PP / g catalyst, the melt index of polypropylene was 25.0 g / 10 min, and the isotacticity was 96.5%.

[0110] Example 3-14

[0111] The polymerization process was the same as in Example 2, except that the amount of hydrogen, the Al / Ti ratio, and the type and ratio of external electron donors were changed. The results are shown in Table 1.

[0112]

[0113] D1: First electron donor, D2: Second electron donor.

[0114] Example 15

[0115] The process was the same as in Example 2, except that the polymerization temperature was 85°C, the catalytic activity was 29.5 kg PP / g catalyst, no significant increase in polymerization temperature or burst polymerization occurred during the polymerization process, the melt index of polypropylene was 25.8 g / 10 min, and the isotacticity was 96.7%.

[0116] Example 17

[0117] The process was the same as in Example 2, except that the polymerization temperature was 90°C, the catalytic activity was 23.9 kg PP / g catalyst, no significant increase in polymerization temperature or burst polymerization occurred during the polymerization process, the melt index of polypropylene was 24.7 g / 10 min, and the isotacticity was 96.2%.

Claims

1. A multi-electron donor composition, wherein, The multi-electron donor composition comprises at least one first electron donor of formula (I) and at least one second electron donor of formula (II); the molar ratio of the first electron donor to the second electron donor is (1:99)-(99:1): R1 and R2 may be the same or different, and R1 is C1-C. 10 Alkyl groups, C3-C 12 cycloalkyl and C6-C 20 Any of the aryl groups; R2 is C3-C 12 cycloalkyl and C6-C 20 Any of the aryl groups; R3, R4, R5, R6 may be the same or different, and each is independently hydrogen, halogen, or C1-C. 10 Alkyl groups, C3-C 12 cycloalkyl and C6-C 20 Any of the aryl groups; R7 and R8 may be the same or different, and each is independently any one of the C1-C5 chain alkyl groups; R9 is C 1-20 Aliphatic groups, C 3-12 Alicyclic groups or C 6-20 Any one of the aromatic groups; R 10 R 11 and R 12 Whether they are the same or different, each is independently C. 1-20 Aliphatic groups or C 3-12 Any one of the alicyclic groups; the alicyclic group, aliphatic group, and aromatic group are substituted or unsubstituted; optionally, the carbon atom of the aliphatic group, the carbon atom of the ring of the alicyclic group, and the aromatic group are replaced by a heteroatom selected from one or more Group IV, Group V, or Group VI.

2. The multi-electron donor composition according to claim 1, wherein, R1 is any one of methyl, ethyl, isopropyl, tert-butyl, isobutyl, cyclopentyl, cyclohexyl, phenyl, 2,6-dimethylphenyl, and 2,6-diisopropylphenyl; R2 is any one of cyclopentyl, cyclohexyl, phenyl, 2,6-dimethylphenyl, and 2,6-diisopropylphenyl. R3, R4, R5 and R6 are each independently any one of hydrogen, fluorine, chlorine, bromine, iodine, methyl, ethyl, isopropyl, tert-butyl, isobutyl, cyclopentyl, cyclohexyl, phenyl, 2,6-dimethylphenyl and 2,6-diisopropylphenyl; R7 and R8 are each any one of C1-C3 alkyl groups; R9 is selected from C 1-20 Aliphatic groups, C 3-12 Alicyclic groups or C 6-20 Aromatic groups; R 10 R 11 and R 12 Each was independently selected from C 1-20 Aliphatic groups or C 3-12 Alicyclic groups; the alicyclic and aromatic groups may be substituted or unsubstituted; optionally, the carbon atom of the alicyclic group, the carbon atom of the ring of the alicyclic group, and the aromatic group may be replaced by one or more heteroatoms selected from N, O, or S; when substituted, the N on the alicyclic group, the alicyclic group, and the aromatic group is replaced by R. a Replace, where R a Selected from H or C 1-20 alkyl.

3. The multi-electron donor composition according to claim 2, wherein, R1 is any one of methyl, isopropyl, cyclohexyl, and phenyl; R2 is any one of cyclohexyl and phenyl. R3, R4, and R5 are hydrogen atoms; R6 is any one of hydrogen, methyl, ethyl, and isopropyl; R7 and R8 are each any one of methyl, ethyl, n-propyl and isopropyl; R9 is selected from C 1-20 Alkyl, C 1-20 alkenyl, C 3-12 cycloalkyl or C 6-20 Aromatic group; R 10 R 11 and R 12 Each was independently selected from C 1-20 Alkyl, C 1-20 alkenyl or C 3-12 Cycloalkyl; wherein the alkyl, alkenyl, cycloalkyl, and aromatic groups are substituted or unsubstituted; optionally, the carbon atoms of the alkyl, alkenyl, cycloalkyl, and aromatic groups are replaced by one or more heteroatoms selected from N, O, or S; when substituted, the N on the alkyl, alkenyl, cycloalkyl, and aromatic groups is replaced by -R. a Replace, where R a Selected from H or C 1-10 alkyl.

4. The multi-electron donor composition according to claim 3, wherein, R7 and R8 are methyl groups; R9 is selected from C 1-10 Alkyl, C 1-10 alkenyl, C 3-10 cycloalkyl or C 6-14 Aromatic group; R 10 R 11 and R 12 Each was independently selected from C 1-10 Alkyl, C 1-10 alkenyl or C 3-10 Cycloalkyl; optionally, the carbon atoms of the alkyl, alkenyl, cycloalkyl, and aromatic groups are replaced by one or more heteroatoms selected from O or S.

5. The multi-electron donor composition according to any one of claims 1 to 4, wherein, The first electron donor is selected from one or more combinations of dicyclopentyl(3-isopropyl-2-methoxyphenyl)methoxysilane, dicyclohexyl(3-isopropyl-2-methoxyphenyl)methoxysilane, dicyclohexyl(2-methoxyphenyl)methoxysilane, dicyclopentyl(2-methoxyphenyl)methoxysilane, phenylmethyl(3-isopropyl-2-methoxyphenyl)methoxysilane, cyclohexylmethyl(3-isopropyl-2-methoxyphenyl)methoxysilane, cyclopentylmethyl(3-isopropyl-2-methoxyphenyl)methoxysilane, cyclohexylmethyl(2-methoxyphenyl)methoxysilane, and cyclopentylmethyl(2-methoxyphenyl)methoxysilane; the second electron donor... It is selected from one or more combinations of isooctyloxytrimethylsilane, isooctyloxytriethylsilane, benzoyloxytrimethylsilane, benzoyloxytriethylsilane, isooctyloxymethyldiethylsilane, cyclohexanoyloxyethyldimethylsilane, cyclopentanoyloxyethyldimethylsilane, cyclohexanoyloxytrimethylsilane, cyclopentanoyloxytriethylsilane, sec-butanoyloxytriethylsilane, butanoyloxytrimethylsilane, sec-pentanoyloxytriethylsilane, sec-hexanoyloxytrimethylsilane ester, sec-octanoyloxytrimethylsilane, n-octanoyloxytriethylsilane, sec-octanoyloxyethyldimethylsilane, n-octanoyloxyethyldimethylsilane, sec-heptanoyloxytrimethylsilane, and isopropanoyloxytrimethylsilane.

6. The multi-electron donor composition according to claim 1, wherein, The molar ratio of the first external electron donor to the second external electron donor is 15:85 to 85:

15.

7. The use of the multi-electron donor composition according to any one of claims 1 to 6 in the preparation of ZN catalyst systems.

8. A ZN catalyst system, wherein, The ZN catalyst system comprises the multi-electron donor composition according to any one of claims 1 to 6.

9. The ZN catalyst system according to claim 8, wherein, The ZN catalyst system also includes a solid catalyst component and alkyl aluminum; the solid catalyst component includes a magnesium chloride-supported Ti solid component and an internal electron donor; the internal electron donor is one or more of diester or diether internal electron donors.

10. The ZN catalyst system according to claim 9, wherein, The internal electron donor is selected from one or more combinations of aromatic carboxylic acid diesters, 1,3-diethers, malonates, succinates, glutarates, and diol esters.

11. The ZN catalyst system according to claim 10, wherein, Aromatic carboxylic acid diesters are phthalate esters.

12. The ZN catalyst system according to claim 11, wherein, The malonate compound is shown in formula (III), the succinate compound is shown in formula (III'), and the phthalate compound is shown in formula (III”): R 13 R 14 R 15 R 16 R 17 R 18 R 19 R 20 R 21 R 22 R 23 R 24 Each is either hydrogen or a C1-C8 alkyl group.

13. The ZN catalyst system according to claim 10, wherein, The internal electron donor is selected from one or more combinations of diisobutyl phthalate, di-n-butyl phthalate, di-n-butyl 2-isopropylmalonate, diethyl 2-decylmalonate, diethyl 2-methyl-2-isopropylmalonate, diisobutyl diisopropylsuccinate, and 2,3-diisopropylsuccinic acid.

14. The ZN catalyst system according to claim 9, wherein, The solid catalyst components include magnesium chloride-supported titanium chloride and an internal electron donor.

15. The ZN catalyst system according to any one of claims 8 to 14, wherein, In the ZN catalyst system, the molar ratio of Mg to Ti is 3-9; the molar ratio of Al to Ti is 10-1000; the molar ratio of Si to Ti is 2-50; and the total mass of the ZN catalyst system is 100%, with the internal electron donor content being 7-20%.

16. A method for preparing polyolefins, wherein, The method includes preparing polyolefins using the ZN catalyst system described in any one of claims 8 to 14 as a catalyst and olefins with 3-10 carbon atoms as polymerizing monomers.

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