A catalyst system, an olefin polymerization process and a polyolefin

Abstract

The application provides a catalyst system, an olefin polymerization method and a polyolefin, and relates to the field of catalysts. The catalyst system comprises a titanium-containing catalyst component, an organic aluminum component and an external electron donor, the titanium-containing catalyst component comprises a magnesium halide adduct, a titanium-containing compound and an internal electron donor, the organic aluminum component comprises an organic aluminum compound represented by a general formula AlR I R II R III at least one of the compounds represented by a general formula (V) and triethyl aluminum, in the formula V, R I , R II and R III are the same or different, and each is independently selected from one of chlorine, a C3-C 10 linear alkyl group and a C3-C 10 branched alkyl group, and at least one of R I , R II and R III is one of a C3-C 10 linear alkyl group and a C3-C 10 branched alkyl group. The catalyst system provided by the application shows high melting enthalpy of homopolypropylene prepared in a homopolymerization section, and shows high olefin copolymerization capacity when used in olefin impact copolymerization.

Description

Technical Field

[0001] This invention relates to the field of catalysts, specifically to a catalyst system, an olefin polymerization method, and polyolefins. Background Technology

[0002] Polyolefin resins are a diverse class of thermoplastic resins produced in very large quantities. They offer a wide range of properties and are widely used in industry, agriculture, medicine, construction, automotive, and everyday life. Polypropylene is one of the most produced and widely used general-purpose plastics. Despite its low price and many advantages, polypropylene suffers from a significant drawback: high brittleness, especially at low temperatures, resulting in poor impact resistance, which severely limits its application in some fields. Low-temperature toughness of polypropylene can be improved by blending with elastomers or copolymerizing with a certain amount of ethylene. The most economical method is to homopolymerize propylene in a reactor before reacting it with ethylene to produce ethylene-propylene rubber.

[0003] To meet market demands, researchers have long been dedicated to developing in-reactor alloy products for impact-resistant polypropylene. Chinese patent CN106832583B discloses a method for preventing reactor sticking during the preparation of high-ethylene-content impact-resistant polypropylene. This method involves introducing different inorganic powders in the homopolymerization and copolymerization stages, and simultaneously introducing a bis-α-olefin crosslinking agent in the gas-phase copolymerization stage. This yields impact-resistant polypropylene with an ethylene content as high as 21-30% and good flowability, providing a solution for the stable production of high-rubber-content impact-resistant polypropylene. Chinese patent CN110511303B discloses an olefin polymerization catalyst component using a glycol ester with a (R,R) or (S,S) optical isomer content greater than 95% as a precipitating agent. This catalyst component exhibits high polymerization activity, good hydrogen sensitivity, and high olefin copolymerization ability when used in olefin polymerization reactions. The prepared impact-resistant polypropylene has a high ethylene content and a relatively high rubber phase content. However, these existing technologies do not focus on improving the co-catalyst, and the rigidity-toughness balance of the polypropylene is poor. Summary of the Invention

[0004] Based on the above analysis, the present invention aims to provide a catalyst system, an olefin polymerization method, and a polyolefin to solve at least one of the following existing problems: improving the directional polymerization ability of olefins, improving the copolymerization ability of olefins, and improving the rigidity-toughness balance of polyolefins.

[0005] The objective of this invention is mainly achieved through the following technical solutions:

[0006] In a first aspect, the present invention provides a catalyst system comprising a titanium-containing catalyst component, an organoaluminum component, and an external electron donor, wherein the titanium-containing catalyst component comprises a magnesium halide adduct, a titanium-containing compound, and an internal electron donor, and the organoaluminum component comprises a general formula AlR IR II R III At least one of the compounds shown in Formula V and triethylaluminum, wherein in Formula V, R I R II and R III Whether the two are the same or different, they are each independently selected from chlorine, C3-C 10 Straight-chain alkyl, C3-C 10 One of the branched alkyl groups, and R I R II and R III At least one of them is C3-C 10 Straight-chain alkyl, C3-C 10 One of the branched alkyl groups.

[0007] Preferably, the compound represented by Formula V includes at least one of triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, and triisooctylaluminum.

[0008] Preferably, the molar ratio of triethylaluminum to the compound shown in Formula V is 1:(0.1-5), more preferably 1:(0.1-3).

[0009] Preferably, the molar ratio of the organoaluminum component (calculated as aluminum) to the titanium-containing catalyst component (calculated as titanium) is (70-2000):1, more preferably (100-700):1.

[0010] Preferably, the organoaluminum component comprises triethylaluminum and at least two compounds of formula V.

[0011] Preferably, at least two compounds of formula V include the compound of formula V and the compound of formula V, and the molar ratio of triethylaluminum, the compound of formula V and the compound of formula V is 1:(0.1-5):(0.1-5), preferably 1:(0.1-3):(0.1-3), more preferably 1:(0.1-1):(0.1-1).

[0012] Preferably, in the titanium-containing catalyst component, the molecular formula of the magnesium halide adduct is as shown in Formula I: MgXY-mROH-n(LB1)-k(LB2)-p(LB3) (Formula I); in Formula I, X is chlorine or bromine, and Y is chlorine, bromine, Cl-C 14 Straight-chain or branched alkyl groups, C6-C 14 aryl, C1-C 14 Straight-chain or branched alkoxy groups and C6-C 14 One of the aryl groups; R is C1-C 12 Straight-chain or branched alkyl groups, C3-C 10 cycloalkyl and C7-C 10One of the aralkyl groups; LB1 is a hydroxybenzoate compound represented by formula II, LB2 is a hydroxybenzoate compound represented by formula III, and LB3 is a compound represented by the general formula R6OH (formula IV).

[0013]

[0014] In Equation II, R, R2, R3, R4, and R5 are either the same as or different from the corresponding R, R2, R3, R4, and R5 in Equation III, and are independently defined as follows: R is C1-C 12 Straight-chain or branched alkyl groups, C3-C 10 cycloalkyl and C7-C 10 One of the aralkyl groups; R2, R3, R4, and R5 may be the same or different, and each is independently hydrogen, halogen, nitro, or C1-C. 20 Straight-chain or branched alkyl groups, C3-C 20 cycloalkyl, C6-C 20 aryl and C7-C 20 One of the aralkyl groups; or two or more of R2, R3, R4 and R5 bonded together to form a ring;

[0015] R6 in Equation II may be the same as or different from R6 in Equation IV, and each is independently C1-C. 20 Straight-chain or branched alkyl groups, C3-C 20 cycloalkyl, C6-C 20 aryl and C7-C 20 One of the aryl alkyl groups;

[0016] In Equation I, m is 1-5, n is 0.0005-0.3, k is 0.0005-0.3, and p is 0.0005-0.3.

[0017] Preferably, in the titanium-containing catalyst component, the titanium-containing compound includes titanium trihalide and general formula Ti(OR) 4- m X" m At least one of the titanium-containing compounds shown in Formula VII, wherein R" in Formula VII is C1-C 10 Straight-chain alkyl and C3-C 10 It is one of the branched alkyl groups, where X" is a halogen and m is an integer from 0 to 4.

[0018] Preferably, the titanium-containing compound includes at least one of titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, titanium tetrabutoxy, titanium tetraethoxy, titanium monochlorotributoxy, titanium dichlorodibutoxy, titanium trichlorobutoxy, titanium monochlorotriethoxy, titanium dichlorodiethoxy, titanium trichloroethoxy, and titanium trichloride.

[0019] Preferably, in the catalyst component, the internal electron donor includes at least one of esters, ethers, ketones, and ketone esters.

[0020] Preferably, the external electron donor includes at least one of carboxylic acids, acid anhydrides, esters, ketones, ethers, alcohols, organophosphorus compounds, and organosilicon compounds.

[0021] Preferably, the amount of the external electron donor is 0.005-0.5 mol relative to 1 mol of the organoaluminum component based on aluminum, and more preferably 0.01-0.4 mol.

[0022] Secondly, the present invention provides an olefin polymerization method using the aforementioned catalyst system.

[0023] Preferably, the olefin is an olefin represented by the general formula CH2=CHR (Formula VI), where R in Formula VI is hydrogen, C1-C2, C2-C2, C3-C4, C4-C4, C5-C4, C6-C4, C7-C6 ... 12 Straight-chain alkyl, C3-C 12 Branched alkyl groups and C6-C 12 One of the aryl groups.

[0024] Preferably, the polymerization temperature is 0℃-150℃, and more preferably 60℃-90℃.

[0025] Preferably, in the olefin polymerization method, the organoaluminum component in the catalyst system is added in one step or in two steps.

[0026] Preferably, when the organoaluminum component is added all at once, the olefin polymerization method includes the following steps:

[0027] Step 1: Olefins undergo prepolymerization in the presence of the catalyst system;

[0028] Step 2: Homopolymerization;

[0029] Optionally, step 3: copolymerization;

[0030] or,

[0031] When the organoaluminum component is added in two steps, the olefin polymerization method includes the following steps:

[0032] Step 1: A catalyst system is formed by a mixture including a first organoaluminum component, an external electron donor, and a catalyst component, and the olefin is prepolymerized in the presence of the catalyst system;

[0033] Step 2: Perform the first stage of homopolymerization, then add the second organoaluminum component and continue the second stage of homopolymerization;

[0034] Optionally, step 3: copolymerization reaction.

[0035] Preferably, when the organoaluminum component is added in two steps, the first organoaluminum component includes triethylaluminum, and the second organoaluminum component includes at least one of the compounds shown in Formula V;

[0036] or,

[0037] When the organoaluminum component is added in two steps, the first organoaluminum component includes at least one of the compounds shown in Formula V, and the second organoaluminum component includes triethylaluminum.

[0038] or,

[0039] When the organoaluminum component is added in two steps, the first organoaluminum component is the same as the second organoaluminum component, including at least one of the compounds shown in Formula V and triethylaluminum, wherein the molar ratio of the first organoaluminum component to the second organoaluminum component is (0.2-10):1, preferably (0.3-10):1, more preferably (0.3-5):1.

[0040] Thirdly, the present invention provides a polyolefin obtained by the olefin polymerization method described above.

[0041] Preferably, the polyolefin includes polypropylene.

[0042] Beneficial effects:

[0043] The catalyst system provided by this invention produces homopolymer polypropylene with a high melting enthalpy in the homopolymerization stage. When used for olefin impact copolymerization, it exhibits high olefin copolymerization ability, and the prepared impact polypropylene has a high ethylene content and a high xylene soluble content. Detailed Implementation

[0044] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0045] The endpoints and any values ​​of the ranges referred to herein are not limited to the precise ranges or specific values, which should be understood to include values ​​close to those ranges or specific values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0046] In a first aspect, the present invention provides a catalyst system comprising a titanium-containing catalyst component, an organoaluminum component, and an external electron donor compound, wherein the organoaluminum component comprises at least two organoaluminum compounds.

[0047] In some specific embodiments of the present invention, the organoaluminum component includes the general formula AlR I R II R III At least one of the compounds shown in Formula V and triethylaluminum. In Formula V, R I R II and R III Whether the two are the same or different, they are each independently selected from chlorine, C3-C 10 One of straight-chain and / or branched alkyl groups, and R I R II and R III At least one of them is C3-C 10 One of straight-chain alkyl and / or branched alkyl groups.

[0048] In some specific embodiments of the present invention, the compound represented by Formula V is at least one of triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, and triisooctylaluminum.

[0049] In some specific embodiments of the present invention, the molar ratio of triethylaluminum to the compound shown in Formula V is 1:(0.1 to 5), for example 1:0.2, 1:0.4, 1:0.6, 1:0.8, 1:1, 1:2, 1:3, 1:4, etc., preferably 1:(0.1 to 3).

[0050] In some specific embodiments of the present invention, the organoaluminum component includes triethylaluminum and at least two compounds of formula V, wherein the molar ratio of triethylaluminum and at least two compounds of formula V is 1:(0.1-5):(0.1-5), wherein the value of 0.1-5 can be selected from values ​​such as 0.2, 0.4, 0.6, 0.8, 1, 2, 3, 4, etc., preferably 1:(0.1-3):(0.1-3), and more preferably 1:(0.1-1):(0.1-1).

[0051] In some specific embodiments of the present invention, the molar ratio of the organoaluminum component (calculated as aluminum) to the catalyst component (calculated as titanium) can be (70-2000):1, for example 100:1, 300:1, 500:1, 700:1, 900:1, 1100:1, 1300:1, 1500:1, 1700:1, 1900:1, etc., preferably (100-700):1.

[0052] The catalyst system provided by this invention produces homopolymer polypropylene with a high melting enthalpy in the homopolymerization stage. When used for olefin impact copolymerization, it exhibits high olefin copolymerization ability, and the prepared impact polypropylene has a high ethylene content and a high xylene soluble content.

[0053] In some specific embodiments of the present invention, the titanium-containing catalyst component includes a magnesium halide adduct, a titanium-containing compound, and an internal electron donor. The present invention does not limit the preparation method of the catalyst component; conventional methods in the art can be used. The present invention does not limit the amount of each component in the titanium-containing catalyst component, but only to meet the requirements. According to the present invention, the amounts of the magnesium halide adduct, the titanium compound, and the internal electron donor compound can be appropriately selected according to the expected composition of the catalyst component for olefin polymerization. For example, the molar ratio of the titanium compound, the internal electron donor compound, and the magnesium halide adduct can be (5-100):(0-0.5):1; preferably (20-80):(0.05-0.35):1, where the titanium compound is calculated as titanium element and the magnesium halide adduct is calculated as magnesium element. In the present invention, the amount of titanium compound refers to the total amount of titanium compound used in the preparation of the catalyst component of the present invention.

[0054] In some specific embodiments of the present invention, the titanium-containing catalyst component contains a magnesium halide adduct with the molecular formula shown in Formula I: MgXY-mROH-n(LB1)-k(LB2)-p(LB3) (Formula I). ​​In Formula I, X is chlorine or bromine, and Y is chlorine, bromine, Cl-C 14 Straight-chain or branched alkyl groups, C6-C 14 aryl, C1-C 14 Straight-chain or branched alkoxy groups and C6-C 14 One of the aryl groups; R is C1-C 12 Straight-chain or branched alkyl groups, C3-C 10 cycloalkyl and C7-C 10 One of the aralkyl groups; LB1 is a hydroxybenzoate compound represented by formula II, LB2 is a hydroxybenzoate compound represented by formula III, and LB3 is a compound represented by the general formula R6OH (formula IV).

[0055]

[0056] In Equation II, R is defined the same as R in ROH, which is C1-C. 12 Straight-chain or branched alkyl groups, C3-C 10 cycloalkyl and C7-C 10 One of the aralkyl groups; R2, R3, R4, and R5 may be the same or different, and each is independently hydrogen, halogen, nitro, or C1-C. 20 Straight-chain or branched alkyl groups, C3-C 20 cycloalkyl, C6-C 20 aryl and C7-C 20One of the aralkyl groups; or, two or more of R2, R3, R4 and R5 bonded together to form a ring; R6 is C1-C 20 Straight-chain or branched alkyl groups, C3-C 20 cycloalkyl, C6-C 20 aryl and C7-C 20 One of the aryl alkyl groups;

[0057] In Equation III, R, R2, R3, R4 and R5 are defined the same as in Equation II, and will not be repeated here;

[0058] In Formula IV, R6 in R6OH is defined the same as in Formula II, and will not be repeated here;

[0059] In Equation I, m is 1-5, n is 0.0005-0.3, k is 0.0005-0.3, and p is 0.0005-0.3.

[0060] In this invention, the term "substitution" refers to the replacement of hydrogen atoms on carbon or silicon atoms by substituents.

[0061] In Formula I, preferably, Y is chlorine, bromine, a C1-C5 straight-chain or branched alkyl group, or a C6-C5 alkyl group. 10 aryl, C1-C5 straight-chain or branched alkoxy and C6-C 10 It is one of the aryloxy groups. In some specific embodiments of the present invention, MgXY can be a magnesium halide compound or a mixture of multiple magnesium halide compounds. More preferably, MgXY is one or more of magnesium dichloride, magnesium dibromide, magnesium phenoxychloride, magnesium isopropoxychloride, and magnesium n-butoxychloride. From the perspective of raw material availability, MgXY is further preferably magnesium dichloride.

[0062] In Formula I, preferably, R is a C1-C6 straight-chain or branched alkyl group. More preferably, R is one of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and n-hexyl. In some specific embodiments of the present invention, specific examples of ROH can be, but are not limited to: methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, n-pentanol, isopentanol, n-hexanol, n-octanol, 2-ethylhexanol, ethylene glycol, 1,3-propanediol, and phenylmethanol.

[0063] According to the present invention, in Formula I, when LB1 is a alkyl benzoate compound represented by Formula II, in Formula II, preferably, R is a C1-C6 straight-chain or branched alkyl group; R2, R3, R4 and R5 are each hydrogen, a C1-C8 straight-chain or branched alkyl group, a C3-C6 cycloalkyl group, or a C6-C6 cycloalkyl group. 10 aryl and C7-C 10R6 is one of the aryl alkyl groups; R6 is a C1-C6 straight-chain or branched alkyl group, a C3-C6 cycloalkyl group, or a C6-C6 alkyl group. 10 aryl and C7-C 10 The aralkyl group is one of the following. More preferably, R is one of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and n-hexyl; R2, R3, R4 and R5 are each one of hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, cyclopentyl, n-hexyl, n-heptyl and tolyl; R6 is one of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, benzyl and phenethyl.

[0064] In some specific embodiments of the present invention, LB1 represented by Formula II is preferably one of 4-alkoxybenzoate and 2-alkoxybenzoate; more preferably 2-alkoxybenzoate.

[0065] In some specific embodiments of the present invention, specific examples of LB1 may be, but are not limited to: methyl 2-methoxybenzoate, ethyl 2-methoxybenzoate, n-propyl 2-methoxybenzoate, isopropyl 2-methoxybenzoate, n-butyl 2-methoxybenzoate, isobutyl 2-methoxybenzoate, n-pentyl 2-methoxybenzoate, n-hexyl 2-methoxybenzoate, benzyl 2-methoxybenzoate, phenethyl 2-methoxybenzoate, methyl 2-methoxy-3-methylbenzoate, methyl 2-methoxy-4-methylbenzoate, methyl 2-methoxy-5-methylbenzoate, methyl 2-methoxy-3-ethylbenzoate, methyl 2-methoxy-4-ethylbenzoate, methyl 2-methoxy-5-ethyl ...3-ethylbenzoate, methyl 2-methoxy-4-ethylbenzo Ethyl 2-methoxy-3-methylbenzoate, ethyl 2-methoxy-4-methylbenzoate, ethyl 2-methoxy-5-methylbenzoate, ethyl 2-methoxy-3-ethylbenzoate, ethyl 2-methoxy-4-ethylbenzoate, ethyl 2-methoxy-5-ethylbenzoate, n-propyl 2-methoxy-3-methylbenzoate, n-propyl 2-methoxy-4-methylbenzoate, n-propyl 2-methoxy-5-methylbenzoate, n-propyl 2-methoxy-3-ethylbenzoate, n-propyl 2-methoxy-4-ethylbenzoate, n-propyl 2-methoxy-5-ethylbenzoate, isopropyl 2-methoxy-3-methylbenzoate, isopropyl 2-methoxy-4-methylbenzoate, isopropyl 2-methoxy-5-methylbenzoate, 2- Isopropyl methoxy-3-ethylbenzoate, Isopropyl 2-methoxy-4-ethylbenzoate, Isopropyl 2-methoxy-5-ethylbenzoate, Isobutyl 2-methoxy-3-methylbenzoate, Isobutyl 2-methoxy-4-methylbenzoate, Isobutyl 2-methoxy-5-methylbenzoate, Isobutyl 2-methoxy-3-ethylbenzoate, Isobutyl 2-methoxy-4-ethylbenzoate, Isobutyl 2-methoxy-5-ethylbenzoate, Ethyl 2-methoxy-3-n-propylbenzoate, Ethyl 2-methoxy-4-n-propylbenzoate, Ethyl 2-methoxy-5-n-propylbenzoate, Ethyl 2-methoxy-4-isopropylbenzoate, Ethyl 2-methoxy-4-isobutylbenzoate, Ethyl 2-methoxy-4-tert-butylbenzoate Ethyl benzoate, 2-methoxy-4-pentylbenzoate, 2-methoxy-4-isopentylbenzoate, 2-methoxy-4-cyclopentylbenzoate, 2-ethoxybenzoate, methyl 2-ethoxybenzoate, 2-ethoxybenzoate, n-propyl 2-ethoxybenzoate, isopropyl 2-ethoxybenzoate, n-butyl 2-ethoxybenzoate, isobutyl 2-ethoxybenzoate, n-pentyl 2-ethoxybenzoate, n-hexyl 2-ethoxybenzoate, benzyl 2-ethoxybenzoate, phenethyl 2-ethoxybenzoate, methyl 2-n-butoxybenzoate, ethyl 2-n-butoxybenzoate, n-propyl 2-n-butoxybenzoate, isopropyl 2-n-butoxybenzoate, n-butyl 2-n-butoxybenzoate, isobutyl 2-n-butoxybenzoate2-Butoxybenzoic acid pentyl ester, 2-butoxybenzoic acid hexyl ester, 2-butoxybenzoic acid benzyl ester, and 2-butoxybenzoic acid ethyl ester.

[0066] In some specific embodiments of the present invention, in Formula I, when LB2 is a hydroxybenzoic acid ester compound represented by Formula III, in Formula III, preferably, R is a C1-C6 straight-chain or branched alkyl group; R2, R3, R4 and R5 are each hydrogen, a C1-C8 straight-chain or branched alkyl group, a C3-C6 cycloalkyl group, or a C6-C6 cycloalkyl group. 10 aryl and C7-C 10 One of the aralkyl groups. More preferably, R is one of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, and n-hexyl; R2, R3, R4 and R5 are each one of hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, cyclopentyl, n-hexyl, n-heptyl and tolyl.

[0067] In some specific embodiments of the present invention, LB2 represented by Formula III is preferably one of 4-hydroxybenzoate and 2-hydroxybenzoate; more preferably 2-hydroxybenzoate.

[0068] In some specific embodiments of the present invention, specific examples of LB2 may be, but are not limited to: methyl 2-hydroxybenzoate, ethyl 2-hydroxybenzoate, n-propyl 2-hydroxybenzoate, isopropyl 2-hydroxybenzoate, n-butyl 2-hydroxybenzoate, isobutyl 2-hydroxybenzoate, n-pentyl 2-hydroxybenzoate, n-hexyl 2-hydroxybenzoate, benzyl 2-hydroxybenzoate, phenethyl 2-hydroxybenzoate, methyl 2-hydroxy-3-methylbenzoate, methyl 2-hydroxy-4-methylbenzoate, methyl 2-hydroxy-5-methylbenzoate, 2-hydroxy Methyl 3-ethylbenzoate, methyl 2-hydroxy-4-ethylbenzoate, methyl 2-hydroxy-5-ethylbenzoate, ethyl 2-hydroxy-3-methylbenzoate, ethyl 2-hydroxy-4-methylbenzoate, ethyl 2-hydroxy-5-methylbenzoate, ethyl 2-hydroxy-3-ethylbenzoate, ethyl 2-hydroxy-4-ethylbenzoate, ethyl 2-hydroxy-5-ethylbenzoate, n-propyl 2-hydroxy-3-methylbenzoate, n-propyl 2-hydroxy-4-methylbenzoate, n-propyl 2-hydroxy-5-methylbenzoate, n-propyl 2-hydroxy-3-ethylbenzoate n-Propyl benzoate, n-Propyl 2-hydroxy-4-ethylbenzoate, n-Propyl 2-hydroxy-5-ethylbenzoate, Isopropyl 2-hydroxy-3-methylbenzoate, Isopropyl 2-hydroxy-4-methylbenzoate, Isopropyl 2-hydroxy-5-methylbenzoate, Isopropyl 2-hydroxy-3-ethylbenzoate, Isopropyl 2-hydroxy-4-ethylbenzoate, Isopropyl 2-hydroxy-5-ethylbenzoate, Isobutyl 2-hydroxy-3-methylbenzoate, Isobutyl 2-hydroxy-4-methylbenzoate, Isobutyl 2-hydroxy-5-methylbenzoate, 2-hydroxy Isobutyl 2-ethylbenzoate, 2-hydroxy-4-ethylbenzoate, 2-hydroxy-5-ethylbenzoate, ethyl 2-hydroxy-3-n-propylbenzoate, ethyl 2-hydroxy-4-n-propylbenzoate, ethyl 2-hydroxy-5-n-propylbenzoate, ethyl 2-hydroxy-4-isopropylbenzoate, ethyl 2-hydroxy-4-isobutylbenzoate, ethyl 2-hydroxy-4-tert-butylbenzoate, ethyl 2-hydroxy-4-n-pentylbenzoate, ethyl 2-hydroxy-4-isopentylbenzoate, and ethyl 2-hydroxy-4-cyclopentylbenzoate.

[0069] In some specific embodiments of the present invention, in Formula I, when LB3 is a compound represented by general formula R6OH (Formula IV), R6OH is preferably a C1-C6 straight-chain or branched alkyl group, a C3-C6 cycloalkyl group, or a C6-C4 cycloalkyl group. 10 aryl and C7-C 10R6 is one of the aralkyl groups. More preferably, R6 is one of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, benzyl, and phenethyl. Specific examples of R6OH in this invention can be, but are not limited to: methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, tert-butanol, n-pentanol, isopentanol, n-hexanol, 2-ethylhexanol, phenol, and phenylethanol.

[0070] In some specific embodiments of the present invention, in Formula I, m can be 1-5, preferably 2-3.5, more preferably 2.4-3.5; n can be 0.0005-0.3, preferably 0.001-0.1, more preferably 0.003-0.07; k can be 0.0005-0.3, preferably 0.001-0.1, more preferably 0.003-0.07; p can be 0.0005-0.3, preferably 0.001-0.1, more preferably 0.003-0.07.

[0071] In some specific embodiments of the present invention, the magnesium halide adduct may also contain water, which is derived from water present in the raw materials and / or water added as a separate component during the preparation of the adduct. The preparation method of the magnesium halide adduct is not limited in the present invention; conventional methods in the art can be used.

[0072] In some specific embodiments of the present invention, the titanium-containing compound in the catalyst component is selected from titanium trihalide, general formula Ti(OR) 4-m X" m One or more of the titanium compounds shown in (Formula VII), where R" represents C1-C 10 Straight-chain alkyl and C3-C 10 The titanium-containing compound is selected from any of the branched alkyl groups, where X" is a halogen and m is an integer from 0 to 4. Preferably, the titanium-containing compound is selected from titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, titanium tetrabutoxy, titanium tetraethoxy, titanium monochlorotributoxy, titanium dichlorodibutoxy, titanium trichlorobutoxy, titanium monochlorotriethoxy, titanium dichlorodiethoxy, titanium trichloroethoxy, or titanium trichloride. More preferably, the titanium-containing compound is titanium tetrachloride.

[0073] In some specific embodiments of the present invention, the internal electron donor in the catalyst component may be added before, during, or after the reaction of magnesium halide or magnesium halide adduct with the titanium-containing compound; preferably, it is added during the reaction with the titanium-containing compound. The internal electron donor is a variety of internal electron donors or mixtures of internal electron donors commonly used in the art, and may be an ester, ether, ketone, ketone ester, or other compound. Preferably, the internal electron donor compound is one or more of esters and diether-type compounds. In the present invention, the ester may be one or more of monoaliphatic carboxylic acid esters, polyaliphatic carboxylic acid esters, monoaromatic carboxylic acid esters, polyaromatic carboxylic acid esters, and diol esters. In the present invention, the ester is preferably a polyaromatic carboxylic acid ester. In the present invention, the term "monolithic carboxylic acid ester" refers to a compound formed by the esterification reaction of a monoaliphatic carboxylic acid and a monohydric alcohol. The term "polyaliphatic carboxylic acid ester" refers to a compound formed by the esterification reaction of a polyaliphatic carboxylic acid and a monohydric alcohol. The term "monoaromatic carboxylic acid ester" refers to a compound formed by the esterification reaction of a monoaromatic carboxylic acid and a monohydric alcohol. The term "polyaromatic carboxylic acid ester" refers to compounds formed by the esterification reaction of polyaromatic carboxylic acids and monohydric alcohols.

[0074] In this invention, examples of mono-aliphatic carboxylic acid esters, poly-aliphatic carboxylic acid esters, mono-aromatic carboxylic acid esters, and poly-aromatic carboxylic acid esters can be benzoic acid esters, phthalic acid esters, malonic acid esters, succinic acid esters, glutaric acid esters, neopentanoic acid esters, and carbonates; preferably, alkyl benzoate esters, alkyl phthalate esters, alkyl malonic acid esters, alkyl succinic acid esters, alkyl glutaric acid esters, neopentanoic acid esters, and alkyl carbonate esters.

[0075] Specifically, in this invention, examples of mono-aliphatic carboxylic acid esters, poly-aliphatic carboxylic acid esters, mono-aromatic carboxylic acid esters, and poly-aromatic carboxylic acid esters may include, but are not limited to: ethyl benzoate, diethyl phthalate, diisobutyl phthalate, di-n-butyl phthalate, diisooctyl phthalate, di-n-octyl phthalate, diethyl malonate, di-n-butyl malonate, diisobutyl malonate, diethyl 2,3-diisopropylsuccinate, diisobutyl 2,3-diisopropylsuccinate, di-n-butyl 2,3-diisopropylsuccinate, dimethyl 2,2-diisopropylsuccinate, diethyl 2,3 ... Diisobutyl methylsuccinate, 2-ethyl-2-methylsuccinate, diethyl 2-ethyl-2-methylsuccinate, diethyl glutarate, di-n-butyl glutarate, diisobutyl glutarate, dimethyl carbonate, diethyl carbonate, diisobutyl carbonate, diethyl adipate, di-n-butyl adipate, diethyl sebacate, di-n-butyl sebacate, diethyl maleate, di-n-butyl maleate, diethyl naphthalene dicarboxylate, di-n-butyl naphthalene dicarboxylate, triethyl trimellitate, tri-n-butyl trimellitate, triethyl biphenyltrioxide, tri-n-butyl biphenyltrioxide, tetraethyl pyromellitic acid, and tetra-n-butyl pyromellitic acid.

[0076] In this invention, the term "diol ester" refers to a compound formed by the esterification reaction of a diol with a monocarboxylic acid or a polycarboxylic acid. For example, the diol ester can be a compound represented by Formula VIII:

[0077]

[0078] In equation VIII, R I R II R III R IV R V and R VI Each is hydrogen, C1-C 10 aliphatic hydrocarbon groups, C6-C 10 aryl and C7-C 10 One of the aryl alkyl groups; or R I R II R III R IV R V and R VI Two or more elements are bonded together to form a ring;

[0079] R VII and R VIII Each is C1-C 10 Straight-chain or branched alkyl groups, C3-C 20 cycloalkyl, C6-C 20 aryl and C7-C 20 One of the aryl aliphatic hydrocarbon groups.

[0080] Preferably, in formula VIII, R I R II R III R IV R V and R VI Each of the following is a hydrogen atom, a C1-C6 straight-chain or branched alkyl group, a C2-C6 straight-chain or branched alkenyl group, a C3-C6 cycloalkyl group, or a C6-C6 cycloalkyl group. 10 aryl and C7-C 10 One of the aryl alkyl groups; or, R I R II R III R IV R V and R VI Two or more elements are bonded together to form a ring;

[0081] R VII and R VIIIEach is a C1-C6 straight-chain or branched alkyl group, a C3-C6 cycloalkyl group, or a C6-C6 cycloalkyl group. 10 aryl, C7-C 10 Aryl groups and C7-C 10 One of the aromatic groups.

[0082] More preferably, in formula VIII, R I R II R V and R VI At least one of them is hydrogen, and R I R II R V and R VI They are not both hydrogen.

[0083] More preferably, in formula VIII, R I and R II At least one of them is hydrogen, and in R I and R II When only one of them is hydrogen, R I and R II The other group is one of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, phenyl, and halophenyl; R V and R VI At least one of them is hydrogen, and in R V and R VI When only one of them is hydrogen, R V and R VI The other group is one of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, phenyl, and halophenyl; R III and R IV Each of these is one of hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, allyl, n-pentyl, isopentyl, and n-hexyl, or R III and R IV They bond together to form a fluorene group; R VII and R VIII Each of the following is a single compound: methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, neopentyl, cyclopentyl, cyclohexyl, phenyl, halophenyl, tolyl, halomethylphenyl, benzyl, phenethyl, and styryl.

[0084] In this invention, specific examples of the glycol esters may include, but are not limited to: 1,3-propanediol dibenzoate, 2-methyl-1,3-propanediol dibenzoate, 2-ethyl-1,3-propanediol dibenzoate, 2,2-dimethyl-1,3-propanediol dibenzoate, (R)-1-phenyl-1,3-propanediol dibenzoate, 1,3-diphenyl-1,3-propanediol dibenzoate, 1,3-diphenyl-1,3-propanediol di-n-propionate, 1,3-diphenyl-2-methyl-1,3-propanediol di-n-propionate, 1,3-diphenyl-2-methyl-1,3-propanediol diacetate, 1,3-diphenyl-2,2-dimethyl-1,3-propanediol diacetate, 1,3-diphenyl-2,2-dimethyl-1,3-propanediol dibenzoate, 1,3-diphenyl-2,2-dipropanediol diacet ... -Dimethyl-1,3-propanediol di-n-propionate, 1,3-di-tert-butyl-2-ethyl-1,3-propanediol dibenzoate, 1,3-diphenyl-1,3-propanediol diacetate, 1,3-diisopropyl-1,3-propanediol di(4-n-butylbenzoic acid) ester, 1-phenyl-2-amino-1,3-propanediol dibenzoate, 1-phenyl-2-methyl-1,3-butanediol dibenzoate, 1-phenyl-2-methyl-1,3-butanediol dinepentyl ester, 3-n-butyl-2,4-pentanediol dibenzoate, 3,3-dimethyl-2,4-pentanediol dibenzoate, (2S,4S)-(+)-2,4-pentanediol dibenzoate, (2R,4R)-(+)-2,4-pentanediol dibenzoate Formate esters, 2,4-pentanediol di(p-chlorobenzoic acid) ester, 2,4-pentanediol di(m-chlorobenzoic acid) ester, 2,4-pentanediol di(p-bromobenzoic acid) ester, 2,4-pentanediol di(o-bromobenzoic acid) ester, 2,4-pentanediol di(p-methylbenzoic acid) ester, 2,4-pentanediol di(p-tert-butylbenzoic acid) ester, 2,4-pentanediol di(p-n-butylbenzoic acid) ester, 2-methyl-1,3-pentanediol di(p-chlorobenzoic acid) ester, 2-methyl-1,3-pentanediol di(p-methylbenzoic acid) ester, 2-n-butyl-1,3-pentanediol di(p-methylbenzoic acid) ester, 2-methyl-1,3-pentanediol dinepentate ester, 2-methyl-3-cinnamon Acyloxy-1-n-pentanol benzoate, 2,2-dimethyl-1,3-pentanediol dibenzoate, 2,2-dimethyl-3-cinnamoyloxy-1-n-pentanol benzoate, 2-ethyl-1,3-pentanediol dibenzoate, 2-n-butyl-1,3-pentanediol dibenzoate, 2-allyl-1,3-pentanediol dibenzoate, 2-methyl-1,3-pentanediol dibenzoate, 2-ethyl-1,3-pentanediol dibenzoate, 2-n-propyl-1,3-pentanediol dibenzoate, 2-n-butyl-1,3-pentanediol dibenzoate, 2,2-di-n-propyl-1,3-pentanediol dibenzoate, 1,3-pentanediol di(p-chlorobenzoate), 1,3-pentanediol di(m-chlorobenzoate), 1,3-Pentanediol di(p-bromobenzoic acid) ester, 1,3-Pentanediol di(o-bromobenzoic acid) ester, 1,3-Pentanediol di(p-methylbenzoic acid) ester, 1,3-Pentanediol di(p-tert-butylbenzoic acid) ester, 1,3-Pentanediol di(p-butylbenzoic acid) ester, 3-Cinnamyloxy-1-n-pentanol benzoate, 1,3-Pentanediol dicinnamate, 1,3-Pentanediol di-n-propionate, 2-Ethyl-1,3-Pentanediol dibenzoate, 2-n-Butyl-1,3-Pentanediol dibenzoate, 2-Allyl-1,3-Pentanediol dibenzoate, 2,2,4-Trimethyl-1,3-Pentanediol diisopropylcarboxylate, 1-Trifluoromethyl-3-methyl-2,4-Pentanediol dibenzoate, 2,4-Pentanediol di-p-fluoro 2,4-Pentanediol di(2-furanoic acid) ester, 2-Methyl-6-(1-n-heptene)-2,4-heptanediol dibenzoate, 3-Methyl-6-(1-n-heptene)-2,4-heptanediol dibenzoate, 4-Methyl-6-(1-n-heptene)-2,4-heptanediol dibenzoate, 5-Methyl-6-(1-n-heptene)-2,4-heptanediol dibenzoate, 6-Methyl-6-(1-n-heptene)-2,4-heptanediol dibenzoate, 3-Ethyl-6-(1-n-heptene)-2,4-heptanediol dibenzoate, 4-Ethyl-6-(1-n-heptene)-2,4-heptanediol dibenzoate, 5-Ethyl-6-(1-n-heptene)-2,4-heptanediol dibenzoate -Heptanediol dibenzoate, 6-ethyl-6-(1-n-heptene)-2,4-heptanediol dibenzoate, 3-n-propyl-6-(1-n-heptene)-2,4-heptanediol dibenzoate, 4-n-propyl-6-(1-n-heptene)-2,4-heptanediol dibenzoate, 5-n-propyl-6-(1-n-heptene)-2,4-heptanediol dibenzoate, 6-n-propyl-6-(1-n-heptene)-2,4-heptanediol dibenzoate, 3-n-butyl-6-(1-n-heptene)-2,4-heptanediol dibenzoate, 4-n-butyl-6-(1-n-heptene)-2,4-heptanediol dibenzoate, 5-n-butyl-6-(1-n-heptene)-2,4-heptanediol dibenzoic acid Esters, 6-n-butyl-6-(1-n-heptene)-2,4-heptanediol dibenzoate, 3,5-dimethyl-6-(1-n-heptene)-2,4-heptanediol dibenzoate, 3,5-diethyl-6-(1-n-heptene)-2,4-heptanediol dibenzoate, 3,5-di-n-propyl-6-(1-n-heptene)-2,4-heptanediol dibenzoate, 3,3-dimethyl-6-(1-n-heptene)-2,4-heptanediol dibenzoate, 3,3-diethyl-6-(1-n-heptene)-2,4-heptanediol dibenzoate, 3,3-di-n-propyl-6-(1-n-heptene)-2,4-heptanediol dibenzoate, 3,3-di-n-propyl-6-(1-n-heptene)-2,4-Heptanediol dibenzoate, 3,3-di-n-butyl-6-(1-n-heptene)-2,4-heptanediol dibenzoate, 3-ethyl-3,5-heptanediol dibenzoate, 4-ethyl-3,5-heptanediol dibenzoate, 5-ethyl-3,5-heptanediol dibenzoate, 3-n-propyl-3,5-heptanediol dibenzoate, 4-n-propyl-3,5-heptanediol dibenzoate, 3-n-butyl-3,5-heptanediol dibenzoate, 2,3-dimethyl-3,5-heptanediol dibenzoate esters, 2,4-dimethyl-3,5-heptanediol dibenzoate, 2,5-dimethyl-3,5-heptanediol dibenzoate, 2,6-dimethyl-3,5-heptanediol dibenzoate, 3,5-dimethyl-3,5-heptanediol dibenzoate, 4,4-dimethyl-3,5-heptanediol dibenzoate, 4,5-dimethyl-3,5-heptanediol dibenzoate, 4,6-dimethyl-3,5-heptanediol dibenzoate, 6,6-dimethyl-3,5-heptanediol dibenzoate, 2-methyl 2-Methyl-4-ethyl-3,5-heptanediol dibenzoate, 2-Methyl-5-ethyl-3,5-heptanediol dibenzoate, 3-Methyl-3-ethyl-3,5-heptanediol dibenzoate, 3-Methyl-4-ethyl-3,5-heptanediol dibenzoate, 3-Methyl-5-ethyl-3,5-heptanediol dibenzoate, 4-Methyl-3-ethyl-3,5-heptanediol dibenzoate, 4-Methyl-4-ethyl-3,5-heptanediol dibenzoate Diol dibenzoate, 9,9-bis(benzoyloxymethyl)fluorene, 9,9-bis((m-methoxybenzoyloxy)methyl)fluorene, 9,9-bis((m-chlorobenzoyloxy)methyl)fluorene, 9,9-bis((p-chlorobenzoyloxy)methyl)fluorene, 9,9-bis(cinnamyloxymethyl)fluorene, 9-(benzoyloxymethyl)-9-(propionyloxymethyl)fluorene, 9,9-bis(propionyloxymethyl)fluorene, 9,9-bis(acryloyloxymethyl)fluorene and 9,9-bis(neopentyloxymethyl)fluorene.

[0085] CN1213080C, CN1169845C, WO03 / 068828 and WO03 / 068723 disclose the above-mentioned glycol ester compounds, the contents of which are incorporated herein by reference.

[0086] According to the present invention, the diether-type compound can be any diether-type compound commonly used in the art that can serve as an internal electron donor in olefin polymerization catalysts. For example, the diether-type compound can be a 1,3-diether-type compound represented by general formula IX:

[0087]

[0088] In equation IX, R I RII R III R IV R V and R VI Each is hydrogen, halogen, C1-C 20 Straight-chain or branched alkyl groups, C3-C 20 cycloalkyl, C6-C 20 aryl and C7-C 20 One of the aryl groups, R VII and R VIII Each is C1-C 20 Straight-chain or branched alkyl groups, C3-C 20 cycloalkyl, C6-C 20 aryl and C7-C 20 One of the aryl alkyl groups. In this invention, R I R II R III R IV R V and R VI Two or more elements can bond together to form a ring.

[0089] Preferably, in formula IX:

[0090] R I R II R V and R VI It is hydrogen;

[0091] R VII and R VIII Each is a C1-C4 straight-chain or branched alkyl group, more preferably a methyl group;

[0092] R III It is methyl, ethyl, n-propyl or isopropyl, R IV It is one of ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, isopentyl, 2-ethylhexyl, cyclopentyl, cyclohexyl, methylcyclohexyl, phenyl, and benzyl; or, R III For hydrogen, R IV It is one of ethyl, n-butyl, sec-butyl, tert-butyl, 2-ethylhexyl, cyclohexylethyl, diphenylmethyl, p-chlorophenyl, 1-naphthyl, and 1-decahydronaphthyl; or, R III and R IV The same, and is one of ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, neopentyl, phenyl, benzyl, cyclohexyl, and cyclopentyl; or, R III and R IV They bond to each other to form cyclopentadienyl, fluorenyl, or indene.

[0093] CN1015062B and CN1121368C disclose the above-mentioned diether compounds, and all relevant contents disclosed therein are incorporated herein by reference.

[0094] In some specific embodiments of the present invention, the external electron donor compound can be any of the electron donor compounds commonly used in the art. For example, the external electron donor compound can be one or more of carboxylic acids, acid anhydrides, esters, ketones, ethers, alcohols, organophosphorus compounds, and organosilicon compounds; preferably, it is an organosilicon compound.

[0095] According to the olefin polymerization catalyst system of the present invention, the external electron donor is more preferably of the general formula R. a x R b y Si(OR c ) z The organosilicon compound shown in formula X, wherein R a R b and R c Each is C1-C 18 hydrocarbon groups or C1-C containing heteroatoms 18 The hydrocarbon group; x and y are each integers from 0 to 2, z is an integer from 1 to 3, and x + y + z = 4. More preferably, the general formula R... a x R b y Si(OR c ) z In the middle, R a and R b At least one of them is selected from C3-C 10 Branched alkyl groups with or without heteroatoms, C3-C 10 Cycloalkyl groups with or without heteroatoms and C6-C 10 One of the aryl groups, R c For C1-C 10 Straight-chain alkyl and C3-C 10 One of the branched alkyl groups, preferably methyl, where x is 1, y is 1, and z is 2; or, R b For C3-C 10 Branched alkyl or C3-C 10 cycloalkyl, and R cWhere x is methyl, y is 1, and z is 3. Specifically, examples of the organosilicon compounds may include, but are not limited to: cyclohexylmethyldimethoxysilane, diisopropyldimethoxysilane, n-butylcyclohexyldimethoxysilane, diisobutyldimethoxysilane, diphenyldimethoxysilane, methyl tert-butyldimethoxysilane, dicyclopentyldimethoxysilane, 2-ethylpiperidinyl-2-tert-butyldimethoxysilane, (1,1,1-trifluoro-2-propyl)-2-ethylpiperidinyldimethoxysilane, (1,1,1-trifluoro-2-propyl)-methyldimethoxysilane, cyclohexyltrimethoxysilane, tert-butyltrimethoxysilane, and tert-hexyltrimethoxysilane.

[0096] In some specific embodiments of the present invention, according to the catalyst system of the present invention, the amount of the external electron donor compound is 0.005-0.5 mol relative to 1 mol of the organoaluminum component based on aluminum, for example 0.007, 0.009, 0.01, 0.03, 0.05, 0.08, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45 mol, etc., preferably 0.01-0.4 mol.

[0097] In some specific embodiments of the present invention, the organoaluminum component and optional external electron donor compound may react with the catalyst component alone or as a mixture of the two components.

[0098] In a second aspect, the present invention provides an olefin polymerization method using the catalyst system provided in the first aspect of the present invention.

[0099] The olefin polymerization method provided by this invention, by using the catalyst system provided by this invention, can prepare polymers with high ethylene content and high rubber content (xylene soluble content) and perfect particle morphology.

[0100] The olefin polymerization method provided by this invention does not have any particular limitations on the olefin polymerization conditions or the olefins used.

[0101] In some specific embodiments of the present invention, the olefin in the olefin polymerization method can be an olefin represented by the general formula CH2=CHR (Formula VI), where R in Formula VI can be hydrogen, C1-C2, or C2-C2. 12 Straight-chain alkyl, C3-C 12 Branched alkyl groups and C6-C 12 One of the aryl groups. According to the olefin polymerization method of the present invention, if necessary, the olefin may also contain a small amount of diene. According to the olefin polymerization method of the present invention, the olefin is preferably propylene, or a mixture of propylene and an olefin represented by CH2=CHR, wherein R is one of hydrogen, a C1-C6 straight-chain alkyl group, and a C3-C6 branched alkyl group.

[0102] In some specific embodiments of the present invention, the polymerization in the olefin polymerization method can be either homopolymerization or copolymerization. The polymerization of the olefin can be carried out according to methods known in the art, for example, the polymerization can be bulk polymerization, gas-phase polymerization, slurry polymerization, or a liquid-phase bulk-gas-phase combined polymerization. According to the olefin polymerization method of the present invention, the olefin polymerization temperature can be conventional conditions in the art, for example, the polymerization temperature can be 0℃-150℃, preferably 60℃-90℃; the polymerization reaction pressure can be atmospheric pressure or pressurized. According to the present invention, when the polymerization is a homopolymerization reaction, the raw materials can be propylene and hydrogen; when the polymerization is a copolymerization, the raw materials can be ethylene, propylene, and hydrogen.

[0103] In some specific embodiments of the present invention, in order to significantly improve the copolymerization ability of the catalyst for olefins, thereby increasing the ethylene content and xylene-soluble content in the impact-resistant polypropylene, and increasing the melting enthalpy of the homopolymer polypropylene resin to improve the rigidity of the polypropylene resin, in a preferred embodiment, the catalyst component, organoaluminum component or part of the organoaluminum component and the external electron donor can be pre-complexed; then, the obtained pre-complexed product is pre-polymerized with propylene before the above-mentioned polymerization reaction is carried out; in the homopolymerization stage of the above-mentioned polymerization reaction, the remaining portion of the alkylaluminum of the present invention is selectively added.

[0104] In some specific embodiments of the present invention, when the organoaluminum component is added all at once, the olefin polymerization method includes the following steps:

[0105] Step 1: The organoaluminum component, the external electron donor, and the titanium-containing catalyst component are pre-complexed to form a catalyst system, and the olefins are prepolymerized in the presence of the catalyst system;

[0106] Step 2: Homopolymerization;

[0107] Step 3: Copolymerization reaction.

[0108] In some specific embodiments of the present invention, when the organoaluminum component is added in two steps, the olefin polymerization method includes the following steps:

[0109] Step 1: The first organoaluminum component, the external electron donor, and the catalyst component are pre-complexed to form a catalyst system, and the olefin is pre-polymerized in the presence of the catalyst system;

[0110] Step 2: Perform the first stage of homopolymerization, then add the second organoaluminum component and continue the second stage of homopolymerization;

[0111] Step 3: Copolymerization reaction.

[0112] In some specific embodiments of the present invention, when the organoaluminum component is added in two steps, the first organoaluminum component is triethylaluminum, and the second organoaluminum component is of the general formula AlR. I R II R III At least one of the compounds shown in (Formula V); or, the first organoaluminum component is of the general formula AlR. I R II R III At least one of the compounds shown in (Formula V), wherein the second organoaluminum component is triethylaluminum.

[0113] In some specific embodiments of the present invention, the organoaluminum component is added in two steps: step 1 adds a first organoaluminum component, and step 2 adds a second organoaluminum component. The first organoaluminum component and the second organoaluminum component are the same, having the general formula AlR. I R II R III The mixture of the compound shown in Formula V and triethylaluminum has a molar ratio of (0.1-10):1 between the first organoaluminum component and the second organoaluminum component, for example, 0.2:1, 0.4:1, 0.6:1, 0.8:1, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, etc., preferably (0.2-5):1, more preferably (0.3-5):1. The molar ratio of the triethylaluminum compound shown in Formula V can be referred to the description in Part I of this invention, and will not be repeated here.

[0114] In some specific embodiments of the present invention, in step 1, the pre-complexation conditions include: a pre-complexation temperature of 0°C to 30°C and a pre-complexation time of 1 to 20 min; preferably, the pre-complexation temperature is 0 to 15°C and the pre-complexation time is 2 to 15 min.

[0115] In some specific embodiments of the present invention, in step 1, the prepolymerization conditions include: a prepolymerization temperature of 10-50°C and a prepolymerization time of 0-40 min; preferably, the prepolymerization temperature is 10-25°C and the prepolymerization time is 5-20 min.

[0116] In some specific embodiments of the present invention, the residence time of the catalyst system composition in the above polymerization reaction is 1-7 hours, preferably 2-5 hours. When the organoaluminum component is added all at once, the homopolymerization time in step 2 is 30-160 minutes; when the organoaluminum component is added in two steps, the homopolymerization time in step 2 is 20-90 minutes for the first stage and 10-70 minutes for the second stage, preferably 40-70 minutes for the first stage and 30-60 minutes for the second stage. Furthermore, considering both safety and conversion rate, the preferred polymerization time ratio for the first and second stages is (1.5-4):1, for example: 2:1, 3:1, 3.5:1, etc.

[0117] In some specific embodiments of the present invention, when the organoaluminum component is added all at once, the homopolymerization temperature in step 2 is 60-80°C. When the organoaluminum component is added in two steps, the temperatures of the first and second homopolymerization reactions are each independently 60-80°C. Preferably, the temperatures of the first and second homopolymerization reactions are 60-75°C. Specifically, the temperatures of the first and second homopolymerization reactions can be, but are not limited to, 65°C, 68°C, 70°C, and 75°C.

[0118] In some specific embodiments of the present invention, in step 3, the copolymerization reaction time is 10-60 min, preferably 20-50 min. In some specific embodiments of the present invention, in step 3, the copolymerization reaction temperature is 70-90°C. Preferably, the copolymerization reaction temperature is 75-85°C. The copolymerization temperature can be, but is not limited to, 78°C, 80°C, 82°C, and 85°C.

[0119] In some specific embodiments of the present invention, propylene homopolymerization and ethylene-propylene copolymerization reactions are carried out in an intermittent or continuous manner. By changing the composition of the mixed co-catalyst (organoaluminum component), an impact-resistant resin with high ethylene content is obtained. Specifically, the raw materials for steps 1-2 above include propylene and hydrogen, and the raw materials for step 3 include propylene, α-olefin and hydrogen, wherein the α-olefin is at least one selected from ethylene, 1-butene, 1-pentene, 1-hexene, 1-octene, and 1-decene, preferably at least one selected from ethylene and 1-butene.

[0120] In this invention, the amounts of hydrogen, propylene, and α-olefin are not limited. Hydrogen participates in the polymerization reaction as a molecular weight regulator, and its amount can be determined according to the melt index requirements of the final polypropylene resin. The amounts of propylene and α-olefin can be determined according to requirements.

[0121] Thirdly, the present invention provides a polyolefin obtained by the above-described olefin polymerization method, wherein preferably, the polyolefin is polypropylene.

[0122] The catalyst system provided by this invention and the olefin polymerization method of this invention in olefin polymerization can obtain homopolymer polypropylene with high melting enthalpy and impact-resistant polypropylene with high ethylene content and high rubber content, which is beneficial to the rigidity and toughness balance of high-impact polypropylene resin.

[0123] The following detailed description of preferred embodiments of the present invention illustrates the principles of the invention and is not intended to limit the scope of the invention.

[0124] The testing methods involved in the following embodiments are as follows:

[0125] 1. Polymer isotactic index (II): The isotactic index is determined by the n-heptane extraction method (n-heptane boiling extraction for 2 hours). 3 g of dry polymer sample is placed in a Soxhlet extractor and extracted with boiling n-heptane for 2 hours. The residue is then dried to constant weight. The ratio of the weight of the residue (g) to 3 is the isotactic index.

[0126] 2. Xylene-soluble content (XS): After baking the copolymer in a vacuum drying oven at 75°C for 30 minutes, quickly place it in a desiccator to cool to room temperature; weigh about 2g of the copolymer and place it in a 500ml conical flask, add 200ml of xylene and heat to dissolve. After cooling the dissolved sample at room temperature for 12-14 minutes, place it in a constant temperature water bath at 25°C to cool and crystallize for 60 minutes. After filtering the crystals, heat, bake, weigh, and calculate the content of the soluble matter.

[0127] 3. Ethylene content: The content was determined using a Nicolet Magna-IR760 infrared spectrometer, by hot pressing film formation method, 170℃, 20MPa.

[0128] 4. Enthalpy of fusion: The enthalpy of fusion was measured by differential scanning calorimetry (DSC) in accordance with GB / T 19466, with a heating / cooling rate of 20℃ / min.

[0129] Preparation Example 1

[0130] In a 300 mL glass reaction flask under nitrogen protection, 10 mL of hexane and 90 mL of titanium tetrachloride were added sequentially. The mixture was cooled to -20 °C, and 8.0 g of spherical magnesium halide adduct MgCl2·2.6CH3CH2OH·0.0092-CH3OPhCOOC2H5·0.010 2-OHPhCOOC2H5·0.006CH3OH (preparation method see CN105541877A) was added. The mixture was stirred at -20 °C for 30 minutes. Then, the temperature was slowly increased to 110 °C, and 1.5 mL of diisobutyl phthalate was added during the heating process. After reacting at 110 °C for 30 minutes, the liquid was filtered off. 80 mL of titanium tetrachloride was added, and the temperature was increased to 120 °C. After maintaining the temperature at 120 °C for 30 minutes, the liquid was filtered off. Then, another 80 mL of titanium tetrachloride was added, and the temperature was increased to 120 °C. After maintaining the temperature at 120 °C for 30 minutes, the liquid was filtered off. Finally, the obtained solid was washed five times with hexane at 60°C (80 L / wash), and the solid was dried under vacuum to obtain spherical catalyst component A with a titanium content of 2.5%.

[0131] Preparation Example 2

[0132] In a 300 mL glass reaction flask under nitrogen protection, 18 mL of hexane and 90 mL of titanium tetrachloride were added sequentially. The mixture was cooled to -20 °C, and 8.0 g of spherical magnesium halide adduct MgCl2·2.7CH3CH2OH (preparation method see CN1330086A) was added. The mixture was stirred at -20 °C for 30 minutes. Then, the temperature was slowly increased to 110 °C, and 1.5 mL of diisobutyl phthalate was added during the heating process. After reacting at 110 °C for 30 minutes, the liquid was filtered off. 80 mL of titanium tetrachloride was added, and the temperature was increased to 120 °C. After maintaining the temperature at 120 °C for 30 minutes, the liquid was filtered off. This process was repeated once. Finally, the obtained solid was washed five times with hexane at 60 °C (80 mL hexane per wash); and the solid was dried under vacuum to obtain spherical catalyst component B with a titanium content of 2.4%.

[0133] Example 1

[0134] (1) Homopolymerization of olefins

[0135] The reaction was carried out in a 400 mL stainless steel high-pressure reactor. After the reactor was fully purged with gaseous propylene, 100 g of propylene and 800 mL of hydrogen (controlled by a gas mass flow meter) were added. The temperature was raised to 20 °C. A pre-complexed triethylaluminum (TEA) and trihexylaluminum (THA) mixed solution (TEA to THA molar ratio 3:1, 0.6 mmol / mL), a dodecane solution of cyclohexylmethyldimethoxysilane (concentration 0.08 mmol / mL), and a mixture of catalyst component A (1 mg) (Al:Ti = 410, aluminum:silicon = 16 mol / mol) were automatically injected via a robotic arm. Stirring was started and timing was initiated. After 10 min of prepolymerization, the temperature was rapidly raised to 70 °C for bulk polymerization. After 100 min, the remaining propylene in the reactor was purged, a stop gas was introduced, heating and stirring were stopped, the pressure was released, the polymer was discharged, dried, and weighed.

[0136] (2) Olefin copolymerization

[0137] The polymerization was carried out in a 400 mL stainless steel high-pressure reactor. After the reactor was fully purged with gaseous propylene, 100 g of propylene and 800 mL of hydrogen (controlled by a gas mass flow meter) were added. The temperature was raised to 20 °C. A pre-complexed TEA (0.6 mmol / mL) and THA (0.6 mmol / mL) mixed solution (TEA to THA molar ratio 3:1), a dodecane solution of cyclohexylmethyldimethoxysilane (concentration 0.08 mmol / mL), and a mixture of catalyst component A (1 mg) (Al:Ti = 410, aluminum:silicon = 16 mol / mol) were automatically injected via a robotic arm. Stirring was started and timing was initiated. After 10 min of prepolymerization, the temperature was rapidly raised to 69 °C for bulk polymerization. After 100 min, the remaining propylene in the reactor was purged, and a pre-prepared ethylene / propylene mixed gas (ethylene:propylene = 2:3 mol / mol) was rapidly added. The temperature was rapidly raised to 80 °C. The propylene / ethylene ratio was controlled in real time by gas chromatography during the gas-phase polymerization. After reacting for 30 minutes, a stop gas is introduced, heating and stirring are stopped, the pressure is released, the material is discharged, and the polymer is dried to obtain polypropylene.

[0138] Example 2

[0139] (1) Homopolymerization of olefins

[0140] Propylene polymerization was carried out using the same method as in Example 1 (1), except that the alkyl aluminum compound that was pre-contacted with cyclohexylmethyldimethoxysilane and catalyst A was a mixed solution of TEA and THA (molar ratio of TEA to THA 5:1), Al:Ti = 250, and the aluminum-silicon ratio was the same as in Example 1.

[0141] (2) Olefin copolymerization

[0142] The olefin copolymerization was carried out using the same method as in Example 1 (2), except that the alkyl aluminum compound that was pre-contacted with cyclohexylmethyldimethoxysilane and catalyst A was a mixed solution of TEA and THA (molar ratio of TEA to THA 5:1), Al:Ti = 250, and the aluminum-silicon ratio was the same as in Example 1.

[0143] Example 3

[0144] (1) Homopolymerization of olefins

[0145] Propylene polymerization was carried out using the same method as in Example 1 (1), except that the alkyl aluminum compound that was pre-contacted with cyclohexylmethyldimethoxysilane and catalyst A was a mixed solution of TEA and THA (molar ratio of TEA to THA 1:1), Al:Ti = 410, and the aluminum-silicon ratio was the same as in Example 1.

[0146] (2) Olefin copolymerization

[0147] The same method as in Example 1 (2) was used for olefin copolymerization, except that the alkyl aluminum compound that was pre-contacted with cyclohexylmethyldimethoxysilane and catalyst A was a mixed solution of TEA and THA (molar ratio of TEA to THA 1:1), Al:Ti = 410, and the aluminum-silicon ratio was the same as in Example 1.

[0148] Example 4

[0149] (1) Homopolymerization of olefins

[0150] Propylene polymerization was carried out using the same method as in Example 1 (1), except that the alkyl aluminum compound that was pre-contacted with cyclohexylmethyldimethoxysilane and catalyst A was a mixed solution of TEA and THA (molar ratio of TEA to THA 1:3), Al:Ti = 410, and the aluminum-silicon ratio was the same as in Example 1.

[0151] (2) Olefin copolymerization

[0152] The olefin copolymerization was carried out using the same method as in Example 1 (2), except that the alkyl aluminum compound that was pre-contacted with cyclohexylmethyldimethoxysilane and catalyst A was a mixed solution of TEA and THA (molar ratio of TEA to THA 1:3), Al:Ti = 410, and the aluminum-silicon ratio was the same as in Example 1.

[0153] Example 5

[0154] (1) Homopolymerization of olefins

[0155] Propylene polymerization was carried out using the same method as in Example 1 (1), except that the alkyl aluminum compound that was pre-contacted with cyclohexylmethyldimethoxysilane and catalyst A was a mixed solution of TEA and triisooctylaluminum (TOA) (molar ratio of TEA to TOA 3:1), Al:Ti = 500, and the aluminum-silicon ratio was the same as in Example 1.

[0156] (2) Olefin copolymerization

[0157] The olefin copolymerization was carried out using the same method as in Example 1 (2), except that the alkyl aluminum compound that was pre-contacted with cyclohexylmethyldimethoxysilane and catalyst A was a mixed solution of TEA and TOA (molar ratio of TEA to TOA 3:1), Al:Ti = 500, and the aluminum-silicon ratio was the same as in Example 1.

[0158] Example 6

[0159] (1) Homopolymerization of olefins

[0160] Propylene polymerization was carried out using the same method as in Example 1 (1), except that the alkyl aluminum compound that was pre-contacted with cyclohexylmethyldimethoxysilane and catalyst A was a mixed solution of TEA and TOA (molar ratio of TEA to TOA 1:1), Al:Ti = 700, and the aluminum-silicon ratio was the same as in Example 1.

[0161] (2) Olefin copolymerization

[0162] The olefin copolymerization was carried out using the same method as in Example 1 (2), except that the alkyl aluminum compound that was pre-contacted with cyclohexylmethyldimethoxysilane and catalyst A was a mixed solution of TEA and TOA (molar ratio of TEA to TOA 1:1), Al:Ti = 700, and the aluminum-silicon ratio was the same as in Example 1.

[0163] Example 7

[0164] (1) Homopolymerization of olefins

[0165] Propylene polymerization was carried out using the same method as in Example 1 (1), except that the alkyl aluminum compound that was pre-contacted with cyclohexylmethyldimethoxysilane and catalyst A was a mixed solution of TEA and TOA (molar ratio of TEA to TOA 1:3), Al:Ti = 700, and the aluminum-silicon ratio was the same as in Example 1.

[0166] (2) Olefin copolymerization

[0167] The olefin copolymerization was carried out using the same method as in Example 1 (2), except that the alkyl aluminum compound that was pre-contacted with cyclohexylmethyldimethoxysilane and catalyst A was a mixed solution of TEA and TOA (molar ratio of TEA to TOA 1:3), Al:Ti = 700, and the aluminum-silicon ratio was the same as in Example 1.

[0168] Example 8

[0169] (1) Homopolymerization of olefins

[0170] Propylene polymerization was carried out using the same method as in Example 1 (1), except that before the catalyst component came into contact with propylene, the alkyl aluminum component that was pre-complexed with the dodecane solution of catalyst component A and cyclohexylmethyldimethoxysilane was TEA. After the homopolymerization reaction of propylene was 40 min, the second alkyl aluminum component THA (TEA:THA = 3:1, Al:Ti = 410, aluminum:silicon = 16 mol / mol) was added by a robotic arm, and the homopolymerization reaction was continued for another 60 min.

[0171] (2) Olefin copolymerization

[0172] Olefin copolymerization was carried out using the same method as in Example 1(2), except that before the catalyst component came into contact with propylene, the alkyl aluminum component TEA was pre-complexed with catalyst component A and the dodecane solution of cyclohexylmethyldimethoxysilane. After 40 min of homopolymerization of propylene, the second alkyl aluminum component THA (TEA:THA = 3:1, Al:Ti = 410, Aluminum:Silicon = 16 mol / mol) was added via a robotic arm, and the homopolymerization reaction continued for another 60 min. Then, the remaining propylene in the reactor was emptied, and a pre-prepared ethylene / propylene mixture (ethylene:propylene = 2:3 mol / mol) was quickly added, and the temperature was rapidly raised to 80°C. During gas-phase polymerization, the propylene / ethylene ratio was controlled in real time by gas chromatography. After 30 min of reaction, a stop gas was introduced, heating was stopped, stirring was stopped, pressure was released, the product was discharged, and the polymer was dried to obtain polypropylene.

[0173] Example 9

[0174] (1) Homopolymerization of olefins

[0175] Propylene polymerization was carried out using the same method as in Example 1 (1), except that the alkyl aluminum compound that was pre-contacted with cyclohexylmethyldimethoxysilane and catalyst A was a mixed solution of TEA, THA and TOA (molar ratio of TEA, THA and TOA 2:1:1), Al:Ti = 500, and the aluminum-silicon ratio was the same as in Example 1.

[0176] (2) Olefin copolymerization

[0177] The olefin copolymerization was carried out using the same method as in Example 1 (2), except that the alkyl aluminum compound that was pre-contacted with cyclohexylmethyldimethoxysilane and catalyst A was a mixed solution of TEA, THA and TOA (molar ratio of TEA, THA and TOA 2:1:1), Al:Ti = 500, and the aluminum-silicon ratio was the same as in Example 1.

[0178] Comparative Example 1

[0179] (1) Homopolymerization of olefins

[0180] Propylene polymerization was carried out using the same method as in Example 1 (1), except that the alkyl aluminum compound that was pre-contacted with cyclohexylmethyldimethoxysilane and catalyst A was TEA, Al:Ti = 410, and the aluminum-silicon ratio was the same as in Example 1.

[0181] (2) Olefin copolymerization

[0182] The olefin copolymerization was carried out using the same method as in Example 1 (2), except that the alkyl aluminum compound that was pre-contacted with cyclohexylmethyldimethoxysilane and catalyst A was TEA, Al:Ti = 410, and the aluminum-silicon ratio was the same as in Example 1.

[0183] Comparative Example 2

[0184] (1) Homopolymerization of olefins

[0185] Propylene polymerization was carried out using the same method as in Example 1 (1), except that the alkyl aluminum compound that was pre-contacted with cyclohexylmethyldimethoxysilane and catalyst A was THA, Al:Ti = 410, and the aluminum-silicon ratio was the same as in Example 1.

[0186] (2) Olefin copolymerization

[0187] The olefin copolymerization was carried out using the same method as in Example 1 (2), except that the alkyl aluminum compound that was pre-contacted with cyclohexylmethyldimethoxysilane and catalyst A was THA, Al:Ti = 410, and the aluminum-silicon ratio was the same as in Example 1.

[0188] Example 10

[0189] (1) Homopolymerization of olefins

[0190] Propylene polymerization was carried out using the same method as in Example 1 (1), except that “catalyst component A” was replaced with “catalyst component B” (Al:Ti = 410, aluminum:silicon = 16 mol / mol).

[0191] (2) Olefin copolymerization

[0192] The olefin copolymerization was carried out using the same method as in Example 1(2), except that “catalyst component A” was replaced with “catalyst component B” (Al:Ti = 410, aluminum:silicon = 16 mol / mol).

[0193] Example 11

[0194] (1) Homopolymerization of olefins

[0195] Propylene polymerization was carried out using the same method as in Example 1(1), except that Al:Ti = 40 and the aluminum-silicon ratio was the same as in Example 1.

[0196] (2) Olefin copolymerization

[0197] The olefin copolymerization was carried out using the same method as in Example 1(2), except that Al:Ti = 40 and the aluminum-silicon ratio was the same as in Example 1.

[0198] Example 12

[0199] (1) Homopolymerization of olefins

[0200] Propylene polymerization was carried out using the same method as in Example 1(1), except that a pre-complexed first alkyl aluminum component, namely a mixture of triethylaluminum (TEA) and trihexylaluminum (THA) (3:1, 0.6 mmol / mL), a dodecane solution of cyclohexylmethyldimethoxysilane (concentration 0.08 mmol / mL), and a mixture of catalyst component A (1 mg) were automatically injected via a robotic arm, and stirring was started and timed. After 10 min of prepolymerization, the temperature was rapidly increased to 70 °C for bulk polymerization. After 40 min of homopolymerization of propylene, a mixture of the second alkyl aluminum component, triethylaluminum (TEA) and trihexylaluminum (THA) (3:1, 0.6 mmol / mL), was added via a robotic arm to continue the homopolymerization reaction for another 60 min. The molar ratio of the first alkyl aluminum component to the second alkyl aluminum component was 1:1. (Al:Ti = 410, Aluminum:Silicon = 16 mol / mol)

[0201] (2) Olefin copolymerization

[0202] Propylene polymerization was carried out using the same method as in Example 1(1), except that a mixture of pre-complexed first alkyl aluminum component triethylaluminum (TEA) and trihexylaluminum (THA) (3:1, 0.6 mmol / mL), a dodecane solution of cyclohexylmethyldimethoxysilane (concentration 0.08 mmol / mL), and catalyst component A (1 mg) was automatically injected via a robotic arm, and stirring was started and timed. After 10 min of prepolymerization, the temperature was rapidly increased to 69 °C for bulk polymerization. After 40 min of homopolymerization of propylene, a mixture of second alkyl aluminum component triethylaluminum (TEA) and trihexylaluminum (THA) (3:1, 0.6 mmol / mL) was added via a robotic arm to continue the homopolymerization reaction for 60 min. The molar ratio of the first alkyl aluminum component to the second alkyl aluminum component was 1:1 (Al:Ti = 410, aluminum:silicon = 16 mol / mol).

[0203] Example 13

[0204] This embodiment is basically the same as Example 1, except that the alkyl aluminum compound used is triethylaluminum and triisobutylaluminum (3:1, 0.6 mmol / mL), Al:Ti = 410, aluminum:silicon = 16 mol / mol.

[0205] Comparative Example 3

[0206] (1) Homopolymerization of olefins

[0207] Propylene polymerization was carried out using the same method as in Example 7(1), except that the alkyl aluminum compound that was pre-contacted with cyclohexylmethyldimethoxysilane and catalyst A was TOA, Al:Ti = 700, and the aluminum-silicon ratio was the same as in Example 7.

[0208] (2) Olefin copolymerization

[0209] The same method as in Example 7(2) was used for olefin copolymerization, except that the alkyl aluminum compound that was pre-contacted with cyclohexylmethyldimethoxysilane and catalyst A was TOA, Al:Ti = 700, and the aluminum-silicon ratio was the same as in Example 7.

[0210] The aggregation results of all examples and comparative examples are summarized in Table 1 below.

[0211] Table 1 Performance parameters of the examples and comparative examples

[0212]

[0213]

[0214] Table 1 lists the test results of polymers obtained from olefin homopolymerization and impact copolymerization using the catalyst system for olefin polymerization according to the present invention. The data shows that, compared to existing catalyst systems containing a single alkyl aluminum component, the polypropylene homopolymer prepared by the catalyst system composition and olefin polymerization method according to the present invention has a high enthalpy of melt, and the prepared impact copolymer has a high ethylene content and a high xylene-soluble content. The high enthalpy of melt is beneficial to improving the resin's flexural modulus, imparting high rigidity to the resin, while the high xylene-soluble content is beneficial to improving the resin's impact strength, imparting high toughness to the resin. This will contribute to improving the rigidity-toughness balance of the impact-resistant polypropylene resin prepared by the catalyst system composition and olefin polymerization method according to the present invention, making it well-suited for applications in automobiles, home appliances, and children's toys where a high balance of rigidity and toughness in polypropylene resin is required. The high impact resistance can also significantly improve the resin's service life in cold regions.

[0215] It should be noted that the embodiments described above are only for explaining the present invention and do not constitute any limitation on the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory terms, not limiting terms. Modifications can be made to the present invention within the scope of the claims, and revisions can be made to the present invention without departing from the scope and spirit of the present invention. Although the present invention described herein relates to specific methods, materials, and embodiments, it does not mean that the present invention is limited to the specific examples disclosed herein; on the contrary, the present invention can be extended to all other methods and applications with the same function.

Claims

1. A catalyst system, characterized in that, The catalyst comprises a titanium-containing catalyst component, an organoaluminum component, and an external electron donor. The titanium-containing catalyst component includes magnesium halide adducts, titanium-containing compounds, and an internal electron donor. The organoaluminum component includes components of the general formula AlR. I R II R III At least one of the compounds shown in (Formula V) and triethylaluminum, In formula V, R I R II and R III Whether the two are the same or different, they are each independently selected from chlorine, C3-C 10 Straight-chain alkyl, C3-C 10 One of the branched alkyl groups, and R I R II and R III At least one of them is C3-C 10 Straight-chain alkyl, C3-C 10 One of the branched alkyl groups.

2. The catalyst system according to claim 1, characterized in that, The compound shown in Formula V includes at least one of triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, and triisooctylaluminum; And / or, the molar ratio of triethylaluminum to the compound shown in formula V is 1:(0.1 to 5), preferably 1:(0.1 to 3); And / or, the molar ratio of the organoaluminum component (calculated as aluminum) to the titanium-containing catalyst component (calculated as titanium) is (70-2000):1, preferably (100-700):

1.

3. The catalyst system according to claim 1 or 2, characterized in that, The organoaluminum component comprises triethylaluminum and at least two compounds of formula V. Preferably, at least two compounds of formula V include the compound of formula V and the compound of formula V, and the molar ratio of triethylaluminum, the compound of formula V and the compound of formula V is 1:(0.1-5):(0.1-5), preferably 1:(0.1-3):(0.1-3), more preferably 1:(0.1-1):(0.1-1).

4. The catalyst system according to any one of claims 1-3, characterized in that, In the titanium-containing catalyst component, the molecular formula of the magnesium halide adduct is shown in Formula I: MgXY-mROH-n(LB1)-k(LB2)-p(LB3) (Formula I); In Formula I, X is chlorine or bromine, and Y is chlorine, bromine, or Cl-C. 14 Straight-chain or branched alkyl groups, C6-C 14 aryl, C1-C 14 Straight-chain or branched alkoxy groups and C6-C 14 One of the aryl groups; R is C1-C 12 Straight-chain or branched alkyl groups, C3-C 10 cycloalkyl and C7-C 10 One of the aralkyl groups; LB1 is a hydroxybenzoate compound represented by formula II, LB2 is a hydroxybenzoate compound represented by formula III, and LB3 is a compound represented by the general formula R6OH (formula IV). In Equation II, R, R2, R3, R4, and R5 are either the same as or different from the corresponding R, R2, R3, R4, and R5 in Equation III, and are independently defined as follows: R is C1-C 12 Straight-chain or branched alkyl groups, C3-C 10 cycloalkyl and C7-C 10 One of the aralkyl groups; R2, R3, R4, and R5 may be the same or different, and each is independently hydrogen, halogen, nitro, or C1-C. 20 Straight-chain or branched alkyl groups, C3-C 20 cycloalkyl, C6-C 20 aryl and C7-C 20 One of the aralkyl groups; or two or more of R2, R3, R4 and R5 bonded together to form a ring; R6 in Equation II may be the same as or different from R6 in Equation IV, and each is independently C1-C. 20 Straight-chain or branched alkyl groups, C3-C 20 cycloalkyl, C6-C 20 aryl and C7-C 20 One of the aryl alkyl groups; In Equation I, m is 1-5, n is 0.0005-0.3, k is 0.0005-0.3, and p is 0.0005-0.

3.

5. The catalyst system according to any one of claims 1-4, characterized in that, The titanium-containing catalyst component includes titanium trihalide and titanium compounds of the general formula Ti(OR). 4-m X" m At least one of the titanium-containing compounds shown in Formula VII, wherein R" in Formula VII is C1-C 10 Straight-chain alkyl and C3-C 10 One of the branched alkyl groups, where X" is a halogen and m is an integer from 0 to 4; Preferably, the titanium-containing compound includes at least one of titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, titanium tetrabutoxy, titanium tetraethoxy, titanium monochlorotributoxy, titanium dichlorodibutoxy, titanium trichloromonobutoxy, titanium monochlorotriethoxy, titanium dichlorodiethoxy, titanium trichloromonoethoxy, and titanium trichloride. And / or, in the titanium-containing catalyst component, the internal electron donor includes at least one of esters, ethers, ketones, and ketone ester compounds.

6. The catalyst system according to any one of claims 1-5, characterized in that, The external electron donor includes at least one of carboxylic acids, acid anhydrides, esters, ketones, ethers, alcohols, organophosphorus compounds, and organosilicon compounds; And / or, relative to 1 mole of the organoaluminum component based on aluminum, the amount of the external electron donor is 0.005-0.5 moles, preferably 0.01-0.4 moles.

7. A method for olefin polymerization, characterized in that, The catalyst system according to any one of claims 1-6 is used; Preferably, the olefin is an olefin represented by the general formula CH2=CHR (Formula VI), where R in Formula VI is hydrogen, C1-C2, C2-C2, C3-C4, C4-C4, C5-C4, C6-C4, C7-C6 ... 12 Straight-chain alkyl, C3-C 12 Branched alkyl groups and C6-C 12 One of the aryl groups; Preferably, the polymerization temperature is 0℃-150℃, and more preferably 60℃-90℃; Preferably, in the olefin polymerization method, the organoaluminum component in the catalyst system is added in one step or in two steps.

8. The method according to claim 7, characterized in that, When the organoaluminum component is added all at once, the olefin polymerization method includes the following steps: Step 1: Olefins undergo prepolymerization in the presence of the catalyst system; Step 2: Homopolymerization; Optionally, step 3: copolymerization; or, When the organoaluminum component is added in two steps, the olefin polymerization method includes the following steps: Step 1: A catalyst system is formed by a mixture including a first organoaluminum component, an external electron donor, and a catalyst component, and the olefin is prepolymerized in the presence of the catalyst system; Step 2: Perform the first stage of homopolymerization, then add the second organoaluminum component and continue the second stage of homopolymerization; Optionally, step 3: copolymerization reaction.

9. The method according to any one of claims 7-8, characterized in that, When the organoaluminum component is added in two steps, the first organoaluminum component includes triethylaluminum, and the second organoaluminum component includes at least one of the compounds shown in Formula V. or, When the organoaluminum component is added in two steps, the first organoaluminum component includes at least one of the compounds shown in Formula V, and the second organoaluminum component includes triethylaluminum. or, When the organoaluminum component is added in two steps, the first organoaluminum component is the same as the second organoaluminum component, including at least one of the compounds shown in Formula V and triethylaluminum, wherein the molar ratio of the first organoaluminum component to the second organoaluminum component is (0.2-10):1, preferably (0.3-10):1, more preferably (0.3-5):

1.

10. A polyolefin obtained by the olefin polymerization method according to any one of claims 7-9, preferably, the polyolefin comprising polypropylene.

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