Catalyst for olefin polymerization and its application

Abstract

The present invention discloses a catalyst for olefin polymerization and its application. The catalyst for olefin polymerization comprises (A) a solid catalyst component, which is a reactant of magnesium halide, organic epoxy compound, organic phosphorus compound, organic alcohol compound, silicon ester compound and titanium halide or its derivative; (B) a cocatalyst; (C) an external electron donor compound of the compound shown in formula (I). When the catalyst of the present invention is used for ethylene polymerization, it shows high catalytic activity, and can also show high polymer melt index under polymerization conditions of high hydrogen to ethylene ratio; and show low polymer melt index under polymerization conditions of low hydrogen to ethylene ratio. Moreover, the catalyst preparation process is simple, and it is very suitable for ethylene slurry polymerization process and catalyst combination polymerization process with excellent hydrogen regulation performance.

Description

Technical Field

[0001] The present invention relates to the field of olefin polymerization catalysts, in particular to an olefin polymerization catalyst and application thereof. Background Art

[0002] At present, Ziegler-Natta type slurry polyethylene catalysts have made great progress in terms of activity, bulk density of powder, fine powder content, oligomers, etc., and basically meet the requirements of existing process production. With the continuous upgrading of the polyolefin industry structure, a large number of new process technologies have been built and put into production, and new products have been developed, high-performance catalysts are needed to meet production needs. When producing bimodal resin products, a large amount of hydrogen needs to be added during the high melt index polymerization of existing domestic catalysts, which can easily cause problems such as decreased catalyst activity, increased ethylene ethane reaction, and short safe operation cycle of the device. The imported catalyst is too sensitive to hydrogen adjustment during low melt index polymerization, the production device fluctuates greatly, the product quality is unstable, and it is difficult to produce high-value-added resins such as bimodal pipe materials for a long period of time. There are also problems such as short device operation cycle when producing bimodal film materials, especially the pipe products have flow lines and pitting. In order to better meet the needs of industrial production and produce resin products with better performance, it is necessary to provide catalyst products with better hydrogen adjustment performance while ensuring the basic performance of existing catalysts.

[0003] In the prior art, introducing some electron donors into olefin polymerization catalysts can improve the hydrogen regulation performance of the catalyst, such as the Chinese patents with publication numbers CN1958620A and CN103772536A, which respectively introduce silane electron donors and benzoate electron donors. Introducing other electron donors can improve the copolymerization performance of the catalyst, such as the Chinese patents with publication numbers CN1726230A, CN1798774A and CN101050248A, which respectively introduce electron donors such as alcohols, ketones, amines, amides, nitrile, alkoxysilane, aliphatic ethers and aliphatic carboxylates. Introducing certain electron donors into the catalyst can improve the activity of the catalyst, such as the technical solution of the Chinese patent with publication number CN102977232A, which introduces halogenated alkanes.

[0004] The electron donors mentioned above can only improve the performance of olefin polymerization catalysts in a certain aspect and can no longer meet the needs of industrial production. It is necessary to find a type of electron donor that can give the catalyst the characteristics of high hydrogen and high melt index, and low hydrogen and low melt index, so as to meet the needs of industrial production equipment to produce single-peak high melt index products and multi-peak pipes, membrane materials and other products. Summary of the invention

[0005] In order to solve the above problems existing in the prior art, the present invention provides a catalyst for olefin polymerization, and specifically relates to a catalyst for olefin polymerization and its application.

[0006] The inventors have found through research that when a silicon ester compound is introduced as an internal electron donor and a compound of the general formula (I) is introduced as an external electron donor during the preparation of the catalyst, the catalyst for olefin polymerization can not only show good activity and copolymerization performance, but also show a high polymer melt index under polymerization conditions of a high hydrogen-to-ethylene ratio (e.g., hydrogen partial pressure: ethylene partial pressure ≥ 3); and show a low polymer melt index under polymerization conditions of a low hydrogen-to-ethylene ratio (e.g., hydrogen partial pressure: ethylene partial pressure ≤ 1). Based on this finding, the present invention is proposed.

[0007] One of the objects of the present invention is to provide a catalyst for olefin polymerization, comprising the following components:

[0008] (A) Solid Catalyst Component

[0009] The solid catalyst components are reactants of magnesium halide, organic epoxy compound, organic phosphorus compound, organic alcohol compound, silicon ester compound and titanium halide or its derivatives.

[0010] (B) Promoter

[0011] The co-catalyst is selected from an organoaluminum compound. Preferably, the general formula of the organoaluminum compound is AlR 1 e X 1 f H g , where R 1 is hydrogen or C l ~C 20 Hydrocarbon, X 1 is a halogen atom, preferably fluorine, chlorine or bromine; e, f, g are each independently a natural number of 0 to 3, and e+f+g=3.

[0012] The organoaluminum compound can be preferably selected from Al(CH3)3, Al(CH2CH3)3, Al(iso-Bu)3, AlH(CH2CH3)2, AlCl(CH2CH3)2, AlH(i-Bu)2, AlCl 1.5 (CH2CH3) 1.5 , AlCl(CH2CH3)2, AlCl2(CH2CH3), Al(n-C6H 13 )3. Al(n-C8H 17 )3, etc., more preferably Al(CH2CH3)3, Al(i-Bu)3, Al(n-C6H 13 )3. Al(n-C8H 17 )3, AlEt2Cl; most preferably Al(CH2CH3)3 and / or Al(i-Bu)3.

[0013] The usage ratio of the (A) solid catalyst component to the (B) co-catalyst is (5-500):1, preferably (20-200):1, more preferably (50-200:1), and further preferably (100-150:1), based on the molar ratio of the aluminum in the co-catalyst to the titanium in the solid catalyst component. For example, it can be 5:1, 10:1, 20:1, 50:1, 100:1, 150:1, 200:1, 250:1, 300:1, 350:1, 400:1, 450:1, 500:1, etc.

[0014] (C) External electron donor

[0015] The external electron donor is a compound represented by formula (I),

[0016]

[0017] In formula (I), any one of R1, R2, R3, R4, and R5 is RO, and the others are the same or different and are independently selected from hydrogen, C1 to C 20 A straight chain alkyl or branched chain alkyl, cycloalkyl, aryl, alkaryl or aralkyl group, R is selected from C1 to C 20 The invention can be a straight-chain alkyl group or a branched-chain alkyl group, a cycloalkyl group, an aryl group, an alkaryl group or an aralkyl group.

[0018] Preferably, R is selected from C1 to C 20 Straight chain alkyl or branched chain alkyl, C3~C 20 Cycloalkyl, C6~C 10 Aryl, C6~C 10 An alkylaryl or aralkyl group.

[0019] More preferably, the external electron donor is selected from at least one of p-methoxyphenol, o-methoxyphenol, m-methoxyphenol, p-ethoxyphenol, o-ethoxyphenol, m-ethoxyphenol, p-propoxyphenol, o-propoxyphenol, m-propoxyphenol, p-butoxyphenol, o-butoxyphenol, m-butoxyphenol, p-hexyloxyphenol, o-hexyloxyphenol, m-hexyloxyphenol, p-octyloxyphenol, o-octyloxyphenol, m-octyloxyphenol, p-nonyloxyphenol, m-nonyloxyphenol, o-nonyloxyphenol, dodecyloxyphenol, tetradecyloxyphenol, octadecyloxyphenol, phenoxyphenol or hydroxyphenyl benzyl ether.

[0020] The molar ratio of the external electron donor to the titanium in the solid catalyst component can be (0.05-50):1, preferably (0.1-10):1, more preferably (0.5-4):1, and further preferably (0.8-1.8):1. For example, it can be 0.05:1, 0.1:1, 0.5:1, 1:1, 2:1, 3:1, 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, 20:1, 30:1, 40:1, 50:1, etc.

[0021] In the solid catalyst component (A) of the present invention, the magnesium halide is magnesium dihalide, which can be at least one of magnesium dichloride, magnesium dibromide or magnesium diiodide, among which magnesium dichloride is the best.

[0022] In the solid catalyst component (A) of the present invention, the organic epoxy compound is selected from at least one of C2-C8 aliphatic olefins, dienes or halogenated aliphatic olefins or dienes oxides, and glycidyl ethers or internal ethers. Specifically, it can be selected from at least one of ethylene oxide, propylene oxide, butylene oxide, epichlorohydrin, methyl glycidyl ether, diglycidyl ether, tetrahydrofuran, etc. Among them, at least one of ethylene oxide, propylene oxide, epichlorohydrin, and tetrahydrofuran is preferred, and at least one of tetrahydrofuran and epichlorohydrin is more preferred.

[0023] In the solid catalyst component (A) of the present invention, the organophosphorus compound may be selected from at least one of the group consisting of alkyl esters of orthophosphoric acid, alkyl esters of phosphorous acid, halogenated alkyl esters of orthophosphoric acid, and halogenated alkyl esters of phosphorous acid. Specifically, the organophosphorus compound may be selected from at least one of trimethyl orthophosphate, triethyl orthophosphate, tributyl orthophosphate, triphenyl phosphite, trimethyl phosphite, triethyl phosphite, tributyl phosphite, triphenyl phosphite, and benzyl phosphite. Preferably, at least one of trimethyl orthophosphate, triethyl orthophosphate, or tributyl orthophosphate is selected, and tributyl orthophosphate is most preferred.

[0024] In the solid catalyst component (A) of the present invention, the organic alcohol compound is selected from C1 to C 10 Straight chain or branched chain or cycloalkyl alcohol, C6~C 20 Alcohol containing aromatic groups; preferably, the organic alcohol compound can be selected from C 1～ C 10 aliphatic alcohol compounds. Specifically, the alcohol may include aliphatic alcohols: methanol, ethanol, propanol, isopropanol, butanol, isobutanol, glycerol, hexanol, 2-methylpentanol, 2-ethylbutanol, n-heptanol, n-octanol, decanol, etc.; cycloalkanols such as cyclohexanol, methylcyclohexanol, etc.; aromatic alcohols such as at least one of benzyl alcohol, methylbenzyl alcohol, ɑ-methylbenzyl alcohol, ɑ, ɑ-dimethylbenzyl alcohol, etc. Preferably, ethanol, butanol, 2-ethylhexanol, glycerol, etc. There is no particular restriction on the proportion of each alcohol in the alcohol composition.

[0025] In the solid catalyst component (A) of the present invention, the general formula of the silicon ester compound is R 2 x R 3 y Si(OR 4 ) Z , where R 2 and R 3 They are C1~C 10 The hydrocarbon or halogen, R 4 C1~C 10 A hydrocarbon group, wherein x, y, z are integers, 0≤x≤2, 0≤y≤2 and 0≤z≤4, and x+y+z=4.

[0026] The silicon ester compound may include: tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, tetra(2-ethylhexyloxy)silane, ethyltrimethoxysilane, ethyltriethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, n-propyltriethoxysilane, n-propyltrimethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, cyclopentyltrimethoxysilane, cyclopentyltriethoxysilane, 2-methylcyclopentyltrimethoxysilane, 2,3-dimethoxysilane, 2-methylcyclopentyltrimethoxysilane, 2,3-dimethoxysilane, 2-methylcyclopentyltrimethoxysilane, 2,3-dimethoxysilane, 2-methylcyclopentyltrimethoxysilane, 2,3-dimethoxysilane, 2-methylcyclopentyltriethoxysilane, 2,3-dimeth ...methoxysilane, 2,3-dimethoxysilane, 2-propyltriethoxysilane, 2-propyltriethoxysil Methylcyclopentyltrimethoxysilane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, tert-butyltriethoxysilane, n-butyltrimethoxysilane, n-butyltriethoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, monochlorotrimethoxysilane, monochlorotriethoxysilane, ethyltriisopropoxysilane, vinyltributoxysilane, trimethylphenoxysilane, Methyltriallyloxysilane, vinyltriacetoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diisopropyldimethoxysilane, diisopropyldiethoxysilane, tert-butylmethyldimethoxysilane, tert-butylmethyldiethoxysilane, tert-amylmethyldiethoxysilane, dicyclopentyldimethoxysilane, dicyclopentyldiethoxysilane, methylcyclopentyldiethoxysilane, methylcyclopentyldimethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, methyl Phenyldiethoxysilane, methylphenyldimethoxysilane, bis-o-tolyldimethoxysilane, bis-o-tolyldiethoxysilane, bis-m-tolyldimethoxysilane, bis-m-tolyldiethoxysilane, bis-p-tolyldimethoxysilane, bis-p-tolyldiethoxysilane, trimethylmethoxysilane, trimethylethoxysilane, tricyclopentylmethoxysilane, tricyclopentylethoxysilane, dicyclopentylmethylmethoxysilane or cyclopentyldimethylmethoxysilane or a mixture of the above may be used.

[0027] More preferably, the silicon ester compound is selected from at least one of tetramethoxysilane, tetraethoxysilane or tetrabutoxysilane.

[0028] The general formula of the titanium halide or its derivative can be Ti(OR9) d X b , where R9 is C1~C 14 a hydrocarbon group, preferably a C1-C8 alkyl group; X is a halogen atom, d and b are each independently an integer of 0 to 4, and d+b=3 or 4, and may specifically include at least one of: TiCl3, TiBr4, TiCl4, Ti(OC2H5)Cl3, Ti(OCH3)Cl3, Ti(OC4H9)Cl3, Ti(OC2H5)Br3, Ti(OC2H5)2Cl2, Ti(OCH3)2Cl2, Ti(OCH3)2I2, Ti(OC2H5)3Cl, Ti(OCH3)3Cl, Ti(OC2H5)3I, Ti(OC2H5)4, Ti(OC3H7)4, Ti(OC4H9)4, etc. At least one of TiCl3, TiCl4, TiBr4, Ti(OC2H5)2Cl2, Ti(OCH3)Cl3, Ti(OC2H5)Cl3, Ti(OC2H5)3Cl, Ti(OC4H9)Cl3, and Ti(OC4H9)4 is preferred. TiCl4 is the best.

[0029] The solid catalyst component is prepared by the following steps: reacting magnesium halide with organic epoxy compounds, organic phosphorus compounds and organic alcohol compounds to form a uniform solution; and then mixing with silicon ester compounds, transition metal titanium halides or their derivatives to obtain the solid catalyst component.

[0030] Preferably, the method for preparing the solid catalyst component comprises the following steps:

[0031] Under stirring, magnesium halide is dissolved in an organic epoxy compound and an organic phosphorus compound to form a uniform transparent solution, and the dissolution temperature is 50-90°C. In the process of forming the uniform transparent solution or after the solution is formed, an organic alcohol compound is added, and the reaction is carried out for a certain time (specifically 1.5-4 hours) to obtain a reaction solution; the reaction solution is mixed with a silicone ester compound, a transition metal titanium halide or a derivative thereof at -30°C to 0°C; the mixture is slowly heated to 50-120°C for reaction, and solid matter is precipitated after the reaction is completed, and the mother liquor is filtered and removed, and the solid matter is washed with an inert solvent to obtain the solid catalyst component.

[0032] Among them, regarding the preparation of the magnesium halide solution: the magnesium halide solution is a uniform solution obtained by dissolving the magnesium halide in a solvent system composed of an organic epoxy compound and an organic phosphorus compound, and an organic alcohol compound is added during the process of forming the solution or after the solution is formed, and the reaction is carried out for a certain period of time to obtain a reaction solution; the solvent system referred to here includes the use or non-use of an inert diluent.

[0033] The magnesium halide used has a particle size that can be dissolved under stirring. During the dissolution, an inert diluent such as benzene, toluene, xylene, 1,2-dichloroethane, chlorobenzene and other hydrocarbons or halogenated hydrocarbon compounds may or may not be added. Benzene, toluene and xylene are preferred, and toluene and xylene are more preferred.

[0034] The amount ratio of magnesium halide, organic epoxy compound, organic phosphorus compound, organic alcohol compound, silicon ester compound, transition metal titanium halide or its derivatives is, per mole of magnesium halide, 0.2 to 10 moles of organic epoxy compound, preferably 0.3 to 4.0 moles, more preferably 0.5 to 1.5 moles; 0.1 to 10 moles of organic phosphorus compound, preferably 0.2 to 4.0 moles, more preferably 0.5 to 1.2 moles; 0.1 to 6 moles of organic alcohol compound, preferably 0.1 to 3 moles, more preferably 1 to 2 moles; 0.1 to 1 mole of silicon ester compound, preferably 0.2 to 0.7 moles, more preferably 0.3 to 0.6 moles; 1 to 20 moles of transition metal titanium halide or its derivatives, preferably 1 to 15 moles, more preferably 5 to 15 moles, further preferably 5 to 12 moles.

[0035] In the olefin polymerization catalyst obtained in the present invention, the titanium content is 3 to 10% (weight content), preferably 3 to 7% (weight content).

[0036] The second object of the present invention is to provide the use of the catalyst for olefin polymerization in ethylene homopolymerization or copolymerization.

[0037] In specific applications, any two of the components (A) solid catalyst component, component (B) co-catalyst and component (C) external electron donor can be pre-mixed and then mixed with another component (for example, the (A) solid catalyst component and the (C) external electron donor can be mixed and then the (B) co-catalyst can be added in sequence) to carry out ethylene homopolymerization or copolymerization; or the component (A) solid catalyst component, component (B) co-catalyst and component (C) external electron donor can be added simultaneously to carry out ethylene homopolymerization or copolymerization.

[0038] The catalyst of the present invention is suitable for homopolymerization of ethylene or copolymerization of ethylene and other α-olefins, wherein the α-olefin is one of propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, and 4-methylpentene-1. The polymerization can be carried out in liquid phase or gas phase, and the polymerization temperature can be 0 to 150° C., preferably 60 to 90° C.

[0039] Examples of the liquid polymerization medium include inert solvents such as saturated aliphatic hydrocarbons such as isobutane, hexane, heptane, cyclohexane, naphtha, raffinate, hydrogenated gasoline, kerosene, benzene, toluene, xylene, or aromatic hydrocarbons.

[0040] In addition, in order to adjust the molecular weight of the final polymer, hydrogen can be used as a molecular weight regulator.

[0041] Due to the addition of the internal electron donor silicon ester compound and the external electron donor compound of the general formula (I), the olefin polymerization catalyst obtained by the present invention can not only show good activity and copolymerization performance, but also show a high polymer melt index under the polymerization conditions of high hydrogen-ethylene ratio (for example, hydrogen partial pressure: ethylene partial pressure ≥ 3); and show a low polymer melt index under the polymerization conditions of low hydrogen-ethylene ratio (for example, hydrogen partial pressure: ethylene partial pressure ≤ 1). When the catalyst system of the present invention is used for ethylene polymerization, it shows high catalytic activity and more suitable hydrogen adjustment sensitivity. In addition, the catalyst preparation process is simple, and it is very suitable for ethylene slurry polymerization process and catalyst combination polymerization process requiring excellent hydrogen adjustment sensitivity. DETAILED DESCRIPTION

[0042] The present invention is described in detail below in conjunction with specific embodiments. It is necessary to point out that the following embodiments are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by those skilled in the art based on the contents of the present invention still fall within the scope of protection of the present invention.

[0043] The raw materials used in the examples and comparative examples, unless otherwise specified, are disclosed in the prior art, for example, they can be directly purchased or prepared according to the preparation methods disclosed in the prior art.

[0044] Experimental test method:

[0045] 1. Relative weight percentage of titanium element in solid catalyst component: by spectrophotometry.

[0046] 2. Polymer melt index (MI): determined according to ASTM D1238-99, load 2.16 kg, 190°C.

[0047] Example 1

[0048] (1) Preparation of solid catalyst component A

[0049] In a reactor fully replaced with high-purity nitrogen, 4.0g magnesium dichloride, 50mL toluene, 3mL epichlorohydrin, 8mL tributyl phosphate, and 4mL ethanol were added in sequence, and the reaction mixture was heated to 70°C under stirring. When the solid was completely dissolved to form a uniform solution, it was reacted at 70°C for 2 hours. The system was cooled to -20°C, 40mL titanium tetrachloride was slowly added dropwise, and after 30 minutes of constant temperature, 4.0mL tetraethoxysilane was slowly added dropwise, and then the temperature was gradually raised to 85°C, and the reaction was reacted at 85°C for 2 hours. Stop the stirring of the reactor, let the reaction mixture stand, the suspension was quickly layered, the supernatant was removed, and the precipitate was washed four times with hexane. Dry with high-purity nitrogen to obtain a solid catalyst component A with good fluidity.

[0050] (2) Homopolymerization

[0051] ①Polymerization reaction with low hydrogen / ethylene ratio

[0052] A stainless steel reactor with a volume of 2L was fully replaced with high-purity nitrogen, and then 1L of hexane and 1.0mL of 1M triethylaluminum were added, and then the solid catalyst component (containing 0.4mg Ti) and p-methoxyphenol prepared by the above method were added, and the molar ratio of the amount of p-methoxyphenol added to the catalyst Ti was 1:1. The temperature was raised to 70°C, hydrogen was introduced to make the pressure in the reactor reach 0.28MPa, and ethylene was introduced to keep the total pressure in the reactor at 0.73MPa. Polymerization was carried out at 80°C for 2 hours. The polymerization results are shown in Table 1.

[0053] ②Polymerization reaction with high hydrogen / ethylene ratio

[0054] A stainless steel reactor with a volume of 2L was fully replaced with high-purity nitrogen, and then 1L of hexane and 1.0mL of 1M triethylaluminum were added, and then the solid catalyst component (containing 0.4mg Ti) and p-methoxyphenol prepared by the above method were added, and the molar ratio of the amount of p-methoxyphenol added to the catalyst Ti was 1:1. The temperature was raised to 75°C, hydrogen was introduced to make the pressure in the reactor reach 0.58MPa, and ethylene was introduced to make the total pressure in the reactor reach 0.73MPa, and polymerization was carried out at 85°C for 2 hours. The polymerization results are shown in Table 2.

[0055] Example 2

[0056] The solid catalyst component A is the same as in Example 1, except that the amount of p-methoxyphenol added in polymerization ① and polymerization ② is adjusted so that the molar ratio of p-methoxyphenol to Ti in the catalyst is 1.5:1. The polymerization results are shown in Tables 1 and 2, respectively.

[0057] Example 3

[0058] The solid catalyst component A is the same as in Example 1, except that the amount of p-methoxyphenol added in polymerization ① and polymerization ② is adjusted so that the molar ratio of p-methoxyphenol to Ti in the catalyst is 2.0:1. The polymerization results are shown in Tables 1 and 2, respectively.

[0059] Example 4

[0060] The solid catalyst component A is the same as in Example 1, except that the amount of p-methoxyphenol added in polymerization ① and polymerization ② is adjusted so that the molar ratio of p-methoxyphenol to Ti in the catalyst is 2.5:1. The polymerization results are shown in Tables 1 and 2, respectively.

[0061] Example 5

[0062] The solid catalyst component A is the same as in Example 1, except that the p-methoxyphenol added in polymerization ① and polymerization ② is replaced by p-ethoxyphenol, and the molar ratio of the added amount of p-ethoxyphenol to the Ti in the catalyst is 1:1. The polymerization results are shown in Tables 1 and 2, respectively.

[0063] Example 6

[0064] The solid catalyst component A is the same as in Example 1, except that the p-methoxyphenol added in polymerization ① and polymerization ② is replaced by p-ethoxyphenol, and the molar ratio of the amount of p-ethoxyphenol added to Ti in the catalyst is 1.5:1. The polymerization results are shown in Tables 1 and 2, respectively.

[0065] Example 7

[0066] The solid catalyst component A is the same as in Example 1, except that the p-methoxyphenol added in polymerization ① and polymerization ② is replaced by p-ethoxyphenol, and the molar ratio of the amount of p-ethoxyphenol added to Ti in the catalyst is 2.0:1. The polymerization results are shown in Tables 1 and 2, respectively.

[0067] Example 8

[0068] The solid catalyst component A is the same as that in Example 1, except that the p-methoxyphenol added in polymerization ① and polymerization ② is replaced by p-ethoxyphenol, and the molar ratio of the amount of p-ethoxyphenol added to Ti in the catalyst is 2.5:1. The polymerization results are shown in Tables 1 and 2, respectively.

[0069] Example 9

[0070] Solid catalyst component A is the same as in Example 1, except that p-methoxyphenol added in polymerization ① and polymerization ② is replaced by p-butoxyphenol, and the molar ratio of the amount of p-butoxyphenol added to Ti in the catalyst is 1:1. The polymerization results are shown in Tables 1 and 2, respectively.

[0071] Example 10

[0072] The solid catalyst component A is the same as in Example 1, except that the p-methoxyphenol added in polymerization ① and polymerization ② is replaced by p-butoxyphenol, and the molar ratio of the amount of p-butoxyphenol added to Ti in the catalyst is 1.5:1. The polymerization results are shown in Tables 1 and 2, respectively.

[0073] Embodiment 11

[0074] The solid catalyst component A is the same as in Example 1, except that the p-methoxyphenol added in polymerization ① and polymerization ② is replaced by p-butoxyphenol, and the molar ratio of the amount of p-butoxyphenol added to Ti in the catalyst is 2.0:1. The polymerization results are shown in Tables 1 and 2, respectively.

[0075] Example 12

[0076] The solid catalyst component A is the same as in Example 1, except that the p-methoxyphenol added in polymerization ① and polymerization ② is replaced by p-butoxyphenol, and the molar ratio of the amount of p-butoxyphenol added to Ti in the catalyst is 2.5:1. The polymerization results are shown in Tables 1 and 2, respectively.

[0077] Embodiment 13

[0078] (1) Preparation of solid catalyst component B

[0079] In a reactor fully replaced with high-purity nitrogen, 4.0g magnesium dichloride, 70mL toluene, 4mL epichlorohydrin, 7mL tributyl phosphate, and 5mL ethanol were added in sequence, and the reaction mixture was heated to 70°C under stirring. When the solid was completely dissolved to form a uniform solution, it was reacted at 70°C for 2 hours. The system was cooled to -20°C, 60mL titanium tetrachloride was slowly added dropwise, and after the constant temperature was maintained for 30 minutes, 3.5mL tetraethoxysilane was slowly added dropwise, and then the temperature was gradually increased to 85°C, and the reaction was kept at 85°C for 2 hours. Stop the stirring of the reactor, let the reaction mixture stand, the suspension was quickly layered, the supernatant was removed, and the precipitate was washed four times with hexane. Dry with high-purity nitrogen to obtain a solid catalyst component B with good fluidity.

[0080] (2) Homopolymerization

[0081] ①Polymerization reaction with low hydrogen / ethylene ratio

[0082] A stainless steel reactor with a volume of 2L was fully replaced with high-purity nitrogen, and then 1L of hexane and 1.0mL of 1M triethylaluminum were added, and then the solid catalyst component (containing 0.4mg Ti) and p-methoxyphenol prepared by the above method were added, and the molar ratio of the amount of p-methoxyphenol added to the catalyst Ti was 1:1. The temperature was raised to 70°C, hydrogen was introduced to make the pressure in the reactor reach 0.28MPa, and ethylene was introduced to keep the total pressure in the reactor at 0.73MPa. Polymerization was carried out at 80°C for 2 hours. The polymerization results are shown in Table 1.

[0083] ②Polymerization reaction with high hydrogen / ethylene ratio

[0084] A stainless steel reactor with a volume of 2L was fully replaced with high-purity nitrogen, and then 1L of hexane and 1.0mL of 1M triethylaluminum were added, and then the solid catalyst component (containing 0.4mg Ti) and p-methoxyphenol prepared by the above method were added, and the molar ratio of the amount of p-methoxyphenol added to the catalyst Ti was 1:1. The temperature was raised to 75°C, hydrogen was introduced to make the pressure in the reactor reach 0.58MPa, and ethylene was introduced to make the total pressure in the reactor reach 0.73MPa, and polymerization was carried out at 85°C for 2 hours. The polymerization results are shown in Table 2.

[0085] Comparative Example 1

[0086] (1) Preparation of solid catalyst component

[0087] In a reactor fully replaced with high-purity nitrogen, add 4.0g magnesium dichloride, 50mL toluene, 3mL epichlorohydrin, 8mL tributyl phosphate, and 4mL ethanol in turn, and heat to 70°C under stirring. When the solid is completely dissolved to form a uniform solution, react at 70°C for 2 hours. The system is cooled to -20°C, 40mL titanium tetrachloride is slowly added dropwise, and after the constant temperature is maintained for 30 minutes, 4.0mL tetraethoxysilane is slowly added dropwise, and then the temperature is gradually increased to 85°C, and the reaction is maintained at 85°C for 2 hours. Stop stirring, let it stand, the suspension quickly separates, the upper clear liquid is removed, and the precipitate is washed four times with hexane. Dry with high-purity nitrogen to obtain a solid catalyst component with good fluidity.

[0088] (2) Homopolymerization

[0089] ①Polymerization reaction with low hydrogen / ethylene ratio

[0090] A stainless steel reactor with a volume of 2L was fully replaced with high-purity nitrogen, and then 1L of hexane and 1.0mL of 1M triethylaluminum were added, and then the solid catalyst component (containing 0.4mgTi) prepared by the above method was added. The temperature was raised to 70°C, hydrogen was introduced to make the pressure in the reactor reach 0.28MPa, and ethylene was introduced to keep the total pressure in the reactor at 0.73MPa. Polymerization was carried out at 80°C for 2 hours. The polymerization results are shown in Table 1.

[0091] ②Polymerization reaction with high hydrogen / ethylene ratio

[0092] A stainless steel reactor with a volume of 2L was fully replaced with high-purity nitrogen, and then 1L of hexane and 1.0mL of 1M triethylaluminum were added, and then the solid catalyst component (containing 0.4mgTi) prepared by the above method was added. The temperature was raised to 75°C, hydrogen was introduced to make the pressure in the reactor reach 0.58MPa, and then ethylene was introduced to make the total pressure in the reactor reach 0.73MPa. Polymerization was carried out at 85°C for 2 hours. The polymerization results are shown in Table 2.

[0093] Comparative Example 2

[0094] The preparation of the solid catalyst component is the same as that of Comparative Example 1, except that the internal electron donor tetraethoxysilane is not added. The polymerization conditions are the same as those of Comparative Example 1. The polymerization results are shown in Tables 1 and 2, respectively.

[0095] 1) Preparation of solid catalyst component

[0096] Table 1

[0097]

[0098] It can be seen from the data in Table 1 that after adding the internal electron donor silicone ester compound and the external electron donor compound of general formula (I), the catalyst of the present invention has higher activity and lower melt index under low hydrogen polymerization conditions. This feature is beneficial to the smooth production of the low melt index polymerization part when the device is used for bimodal resin production, and the product quality is easy to control.

[0099] Table 2

[0100]

[0101] From the data in Table 2, it can be seen that after adding the internal electron donor silicon ester compound and the external electron donor compound of the general formula (I), the activity and hydrogen adjustment sensitivity of the catalyst of the present invention under high hydrogen polymerization conditions are significantly better than those of the comparative example. This feature is conducive to the production of bimodal products in the slurry polymerization process and the production of high melt index products in the gas phase polymerization process, and can reduce the amount of hydrogen added, reduce the ethylene ethanolysis reaction, and improve the activity of the catalyst. It can be seen that the combined effect of the silicon ester compound and the compound of the general formula (I) can improve the activity of the catalyst and the hydrogen adjustment sensitivity of the high melt index polymerization.

[0102] The embodiments of the present invention have been described above, and the above description is exemplary, not exhaustive, and is not limited to the disclosed embodiments. Many modifications and changes will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments.

Claims

1. A catalyst for olefin polymerization, comprising: (A) a solid catalyst component, which is a reactant of a magnesium halide, an organic epoxy compound, an organic phosphorus compound, an organic alcohol compound, a silicon ester compound and a titanium halide or a derivative thereof, wherein, per mole of magnesium halide, the organic epoxy compound is 0.2 to 10 moles, the organic phosphorus compound is 0.1 to 10 moles, the organic alcohol compound is 0.1 to 6 moles, the silicon ester compound is 0.1 to 1 mole, and the titanium halide or a derivative thereof is 1 to 20 moles; (B) a co-catalyst selected from organoaluminum compounds; (C) an external electron donor, wherein the external electron donor is a compound represented by formula (I), In formula (I), any one of R1, R2, R3, R4, and R5 is RO, and the others are the same or different and are independently hydrogen, C1-C 20 A straight chain alkyl or branched chain alkyl, cycloalkyl, aryl, alkaryl, aralkyl, R is selected from C1 to C 20 A straight-chain alkyl group or a branched-chain alkyl group, a cycloalkyl group, an aryl group, an alkaryl group, or an aralkyl group; The general formula of the silicone ester compound is R 2 x R 3 y Si(OR 4 ) z , where R 2 and R 3 C1~C 10 Hydrocarbon, halogen, R 4 C1~C 10 A hydrocarbon group, x, y, z are integers, 0≤x≤2, 0≤y≤2 and 0≤z≤4, and x+y+z=4.

2. The catalyst for olefin polymerization according to claim 1, characterized in that: The magnesium halide is selected from at least one of magnesium dichloride, magnesium dibromide and magnesium diiodide; The organic epoxy compound is selected from at least one of oxides, glycidyl ethers, and internal ethers of C2-C8 aliphatic olefins, dienes, or halogenated aliphatic olefins or dienes; The organic phosphorus compound is selected from at least one of a hydrocarbyl ester of orthophosphoric acid, a hydrocarbyl ester of phosphorous acid, a halogenated hydrocarbyl ester of orthophosphoric acid, and a halogenated hydrocarbyl ester of phosphorous acid; The organic alcohol compound is selected from C1 to C 10 Straight chain or branched chain or cycloalkyl alcohol, C6~C 20 Alcohols containing aromatic groups; The general formula of the titanium halide or its derivative is Ti(OR9) d X b , where R9 is C1~C 14 X is a halogen atom, d and b are each independently an integer of 0 to 4, and d+b=3 or 4; The general formula of the organoaluminum compound is AlR 1 e X 1 f H g , where R 1 is hydrogen or C l ~C 20 Hydrocarbon, X 1 is a halogen atom; e, f, and g are each independently a natural number from 0 to 3, and e+f+g=3.

3. The catalyst for olefin polymerization according to claim 2, characterized in that: The organoaluminum compound is selected from Al(CH3)3, Al(CH2CH3)3, Al(iso-Bu)3, AlH(CH2CH3)2, AlCl(CH2CH3)2, AlH(i-Bu)2, AlCl 1.5 (CH2CH3) 1.5 、AlCl2(CH2CH3), Al(n-C6H 13 )3. Al(n-C8H 17 ) At least one of 3; The external electron donor is selected from at least one of p-methoxyphenol, o-methoxyphenol, m-methoxyphenol, p-ethoxyphenol, o-ethoxyphenol, m-ethoxyphenol, p-propoxyphenol, o-propoxyphenol, m-propoxyphenol, p-butoxyphenol, o-butoxyphenol, m-butoxyphenol, p-hexyloxyphenol, o-hexyloxyphenol, m-hexyloxyphenol, p-octyloxyphenol, o-octyloxyphenol, m-octyloxyphenol, p-nonyloxyphenol, m-nonyloxyphenol, o-nonyloxyphenol, dodecyloxyphenol, tetradecyloxyphenol, octadecyloxyphenol, phenoxyphenol, and hydroxyphenyl benzyl ether.

4. The catalyst for olefin polymerization according to claim 2, characterized in that: The organic alcohol compound is selected from C1 to C 10 of aliphatic alcohols; The silicone ester compound is selected from tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, tetra(2-ethylhexyloxy)silane, ethyltrimethoxysilane, ethyltriethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, n-propyltriethoxysilane, n-propyltrimethoxysilane, decyltrimethoxysilane, decyltriethoxysilane, cyclopentyltrimethoxysilane, cyclopentyltriethoxysilane, 2-methylcyclopentyltrimethoxysilane, 2,3-dimethoxysilane, 2-methylcyclopentyltrimethoxysilane, 2,3-dimethoxysilane, 2-methylcyclopentyltrimethoxysilane, 2,3-dimethoxysilane, 2-methylcyclopentyltrimethoxysilane, 2,3-dimethoxysilane, 2-methylcyclopentyltrimethoxysilane, 2,3-dimethoxysilane, 2-methylcyclopentyltrieth ...-methylcyclopentyltrimethoxysilane, 2,3-dimethoxysilane, 2-methylcyclopentyltrimethoxysilane, 2,3-dimethoxysilane, 2-methylcyclopentyltrimethoxysilane, 2,3-dimethoxysilane, 2-methylcyclopentyltrimethoxysilane, 2,3-dimethoxysilane, 2-methylcyclopentyltriethoxysilane, 2-methylcyclopentyltrimethoxysilane, 2, Methylcyclopentyltrimethoxysilane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, tert-butyltriethoxysilane, n-butyltrimethoxysilane, n-butyltriethoxysilane, isobutyltrimethoxysilane, isobutyltriethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, monochlorotrimethoxysilane, monochlorotriethoxysilane, ethyltriisopropoxysilane, vinyltributoxysilane, trimethylphenoxy Silane, methyl triallyloxysilane, vinyl triacetoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diisopropyldimethoxysilane, diisopropyldiethoxysilane, tert-butylmethyldimethoxysilane, tert-butylmethyldiethoxysilane, tert-amylmethyldiethoxysilane, dicyclopentyldimethoxysilane, dicyclopentyldiethoxysilane, methylcyclopentyldiethoxysilane, methylcyclopentyldimethoxysilane, diphenyldimethoxysilane, diphenyldiethoxy At least one of silane, methylphenyldiethoxysilane, methylphenyldimethoxysilane, bis-o-tolyldimethoxysilane, bis-o-tolyldiethoxysilane, bis-m-tolyldimethoxysilane, bis-m-tolyldiethoxysilane, bis-p-tolyldimethoxysilane, bis-p-tolyldiethoxysilane, trimethylmethoxysilane, trimethylethoxysilane, tricyclopentylmethoxysilane, tricyclopentylethoxysilane, dicyclopentylmethylmethoxysilane, and cyclopentyldimethylmethoxysilane; The titanium halide or its derivative is selected from at least one of TiCl3, TiBr4, TiCl4, Ti(OC2H5)Cl3, Ti(OCH3)Cl3, Ti(OC4H9)Cl3, Ti(OC2H5)Br3, Ti(OC2H5)2Cl2, Ti(OCH3)2Cl2, Ti(OCH3)2I2, Ti(OC2H5)3Cl, Ti(OCH3)3Cl, Ti(OC2H5)3I, Ti(OC2H5)4, Ti(OC3H7)4, and Ti(OC4H9)4.

5. The catalyst for olefin polymerization according to claim 1, characterized in that: The molar ratio of aluminum in the co-catalyst to titanium in the solid catalyst component is (5-500):1; The molar ratio of the external electron donor to the titanium in the solid catalyst component is (0.05-50):

1.

6. The catalyst for olefin polymerization according to claim 5, characterized in that: The molar ratio of aluminum in the co-catalyst to titanium in the solid catalyst component is (20-200):1; The molar ratio of the external electron donor to the titanium in the solid catalyst component is (0.1-10):

1.

7. The catalyst for olefin polymerization according to claim 1, characterized in that The solid catalyst component is prepared by the following steps: The magnesium halide is reacted with an organic epoxy compound, an organic phosphorus compound and an organic alcohol compound to form a uniform reaction solution; and then mixed with a silicon ester compound, a titanium halide or a derivative thereof to obtain the solid catalyst component.

8. The catalyst for olefin polymerization according to claim 7, characterized in that: A magnesium halide, an organic epoxy compound and an organic phosphorus compound are mixed to form a uniform solution at a mixing temperature of 50 to 90°C, wherein an organic alcohol compound is added during or after the uniform solution is formed, followed by reaction to obtain a reaction solution; the reaction solution is mixed with a silicone ester compound, a titanium halide or a derivative thereof at -30 to 0°C; the obtained mixture is slowly heated to 50 to 120°C for reaction, and solid matter is precipitated after the reaction is completed, and the solid catalyst component is obtained by filtration.

9. Use of the olefin polymerization catalyst according to any one of claims 1 to 8 in ethylene homopolymerization or copolymerization.

10. The use according to claim 9, characterized in that: Premixing any two of the solid catalyst component, the co-catalyst and the external electron donor, and then mixing with another component to carry out ethylene homopolymerization or copolymerization; or The solid catalyst component, the co-catalyst and the external electron donor are added simultaneously to carry out ethylene homopolymerization or copolymerization.

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