A catalyst component for the polymerization of olefins, a catalyst and use thereof

Abstract

This invention provides a catalyst component, a catalyst, and its application for olefin polymerization. The catalyst component comprises Mg, Ti, halogen, and a 2,6-dicarboxylate-4-pyranone internal electron donor. The 2,6-dicarboxylate-4-pyranone internal electron donor has the structure shown in Formula I. The catalyst component and the catalyst exhibit high catalytic activity, generally higher than that of commonly used phthalate and diether internal electron donor catalysts in industry. Furthermore, the polymer obtained by catalytic polymerization has regular particle size, high packing density, high isotacticity, and moderate molecular weight distribution.

Description

Technical Field

[0001] This invention relates to a solid catalyst component for olefin polymerization, belonging to the field of polyolefin catalysts. Background Technology

[0002] Currently, Ziegler-Natta catalysts (ZN catalysts) still dominate the production of polyolefins. Most ZN catalyst development focuses on developing highly active and stereoregularly oriented catalysts and improving their copolymerization capabilities. Traditional ZN catalysts (transition metal compounds such as titanium chemically bonded to a magnesium support) offer high catalytic efficiency, produce polymers with good overall performance, and are low-cost. Therefore, the vast majority of catalysts used in polypropylene production worldwide are still based on ZN catalytic systems, characterized by high activity, high stereoregularity, long lifespan, and customizable product structures. The development of ZN catalysts shows that, as early as the advent of the first generation of catalysts, it was discovered that adding a third component (mostly an electron donor, also known as a Lewis base; those added during catalyst preparation are called internal electron donors, while those added during polymerization are called external electron donors) significantly impacts olefin polymerization behavior and polymer properties. Changing the internal electron donor in the catalyst can maximally alter the properties of the catalyst's active center, thereby maximizing the change in catalyst performance. Therefore, the development of novel electron donors has always been a hot topic in ZN polypropylene catalyst research and development.

[0003] The high-performance internal electron donor compounds with distinctive features in the prior art mainly include: (1) fatty acid esters and aromatic esters, mainly phthalate esters; (2) diethers (e.g., compounds disclosed in EP0361493 and EP0728724); (3) succinates (e.g., compounds disclosed in WO9856834, WO0063261 and WO03022894); (4) glycol esters (e.g., compounds disclosed in WO9856834, WO0063261 and WO03022894); and (5) compounds with other functional groups (compounds disclosed in CN1105671, CN1242780 and US20060128558), etc. However, in practical applications, the above-mentioned compounds all have certain problems as internal electron donors for olefin polymerization catalysts. Although catalysts using 1,3-diether compounds as internal electron donors have high activity and good hydrogen-modulated sensitivity, the relative molecular mass distribution of the synthesized PP is narrow, which is not conducive to the development of different grades of PP. Succinate compounds as internal electron donors have the advantage of producing PP with a wider relative molecular mass distribution, but the stereoregularity of PP and the hydrogen-modulated sensitivity of the catalyst need to be improved. The activity of glycol ester catalytic systems is generally not as ideal as that of diether systems.

[0004] Currently, phthalate compounds are the most widely used internal electron donors in polyolefin industry. Catalysts prepared from phthalates exhibit moderate activity, good stereoselectivity, and low cost. However, as commonly used plasticizers, phthalates pose significant risks to human reproductive health and the environment, creating a substantial demand for alternatives. The use of most phthalate compounds has already been restricted. Therefore, developing novel electron donors with excellent activity, good stereoselectivity, superior overall performance, and low cost to replace the widely used phthalate electron donor compounds and applying them to the preparation of highly efficient Ziegler-Natta catalysts has been a common research goal in the field of polyolefin catalysts in recent years. Summary of the Invention

[0005] To address the aforementioned problems, the present invention aims to provide a catalyst component, catalyst, and its application for olefin polymerization. This catalyst component and catalyst exhibit high catalytic activity, generally exceeding that of commonly used phthalate and diether internal electron-donating catalysts in industry. Furthermore, the polymer obtained from the catalytic polymerization has regular particle size, high packing density, high isotacticity, and moderate molecular weight distribution.

[0006] To achieve the above objectives, the present invention provides a catalyst component for olefin polymerization, comprising: Mg, Ti, halogen, and a 2,6-dicarboxylate-4-pyranone internal electron donor; wherein the 2,6-dicarboxylate-4-pyranone internal electron donor has the structure shown in Formula I:

[0007]

[0008] In Equation I, R 1 R 2 R 3 and R 4 Whether the elements are the same or different, they are each independently selected from H, halogens, and C1-C. 20 hydrocarbon group; more preferably, R 1 R 2 R 3 and R 4 Each contains heteroatoms selected from one or more combinations of N, O, S, P, Si, and halogens; more preferably, R 1 R 2 R 3 and R 4 Two or more bonds in a ring are formed.

[0009] According to a specific embodiment of the present invention, preferably, in formula I, R 1 R 2 R 3 and R 4The substituents, whether identical or different, are independently selected from H, halogens, and the following substituents with 20 or fewer carbon atoms: straight-chain or branched alkyl, cycloalkyl, alkenyl, ester, phenyl, alkylphenyl, phenylalkyl, indene, benzyl, haloalkyl, heteroatom-containing alkyl, halocycloalkyl, heteroatom-containing cycloalkyl, halophenyl, heteroatom-containing phenyl, haloalkylphenyl, heteroatom-containing alkylphenyl, halophenylalkyl, heteroatom-containing phenylalkyl, haloindenyl, heteroatom-containing indene, halobenzyl, heteroatom-containing benzyl, heterocyclic aryl substituents; the heteroatoms include one or more combinations of N, O, S, P, and Si.

[0010] According to a specific embodiment of the present invention, preferably, in formula I, R 1 R 2 R 3 and R 4 Each is independently selected from H, halogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, cyclopentyl, n-hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, C 11 -C 20 The following substituents with 20 or fewer carbon atoms, whether linear or branched alkyl groups: alkenyl, phenyl, m-chlorophenyl, p-chlorophenyl, o-chlorophenyl, m-methoxyphenyl, p-methoxyphenyl, o-methoxyphenyl, p-methylphenyl, p-nitrophenyl, m-nitrophenyl, benzyl and its derivatives, phenethyl and its derivatives, furanyl, pyrroleyl, thiophenyl, indene; more preferably, the alkenyl group includes propenyl, butenyl, pentenyl, and hexenyl.

[0011] According to a specific embodiment of the present invention, preferably, R 1 R 2 Each is independently selected from phenyl and its derivatives, with a further preference for halophenyl.

[0012] According to a specific embodiment of the present invention, preferably, the internal electron donor of the 2,6-dicarboxylate-4-pyranone class includes di-n-butyl 2,6-dicarboxylate-4-pyranone, diethyl 2,6-dicarboxylate-4-pyranone, diisobutyl 2,6-dicarboxylate-4-pyranone, dicyclohexyl 2,6-dicarboxylate-4-pyranone, di(tetradecyl) 2,6-dicarboxylate-4-pyranone, diphenyl 2,6-dicarboxylate-4-pyranone, and 2,6- Diphenylethyl dicarboxylate-4-pyranone, di-m-chlorophenyl 2,6-dicarboxylate-4-pyranone, di-p-chlorophenyl 2,6-dicarboxylate-4-pyranone, di-o-chlorophenyl 2,6-dicarboxylate-4-pyranone, di-p-methylphenyl 2,6-dicarboxylate-4-pyranone, di-m-methoxyphenyl 2,6-dicarboxylate-4-pyranone, di-p-methoxyphenyl 2,6-dicarboxylate-4-pyranone, di-o-methoxyphenyl 2,6-dicarboxylate-4-pyranone, 2... 6-Dicarboxylic acid di(α-furanyl ester)-4-pyranone, 2,6-dicarboxylic acid di(5-pentenyl ester)-4-pyranone, 2,6-dicarboxylic acid di-p-nitrobenzene ester-4-pyranone, 2,6-dicarboxylic acid di-n-butyl ester-4-pyranone, 2,6-dicarboxylic acid di-n-butyl ester-3,5-dimethyl-4-pyranone, 2,6-dicarboxylic acid diethyl ester-3-phenyl-4-pyranone, 2,6-dicarboxylic acid diethyl ester-3-chloro-4-pyranone, 2,6-dimethyl One or more of the following: diethyl ester-3-bromo-4-pyranone, diisopropyl 2,6-dicarboxylate-4-pyranone, dibenzyl 2,6-dicarboxylate-4-pyranone, ethyl 2-carboxylate-6-butyl ester-4-pyranone, butyl 2-carboxylate-6-phenyl ester-4-pyranone, dibutyl 2,6-dicarboxylate-3-methyl-4-pyranone, and dibutyl 2,6-dicarboxylate-3-methyl-5-ethyl-4-pyranone.

[0013] The 2,6-dicarboxylate-4-pyranone compound shown in Formula I can be synthesized by methods including, but not limited to, the following:

[0014] The synthetic route is shown in reaction formula I. Oxalic acid is esterified to obtain the corresponding oxalate diester (some oxalate diesters can be purchased directly), and then reacted with acetone or other substituted ketones to obtain the corresponding products.

[0015] Reaction formula I:

[0016]

[0017] Alternatively, the synthesis can be carried out using the synthetic route shown in Reaction II. This route uses inexpensive diethyl oxalate and acetone or other substituted ketones as starting materials, followed by reaction with an alcohol to obtain the substituted 2,6-dicarboxylate-4-pyranone compound. This route requires only two steps to obtain the target product, and many alcohols can be used. 1OH can be used to enrich the product structure; or it can be reacted with a mixture of two alcohols (synthetic route shown in reaction formula III) to obtain a mixture of three substituted 2,6-dicarboxylate-4-pyranones, which can be used directly as internal electron donors without separation. The proportion of each component in the mixture can be adjusted by the ratio of the two alcohols added to the reactants, and the proportion of each component can be determined by analysis methods such as chromatography-mass spectrometry and nuclear magnetic resonance. Alternatively, the product of the first step, 2,6-dicarboxylate-4-pyranone (CAS No.: 99-32-1), can be purchased directly and esterified in one step to obtain 2,6-dicarboxylate-4-pyranone.

[0018] Reaction formula II:

[0019]

[0020] Reaction Formula III:

[0021]

[0022] According to a specific embodiment of the present invention, preferably, the catalyst component comprises a titanium compound, a magnesium compound, and the 2,6-dicarboxylate-4-pyranone internal electron donor; the precursor of the magnesium compound is selected from X. n Mg(OR a ) 2-n MgCl2·mR a OH, R a 2-n MgX n One or more combinations of MgCl2 / SiO2, MgCl2 / Al2O3, magnesium halides, and titanium alkoxides, wherein m is 0.1-6, 0≤n≤2, X is a halogen, and R a For C1-C 20 The hydrocarbon group; the general formula of the titanium compound is TiX. N (OR b ) 4-N In the formula, R b For C1-C 20 The hydrocarbon group, where X is a halogen and N is 1-4.

[0023] According to a specific embodiment of the present invention, preferably, the magnesium compound is an alkoxide of magnesium dihalide; or, the magnesium compound is a liquid magnesium compound (a magnesium compound dissolved in a liquid); or, the magnesium compound is a derivative in which at least one halogen atom in a magnesium dihalide molecule is replaced by an alkyl group or a halogenated alkyl group; more preferably, it is an alkyloxy magnesium compound; and even more preferably, it is alkoxy magnesium and / or aryloxy magnesium.

[0024] According to a specific embodiment of the present invention, preferably, the titanium compound includes one or a combination of two or more of titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, and titanium alkoxyhalides.

[0025] According to a specific embodiment of the present invention, preferably, the alkyl titanium halide includes one or a combination of two or more of methoxy titanium trichloride, ethoxy titanium trichloride, propoxy titanium trichloride, n-butoxy titanium trichloride, dimethoxy titanium dichloride, diethoxy titanium dichloride, dipropoxy titanium dichloride, di-n-butoxy titanium dichloride, trimethoxy titanium chloride, triethoxy titanium chloride, tripropoxy titanium chloride, and tri-n-butoxy titanium chloride.

[0026] According to a specific embodiment of the present invention, preferably, the titanium compound is titanium tetrachloride.

[0027] According to a specific embodiment of the present invention, preferably, the molar ratio of the 2,6-dicarboxylate-4-pyranone internal electron donor to the magnesium compound calculated as magnesium element is 0.01-5.0:1, more preferably 0.05-3.0:1.

[0028] The present invention does not specifically limit the preparation method of the above-mentioned solid catalyst components, which can be carried out according to the following listed methods:

[0029] Method 1: A magnesium alkoxide or magnesium chloroalkoxide, excess TiCl4, and an internal electron donor compound are reacted at a temperature of 80℃-135℃; preferably, a compound of the general formula TiX can be used. N (OR b ) 4-N Titanium compounds (where R) b For C1-C 20 The hydrocarbon group, where X is a halogen and N = 1-4; preferably TiCl4) and the general formula MgCl2·mR a The adduct of OH (where m is a number from 0.1 to 6, preferably 2 to 4, and R) a For C1-C 20 Solid catalyst components are prepared by reacting hydrocarbon groups (or internal electron donors); wherein the general formula is MgCl2·mR a OH adducts can be suitably prepared into spherical form by mixing an alcohol and magnesium chloride in the presence of an inert hydrocarbon immiscible with the adduct, followed by rapid quenching of the emulsion, thereby solidifying the adduct into spherical particles (see disclosures in US4399054 and US4469648). The spherical adducts obtained by this method can react directly with titanium compounds, or they can be pre-treated with a thermally controlled dealcoholization process (80°C–130°C) to obtain a dealcoholization adduct (wherein the molar number of alcohol is generally less than 3, preferably between 0.1 and 2.5), before proceeding with subsequent reactions.

[0030] For example, the adduct or dealcohol adduct is suspended in cold TiCl4 (typically -25°C to 0°C) to react with a titanium compound, and the mixture is heated to 80°C to 130°C and held at this temperature for 0.5 to 2 hours. The treatment with TiCl4 can be performed once or multiple times, and an internal electron donor compound can be added during the TiCl4 treatment. This treatment can be repeated once or multiple times.

[0031] Method 2: A magnesium compound is dissolved in a solvent system consisting of an organic epoxy compound, an organophosphorus compound, and an inert diluent to form a homogeneous solution. This solution is then mixed with a titanium compound, and a solid is precipitated in the presence of a precipitation aid. This solid is treated with an internal electron-donating compound to load the compound onto the solid. If necessary, further treatment with titanium tetrahalide and an inert diluent is performed. The precipitation aid is one of organic anhydrides, organic acids, ethers, or ketones. The components, per mole of magnesium halide, are: organic epoxy compound 0.2-10 mol, organophosphorus compound 0.1-3 mol, precipitation aid 0-1.0 mol, and Ti compound 0.5-150 mol (based on moles of titanium).

[0032] Method 3: React a TiCl4 or hydroxyl-titanium aromatic hydrocarbon solution (e.g., toluene, xylene, etc.) with a dialkoxymagnesium compound such as magnesium (preferably diethoxymagnesium) or diaryloxymagnesium at -25-0°C, and halogenate at 80-130°C. This treatment with the TiCl4 aromatic hydrocarbon solution can be repeated once or multiple times, and an internal electron donor compound can be added once or in batches during multiple such treatments. For example, the preparation method of the titanium-containing solid catalyst component disclosed in US5077357 can be used as follows: Add magnesium ethoxy, tetraethoxytitanium, o-cresol, ethanol, and chlorobenzene sequentially, and stir; quickly add a TiCl4 / chlorobenzene solution to the above liquid, heat until completely dissolved, and continue heating to a specific temperature; use N2 to bubble away the ethanol reactants, continue stirring for a certain period of time, then wash once with hot chlorobenzene, wash twice with isooctane, and then dry with N2 to obtain the support. Alternatively, as in another example: TiCl4, tetraethoxytitanium, ethoxymagnesium and o-cresol are added to chlorobenzene in sequence and stirred; ethanol is added, and after the ethoxymagnesium dissolves at high temperature, stirring is continued for 3 hours; the mixture is filtered while hot, then washed once with warm chlorobenzene, once with isooctane, and finally dried with N2.

[0033] Method 4: Magnesium dichloride is pre-activated using existing methods, and then treated with excess TiCl4 at approximately 80°C-135°C, wherein the solution contains an internal electron-donating compound. The solid is treated with TiCl4 multiple times and washed with hexane to remove any unreacted TiCl4.

[0034] Method 5: Prepare the titanium-containing solid catalyst component according to the preparation method disclosed in CN1208045: First, contact the liquid magnesium compound and the liquid titanium compound at low temperature in the presence of a compound selected from alcohols, phenols, ketones, aldehydes, ethers, amines, pyridines and esters to precipitate a solid. The contact temperature is generally -70°C to 200°C, preferably -30°C to 130°C. During the contact process, treat with an internal electron donor compound.

[0035] Method Six: Anhydrous magnesium chloride and an internal electron donor compound are co-milled under conditions where magnesium dichloride is activated. The resulting product can be treated once or multiple times with excess TiCl4 at a temperature of 80°C-130°C, followed by washing with a hydrocarbon solvent until chloride ions are removed. A more detailed method is as follows: The product obtained by co-milling anhydrous magnesium dichloride, a titanium compound, and an internal electron donor compound is treated with a haloalkane such as 1,2-dichloroethane, chlorobenzene, or dichloromethane. This treatment is carried out at a temperature between 40°C and the boiling point of the haloalkane for 1-4 hours, followed by washing with an inert hydrocarbon solvent such as hexane.

[0036] Method 7: Magnesium compounds supported on inorganic oxides such as SiO2, alumina, or porous silica gel are used as supports for preparation. The mixture is then activated using well-known methods and treated with an excess of TiCl4 at a temperature of approximately 80℃-135℃. During the treatment process, an internal electron donor compound is added.

[0037] The reaction of the above-mentioned catalyst components leads to the formation of magnesium halides in an active form. Typical crystalline magnesium halides have a regular structure and can support very little Ti, resulting in low catalytic activity. To prepare highly active supported catalysts, magnesium halides must undergo activation treatment. Activation methods include using physical and / or chemical methods to prepare them into microcrystals so that active centers are supported on the surface, edges, and defects of the magnesium halide. These treated magnesium halide microcrystals suitable for supporting Ti are called "activated magnesium halides." Besides these reactions, other methods are known in the literature to form magnesium halides in an active form from starting materials different from magnesium halides.

[0038] In any method for preparing the catalyst component, the aforementioned internal electron donor compound can be added directly or optionally, for example, in situ prepared using a suitable precursor that can be converted in the desired internal electron donor compound via known chemical reactions such as esterification or transesterification. Typically, the aforementioned internal electron donor compound is used at a molar ratio of 0.01-5:1, preferably 0.05-3.0:1, relative to the molar number of MgCl2. Furthermore, the internal electron donor compound can be added simultaneously or separately during the preparation process, either in batches or in any order and combination.

[0039] The present invention also provides a catalyst for olefin polymerization, the composition of which includes the above-described catalyst components and an organoaluminum compound.

[0040] According to a specific embodiment of the present invention, preferably, the organoaluminum compound has the general formula AlR c p X (3-p) , where R c It is hydrogen or C1-C 20 The hydrocarbon group, X is a halogen, and p is an integer 0 ≤ p ≤ 3.

[0041] According to a specific embodiment of the present invention, preferably, the organoaluminum compound includes one or more of the following: trialkylaluminum compound, alkylaluminum halide, alkylaluminum hydride, alkylaluminum sesquichloride, and alkylaluminoxane.

[0042] According to a specific embodiment of the present invention, preferably, the trialkylaluminum compound includes one or more of trimethylaluminum, triethylaluminum, triisobutylaluminum, tri-n-butylaluminum, tri-n-hexylaluminum, and trioctylaluminum; the alkylaluminum halide includes AlEt2Cl; and the alkylaluminum sesquichloride includes Al2Et3Cl3.

[0043] According to a specific embodiment of the present invention, preferably, the molar ratio of the organoaluminum compound to the titanium atoms in the catalyst component is 1-1000:1, more preferably 50-800:1.

[0044] According to a specific embodiment of the present invention, preferably, the raw material composition of the catalyst further includes an external electron donor.

[0045] According to a specific embodiment of the present invention, preferably, the external electron donor is a siloxane compound.

[0046] According to a specific embodiment of the present invention, preferably, the general formula of the siloxane compound is R'. t Si(OR”) 4-t In this context, R' and R” are each independently selected from C1-C18 The hydrocarbon group, where t is an integer of 0 ≤ t ≤ 3; more preferably, R' and R” respectively contain heteroatoms; more preferably, the heteroatoms include one or more combinations of N, O, S, P, and Si.

[0047] According to a specific embodiment of the present invention, preferably, the siloxane compound includes trimethylmethoxysilane, trimethylethoxysilane, tri-n-propylmethoxysilane, tri-n-propylethoxysilane, tri-n-butylmethoxysilane, triisobutylethoxysilane, tricyclohexylmethoxysilane, tricyclohexylethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, di-n-propyldimethoxysilane, diisopropyldimethoxysilane, di-n-propyldiethoxysilane, diisopropyldiethoxysilane, di-n-butyldiethoxysilane, diisobutyldiethoxysilane, di-tert-butyldimethoxysilane, di-tert-butyldimethoxysilane, di-n-butyldimethoxysilane, diisobutyldimethoxysilane, diisobutyldimethoxysilane, di-tert- ... Silane, di-tert-butyldiethoxysilane, di-n-butyldiethoxysilane, n-butylmethyldimethoxysilane, di(2-ethylhexyl)dimethoxysilane, di(2-ethylhexyl)diethoxysilane, dicyclohexyldimethoxysilane, dicyclohexyldiethoxysilane, dicyclohexyldimethoxysilane, dicyclopentyldimethoxysilane, dicyclopentyldiethoxysilane, cyclohexylmethyldimethoxysilane, cyclohexylmethyldiethoxysilane, cyclohexylethyldimethoxysilane, cyclohexylisopropyldimethoxysilane, cyclohexylethyldiethoxysilane, cyclopentylmethyldimethoxysilane, cyclopentylethyldiethoxysilane, cyclopentylisopropyldiethoxysilane, cyclopentylisobutyldimethoxysilane, cyclohexyl-n-propyl Dimethoxysilane, cyclohexyl-n-propyldiethoxysilane, cyclohexyl-n-butyldiethoxysilane, pentylmethyldimethoxysilane, pentylmethyldiethoxysilane, pentylethyldimethoxysilane, pentylethyldiethoxysilane, cyclohexyldimethylmethoxysilane, cyclohexyldiethylmethoxysilane, cyclohexyldiethylmethoxysilane, cyclohexyldiethylethoxysilane, 2-ethylhexyltrimethoxysilane, cyclohexyldimethoxysilane, cyclohexyldiethoxysilane, 2-ethylhexyltriethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, n-propyltrimethoxysilane, n-propyltriethoxysilane, isopropyltrimethoxysilane, isopropyltriethoxysilane, n-butyl 2-Ethylhexyltrimethoxysilane, isobutyltrimethoxysilane, tert-butyltrimethoxysilane, n-butyltriethoxysilane, cyclohexyltrimethoxysilane, cyclohexyltriethoxysilane, cyclopentyltrimethoxysilane, cyclopentyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, 2-ethylhexyltrimethoxysilane, 2-ethylhexyltriethoxysilane, pentyltrimethoxysilane, pentyltriethoxysilane, tetramethoxysilane, tetraethoxysilane, cyclohexylcyclopentyldimethoxysilane, cyclohexylcyclopentyldiethoxysilane, cyclohexylcyclopentyldipropoxysilane, 3-methylcyclohexylcyclopentyldimethoxysilane, 4-methylcyclohexylcyclopentyldimethoxysilane, 3,One or more combinations of 5-dimethylcyclohexylcyclopentyldimethoxysilane, 3-methylcyclohexylcyclohexyldimethoxysilane, di(3-methylcyclohexyl)dimethoxysilane, 4-methylcyclohexylcyclohexyldimethoxysilane, di(4-methylcyclohexyl)dimethoxysilane, 3,5-dimethylcyclohexylcyclohexyldimethoxysilane, di(3,5-dimethylcyclohexyl)dimethoxysilane, tetrapropoxysilane, and tetrabutoxysilane.

[0048] According to a specific embodiment of the present invention, preferably, the siloxane compound includes di-n-propyl dimethoxysilane, diisopropyl dimethoxysilane, di-n-butyl dimethoxysilane, diisobutyl dimethoxysilane, di-tert-butyl dimethoxysilane, di-n-butyl diethoxysilane, tert-butyl trimethoxysilane, dicyclohexyl dimethoxysilane, dicyclohexyl diethoxysilane, cyclohexylmethyl dimethoxysilane, and cyclohexylethyl diethoxysilane. One or more combinations of cyclohexylethyldimethoxysilane, cyclohexylethyldiethoxysilane, cyclopentylmethyldimethoxysilane, cyclopentylmethyldiethoxysilane, cyclopentylethyldimethoxysilane, cyclohexylcyclopentyldimethoxysilane, cyclohexylcyclopentyldiethoxysilane, 3-methylcyclohexylcyclopentyldimethoxysilane, 4-methylcyclohexylcyclopentyldimethoxysilane, and 3,5-dimethylcyclopentyldimethoxysilane.

[0049] According to a specific embodiment of the present invention, preferably, the siloxane compound includes one or more combinations of cyclohexylmethyldimethoxysilane, diisopropyldimethoxysilane, di-n-butyldimethoxysilane, diisobutyldimethoxysilane, diphenyldimethoxysilane, phenyltriethoxysilane, 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.

[0050] According to a specific embodiment of the present invention, preferably, the molar ratio of silicon in the external electron donor to titanium in the catalyst component is 0.002-100:1, more preferably 0.01-20:1, and even more preferably 0.01-5:1.

[0051] The present invention also provides the application of the above-mentioned catalyst in olefin polymerization.

[0052] According to a specific embodiment of the present invention, preferably, the olefin comprises straight-chain or branched olefins, such as ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 3-methyl-1-butene, 4-methyl-1-pentene, butadiene, vinylcyclopentene, and vinylcyclohexene, or a combination of two or more of these.

[0053] According to a specific embodiment of the present invention, preferably, the polymerization includes ethylene and / or propylene polymerization.

[0054] According to a specific embodiment of the present invention, preferably, the polymerization includes homopolymerization or copolymerization.

[0055] According to a specific embodiment of the present invention, preferably, the order of adding the components in the catalyst during the catalytic process is arbitrary, with the organoaluminum compound being added to the polymerization system first, followed by the external electron donor, and finally the catalyst components.

[0056] According to a specific embodiment of the present invention, preferably, in the above applications, the polymerization process can be carried out with or without a solvent; the olefin monomer can be in the gas phase or liquid phase; more preferably, hydrogen can be further added as a molecular weight regulator (polymerization can also be carried out without a molecular weight regulator); continuous polymerization or batch polymerization processes can be applied, and the polymerization reaction can be carried out in one step, two steps or multiple steps.

[0057] According to a specific embodiment of the present invention, preferably, the polymerization temperature is ≤200℃, more preferably 20-100℃, and even more preferably 40-80℃; the polymerization pressure is ≤10MPa, more preferably 0.3-5MPa.

[0058] The present invention has the following beneficial effects:

[0059] This invention provides a catalyst component using 2,6-dicarboxylate-4-pyranone as an internal electron donor. The internal electron donor compound in this catalyst component contains various oxygen-containing functional groups such as ketones, ethers, and esters in its six-membered ring structure, making it easier for internal electron donors with single or double oxygen functional groups to coordinate to the active site of the catalyst. Furthermore, the skeletal stereochemistry of its structure and the steric hindrance of different substituents facilitate the participation of functional groups in the formation of the active site. Catalysts prepared from internal electron donor compounds of the same series with different substituents generally exhibit higher activity than phthalate-based internal electron donor catalysts, and higher activity than diether-based catalysts, with good stereoselectivity, high isotacticity of the resulting polymers, and moderate molecular weight distribution. Polyolefin catalysts prepared using this type of internal electron donor can avoid the use of phthalate-based internal electron donors, which have reproductive and environmental toxicity, and have broader industrial application prospects in countries and regions that restrict the use of phthalate plasticizers. Detailed Implementation

[0060] In order to provide a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention will now be described in detail below, but it should not be construed as limiting the scope of implementation of the present invention.

[0061] In the following examples, the preparation of the catalyst was carried out under the protection of high-purity nitrogen.

[0062] The isotacticity of polymers was determined by the heptane extraction method (boiling heptane extraction for 6 hours): two grams of dry polymer sample were placed in an extractor and extracted with boiling heptane for 6 hours. The residue was then dried to constant weight. The ratio of the obtained polymer weight (g) to 2 is the isotacticity.

[0063] The bulk density of the polymer was determined using the method specified in JB / T 2412-2008.

[0064] The molecular weight distribution of the polymer was determined by PL-220 gel permeation chromatography at 150 °C with trichlorobenzene as solvent (standard: polystyrene, flow rate 1.0 mL / min, column: 3xPlgel 10um M1Xed-B 300x7.5nm).

[0065] Preparation example: Synthesis of 2,6-dicarboxylate-4-pyranone compounds represented by Formula I

[0066] The synthesis of 1,2,6-dibutyl ester-4-pyranone is carried out through the following steps:

[0067] (1) Dissolve sodium (11.8 g, 0.5 mol, 2.04 eq.) in anhydrous ethanol (180 mL) to obtain a solution for later use; within 15 minutes, add anhydrous acetone (14.5 g, 19 mL, 0.25 mol, 1 eq.) and diethyl oxalate (77.5 g, 72 mL, 0.53 mol, 2.12 eq.) to the aforementioned solution to form a yellow precipitate; keep the reaction mixture at 60 °C for one hour, then add HCl (aq. 37%, 100 mL) and water (50 mL). The solution was stirred at 50°C for 20 hours, then water and ethanol (approximately 230 mL) were removed under reduced pressure. Water (150 mL) and HCl (aq. 37%, 25 mL) were then added to the mixture and stirred until silica gel TLC (elution buffer: 3 / 7 (v / v), 10% NaCl aqueous solution / ethanol) showed only one spot. After cooling to room temperature, the crystals were filtered off, washed with water, and then washed with cold acetone. The crude product was recrystallized to give a white powder of 4-pyranone-2,6-dicarboxylic acid (35.0 g, yield: 76%).

[0068] (2) In a 1L three-necked flask, add 4-pyranone-2,6-dicarboxylic acid (5.5g), n-butanol (100mL), and concentrated sulfuric acid (0.6mL), heat under reflux for 2 hours, and cool to room temperature; pour the reaction solution into a saturated sodium bicarbonate solution, extract twice with ethyl acetate (100mL×2), combine the organic phases, wash with saturated brine (100mL×2), concentrate and recrystallize to obtain the product 2,6-dicarboxylic acid di-n-butyl ester-4-pyranone (a1, 7.1g, yield 79%). 1 ¹H NMR (500MHz, Chloroform-d) δ / ppm: 6.81 (s, 2H), 4.14 (t, J = 8.7Hz, 4H), 1.77 (p, J = 8.9Hz, 4H), 1.52–1.41 (m, 4H), 0.97 (t, J = 5.6Hz, 6H). Detailed structural information is shown in Table 1.

[0069] 2. Other 2,6-dicarboxylate-4-pyranone compounds (a2-a25) were synthesized using the route described above (other existing synthetic routes may also be used). The starting material was selected from oxalic acid or diethyl oxalate, which underwent an addition reaction with acetone or other ketones, followed by esterification with one or two alcohols to obtain the corresponding 2,6-dicarboxylate-4-pyranone products. When reacting with two alcohols, a mixture of three products was obtained, which could be used directly as an internal electron donor composition without separation. The structures and NMR results of the other 2,6-dicarboxylate-4-pyranone compounds (a2-a25) are shown in Table 1.

[0070]

[0071] Table 1 shows the 2,6-dicarboxylate-4-pyranone compounds of Formula I.

[0072]

[0073]

[0074]

[0075]

[0076] Preparation of catalyst components

[0077] Example 1

[0078] This embodiment provides a catalyst component, the preparation method of which is as follows:

[0079] In a 500 mL stirred flask fully purged with nitrogen, 10 g of MgCl2·2.5C2H5OH microspheres and 150 mL of titanium tetrachloride were added to prepare a suspension. The suspension was then maintained at -15 °C for 1 hour, and slowly heated to 80 °C. 3 g (10 mmol) of di-n-butyl 2,6-dicarboxylate-4-pyranone was added, and the temperature was further increased to 110 °C and held for 1 hour. The liquid was then filtered clean. The resulting solid was washed three times with 120 mL of titanium tetrachloride at 110 °C, and then washed four times with 150 mL of hexane at 60 °C. The liquid was filtered off and dried to obtain solid catalyst component E1. The titanium content, internal electron donor content, and polymerization data of this solid catalyst component are shown in Table 2.

[0080] Example 2-25

[0081] Examples 2-25 each provide a catalyst component E2-E25, the preparation process of which is as shown in Example 1, except that 2,6-dibutyl 2,6-dicarboxylate-4-pyranone is replaced with 10 mmol of compounds a2-a25 in Table 1 in sequence.

[0082] Example 26

[0083] This embodiment provides a catalyst component, the preparation method of which is as follows:

[0084] In a 500 mL stirred flask equipped with a stirrer and fully purged with nitrogen, 10 g of anhydrous magnesium chloride, 150 mL of toluene, 17 mL of epichlorohydrin, and 16 mL of tributyl phosphate were added at room temperature. The mixture was heated to 50 °C with stirring and maintained for 2 hours until the solid was completely dissolved. Then, 2.40 g of phthalic anhydride was added, and the mixture was maintained for another hour. The solution was cooled to -25 °C, and 110 mL of titanium tetrachloride was added dropwise over 1 hour. The temperature was slowly raised to 80 °C, and the solid was gradually washed away during the heating process. 3 g of di-n-butyl 2,6-dicarboxylate-4-pyranone was added, and the mixture was maintained at 80 °C for 1 hour. After filtration, the solution was washed twice with 200 mL of toluene. Then, 120 mL of toluene and 80 mL of titanium tetrachloride were added, and the temperature was further raised to 110 °C and maintained for 2 hours. The liquid was then filtered clean, and the process was repeated once more. The liquid was filtered off, and the resulting solid was washed once with 100 mL of dichloroethane and four times with hexane. After drying, solid catalyst component E26 was obtained. The titanium content, internal electron donor content, and polymerization data of this solid catalyst component are shown in Table 2.

[0085] Example 27

[0086] This embodiment provides a catalyst component, the preparation method of which is as follows:

[0087] In a 500 mL stirred flask equipped with a stirrer and fully purged with nitrogen, 8 g of magnesium diethoxy and 100 mL of toluene were added to prepare a suspension. 25 mL of titanium tetrachloride was added dropwise at -15 °C. After the addition was complete, the temperature was slowly raised to 0 °C, and then 50 mL of titanium tetrachloride was added dropwise. The temperature was then slowly raised to 80 °C, and 2.5 g of di-n-butyl 2,6-dicarboxylate-4-pyranone was added. The temperature was further raised to 110 °C and held constant for 2 hours. The liquid was then filtered off. The resulting solid was washed three times with 100 mL of titanium tetrachloride at 125 °C. The solid was then washed four times with 120 mL of hexane at 60 °C. The liquid was filtered off and the solid was dried to obtain solid catalyst component E27.

[0088] Comparative Example 1

[0089] This comparative example provides a catalyst component D1, which is prepared in the same manner as in Example 1, except that 2,6-dibutyl 4-dimethyl phthalate is replaced with 10 mmol of dibutyl phthalate (DN).

[0090] Comparative Example 2

[0091] This comparative example provides a catalyst component D2, which is prepared in the same way as in Example 1, except that 2,6-dibutyl 2,6-dicarboxylate-4-pyranone is replaced with 10 mmol of 9,9-dimethoxyfluorene (FLU).

[0092] polymerization

[0093] The solid catalyst components obtained above were used as components for olefin polymerization catalysts for polymerization evaluation:

[0094] After the 5L stainless steel reactor was fully purged with nitrogen, 5 mL of a 0.5 mol / L triethylaluminum hexane solution, 1 mL of a 0.1 mol / L methylcyclohexyldimethoxysilane hexane solution, and 10 mg of the prepared catalyst were added. Then, 10 mL of hexane was added to flush the feed line, followed by 2 L (under standard conditions) of hydrogen and 2.5 L of purified propylene. The reaction was prepolymerized at 25°C for 5 minutes, then the temperature was raised to 70°C, and polymerization was carried out at this temperature for 1 hour. After the reaction was completed, the reactor was cooled and stirring was stopped. The reaction product was discharged and dried to obtain the polymer. Polymerization data are shown in Table 2.

[0095] Table 2

[0096]

[0097]

[0098] As shown in Table 2, the catalysts containing internal electron donors of 2,6-dicarboxylate-4-pyranone compounds with different substituents in Examples 1-25, under the same preparation conditions, exhibited higher activity than the phthalate-based internal electron donor catalyst of Comparative Example 1, and higher activity than the diether catalyst of Comparative Example 2. Furthermore, they demonstrated good stereoselectivity, high isotacticity of the resulting polymers, and moderate molecular weight distribution. The catalysts also exhibited regular particle size and high packing density. Examples 26 and 27, using different preparation methods with 2,6-dicarboxylate-4-pyranone catalysts, also displayed excellent performance with high activity and high stereoselectivity.

Claims

1. A catalyst component for olefin polymerization, comprising: Mg, Ti, halogens, and 2,6-dicarboxylate-4-pyranone internal electron donors; in, The 2,6-dicarboxylate-4-pyranone internal electron donor has the structure shown in Formula I: Formula I, In Equation I, R 1 R 2 Whether the two are the same or different, they are each independently selected from C1-C. 20 The hydrocarbon group, or the C1-C group containing one or more heteroatoms selected from N, O and halogens. 20 hydrocarbon group; R 3 and R 4 Whether the elements are the same or different, they are each independently selected from H, halogens, and C1-C. 20 The hydrocarbon group, or the C1-C group containing one or more heteroatoms selected from N, O and halogens. 20 hydrocarbon group; Optional, R 1 R 2 R 3 and R 4 Two or more bonds in a ring are formed.

2. The catalyst component according to claim 1, wherein, In Equation I, R 1 R 2 R 3 and R 4 Whether identical or different, each is independently selected from straight-chain or branched alkyl, cycloalkyl, alkenyl, ester, phenyl, alkylphenyl, phenylalkyl, indole, or each is independently selected from alkyl, cycloalkyl, phenyl, alkylphenyl, phenylalkyl, indole, or each contains heteroatoms selected from one or more combinations of N, O and halogens within 20 carbon atoms.

3. The catalyst component according to claim 2, wherein, In Equation I, R 1 R 2 R 3 and R 4 Each is independently selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, cyclopentyl, n-hexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, C 11 -C 20 Straight-chain or branched alkyl groups, and the following substituents with 20 or fewer carbon atoms: alkenyl, phenyl, m-chlorophenyl, p-chlorophenyl, o-chlorophenyl, m-methoxyphenyl, p-methoxyphenyl, o-methoxyphenyl, p-methylphenyl, p-nitrophenyl, m-nitrophenyl, benzyl, phenethyl, furanyl, pyrroleyl, indene.

4. The catalyst component according to claim 3, wherein, R 1 R 2 Each is independently selected from halophenyl groups.

5. The catalyst component according to claim 1, wherein, The internal electron donors of the 2,6-dicarboxylate-4-pyranone class include di-n-butyl 2,6-dicarboxylate-4-pyranone, diethyl 2,6-dicarboxylate-4-pyranone, diisobutyl 2,6-dicarboxylate-4-pyranone, dicyclohexyl 2,6-dicarboxylate-4-pyranone, di(tetradecyl) 2,6-dicarboxylate-4-pyranone, diphenyl 2,6-dicarboxylate-4-pyranone, and diphenyl 2,6-dicarboxylate-4-pyranone. 4-Pyranone, di-m-chlorophenyl 2,6-dicarboxylate-4-pyranone, di-p-chlorophenyl 2,6-dicarboxylate-4-pyranone, di-o-chlorophenyl 2,6-dicarboxylate-4-pyranone, di-p-methylphenyl 2,6-dicarboxylate-4-pyranone, di-m-methoxyphenyl 2,6-dicarboxylate-4-pyranone, di-p-methoxyphenyl 2,6-dicarboxylate-4-pyranone, di-o-methoxyphenyl 2,6-dicarboxylate-4-pyranone, 2, 6-Dicarboxylic acid di(α-furanyl ester)-4-pyranone, 2,6-dicarboxylic acid di(5-pentenyl ester)-4-pyranone, 2,6-dicarboxylic acid di-p-nitrobenzene ester-4-pyranone, 2,6-dicarboxylic acid di-n-butyl ester-3,5-dimethyl-4-pyranone, 2,6-dicarboxylic acid diethyl ester-3-phenyl-4-pyranone, 2,6-dicarboxylic acid diethyl ester-3-chloro-4-pyranone, 2,6-dicarboxylic acid diethyl ester-3-bromo- One or more of the following: 4-pyranone, diisopropyl 2,6-dicarboxylate-4-pyranone, dibenzyl 2,6-dicarboxylate-4-pyranone, ethyl 2-carboxylate-6-butyl 4-pyranone, butyl 2-carboxylate-6-phenyl 4-pyranone, dibutyl 2,6-dicarboxylate-3-methyl-4-pyranone, and dibutyl 2,6-dicarboxylate-3-methyl-5-ethyl-4-pyranone.

6. The catalyst component according to any one of claims 1-5, wherein, The catalyst component comprises titanium compounds, magnesium compounds, and the 2,6-dicarboxylate-4-pyranone internal electron donor; The precursor of the magnesium compound is selected from X. n Mg(OR a ) 2-n MgCl2·mR a OH, R a 2-n MgX n One or more combinations of MgCl2 / SiO2, MgCl2 / Al2O3, magnesium halides, and titanium alkoxides, wherein m is 0.1-6, 0≤n≤2, X is a halogen, and R a For C1-C 20 hydrocarbon group; The general formula of the titanium compound is TiX. N (OR b ) 4-N In the formula, R b For C1-C 20 The hydrocarbon group, where X is a halogen and N is 1-4.

7. The catalyst component according to claim 6, wherein, The magnesium compound is an alkoxide of magnesium dihalide; Alternatively, the magnesium compound may be a liquid magnesium compound; Alternatively, the magnesium compound is a derivative in which at least one halogen atom in a magnesium dihalide molecule is replaced by an alkyl or haloalkyl group.

8. The catalyst component according to claim 7, wherein, The magnesium compound is an alkyl oxymagnesium compound.

9. The catalyst component according to claim 8, wherein, The magnesium compound is alkoxymagnesium and / or aryloxymagnesium.

10. The catalyst component according to claim 6, wherein, The titanium compound includes one or more of titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, and titanium alkoxyhalides.

11. The catalyst component according to claim 10, wherein, The alkoxy titanium halide includes one or more combinations of methoxy titanium trichloride, ethoxy titanium trichloride, propoxy titanium trichloride, n-butoxy titanium trichloride, dimethoxy titanium dichloride, diethoxy titanium dichloride, dipropoxy titanium dichloride, di-n-butoxy titanium dichloride, trimethoxy titanium chloride, triethoxy titanium chloride, tripropoxy titanium chloride, and tri-n-butoxy titanium chloride.

12. The catalyst component according to claim 10, wherein, The titanium compound is titanium tetrachloride.

13. The catalyst component according to claim 6, wherein, The molar ratio of the 2,6-dicarboxylate-4-pyranone internal electron donor to the magnesium compound is 0.01-5.0:1, and the magnesium compound is calculated based on magnesium element.

14. The catalyst component according to claim 13, wherein, The molar ratio of the 2,6-dicarboxylate-4-pyranone internal electron donor to the magnesium compound is 0.05-3.0:

1.

15. A catalyst for olefin polymerization, comprising the catalyst component as described in any one of claims 1-14 and an organoaluminum compound.

16. The catalyst according to claim 15, wherein, The general formula of the organoaluminum compound is AlR c p X (3-p) , where R c It is hydrogen or C1-C 20 The hydrocarbon group, X is a halogen, and p is an integer 0 ≤ p ≤ 3.

17. The catalyst according to claim 16, wherein, The organoaluminum compounds include one or more of the following: trialkylaluminum compounds, alkylaluminum halides, and alkylaluminum sesquichlorides.

18. The catalyst according to claim 17, wherein, The trialkylaluminum compound includes one or more of trimethylaluminum, triethylaluminum, triisobutylaluminum, tri-n-butylaluminum, tri-n-hexylaluminum, and trioctylaluminum; the alkylaluminum halide includes AlEt2Cl; and the alkylaluminum sesquichloride includes Al2Et3Cl3.

19. The catalyst according to claim 15, wherein, The molar ratio of the organoaluminum compound to the titanium atoms in the catalyst component is 1-1000:

1.

20. The catalyst according to claim 19, wherein, The molar ratio of the organoaluminum compound to the titanium atoms in the catalyst component is 50-800:

1.

21. The catalyst according to claim 15, wherein, The catalyst's feedstock composition also includes an external electron donor.

22. The catalyst according to claim 21, wherein, The external electron donor is a siloxane compound.

23. The catalyst according to claim 22, wherein, The general formula of the siloxane compound is R' t Si(OR'') 4-t Where R' and R'' are each independently selected from C1-C 18 The hydrocarbon group, where t is an integer 0 ≤ t ≤ 3.

24. The catalyst according to claim 21, wherein, The molar ratio of silicon in the external electron donor to titanium in the catalyst component is 0.002-100:

1.

25. The catalyst according to claim 24, wherein, The molar ratio of silicon in the external electron donor to titanium in the catalyst component is 0.01-20:

1.

26. The catalyst according to claim 25, wherein, The molar ratio of silicon in the external electron donor to titanium in the catalyst component is 0.01-5:

1.

27. The use of the catalyst according to any one of claims 15-26 in olefin polymerization.

28. The application according to claim 27, wherein, The olefins include one or more of ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, 3-methyl-1-butene, 4-methyl-1-pentene, butadiene, vinylcyclopentene, and vinylcyclohexene.

29. The application according to claim 28, wherein, The polymerization includes the polymerization of ethylene and / or propylene.

30. The application according to claim 27, wherein, The polymerization includes homopolymerization or copolymerization.

31. The application according to claim 27, wherein, The polymerization temperature is ≤200℃ and the polymerization pressure is ≤10MPa.

32. The application according to claim 31, wherein, The polymerization temperature is 20-100℃; the polymerization pressure is 0.3-5MPa.

33. The application according to claim 32, wherein, The polymerization temperature is 40-80℃.

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