2,3-Dihalogen-substituted maleate-type internal electron donor and its preparation method and application

Abstract

The present invention discloses a 2,3-dihalogen-substituted maleate-type internal electron donor, its preparation method, and application. The internal electron donor has the structural formula shown in Formula I below. Using the 2,3-dihalogen-substituted maleate provided by the present invention as an internal electron donor, an ultrahighly active polypropylene catalyst (activity >36 kgPP / (g.Cat.h)) can be obtained. Compared with 2,3-dialkyl-substituted maleates or 2,3-diaryl-substituted maleates, the catalyst performance is superior. #imgabs0#

Description

Technical Field

[0001] The present invention relates to the design, synthesis and application of an internal electron donor in a polypropylene catalyst, and in particular to a 2,3-disubstituted maleate type internal electron donor and a preparation method and application thereof. Background Art

[0002] Phthalic acid diesters are the primary internal electron donors used in Ziegler-Natta (ZN) catalysts for propylene polymerization. While their use as internal electron donors is beneficial for obtaining highly active and isotactic polypropylene, the residual phthalic acid diesters in the resulting polypropylene, which cannot be removed, can still cause harm to the human body. Currently, the use of these compounds is restricted in the EU, and it is foreseeable that their use in China will also be restricted in the near future. Therefore, the development of clean internal electron donors specifically for ZN catalysts for propylene polymerization is imperative.

[0003] Maleic acid and its derivatives are widely used in pharmaceutical synthesis. For example, N,N-dimethyl-γ-(4-chlorophenyl)-2-pyridinylpropylamine maleate, commonly known as "chlorpheniramine," is a common anti-allergic drug; (±)-3,4,5-trimethoxybenzoic acid (2-dimethylamino-2-phenyl)butyl ester maleate, commonly known as "trimebutine maleate tablets," is a common gastrointestinal motility inhibitor; and (E)-5-methoxy-4'-trifluoromethylvaleriophenone-oxy-(2-aminoacetyl oxime) maleate, also known as "fluvoxamine maleate," is a drug used to treat depression and obsessive-compulsive disorder. These facts demonstrate that maleic acid and its derivatives have a relatively good safety profile, with no studies reporting harm to humans.

[0004] Chinese patent CN201210480335.9 discloses a technology for preparing a high-activity, highly isotactic polypropylene catalyst using a maleic acid diester as an internal electron donor.

[0005]

[0006] When this patent uses 2,3-dialkyl-substituted maleic acid diester as the internal electron donor, the catalyst activity can reach a maximum of 28.3 kg PP / (g.Cat.h), and the isotacticity of polypropylene can reach 98.7%.

[0007] However, this patent still has two shortcomings: (1) the synthesis technology of 2,3-dialkyl-substituted maleic acid diester is difficult and costly; (2) the activity of the catalyst is low and cannot meet the new requirements for low ash content of polypropylene in the context of the new era. Summary of the Invention

[0008] In view of this, the present invention provides a 2,3-dihalogen-substituted maleate-type internal electron donor and its preparation method and application. Specifically, the present invention provides the following technical solutions:

[0009] A 2,3-dihalogen-substituted maleate-type internal electron donor having the structural formula shown in Formula I below:

[0010]

[0011] Among them, X 1 and X 2 are the same or different and are independently selected from one of fluorine, chlorine, bromine and iodine; R 1 and R 2 The same or different, independently selected from C 1-12 alkyl.

[0012] According to the present invention, the R 1 and R 2 The same or different, independently selected from C 1-6 Alkyl, more preferably C 3-5 alkyl.

[0013] According to the present invention, the internal electron donor is selected from the group consisting of dipropyl 2,3-difluoromaleate, di-n-butyl 2,3-difluoromaleate, diisobutyl 2,3-difluoromaleate, di-n-pentyl 2,3-difluoromaleate, diisopentyl 2,3-difluoromaleate, dipropyl 2,3-dichloromaleate, di-n-butyl 2,3-dichloromaleate, diisobutyl 2,3-dichloromaleate, di-n-pentyl 2,3-dichloromaleate, diisopentyl 2,3-dichloromaleate, dipropyl 2,3-dibromomaleate, di-n-butyl 2,3-dibromomaleate, diisobutyl 2,3-dibromomaleate, di-n-pentyl 2,3-dibromomaleate, diisopentyl 2,3-diiodomaleate, dipropyl 2,3-dibromomaleate, Di-n-butyl 2,3-diiodomaleate, diisobutyl 2,3-diiodomaleate, di-n-pentyl 2,3-diiodomaleate, diisopentyl 2,3-diiodomaleate, di-n-butyl 2-fluoro-3-chloromaleate, di-n-butyl 2-fluoro-3-bromomaleate, di-n-butyl 2-fluoro-3-iodomaleate, di-n-butyl 2-chloro-3-bromomaleate, di-n-butyl 2-chloro-3-iodomaleate, di-n-butyl 2-bromo-3-iodomaleate, di-n-butyl 2-bromo-3-iodomaleate, di-n-butyl 2-fluoro-3-chloromaleate, diisobutyl 2-fluoro-3-bromomaleate, diisobutyl 2-fluoro-3-iodomaleate, diisobutyl 2-chloro-3-bromomaleate, diisobutyl 2-chloro-3-iodomaleate, or diisobutyl 2-bromo-3-iodomaleate.

[0014] Specifically, the internal electron donor is selected from one of the compounds represented by the following formulas I-1 to I-5:

[0015]

[0016] The present invention also provides a method for synthesizing the above-mentioned 2,3-dihalogen-substituted maleate-type internal electron donor, the method comprising:

[0017] 1) mixing maleic anhydride and a halogenating agent to carry out a halogenation reaction to prepare an intermediate product;

[0018] 2) reacting the intermediate product of step 1) with an alcohol compound in the presence of a catalyst to prepare a 2,3-dihalogen-substituted maleate-type internal electron donor as shown in formula I.

[0019] According to the present invention, the reaction formula of step 1) is as follows:

[0020]

[0021] According to the present invention, the reaction formula of step 2) is as follows:

[0022]

[0023] According to the present invention, in step 1), the halogenating agent is selected from one or more of hydrofluoric acid, thionyl chloride, bromine, and potassium iodide.

[0024] According to the present invention, in step 1), the molar ratio of maleic anhydride to the halogenating agent is 1:(6-20), preferably 1:(8-17).

[0025] According to the present invention, in step 1), the maleic anhydride can be first dispersed in an organic base, and the organic base is at least one of triethylamine and pyridine; the molar ratio of the maleic anhydride to the organic base is 1:(2-10), exemplified by 1:2, 1:4, 1:6, 1:8 or 1:10.

[0026] According to the present invention, in step 1), the halogenation reaction is first carried out at -10 to 0°C for 30 minutes to 2 hours, and then heated at 50 to 90°C for 30 minutes to 2 hours.

[0027] According to the present invention, step 1) further comprises a post-processing step, which comprises: after the halogenation reaction is completed, removing the unreacted halogenation reagent from the reaction system, dissolving the remaining solid with toluene, removing by-products, and evaporating to obtain a purified intermediate product.

[0028] According to the present invention, in step 1), after the reaction is completed, post-processing processes such as distillation, separation, washing, and drying are also included.

[0029] According to the present invention, in step 2), the alcohol compound is R 1 -OH and / or R 2 -OH, R1 and R 2 Exemplarily, the alcohol compound is selected from at least one of n-butanol, propanol, isobutanol, n-pentanol, and isopentanol.

[0030] According to the present invention, in step 2), the catalyst is selected from one or more of concentrated sulfuric acid, trifluoromethanesulfonic acid, and p-toluenesulfonic acid.

[0031] According to the present invention, in step 2), the mass volume ratio of the intermediate product, the alcohol compound, and the catalyst is (5-25) g: (30-50) mL: 1 mL, preferably (7-20) g: (35-45) mL: 1 mL.

[0032] According to the present invention, in step 2), the reaction can be carried out in a solvent, and the solvent is benzene or toluene; in step 2), the concentration of the reaction solution is 0.1 g / mL to 5 g / mL.

[0033] According to the present invention, in step 2), after the reaction is completed, a post-treatment process such as separation and purification using a chromatography column is also included.

[0034] The present invention also provides the use of the 2,3-dihalogen-substituted maleate type internal electron donor in a catalyst system.

[0035] According to the present invention, the internal electron donor is used in a catalyst system for olefin polymerization, specifically a solid catalyst system.

[0036] The present invention also provides a solid catalyst component for olefin polymerization, wherein the solid catalyst component comprises the 2,3-dihalogen-substituted maleate type internal electron donor.

[0037] According to the present invention, in the solid component of the catalyst, based on 100% by mass, the mass percentage of the internal electron donor is 7 wt.%-10 wt.%, preferably 7 wt.%-9 wt.%.

[0038] According to the present invention, the solid component of the catalyst further comprises a titanium active component, and the mass percentage of the titanium active component (calculated as titanium element) is 0.5wt.%-2.5wt.%, preferably 1.5wt.%-2.5wt.%.

[0039] According to the present invention, the titanium active component is a titanium compound having a structure shown in the following formula (II):

[0040] TiX 3 p (OR 3 ) 4-p ...(II)

[0041] where X3 represents a halogen atom, preferably chlorine or bromine; more preferably chlorine;

[0042] p is an integer from 0 to 4;

[0043] R 3 is a hydrocarbon group containing 1 to 10 carbon atoms, which may be a saturated or unsaturated hydrocarbon group, and may be a straight chain, branched chain, or cyclic hydrocarbon group, and the hydrocarbon group may also contain heteroatoms such as S, N, O, Si, etc. Preferably, the R 3 Selected from C 1-10 Alkyl, C 2-10 Alkenyl, C 2-10 Alkynyl, C 3-10 Cycloalkyl, C 6-12 Aryl, etc., more preferably C 1-10 Alkyl. When there are two or more R 3 When , they may be the same or different.

[0044] For example, R 3 It can be methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-decyl, allyl, butenyl, cyclopentyl, cyclohexyl, cyclohexenyl, phenyl, benzyl, tolyl, phenethyl, etc.

[0045] According to the present invention, the titanium active component can be at least one of tetraalkoxytitanium, such as tetramethoxytitanium, tetraethoxytitanium, tetra-n-propoxytitanium, tetraisopropoxytitanium, tetra-n-butoxytitanium, tetraisobutoxytitanium, tetracyclohexyloxytitanium, and tetraphenoxytitanium; titanium tetrahalide, such as titanium tetrachloride, titanium tetrabromide, and titanium tetraiodide; alkoxytitanium trihalide, such as methoxytitanium trichloride, ethoxytitanium trichloride, n-propoxytitanium trichloride, n-butoxytitanium trichloride, and ethoxytitanium tribromide; dialkoxytitanium dihalide, such as dimethoxytitanium dichloride, diethoxytitanium dichloride, diisopropoxytitanium dichloride, dipropoxytitanium dichloride, and diethoxytitanium dibromide; and trialkoxytitanium monohalide, such as trimethoxytitanium chloride, triethoxytitanium chloride, triisopropoxytitanium chloride, tri-n-propoxytitanium chloride, and tri-n-butoxytitanium chloride. Among them, halogen-containing titanium compounds are preferred, especially titanium tetrachloride.

[0046] According to the present invention, the raw materials for preparing the solid component of the catalyst may further include magnesium halide, monohydric alcohol compound and titanate.

[0047] According to the present invention, the magnesium halide is selected from one of magnesium chloride, magnesium bromide and magnesium iodide, preferably anhydrous magnesium chloride.

[0048] According to the present invention, the monohydric alcohol compound is selected from C 1-10 Alkyl-OH is preferably ethanol, propanol, butanol, isooctyl alcohol or 2-ethyl-hexanol.

[0049] According to the present invention, the titanate is a tetratitanate compound with the general formula of Ti(OR)4, wherein R is C 1-8 Alkyl and C 3-8 The cycloalkyl group is, for example, tetramethyl titanate, tetraethyl titanate, tetrapropyl titanate or tetrabutyl titanate, preferably tetrabutyl titanate.

[0050] The present invention also provides a catalyst system, which comprises the solid catalyst component for olefin polymerization.

[0051] The present invention also provides a method for olefin polymerization, which adopts the catalyst system.

[0052] According to a preferred technical solution of the present invention, the olefin can be selected from α-olefins such as ethylene, propylene, butene, and 1-hexene.

[0053] According to another preferred technical solution of the present invention, the polymerization includes homopolymerization and copolymerization.

[0054] Terminology Explanation and Description

[0055] The term "C 1-12 "Alkyl" means straight-chain and branched alkyl groups having 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12 carbon atoms, "C 1-6 The term "alkyl" refers to straight-chain and branched alkyl groups having 1, 2, 3, 4, 5 or 6 carbon atoms. The alkyl group is, for example, methyl, ethyl, propyl, butyl, pentyl, hexyl, isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, 2-methylbutyl, 1-methylbutyl, 1-ethylpropyl, 1,2-dimethylpropyl, neopentyl, 1,1-dimethylpropyl, 4-methylpentyl, 3-methylpentyl, 2-methylpentyl, 1-methylpentyl, 2-ethylbutyl, 1-ethylbutyl, 3,3-dimethylbutyl, 2,2-dimethylbutyl, 1,1-dimethylbutyl, 2,3-dimethylbutyl, 1,3-dimethylbutyl or 1,2-dimethylbutyl, or the like or isomers thereof.

[0056] The term "C 3-10 "Cycloalkyl" is understood to mean a saturated monovalent monocyclic, bicyclic hydrocarbon ring or bridged cycloalkane having 3, 4, 5, 6, 7, 8, 9 or 10 carbon atoms. 3-10 The cycloalkyl group may be a monocyclic hydrocarbon group, such as cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl or cyclodecyl, or a bicyclic hydrocarbon group such as decalin. The cycloalkyl group may be a spiro ring, such as spiro[3,3] ring, spiro[3,4] ring, spiro[3,5] ring, spiro[4,4] ring, spiro[4,5] ring, spiro[5,5] ring.

[0057] “C2-10 "Alkenyl" is understood to mean preferably a linear or branched monovalent hydrocarbon radical containing one or more double bonds and having 2, 3, 4, 5, 6, 7, 8, 9 or 10 carbon atoms, for example having 2, 3, 4, 5 or 6 carbon atoms (i.e., C 2-6 alkenyl), having 2 or 3 carbon atoms (i.e., C 2-3 It is understood that when the alkenyl group contains more than one double bond, the double bonds may be separated from one another or conjugated. The alkenyl group is, for example, vinyl, allyl, (E)-2-methylvinyl, (Z)-2-methylvinyl, (E)-but-2-enyl, (Z)-but-2-enyl, (E)-but-1-enyl, (Z)-but-1-enyl, pent-4-enyl, (E)-pent-3-enyl, (Z)-pent-3-enyl, (E)-pent-2-enyl, (Z)-pent-2-enyl, (E)- Pent-1-enyl, (Z)-pent-1-enyl, hex-5-enyl, (E)-hex-4-enyl, (Z)-hex-4-enyl, (E)-hex-3-enyl, (Z)-hex-3-enyl, (E)-hex-2-enyl, (Z)-hex-2-enyl, (E)-hex-1-enyl, (Z)-hex-1-enyl, isopropenyl, 2-methylprop-2-enyl, 1-methylprop-2-enyl , 2-methylprop-1-enyl, (E)-1-methylprop-1-enyl, (Z)-1-methylprop-1-enyl, 3-methylbut-3-enyl, 2-methylbut-3-enyl, 1-methylbut-3-enyl, 3-methylbut-2-enyl, (E)-2-methylbut-2-enyl, (Z)-2-methylbut-2-enyl, (E)-1-methylbut-2-enyl, (Z)-1-methyl But-2-enyl, (E)-3-methylbut-1-enyl, (Z)-3-methylbut-1-enyl, (E)-2-methylbut-1-enyl, (Z)-2-methylbut-1-enyl, (E)-1-methylbut-1-enyl, (Z)-1-methylbut-1-enyl, 1,1-dimethylprop-2-enyl, 1-ethylprop-1-enyl, 1-propylvinyl, 1-isopropylvinyl.

[0058] The term "C 2-10 "Alkynyl" is understood to mean preferably a linear or branched monovalent hydrocarbon radical containing one or more triple bonds and having 2, 3, 4, 5, 6, 7, 8, 9 or 10 carbon atoms, for example having 2, 3, 4, 5 or 6 carbon atoms (i.e. "C 2-6 Alkynyl”), having 2 or 3 carbon atoms (“C 2-3The alkynyl group is, for example, ethynyl, prop-1-ynyl, prop-2-ynyl, but-1-ynyl, but-2-ynyl, but-3-ynyl, pent-1-ynyl, pent-2-ynyl, pent-3-ynyl, pent-4-ynyl, hex-1-ynyl, hex-2-ynyl, hex-3-ynyl, hex-4-ynyl, hex-5-ynyl, 1-methylprop-2-ynyl, 2-methylbut-3-ynyl, 1-methylbut-3-ynyl, 1-methylbut-2-ynyl, 3-methylbut-1-ynyl, 1-ethylprop-2-ynyl, 3-methylpent-4-ynyl, 2-methylpent-4-ynyl, 1-methylpent-4-ynyl, In some embodiments, the alkynyl group is ethynyl, prop-1-ynyl or prop-2-ynyl.

[0059] The term "C 6-12 "Aryl" is understood to mean preferably a monovalent aromatic or partially aromatic monocyclic, bicyclic or tricyclic hydrocarbon ring ("C 6-12 or a ring having 9 carbon atoms ("C9 aryl"), for example indanyl or indenyl, or a ring having 10 carbon atoms ("C 10 "aryl"), such as tetrahydronaphthyl, dihydronaphthyl or naphthyl. When the C 6-12 When the aryl group is substituted, it may be monosubstituted or polysubstituted. Furthermore, there is no limitation on the position of substitution, and for example, substitution may be at the ortho, para or meta position.

[0060] Beneficial effects of the present invention

[0061] (1) Using the 2,3-dihalogen-substituted maleate provided by the present invention as an internal electron donor, an ultra-high activity polypropylene catalyst (activity >36 kg PP / (g.Cat.h)) can be obtained. Compared with 2,3-dialkyl-substituted maleate or 2,3-diaryl-substituted maleate, the performance of the catalyst is better.

[0062] (2) Using cheap and readily available maleic anhydride as raw material, the synthesis of 2,3-dihalogen-substituted maleic acid ester can be efficiently achieved through a two-step reaction. The method is simple, easy and low in cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] Figure 1 This is the H NMR spectrum of di-n-butyl 2,3-dichloromaleate in Example 1.

[0064] Figure 2 This is the C NMR spectrum of di-n-butyl 2,3-dichloromaleate in Example 1.

[0065] Figure 3 This is the mass spectrum of di-n-butyl 2,3-dichloromaleate in Example 1.

[0066] Figure 4 is a SEM image of the catalyst in Example 1. DETAILED DESCRIPTION

[0067] As mentioned above, the present invention also provides a method for preparing the solid component of the olefin polymerization catalyst, the method comprising:

[0068] (S1) Preparation of alcoholate solution:

[0069] Mixing and reacting a magnesium halide, a monohydric alcohol compound, a titanate, and a 2,3-dihalogen-substituted maleate-type internal electron donor represented by Formula I in an alkane solvent to obtain a stable and uniform alcoholate solution;

[0070] (S2) Preparation of solid catalyst component:

[0071] Under an inert atmosphere, the alcoholate solution in step (S1) is mixed with the titanium active component. When the system temperature rises to 80-135°C, a 2,3-dihalogen-substituted maleate type internal electron donor is added to react to obtain a solid component of the olefin polymerization catalyst.

[0072] According to the present invention, the preparation method further comprises a step (S3) in which, after the reaction in step (S2) is completed, the liquid is filtered, a titanium active component is added, and the reaction is continued at a temperature of 80 to 135° C. to obtain a solid component of the olefin polymerization catalyst. Adding the titanium active component in step (S3) of the present invention can increase the titanium content in the solid phase component of the catalyst.

[0073] According to the present invention, in step (S1), the molar ratio of the monohydric alcohol compound, the magnesium halide and the 2,3-dihalogen-substituted maleate type internal electron donor is (1-10):1:(0.01-0.2), preferably (2-8):1:(0.05-0.15), and more preferably (3-6):1:(0.08-0.15).

[0074] According to the present invention, in step (S1), the molar ratio of titanate to 2,3-dihalogen-substituted maleate type internal electron donor is 1:(1:5), illustratively 1:1.

[0075] According to the present invention, in step (S1), the ratio of the alkane solvent to the magnesium halide is (0.5-20):1, expressed in mL / g, preferably (1-15):1, and more preferably (3-10):1.

[0076] According to the present invention, in step (S1), the alkane solvent is selected from C8-C 12 An alkane solvent; for example, decane.

[0077] According to the present invention, in step (S1), the reaction temperature is 40 to 200° C., preferably 60 to 180° C., more preferably 80 to 150° C.; and the reaction time is 1 to 6 hours.

[0078] According to the present invention, the volume ratio of the titanium active component added in step (S2) to the titanium active component added in step (S3) is (0.6-1):1.

[0079] According to the present invention, in step (S2) and step (S3), the volume ratio of the total volume of the added titanium active component to the alcoholate solution is (1-4):1.

[0080] According to the present invention, in step (S2), the molar ratio of the added amount of 2,3-dihalogen-substituted maleate type internal electron donor to the magnesium halide is (0.01-0.2):1, preferably (0.06-0.15):1.

[0081] According to the present invention, in step (S3), after the titanium active component is added, the reaction is continued at a temperature of 80 to 135° C. for 1 to 4 hours.

[0082] According to the present invention, in the method for preparing the solid catalyst for olefin polymerization, the molar ratio of the total amount of the 2,3-dihalogen-substituted maleate-type internal electron donor added twice to the magnesium halide is (0.05-0.25):1.

[0083] According to the present invention, step (S2) or step (S3) further comprises a post-treatment step: after the reaction is completed, the reaction liquid is filtered out, washed with hexane, and dried to obtain a catalyst solid component.

[0084] As an exemplary embodiment of the present invention, the method for preparing the solid component of the olefin polymerization catalyst specifically includes:

[0085] (S1) Preparation of alcoholate solution:

[0086] A magnesium halide, a monohydric alcohol compound, a titanate, and a 2,3-dihalogen-substituted maleate-type internal electron donor represented by Formula I are fully reacted in an alkane solvent, wherein the molar ratio of the monohydric alcohol compound to the magnesium halide is (1-10):1; the molar ratio of the 2,3-dihalogen-substituted maleate-type internal electron donor to the magnesium halide is (0.01-0.2):1; the molar amount of the titanate and the 2,3-dihalogen-substituted maleate-type internal electron donor are equal; the ratio of the alkane solvent to the magnesium halide is (0.5-20):1 (mL / g), and the reaction is carried out at 40-200° C. for 1-6 hours to obtain a stable and uniform alcoholate solution;

[0087] (S2) Preparation of a solid catalyst component: adding the alcoholate solution prepared above to a reactor fully purged with nitrogen and filled with a titanium active component at -25 to 40°C, after sufficient contact, starting to heat up, and when the temperature rises to 80 to 135°C, adding a 2,3-dihalogen-substituted maleate-type internal electron donor at a molar ratio of (0.01 to 0.2) to magnesium halide:1, and reacting at this temperature for 1 to 4 hours. After the reaction is completed, filtering out the liquid, and then adding the titanium active component, continuing to react at a temperature of 80 to 135°C for 1 to 4 hours, filtering out the liquid, washing with a solvent, and drying to obtain a titanium catalyst solid component, wherein the volume ratio of the total amount of the titanium active component added to the alcoholate solution is (1 to 4):1;

[0088] The molar ratio of the total amount of the 2,3-dihalogen-substituted maleate-type internal electron donor added twice to the magnesium halide is (0.05-0.25):1.

[0089] The technical solutions of the present invention will be described in further detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanations of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are encompassed within the scope of protection that the present invention is intended to protect.

[0090] Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.

[0091] 1. In Examples 1-5 and Comparative Examples 1-2, the polymerization activity was calculated by the following method:

[0092] The unit of polymerization activity is g PP / g Cat.h.

[0093]

[0094] 2. In Examples 1-5 and Comparative Examples 1-2, the isotacticity of polypropylene was determined by the n-heptane extraction method: boiling n-heptane was used for extraction for 6 hours, and the percentage of insoluble matter in the total weight was determined after drying.

[0095] 3. The titanium content of the catalyst component was analyzed by energy dispersive spectroscopy (EDS); the electron donor content in the catalyst component was analyzed by gas chromatography (GC).

[0096] Example 1

[0097] (1) Synthesis of di-n-butyl 2,3-dichloromaleate I-1:

[0098]

[0099] To a 250 mL dried three-necked flask, add 9.8 g (0.1 mol) of maleic anhydride and 16.6 mL (0.2 mol) of pyridine, and displace the nitrogen atmosphere. Add 100 mL (1.38 mol) of thionyl chloride in an ice-water bath, and allow to react for 1 hour. Then, heat to 75°C and reflux for 40 minutes. Post-processing: Distill off the unreacted thionyl chloride, dissolve the remaining solid in toluene, filter out the byproduct pyridine hydrochloride, and evaporate the solvent to dryness to obtain 10.9 g of the intermediate product (66% yield).

[0100] A 250 mL single-necked flask was charged with the intermediate, 40 mL of n-butanol, and 100 mL of toluene. 1 mL of concentrated sulfuric acid was added as a catalyst. The mixture was heated (e.g., to 120°C) and refluxed to remove water. The reaction was monitored by TLC. The reaction was completed when the starting material was completely converted. The product was isolated and purified using a chromatography column to obtain 15.5 g of di-n-butyl 2,3-dichloromaleate in a yield of 79%.

[0101] (2) Preparation of catalyst: 5 g of anhydrous magnesium chloride, 18.9 g of isooctyl alcohol, 2.2 g (7.4 mmol) of di-n-butyl 2,3-dichloromaleate, 2.65 g of tetrabutyl titanate and 30 mL of dry decane were added to a reaction flask and reacted at 130°C for 4 hours under nitrogen protection to fully dissolve the anhydrous magnesium chloride and obtain a stable and uniform alcoholate solution. The reaction system was slowly cooled to room temperature. The solution was added dropwise to a reactor that was fully purged with nitrogen and contained 200 mL of titanium tetrachloride at -20°C within 1 hour. After the addition was completed, the temperature was raised to 110°C over 3.5 hours, and 1.3 g (4.4 mmol) of di-n-butyl 2,3-dichloromaleate was added and reacted at this temperature for 2 hours. After the reaction was completed, the liquid was filtered out and 200 ml of titanium tetrachloride was added again and reacted at 110°C for 2 hours. After the reaction was completed, the reaction liquid was filtered out, washed 6 times with dried hexane, and dried to obtain the catalyst.

[0102] (3) Propylene polymerization: 20 mL of triethylaluminum solution was added to a 5 L reactor to remove impurities. 20 mg of the above catalyst, 1.0 mL of diisopropyldimethoxysilane solution (the molar ratio of silicon in the external electron donor to titanium in the titanium active component was 20:1), and 10 mL of triethylaluminum solution (Al / Ti = 100, mol ratio) were then added to the reactor. The hydrogen inlet valve was opened and 0.1 MPa of hydrogen was added. 1200 g of propylene liquid was then added, and stirring (12 Hz) and automatic temperature control of the reactor were started (reaction temperature was 70°C, the lower limit temperature of the reaction was 69.5°C, and the upper limit temperature was 70.5°C). When the reaction temperature first reached 68.5°C, the reaction timer was started, and the reaction time was 60 min. The automatic temperature control of the reactor was stopped, and the unreacted propylene in the reactor was vented. The reactor was then opened to discharge the materials, and the polypropylene product was obtained. The experimental results are shown in Table 1.

[0103] Figure 1 This is the H NMR spectrum of di-n-butyl 2,3-dichloromaleate in Example 1.

[0104] Figure 2 This is the C NMR spectrum of di-n-butyl 2,3-dichloromaleate in Example 1.

[0105] Figure 3 This is the mass spectrum of di-n-butyl 2,3-dichloromaleate in Example 1.

[0106] Figure 4 is a SEM image of the catalyst in Example 1.

[0107] Example 2

[0108] (1) Synthesis of diisobutyl 2,3-dichloromaleate I-2:

[0109]

[0110] The same method as in Example 1 was used to carry out the alcoholysis reaction of the acid anhydride, except that isobutanol was used instead of n-butanol to obtain the target product, diisobutyl 2,3-dichloromaleate, with a total yield of 53%.

[0111] (2) Propylene Polymerization: The catalyst was prepared using the same method as in Example 1, except that diisobutyl 2,3-dichloromaleate was substituted for di-n-butyl 2,3-dichloromaleate. Propylene polymerization was then carried out. The experimental results are shown in Table 1.

[0112] Example 3

[0113] (1) Synthesis of di-n-butyl 2,3-dibromomaleate I-3:

[0114]

[0115] The same method as in Example 1 was used, except that bromine was used instead of thionyl chloride as the halogenating agent to carry out the reaction, and the target product, di-n-butyl 2,3-dibromomaleate, was obtained in a total yield of 51%.

[0116] (2) Propylene Polymerization: The catalyst was prepared using the same method as in Example 1, except that di-n-butyl 2,3-dibromomaleate was substituted for di-n-butyl 2,3-dichloromaleate. Propylene polymerization was then carried out. The experimental results are shown in Table 1.

[0117] Example 4

[0118] (1) Synthesis of diisobutyl 2,3-dibromomaleate I-4:

[0119]

[0120] The same method as in Example 3 was used to carry out the alcoholysis reaction of the acid anhydride, except that isobutanol was used instead of n-butanol to obtain the target product, diisobutyl 2,3-dibromomaleate, with a total yield of 61%.

[0121] (2) Propylene Polymerization: The catalyst was prepared using the same method as in Example 1, except that diisobutyl 2,3-dibromomaleate was substituted for di-n-butyl 2,3-dichloromaleate. Propylene polymerization was then carried out. The experimental results are shown in Table 1.

[0122] Example 5

[0123] (1) Synthesis of di-n-butyl 2-chloro-3-bromomaleate I-5:

[0124]

[0125] The same method as in Example 1 was used, with bromine (6.9 mol) and thionyl chloride (7.0 mol) used as halogenating agents to react, and the target product, di-n-butyl 2-chloro-3-bromomaleate, was finally obtained in a total yield of 61%.

[0126] (2) Propylene Polymerization: The same method as in Example 1 was used to prepare a catalyst using di-n-butyl 2-chloro-3-bromomaleate I-5 as an internal electron donor, and propylene polymerization was carried out. The experimental results are shown in Table 1.

[0127] Comparative Example 1

[0128]

[0129] The same method as in Example 1 was used to prepare a catalyst using di-n-butyl 2,3-diisobutylmaleate (i.e., Formula I-6) disclosed in Chinese Patent No. CN201210480335.9 as an internal electron donor, and propylene polymerization was performed. The experimental results are shown in Table 1.

[0130] Comparative Example 2

[0131]

[0132] The same method as in Example 1 was used to prepare a catalyst using di-n-butyl 2,3-diphenylmaleate (i.e., Formula I-7) as an internal electron donor, and propylene polymerization was carried out. The experimental results are shown in Table 1.

[0133] Table 1 Experimental results

[0134]

[0135]

[0136] In Table 1, the ester content refers to the content of the internal electron donor 2,3-dihalogenated maleate.

[0137] As can be seen from Table 1, the dihalogen-substituted maleate of the present invention is an internal electron donor with good performance, and the compound can be used to prepare a catalyst with excellent performance. When the 2,3-position of maleate is halogen-substituted (Examples 1-5), compared with alkyl substitution (Comparative Example 1) and aryl substitution (Comparative Example 2), the catalyst has a more excellent catalytic activity (>36kg PP / (g.Cat.h)), and the obtained polypropylene has a more excellent isotacticity (>99%). The high activity of the catalyst is actually manifested in the low content of catalyst residues (one of the main components of ash) in the polymer, so a highly active catalyst is beneficial for obtaining a low-ash polymer. The above experimental results show that halogen-substituted maleates have higher activity than other substitutions (alkyl substitution and aryl substitution), and are more conducive to obtaining a low-ash polypropylene product.

[0138] As can be seen from Examples 1-5, the halogen-substituted maleates, whether dichloro-substituted (Examples 1 and 2), dibromo-substituted (Examples 3 and 4), or substituted with two halogens simultaneously (Example 5), all exhibit excellent catalytic activity, and the polypropylene obtained exhibits extremely high isotacticity.

[0139] In summary, the 2,3-dihalogen-substituted maleates provided by the present invention have a simple synthesis route and low synthesis cost. When used as internal electron donors, these compounds exhibit significantly superior catalytic performance compared to dialkyl-substituted maleates and diaryl-substituted maleates. Furthermore, the catalyst activity can exceed 36 kg PP / (g.Cat.h), and the isotacticity of the resulting polypropylene exceeds 99%. This internal electron donor and its catalyst have promising prospects for industrial application.

[0140] The above is an exemplary description of the embodiments of the present invention. However, the scope of protection of the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc. made by those skilled in the art within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A 2,3-dihalogen-substituted maleate-type internal electron donor, characterized in that: The internal electron donor has the structural formula shown in the following formula I: Among them, X 1 and X 2 are the same or different and are independently selected from one of fluorine, chlorine, bromine and iodine; R 1 and R 2 The same or different, independently selected from C 1-12 alkyl.

2. The internal electron donor according to claim 1, characterized in that The internal electron donor is selected from the group consisting of dipropyl 2,3-difluoromaleate, di-n-butyl 2,3-difluoromaleate, diisobutyl 2,3-difluoromaleate, di-n-pentyl 2,3-difluoromaleate, diisopentyl 2,3-difluoromaleate, dipropyl 2,3-dichloromaleate, di-n-butyl 2,3-dichloromaleate, diisobutyl 2,3-dichloromaleate, di-n-pentyl 2,3-dichloromaleate, diisopentyl 2,3-dichloromaleate, dipropyl 2,3-dibromomaleate, di-n-butyl 2,3-dibromomaleate, diisobutyl 2,3-dibromomaleate, di-n-pentyl 2,3-dibromomaleate, diisopentyl 2,3-diiodomaleate, dipropyl 2,3-dibromomaleate, di-n-butyl 2,3-dibromomaleate, diisobutyl 2,3-dibromomaleate, di-n-pentyl 2,3-dibromomaleate, diisopentyl 2,3-diiodomaleate, dipropyl 2,3-dibromomaleate, di-n-butyl 2,3-dibromomaleate, diisobutyl 2,3-dibromomaleate, di-n-pentyl 2,3-dibromomaleate, diisopentyl 2,3-diiodomaleate, dipropyl 2,3-dibromo -di-n-butyl diiodomaleate, diisobutyl 2,3-diiodomaleate, di-n-pentyl 2,3-diiodomaleate, diisopentyl 2,3-diiodomaleate, di-n-butyl 2-fluoro-3-chloromaleate, di-n-butyl 2-fluoro-3-bromomaleate, di-n-butyl 2-fluoro-3-iodomaleate, di-n-butyl 2-chloro-3-bromomaleate, di-n-butyl 2-chloro-3-iodomaleate, di-n-butyl 2-chloro-3-iodomaleate, di-n-butyl 2-bromo-3-iodomaleate, di-n-butyl 2-fluoro-3-chloromaleate, diisobutyl 2-fluoro-3-bromomaleate, diisobutyl 2-fluoro-3-iodomaleate, diisobutyl 2-chloro-3-bromomaleate, diisobutyl 2-chloro-3-iodomaleate or diisobutyl 2-bromo-3-iodomaleate.

3. The internal electron donor according to claim 1, characterized in that The internal electron donor is selected from one of the compounds represented by the following formulas I-1 to I-5:

4. The method for preparing the internal electron donor according to any one of claims 1 to 3, characterized in that: The method comprises: 1) mixing maleic anhydride and a halogenating agent to carry out a halogenation reaction to prepare an intermediate product; 2) reacting the intermediate product of step 1) with an alcohol compound in the presence of a catalyst to prepare a 2,3-dihalogen-substituted maleate-type internal electron donor as shown in formula I.

5. The method according to claim 4, characterized in that In step 1), the halogenating agent is selected from one or more of hydrofluoric acid, thionyl chloride, bromine, and potassium iodide; And / or, in step 1), the molar ratio of maleic anhydride to the halogenating agent is 1:(6-20).

6. The method according to claim 4, characterized in that In step 2), the alcohol compound is R 1 -OH and / or R 2 -OH, R 1 and R 2 has the meaning given in claim 1; And / or, in step 2), the catalyst is selected from one or more of concentrated sulfuric acid, trifluoromethanesulfonic acid, and p-toluenesulfonic acid.

7. The method according to claim 4, characterized in that In step 2), the mass volume ratio of the intermediate product, the alcohol compound, and the catalyst is (5-25) g: (30-50) mL: 1 mL; And / or, in step 2), the reaction is carried out in a solvent, and the solvent is benzene or toluene.

8. Use of the 2,3-dihalogen-substituted maleate internal electron donor according to any one of claims 1 to 3 in a catalyst system.

9. A solid catalyst component for olefin polymerization, characterized in that: The catalyst solid component comprises the 2,3-dihalogen-substituted maleate type internal electron donor according to any one of claims 1 to 3.

10. A catalyst system, characterized in that The catalyst system comprises the solid catalyst component for olefin polymerization according to claim 9.

11. A method for olefin polymerization, characterized in that: The method employs the catalyst system of claim 10.

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