Solid catalyst component for olefin polymerization as well as preparation method, catalyst and application of solid catalyst component

Abstract

The invention belongs to the technical field of olefin polymerization, and relates to a solid catalyst component for olefin polymerization, and a preparation method, a catalyst and application thereof. The solid catalyst component contains a product obtained by reacting a magnesium source, a titanium source and an internal electron donor; the internal electron donor comprises a succinic acid monoester compound and a diether compound, and the preparation method comprises the following steps: carrying out contact reaction on a magnesium source and a titanium source, and adding the internal electron donor in one or more time periods before, during and after the contact reaction of the magnesium source and the titanium source. The preparation method has the advantages that the internal electron donor containing the succinic acid monoester compound and the diether compound is adopted, and a phthalate compound is not used, so that the catalyst is a non-plasticized catalyst; the catalyst provided by the invention has high stereospecificity and good hydrogen regulation sensitivity, the prepared high melt index polymer can maintain high isotactic index, and the product has good processability and mechanical properties.

Description

Technical Field

[0001] The present invention belongs to the technical field of olefin polymerization, and more specifically, relates to a solid catalyst component for olefin polymerization, a preparation method of the solid catalyst component, a catalyst containing the solid catalyst component, and application of the catalyst in olefin polymerization reactions. Background Art

[0002] As an important component of Ziegler-Natta catalyst, internal electron donor compounds play a decisive role in important indicators such as polymerization activity, hydrogen sensitivity, polymer isotacticity, polymer molecular weight and molecular weight distribution. With the development of electron donor compounds, polyolefin catalysts are constantly updated. There are many compounds that can be used as internal electron donors in Ziegler-Natta catalysts: polycarboxylic acids, carboxylates, anhydrides, ketones, ethers, etc. and their derivatives. Among them, dibasic aromatic carboxylic acid esters are more commonly used in industry, such as dibutyl phthalate or diisobutyl phthalate (US6365685B1, US20010020073A1), etc.

[0003] Although catalysts using phthalic acid diesters as internal electron donors have been widely used, the residues of phthalic acid diesters in polypropylene products during the use of such catalysts will affect human fertility. Countries have successively formulated corresponding regulations to restrict the use of plastic products with excessive phthalate content. Therefore, in the development of olefin polymerization catalysts, it is necessary to avoid the use of phthalic acid diester compounds in the preparation process.

[0004] In addition, the stereospecificity of the catalyst determines the isotactic index of the polymer. The higher the isotactic index of the polymer, the higher its regularity and crystallinity. The mechanical properties of the product, such as hardness, stiffness, modulus, fracture and yield strength, are increased. The melting point, thermal stability, aging resistance and radiation resistance are also improved accordingly. In order to develop high-performance polyolefin products, the stereospecificity of the catalyst should be further improved. Summary of the invention

[0005] The inventors unexpectedly discovered during their research that a catalyst containing a succinic acid monoester compound and a diether compound as an internal electron donor has high stereospecificity and good hydrogen adjustment sensitivity, and the prepared high melt index polymer can maintain a high isotactic index, and the product can have both good processing performance and mechanical properties. Based on this discovery, the present invention is proposed.

[0006] In order to achieve the purpose of the present invention, the first aspect of the present invention provides a solid catalyst component for olefin polymerization, wherein the solid catalyst component comprises a product obtained by the reaction of a magnesium source, a titanium source and an internal electron donor;

[0007] Wherein, the internal electron donor comprises a succinic acid monoester compound and a diether compound.

[0008] The second aspect of the present invention provides a method for preparing the solid catalyst component for olefin polymerization, comprising the following steps:

[0009] A magnesium source is contacted with a titanium source for reaction, and an internal electron donor is added at one or more time periods before, during and after the magnesium source is contacted with the titanium source for reaction.

[0010] The third aspect of the present invention provides a catalyst for olefin polymerization, the catalyst comprising:

[0011] (i) the solid catalyst component;

[0012] (ii) at least one alkylaluminum compound; and

[0013] (iii) Optional external electron donor compound.

[0014] The fourth aspect of the present invention provides use of the catalyst for olefin polymerization in olefin polymerization reactions.

[0015] The present invention has the following advantages:

[0016] (1) An internal electron donor containing a succinic acid monoester compound and a diether compound is used, and no phthalate compound is used, so the catalyst is a non-plasticizer catalyst.

[0017] (2) The catalyst of the present invention has high stereospecificity and good hydrogen tuning sensitivity. The prepared high melt index polymer can maintain a high isotactic index, and the product can have both good processing performance and mechanical properties.

[0018] Other features and advantages of the present invention will be described in detail in the following detailed description. DETAILED DESCRIPTION

[0019] The specific embodiments of the present invention are described in detail below. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present invention, and are not used to limit the present invention.

[0020] In order to achieve the purpose of the present invention, the first aspect of the present invention provides a solid catalyst component for olefin polymerization, wherein the solid catalyst component contains a product obtained by the reaction of a magnesium source, a titanium source and an internal electron donor;

[0021] Wherein, the internal electron donor comprises a succinic acid monoester compound and a diether compound.

[0022] According to the present invention, preferably, based on the content of the internal electron donor, the total content of the succinic acid monoester compound and the diether compound is 70-100 weight %, preferably 80-100 weight %.

[0023] According to the present invention, preferably, the succinic acid monoester compound is selected from at least one of the compounds represented by formula (1):

[0024]

[0025] In formula (1), R1 is C1-C 20 Straight or branched alkyl, C3-C 20 Cycloalkyl, C6-C 20 Aryl, C7-C 20 R2 to R5 are each independently selected from hydrogen, C1-C 20 Straight or branched alkyl, C3-C 20 Cycloalkyl, C6-C 20 Aryl, C7-C 20 The C1-C 20 Straight or branched alkyl, C3-C 20 Cycloalkyl, C6-C 20 Aryl, C7-C 20 The aralkyl group or the alkaryl group may contain a hetero atom, and R2 to R5 bonded to the same carbon atom may be bonded to form a ring.

[0026] Further preferably, the succinic acid monoester compound is at least one selected from 4-methoxy-4-oxobutyric acid, 4-ethoxy-4-oxobutyric acid, 4-propoxy-4-oxobutyric acid, 4-tert-butoxy-4-oxobutyric acid and 4-benzyl-4-oxobutyric acid.

[0027] According to a specific embodiment of the present invention, the succinic acid monoester compound is 4-tert-butoxy-4-oxobutanoic acid.

[0028] The present invention does not particularly limit the type of the diether compound, and can be any existing diether compound that can be used as an electron donor in a catalyst for olefin polymerization. Preferably, the diether compound is selected from at least one of the diether compounds represented by formula (2):

[0029]

[0030] In formula (2), R Ⅰ , R Ⅱ , R Ⅲ , R Ⅳ , R Ⅴ and RⅥ The same or different, each independently selected from hydrogen, halogen atoms, C1-C 20 Straight or branched alkyl, C3-C 20 Cycloalkyl, C6-C 20 Aryl, C7-C 20 Arylalkyl and C7-C 20 One of the alkylaryl groups, R Ⅰ -R Ⅵ The groups of R Ⅶ and R Ⅷ may be the same or different and are independently selected from C1-C 20 Straight or branched alkyl, C3-C 20 Cycloalkyl, C6-C 20 Aryl, C7-C 20 Alkyl, C7-C 20 One of the aralkyl groups.

[0031] Specifically preferably, the diether compound is selected from 2-(2-ethylhexyl)-1,3-dimethoxypropane, 2-isopropyl-1,3-dimethoxypropane, 2-butyl-1,3-dimethoxypropane, 2-sec-butyl-1,3-dimethoxypropane, 2-cyclohexyl-1,3-dimethoxypropane, 2-phenyl-1,3-dimethoxypropane, 2-(2-phenylethyl)-1,3-dimethoxypropane, 2-(2-cyclohexylethyl)-1,3-dimethoxypropane, 2-(p-chlorophenyl)-1,3-dimethoxypropane, 2-(diphenylmethyl)-1,3-dimethoxypropane, 2,2-dicyclohexyl-1,3-dimethoxypropane , 2,2-dicyclopentyl-1,3-dimethoxypropane, 2,2-diethyl-1,3-dimethoxypropane, 2,2-dipropyl-1,3-dimethoxypropane, 2,2-diisopropyl-1,3-dimethoxypropane, 2,2-dibutyl-1,3-dimethoxypropane, 2-methyl-2-propyl-1,3-dimethoxypropane, 2-methyl-2-benzyl-1,3-dimethoxypropane, 2-methyl-2-ethyl-1,3-dimethoxypropane, 2-methyl-2-isopropyl-1,3-dimethoxypropane, 2-methyl-2-phenyl-1,3-dimethoxypropane, 2-methyl-2-cyclohexyl-1,3-dimethoxypropane, , 2-bis(2-cyclohexylethyl)-1,3-dimethoxypropane, 2-methyl-2-isobutyl-1,3-dimethoxypropane, 2-methyl-2-(2-ethylhexyl)-1,3-dimethoxypropane, 2,2-diisobutyl-1,3-dimethoxypropane, 2,2-diphenyl-1,3-dimethoxypropane, 2,2-dibenzyl-1,3-dimethoxypropane, 2,2-bis(cyclohexylmethyl)-1,3-dimethoxypropane, 2-isobutyl-2-isopropyl-1,3-dimethoxypropane, 2-(1-methylbutyl)-2-isopropyl-1,3-dimethoxypropane, 2-isopropyl-2-isopentyl-1,3-dimethoxy At least one of propane, 2-phenyl-2-isopropyl-1,3-dimethoxypropane, 2-phenyl-2-sec-butyl-1,3-dimethoxypropane, 2-benzyl-2-isopropyl-1,3-dimethoxypropane, 2-cyclopentyl-2-isopropyl-1,3-dimethoxypropane, 2-cyclopentyl-2-sec-butyl-1,3-dimethoxypropane, 2-cyclohexyl-2-isopropyl-1,3-dimethoxypropane, 2-cyclohexyl-2-sec-butyl-1,3-dimethoxypropane, 2-isopropyl-2-sec-butyl-1,3-dimethoxypropane, 2-cyclohexyl-2-cyclohexylmethyl-1,3-dimethoxypropane and 9,9-dimethoxymethylfluorene.

[0032] Most preferably, the diether compound is 2-isopropyl-2-isopentyl-1,3-dimethoxypropane and / or 9,9-dimethoxymethylfluorene.

[0033] According to the present invention, the amount of the succinic acid monoester compound can be 0.05-1.5 moles, preferably 0.15-1 mole, relative to each mole of the diether compound. The two can be synergistically formulated better using the above preferred amounts. The catalyst has high stereospecificity and good hydrogen regulation sensitivity.

[0034] According to the present invention, the molar ratio of the magnesium source calculated as magnesium element, the titanium source calculated as titanium element and the internal electron donor is 1:15-180:0.1-1, preferably 1:18-150:0.15-0.9.

[0035] In the catalyst component of the present invention, the content of magnesium element is 3-16 parts by weight, preferably 4-15 parts by weight, and more preferably 5-14 parts by weight per part by weight of titanium element; the content of internal electron donor is 2-16 parts by weight, preferably 3-15 parts by weight, and more preferably 4-12 parts by weight.

[0036] In the present invention, the magnesium source can be various magnesium-containing compounds that can be used for olefin polymerization catalysts, for example, the magnesium source can be a magnesium halide, an alcoholate of magnesium, a halogenated alcoholate of magnesium, or a magnesium halide adduct carrier, etc. The magnesium halide can be, for example, magnesium chloride and / or magnesium bromide. The alcoholate of magnesium can be, for example, diethoxymagnesium. The halogenated alcoholate of magnesium can be, for example, ethoxymagnesium chloride. The types of the magnesium halide adduct carrier are well known to those skilled in the art, for example, the magnesium halide adduct carriers disclosed in patent documents CN1091748, CN101050245, CN101486722, CN102796132B, CN102796129B and CN102796128B, and the relevant contents disclosed in these patent documents are all introduced into the present invention as a reference.

[0037] According to the present invention, the titanium source can be a conventional choice in the art, for example, the titanium source can be a titanium source having a general formula of Ti(OR′) 3-a Z a and / or Ti(OR′) 4-b Z b wherein R′ is a C1-C20 alkyl group, Z is F, Cl, Br or I, a is an integer of 1-3, and b is an integer of 1-4. Preferably, the titanium source is one or more of titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, tributoxytitanium chloride, dibutoxytitanium dichloride, butoxytitanium trichloride, triethoxytitanium chloride, diethoxytitanium dichloride, ethoxytitanium trichloride and titanium trichloride.

[0038] The second aspect of the present invention provides a method for preparing the solid catalyst component for olefin polymerization, comprising the following steps:

[0039] The magnesium source and the titanium source are subjected to a contact reaction, and an internal electron donor is added during one or more time periods before, during, and after the contact reaction between the magnesium source and the titanium source. Then, the titanium source is used for one or more treatments, and then washed with an inert solvent to obtain the solid catalyst component.

[0040] The catalyst component for olefin polymerization of the present invention can be prepared by a conventional method. For example, the preparation method of the catalyst component includes: subjecting the magnesium source and the titanium source to a contact reaction, and adding an internal electron donor during one or more time periods before, during, and after the contact reaction between the magnesium source and the titanium source. The components of the internal electron donor can be added separately or simultaneously. The internal electron donor includes a succinic acid monoester compound and a diether compound.

[0041] Preferably, the reaction between the magnesium source and the titanium source can be carried out as follows: the titanium source is cooled to below 0 °C (preferably -5 to -25 °C), then the magnesium source is added, and the mixture is stirred at this temperature for preferably 15 - 50 minutes, and then gradually heated to the reaction temperature (i.e., about 60 - 130 °C) and maintained at this reaction temperature for 0.2 - 10 hours, preferably 0.5 - 6 hours. In the preparation method of the catalyst component for olefin polymerization, the internal electron donor is added during one or more time periods before, during, or after the reaction between the magnesium source and the titanium source. The time period before the reaction between the magnesium source and the titanium source refers to the time period after the magnesium source is added to the reactor and before the temperature is raised to the reaction temperature.

[0042] The third aspect of the present invention provides a catalyst for olefin polymerization, which contains:

[0043] (i) the solid catalyst component described above;

[0044] (ii) at least one alkylaluminum compound; and

[0045] (iii) an optional external electron donor compound.

[0046] In the present invention, the alkylaluminum compound can be various alkylaluminum compounds conventionally used in the art. For example, the general formula of the alkylaluminum can be AlR n X 3-n , where R is an alkyl group of C1 - C8, the hydrogen on the alkyl group is optionally substituted by a halogen atom, X is a halogen, and n is an integer of 0 < n ≤ 3.

[0047] Specific examples of the C1 - C8 alkyl group can include, but are not limited to: methyl, ethyl, propyl, n-butyl, isobutyl, pentyl, hexyl, n-heptyl, n-octyl, and the halogen can be fluorine, chlorine, bromine, iodine.

[0048] Specifically, the alkylaluminum compound can be selected from one or more of triethylaluminum, triisobutylaluminum, tri-n-butylaluminum, tri-n-hexylaluminum, diethylaluminum monochloride, diisobutylaluminum monochloride, di-n-butylaluminum monochloride, di-n-hexylaluminum monochloride, monoethylaluminum dichloride, monoisobutylaluminum dichloride, mono-n-butylaluminum dichloride and mono-n-hexylaluminum dichloride.

[0049] According to the present invention, the amount of the alkyl aluminum compound can be the conventional amount in the art. The molar ratio of aluminum in the alkyl aluminum compound to titanium in the catalyst component can be 1-2000:1, preferably 20-500:1, more preferably 30-300:1.

[0050] In the present invention, the external electron donor can be any of various external electron donors commonly used in the art. For example, the external electron donor can be selected from at least one of carboxylic acids, carboxylic anhydrides, carboxylic esters, ketones, ethers, alcohols, lactones, organophosphorus compounds and organosilicon compounds.

[0051] Preferably, the external electron donor is selected from a group containing at least one Si-OR 19 bond, and the general formula is (R 17 ) x (R 18 ) y Si(OR 19 ) z Silicon compounds, where R 17 , R 18 and R 19 C1-C 18 The hydrocarbon group optionally contains heteroatoms, x and y are each independently an integer of 0-2, z is an integer of 1-3, and the sum of x, y, and z is 4. 17 , R 18 Preferably C3-C 10 The alkyl or cycloalkyl group may contain heteroatoms; R 19 Preferably C1-C 10 The alkyl group may contain a heteroatom.

[0052] Specifically, the external electron donor can be selected from at least one of cyclohexylmethyldimethoxysilane, diisopropyldimethoxysilane, di-n-butyldimethoxysilane, diisobutyldimethoxysilane, diphenyldimethoxysilane, methyl-tert-butyldimethoxysilane, dicyclopentyldimethoxysilane, 2-ethylpiperidinyl-2-tert-butyldimethoxysilane, (1,1,1-trifluoro-2-propyl)-2-ethylpiperidinyldimethoxysilane and (1,1,1-, trifluoro-2-propyl)-methyldimethoxysilane.

[0053] According to the present invention, the amount of the external electron donor can be a conventional amount in the art. The molar ratio of the external electron donor to the aluminum in the alkyl aluminum compound can be 1:1-300, preferably 1:2-100.

[0054] The fourth aspect of the present invention provides use of the catalyst for olefin polymerization in olefin polymerization reactions.

[0055] When the catalyst of the present invention is used for olefin polymerization, the catalyst components, alkyl aluminum compound, and optional external electron donor can be added to the polymerization reactor separately, or mixed and added to the polymerization reactor, or the olefin can be prepolymerized by a prepolymerization method known in the industry and then added to the polymerization reactor.

[0056] In the present invention, the specific type of olefin, the polymerization method and conditions of olefin can be conventionally selected according to the prior art.

[0057] The catalyst of the present invention is particularly suitable for the general formula CH2=CHR 1 Homopolymerization and copolymerization of olefins, wherein R 1 is hydrogen, C1-C6 alkyl or C6-C 12 The aromatic group.

[0058] According to the present invention, the polymerization reaction of the olefin can be carried out according to the existing method, specifically, under the protection of an inert gas, in a liquid phase monomer or an inert solvent containing a polymerizable monomer, or in a gas phase, or by a combined polymerization process in a gas-liquid phase. The temperature of the polymerization reaction can generally be 0-150°C, preferably 60-90°C. The pressure of the polymerization reaction can be normal pressure or higher, for example, 0.01-10MPa, preferably 0.01-5MPa, more preferably 0.1-4Mpa, and the pressure of the present invention refers to the gauge pressure. In the polymerization process, hydrogen can be used as a polymer molecular weight regulator and added to the reaction system to adjust the molecular weight and melt index of the polymer. In addition, in the polymerization process of the olefin, the type and amount of the inert gas and solvent are well known to those skilled in the art and will not be repeated here.

[0059] Parameters not limited in the present invention are all conventional technical means in the art.

[0060] The present invention will be further described below in conjunction with embodiments, but the scope of the present invention is not limited to these embodiments.

[0061] The polymer melt index in the present invention is measured according to GB3682-2000 at 230°C and a load of 2.16 kg.

[0062] The isotactic index of the polymer in the present invention is determined by the heptane extraction method (heptane boiling extraction for 6 hours), that is, 2 g of a dry polymer sample is taken, placed in an extractor and extracted with boiling heptane for 6 hours, then the residue is dried to constant weight, and the ratio of the obtained polymer weight (g) to 2 is the isotactic index.

[0063] Examples 1 to 5 are used to illustrate the catalyst component and catalyst for olefin polymerization and application of the present invention.

[0064] Example 1

[0065] (1) Preparation of catalyst components

[0066] In a 300mL glass reaction bottle, add 80mL of titanium tetrachloride and cool to -20°C, add 36mmol of a magnesium halide carrier (prepared according to the method disclosed in Example 1 of CN1267508C) in terms of magnesium element, then heat to 112°C, and add 2mmol of 4-tert-butoxy-4-oxobutyric acid and 7.5mmol of 2-isopropyl-2-isopentyl-1,3-dimethoxypropane during the heating process. After maintaining at 110°C for 30min, filter out the liquid, wash with titanium tetrachloride, then wash with hexane, and vacuum dry to obtain the catalyst component Cat-1 for olefin polymerization.

[0067] (2) Propylene liquid phase bulk polymerization

[0068] The bulk polymerization of propylene in liquid phase was carried out in a 5L stainless steel autoclave. Under nitrogen protection, 5mL of triethylaluminum hexane solution (concentration of 0.5mmol / mL), 1mL of cyclohexylmethyldimethoxysilane (CHMMS) hexane solution (concentration of 0.1mmol / mL) and 8mg of the above-mentioned catalyst component Cat-1 for olefin polymerization were added to the reactor in sequence. The autoclave was closed, and hydrogen and 2.3L of liquid propylene were added. The temperature was raised to 70°C, and after reacting for 1 hour, the temperature was lowered, the pressure was released, the material was discharged, and the obtained propylene homopolymer was dried, weighed and analyzed. When the amount of hydrogen was 1.5NL, the polymerization activity of the catalyst was 49.2kgPP / gcat. The test results of the isotactic index and melt index of the polymer are shown in Table 1.

[0069] Example 2

[0070] The catalyst component was prepared and propylene liquid phase bulk polymerization was carried out according to the method of Example 1, except that the amounts of 4-tert-butoxy-4-oxobutyric acid and 2-isopropyl-2-isopentyl-1,3-dimethoxypropane added during the heating process were 3.2 mmol and 6.8 mmol, respectively, to obtain catalyst component Cat-2 for olefin polymerization.

[0071] The obtained propylene homopolymer was dried, weighed and analyzed. When the amount of hydrogen was 1.5NL, the polymerization activity of the catalyst was 51.3kgPP / gcat. The test results of the polymer isotactic index and melt index are shown in Table 1.

[0072] Example 3

[0073] The catalyst component was prepared and propylene liquid phase bulk polymerization was carried out according to the method of Example 1, except that 2-isopropyl-2-isopentyl-1,3-dimethoxypropane was not added during the heating process, and the amounts of 4-tert-butoxy-4-oxobutyric acid and 2-isopropyl-2-isopentyl-1,3-dimethoxypropane added were 4.6 mmol and 4.7 mmol, respectively, to obtain a catalyst component Cat-3 for olefin polymerization.

[0074] The obtained propylene homopolymer was dried, weighed and analyzed. When the amount of hydrogen was 1.5 NL, the polymerization activity of the catalyst was 45.7 kg PP / gcat. The test results of the isotactic index and melt index of the polymer are shown in Table 1.

[0075] Example 4

[0076] The catalyst component was prepared and propylene liquid phase bulk polymerization was carried out according to the method of Example 1, except that the amounts of 4-tert-butoxy-4-oxobutyric acid and 2-isopropyl-2-isopentyl-1,3-dimethoxypropane added during the heating process were 1 mmol and 8 mmol, respectively, to obtain catalyst component Cat-4 for olefin polymerization.

[0077] The obtained propylene homopolymer was dried, weighed and analyzed. When the amount of hydrogen was 1.5 NL, the polymerization activity of the catalyst was 47.6 kgPP / gcat. The test results of the polymer isotactic index and melt index are shown in Table 1.

[0078] Example 5

[0079] The catalyst component was prepared and propylene liquid phase bulk polymerization was carried out according to the method of Example 1, except that the amounts of 4-tert-butoxy-4-oxobutyric acid and 2-isopropyl-2-isopentyl-1,3-dimethoxypropane added during the heating process were 5 mmol and 4.1 mmol, respectively, to obtain a catalyst component Cat-5 for olefin polymerization.

[0080] The obtained propylene homopolymer was dried, weighed and analyzed. When the amount of hydrogen was 1.5 NL, the polymerization activity of the catalyst was 43.8 kg PP / gcat. The test results of the polymer isotactic index and melt index are shown in Table 1.

[0081] Example 6

[0082] The catalyst component was prepared and propylene liquid phase bulk polymerization was carried out according to the method of Example 1, except that the amounts of 4-tert-butoxy-4-oxobutanoic acid and 2-isopropyl-2-isopentyl-1,3-dimethoxypropane added during the heating process were 5.8 mmol and 2.9 mmol, respectively, to obtain catalyst component Cat-6 for olefin polymerization.

[0083] The obtained propylene homopolymer was dried, weighed and analyzed. When the amount of hydrogen was 1.5 NL, the polymerization activity of the catalyst was 35.9 kg PP / gcat. The test results of the polymer isotactic index and melt index are shown in Table 1.

[0084] Comparative Example 1

[0085] The catalyst component was prepared and propylene liquid phase bulk polymerization was carried out according to the method of Example 1, except that during the preparation of the catalyst component, 4-tert-butoxy-4-oxobutyric acid was not added, and only 9.5 mmol of 2-isopropyl-2-isopentyl-1,3-dimethoxypropane was added to obtain the catalyst component DCat-1 for olefin polymerization; the obtained propylene homopolymer was dried, weighed and analyzed. When the amount of hydrogen was 1.5 NL, the polymerization activity of the catalyst was 46.3 kgPP / gcat. The test results of the polymer isotactic index and melt index are shown in Table 1.

[0086] Comparative Example 2

[0087] The catalyst component was prepared and propylene liquid phase bulk polymerization was carried out according to the method of Example 1, except that in the preparation process of the catalyst component, 2-isopropyl-2-isopentyl-1,3-dimethoxypropane was not added, and only 9.5 mmol of 4-tert-butoxy-4-oxobutyric acid was added to obtain the catalyst component DCat-2 for olefin polymerization; the obtained propylene homopolymer was dried, weighed and analyzed. When the amount of hydrogen was 1.5 NL, the polymerization activity of the catalyst was 16.9 kgPP / gcat. The test results of the polymer isotactic index and melt index are shown in Table 1.

[0088] Table 1

[0089]

[0090]

[0091] It can be seen from Table 1 that when the internal electron donor contains a certain proportion of succinic acid monoester compounds and diether compounds, the catalyst has both high hydrogen modulation sensitivity and stereospecificity, especially high stereospecificity, and the catalyst component of the present invention does not contain phthalate compounds (plasticizers).

[0092] 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.

[0093] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

Claims

1. A solid catalyst component for olefin polymerization, characterized in that: The solid catalyst component contains a product obtained by the reaction of a magnesium source, a titanium source and an internal electron donor; Wherein, the internal electron donor comprises a succinic acid monoester compound and a diether compound.

2. The solid catalyst component for olefin polymerization according to claim 1, wherein Based on the content of the internal electron donor, the total content of the succinic acid monoester compound and the diether compound is 70-100 weight %, preferably 80-100 weight %.

3. The solid catalyst component for olefin polymerization according to claim 1, wherein The succinic acid monoester compound is selected from at least one of the compounds represented by formula (1): In formula (1), R1 is C1-C 20 Straight or branched alkyl, C3-C 20 Cycloalkyl, C6-C 20 Aryl, C7-C 20 R2 to R5 are each independently selected from hydrogen, C1-C 20 Straight or branched alkyl, C3-C 20 Cycloalkyl, C6-C 20 Aryl, C7-C 20 The C1-C 20 Straight or branched alkyl, C3-C 20 Cycloalkyl, C6-C 20 Aryl, C7-C 20 The aralkyl or alkaryl group may contain a heteroatom, and R2 to R5 attached to the same carbon atom may be bonded to form a ring; Preferably, the succinic acid monoester compound is selected from at least one of 4-methoxy-4-oxobutyric acid, 4-ethoxy-4-oxobutyric acid, 4-propoxy-4-oxobutyric acid, 4-tert-butoxy-4-oxobutyric acid and 4-benzyl-4-oxobutyric acid.

4. The solid catalyst component for olefin polymerization according to claim 1, wherein The diether compound is selected from at least one of the diether compounds represented by formula (2): In formula (2), R Ⅰ , R Ⅱ , R Ⅲ , R Ⅳ , R Ⅴ and R Ⅵ The same or different, each independently selected from hydrogen, halogen atoms, C1-C 20 Straight or branched alkyl, C3-C 20 Cycloalkyl, C6-C 20 Aryl, C7-C 20 Arylalkyl and C7-C 20 One of the alkylaryl groups, R Ⅰ -R Ⅵ The groups of R can be bonded to form a ring; Ⅶ and R Ⅷ The same or different, each independently selected from C1-C 20 Straight or branched alkyl, C3-C 20 Cycloalkyl, C6-C 20 Aryl, C7-C 20 Alkyl, C7-C 20 One of the aralkyl groups; Preferably, the diether compound is selected from 2-(2-ethylhexyl)-1,3-dimethoxypropane, 2-isopropyl-1,3-dimethoxypropane, 2-butyl-1,3-dimethoxypropane, 2-sec-butyl-1,3-dimethoxypropane, 2-cyclohexyl-1,3-dimethoxypropane, 2-phenyl-1,3-dimethoxypropane, 2-(2-phenylethyl)-1,3-dimethoxypropane, 2-(2-cyclohexylethyl)-1,3-dimethoxypropane, 2-(p-chlorophenyl)-1,3-dimethoxypropane, 2-(diphenylmethyl)-1,3-dimethoxypropane, 2,2-dicyclohexyl-1,3-dimethoxypropane, ,2-dicyclopentyl-1,3-dimethoxypropane, 2,2-diethyl-1,3-dimethoxypropane, 2,2-dipropyl-1,3-dimethoxypropane, 2,2-diisopropyl-1,3-dimethoxypropane, 2,2-dibutyl-1,3-dimethoxypropane, 2-methyl-2-propyl-1,3-dimethoxypropane, 2-methyl-2-benzyl-1,3-dimethoxypropane, 2-methyl-2-ethyl-1,3-dimethoxypropane, 2-methyl-2-isopropyl-1,3-dimethoxypropane, 2-methyl-2-phenyl-1,3-dimethoxypropane, 2, 2-bis(2-cyclohexylethyl)-1,3-dimethoxypropane, 2-methyl-2-isobutyl-1,3-dimethoxypropane, 2-methyl-2-(2-ethylhexyl)-1,3-dimethoxypropane, 2,2-diisobutyl-1,3-dimethoxypropane, 2,2-diphenyl-1,3-dimethoxypropane, 2,2-dibenzyl-1,3-dimethoxypropane, 2,2-bis(cyclohexylmethyl)-1,3-dimethoxypropane, 2-isobutyl-2-isopropyl-1,3-dimethoxypropane, 2-(1-methylbutyl)-2-isopropyl-1,3-dimethoxypropane, 2-isopropyl-2-isopentyl-1,3-dimethoxy at least one of propane, 2-phenyl-2-isopropyl-1,3-dimethoxypropane, 2-phenyl-2-sec-butyl-1,3-dimethoxypropane, 2-benzyl-2-isopropyl-1,3-dimethoxypropane, 2-cyclopentyl-2-isopropyl-1,3-dimethoxypropane, 2-cyclopentyl-2-sec-butyl-1,3-dimethoxypropane, 2-cyclohexyl-2-isopropyl-1,3-dimethoxypropane, 2-cyclohexyl-2-sec-butyl-1,3-dimethoxypropane, 2-isopropyl-2-sec-butyl-1,3-dimethoxypropane, 2-cyclohexyl-2-cyclohexylmethyl-1,3-dimethoxypropane and 9,9-dimethoxymethylfluorene; Preferably, the diether compound is 2-isopropyl-2-isopentyl-1,3-dimethoxypropane and / or 9,9-dimethoxymethylfluorene.

5. The solid catalyst component for olefin polymerization according to claim 1, wherein The amount of the succinic acid monoester compound used is 0.05-1.5 moles, preferably 0.15-1 mole, per mole of the diether compound.

6. The solid catalyst component for olefin polymerization according to claim 1, wherein The magnesium source is at least one of a magnesium halide, a magnesium alcoholate or a halogenated alcoholate and a magnesium halide adduct carrier; The titanium source is of the general formula Ti(OR′) 3-a Z a and Ti(OR′) 4-b Z b At least one of the compounds shown, wherein R′ is C1-C 20 The alkyl group is preferably C1-C 12 The alkyl group is preferably a C1-C6 alkyl group, Z is a halogen, a is an integer of 1-3, and b is an integer of 1-4.

7. The solid catalyst component for olefin polymerization according to claim 1, wherein The molar ratio of the magnesium source calculated as magnesium element, the titanium source calculated as titanium element and the internal electron donor is 1:15-180:0.1-1, preferably 1:18-150:0.15-0.

9.

8. The method for preparing a solid catalyst component for olefin polymerization according to any one of claims 1 to 7, characterized in that: The steps include: A magnesium source is contacted with a titanium source for reaction, and an internal electron donor is added in one or more time periods before, during and after the contact reaction of the magnesium source and the titanium source, and then the titanium source is treated once or multiple times, and then washed with an inert solvent to obtain the solid catalyst component.

9. A catalyst for olefin polymerization, characterized in that: The catalyst contains: (i) the solid catalyst component according to any one of claims 1 to 7; (ii) at least one alkylaluminum compound; as well as (iii) Optional external electron donor compound.

10. The catalyst for olefin polymerization according to claim 9, wherein The alkylaluminum compound is selected from at least one of the compounds represented by AlR n X 3-n wherein R is an alkyl group having 1 to 8 carbon atoms, and the hydrogen on the alkyl group is optionally substituted by a halogen atom, X is a halogen, and n is an integer of 0 < n ≤ 3; preferably, the alkylaluminum compound is selected from at least one of triethylaluminum, triisobutylaluminum, tributylaluminum, trihexylaluminum, chloro-diethylaluminum, chloro-diisobutylaluminum, chloro-dibutylaluminum, chloro-dihexylaluminum, dichloro-ethylaluminum, dichloro-isobutylaluminum, dichloro-dibutylaluminum, and dichloro-dihexylaluminum; The external electron donor is selected from at least one of carboxylic acid, carboxylic anhydride, carboxylic ester, ketone, ether, alcohol, lactone, organophosphorus compound and organosilicon compound; preferably, the external electron donor is selected from at least one Si-OR 19 bond, and the general formula is (R 17 ) x (R 18 ) y Si(OR 19 ) z Silicon compounds, where R 17 , R 18 and R 19 C1-C 18 The hydrocarbon group optionally contains heteroatoms, x and y are each independently an integer of 0-2, z is an integer of 1-3, and the sum of x, y, and z is 4, R 17 , R 18 Preferably C3-C 10 The alkyl or cycloalkyl group may contain heteroatoms; R 19 Preferably C1-C 10 The alkyl group may contain a heteroatom.

11. The catalyst for olefin polymerization according to claim 9, wherein The molar ratio of the solid catalyst component calculated as titanium element to the alkyl aluminum compound calculated as aluminum element is 1:1-2000, preferably 1:20-500, more preferably 1:30-300; the molar ratio of the external electron donor to the alkyl aluminum compound calculated as aluminum element is 1:1-300, preferably 1:2-100.

12. Use of the catalyst for olefin polymerization according to any one of claims 9 to 11 in olefin polymerization reactions.

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