Solid catalyst for olefin polymerization

Abstract

The invention discloses a solid catalyst for olefin polymerization, which comprises succinic acid ester with double bonds in a general formula (I) as an internal electron donor, and due to the unique space and electron effects, the catalyst containing the succinic acid ester has better activity, stereospecificity and hydrogen regulation sensitivity in propylene (co) polymerization, and the molecular weight distribution of a polymer is wide. And the method is suitable for development of polymer products with different marks. # imgabs0 #

Description

Technical Field

[0001] The invention belongs to the field of preparation of supported Ziegler-Natta catalysts, and specifically relates to an olefin polymerization catalytic component and a catalyst thereof, and particularly relates to a catalytic component and a catalyst thereof for propylene (co)polymerization. Background Art

[0002] Supported Ziegler-Natta catalyst is a solid titanium catalyst with magnesium, titanium, halogen and electron donor as basic components. It is particularly suitable for the polymerization of α-olefins with 3 or more carbon atoms. The obtained olefin polymer has a high yield and stereoregularity. The electron donor in the catalyst is one of the essential components of the supported Ziegler-Natta catalyst, which can effectively improve the activity and isotacticity of the catalyst. Studies have shown that polyolefin catalysts are constantly updated with the development of electron donor compounds.

[0003] A variety of electron donor compounds have been reported in the literature, such as mono- or poly-carboxylic acid esters, anhydrides, ketones, mono- or poly-ethers, amines, and their derivatives. At present, di-aromatic carboxylic acid ester compounds are more commonly used in industry, such as di-n-butyl phthalate or diisobutyl phthalate (PM Trivedi, et al. J. Polym. Res., 2021, 28, Article number: 45). However, phthalates are typical plasticizers, and long-term use can cause harm to human health. Therefore, researchers have developed many non-phthalate electron donors for supported Ziegler-Natta catalysts. Typical are 1,3-diether compounds. It is a recognized new generation of supported Ziegler-Natta catalyst electron donor compounds with high activity and isotacticity, such as 9,9-di(methoxymethyl)fluorene recently disclosed by CN1090194C, CN00103538, and CN1137155C. In addition, researchers have recently tried to use other compounds as electron donors in olefin polymerization catalyst components, such as 1,8-naphthalene diphenol esters (WO2011084691A2 and US20110213106A1) reported by Chang et al. of BASF and 1,2-benzenediphenol esters (US20190338054A1 and CN102325808A) structures disclosed by Dow. These electron donor-loaded catalysts have high activity and isotacticity. However, whether it is 1,3-diether or diol lipid compounds, the synthesis is difficult, and the molecular weight distribution of the obtained polymer is narrow, making the material difficult to process.

[0004] In order to solve this problem, Basell has developed a catalyst with succinate (butyric acid ester) as an electron donor, which not only has high stereospecific performance and catalytic activity, but also has a wide relative molecular mass distribution of polyolefins (CN1313869). For example, 2,3-diisopropyl succinate disclosed in patents such as WO2002030998 and polycyclic succinate electron donor compounds published by China National Petroleum Corporation (CN101831016A and CN101423571A). However, the synthesis of such compounds is complex and requires the use of low temperatures (such as -85°C, CN201310071720), which greatly limits the synthesis and industrial application of succinate compounds. Summary of the invention

[0005] The object of the present invention is to provide a method for 2 =CHR olefin polymerization catalytic component, wherein R is hydrogen or a hydrocarbon group having 1 to 12 carbon atoms. Another object of the present invention is to provide a catalyst containing the above catalytic component.

[0006] The inventors have found through research that succinate compounds for supported Ziegler-Natta catalysts can be synthesized by reacting 1,3-cyclohexadiene compounds with maleate compounds through a simple DA reaction, which is simple and easy to promote and apply.

[0007] The present invention adopts the following technical solutions to achieve the above invention objectives:

[0008] The present invention provides an olefin polymerization catalyst component, which comprises, by weight percentage, 10% to 25% magnesium, 1% to 10% titanium, 40% to 60% halogen and 1% to 30% internal electron donor, characterized in that the internal electron donor compound is selected from at least one succinate ester in the general formula (I):

[0009]

[0010] Where n≥2 and is a positive integer, the group R 1 and R 2 Same or different from each other, is C 1 ~C 20 a linear or branched alkyl, alkenyl, cycloalkyl, aryl, arylalkyl or alkylaryl radical, optionally containing heteroatoms; the radical R 3 To R 6 are the same as or different from each other and are hydrogen or C 1 ~C 20 a linear or branched alkyl, alkenyl, cycloalkyl, aryl, arylalkyl or alkylaryl group, optionally containing heteroatoms, and R 3 To R 6Two or more groups can bond to each other to form one or more condensed ring structures.

[0011] The general formula (I) can be obtained by Diels-Alder reaction of the corresponding maleate and the corresponding ring-packed diene, as shown in the following reaction formula. 1 -R 6 and X are defined as R in formula (I) 1 -R 6 .

[0012]

[0013] Furthermore, in the above technical solution, in the above compound general formula (I), R 1 and R 2 Preferably C 1 ~C 10 An alkyl, cycloalkyl or arylalkyl group, more preferably C 1 ~C 10 The alkyl group is preferably a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group or a neopentyl group, and particularly preferably an ethyl group, an isopropyl group, an n-butyl group or an isobutyl group.

[0014] Furthermore, in the above technical solution, in the above compound general formula (I), preferably R 3 and R 4 , R 5 and R 6 At least one of the groups is hydrogen, more preferably, R 3 -R 6 All are hydrogen.

[0015] Furthermore, in the above technical scheme, the above compound general formula (I) includes but is not limited to: dimethyl bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylate, diethyl bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylate, diisopropyl 7-methyl-bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylate, dibutyl 7-methoxy-bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylate, 1-methyl-bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylate, diisobutyl formate, diisobutyl 1,4-dimethyl-bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylate, neopentyl alcohol 5,6-dimethyl-bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylate, diisobutyl 1,4,5,6-tetramethyl-bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylate, diisobutyl bicyclo[3.2.2.]non-8-ene-6,7-dicarboxylate, dineopentyl bicyclo[4.2.2.]dec-9-ene-7,8-dicarboxylate.

[0016] Furthermore, in the above technical solution, the particle size distribution of magnesium in the catalyst component is 20 to 250 μm, and the general formula is Mg(OR′)mM (2-m) ·nROH is provided by a magnesium halide alcoholate, as shown in the following reaction formula. 1 ~C 20 alkyl, arylalkyl or aryl; M is halogen; m is an integer of 0≤m≤2; n is a decimal or integer of 0<n<6; R is C 1 ~C 20 An alkyl or arylalkyl group.

[0017] Mg(OR′)mM(2-m)+nROH→Mg(OR′) m M (2-m) ·nROH

[0018] Furthermore, in the above technical scheme, the magnesium halide in the magnesium halide alcoholate is selected from one of magnesium dichloride, magnesium dibromide, chloromethoxymagnesium or chloroethoxymagnesium; the alcohol in the magnesium halide alcoholate is selected from one of methanol, ethanol, n-propanol, isopropanol, n-butanol or isobutanol, preferably ethanol.

[0019] Further, in the above technical scheme, the magnesium halide alcoholate is synthesized according to the literature report (US4399054), and the synthesis of magnesium chloride alcoholate is taken as an example. The specific synthesis method is as follows: 24g of anhydrous MgCl 2 , 390mL vaseline oil, 50mL anhydrous ethanol, 10mL silicone oil and 2mL silan were added to the autoclave, and stirred and heated to 130°C for 3 hours under nitrogen protection to completely dissolve the solid. Then, nitrogen was continuously charged into the autoclave and the pressure was maintained at 1MPa. The discharge valve was opened to allow the mixture in the autoclave to pass through a capillary tube with a diameter of 1.2mm and a length of 3.54m, and washed with hexane 5 times and dried at room temperature to obtain spherical MgCl 2 Ethanol complex carrier.

[0020] Furthermore, in the above technical solution, the titanium in the catalytic component is of the general formula TiA n (OR″) 4-n The compound is provided, wherein R″ is a hydrocarbon group having 1 to 20 carbon atoms; A is a halogen; and n=1 to 4. Specific compounds include: titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, tetrabutoxytitanium, tetraethoxytitanium, monochlorotriethoxytitanium, dichlorodiethoxytitanium or trichloromonoethoxytitanium, preferably titanium tetrachloride.

[0021] The present invention provides a preparation method of a catalytic component a, comprising: (1) adding a spherical magnesium halide alcoholate to a titanium compound at -40 to 10°C, reacting for 1 to 4 hours, wherein the molar ratio of magnesium to titanium is 1:5 to 1:50; (2) heating the temperature to 30 to 80°C, adding an inner electron compound, wherein the molar ratio of magnesium to the inner electron donor compound is 2:1 to 15:1; (3) heating the temperature to 100 to 150°C, reacting for 1 to 4 hours; (4) filtering, then adding the same amount of titanium compound as in step (1), reacting at 110 to 130°C for 1 to 4 hours, and filtering, washing, and drying to obtain the catalyst component a.

[0022] The above catalytic components are the main components, and the present invention can further provide a catalyst for olefin polymerization. Specifically comprising:

[0023] (a) a catalyst component a containing magnesium, titanium, halogen and at least one succinate selected from the group consisting of general formula (I);

[0024] (b) an alkylaluminum compound;

[0025] (c) optionally, an external electron donor component;

[0026] The usage of each component is 1:5-1000:0-500 based on the molar ratio of titanium:aluminum:external electron donor compound.

[0027] Furthermore, in the above technical solution, the alkylaluminum compound is a trialkylaluminum compound, such as triethylaluminum, triisobutylaluminum, tri-n-butylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, a mixture of trialkylaluminum and alkylaluminum halide or alkylaluminum hydride, or an alkylaluminumoxane.

[0028] Furthermore, in the above technical solution, the external electron donor can be selectively added as needed. For olefin polymers that need to have very high stereoregularity (such as an isotactic index greater than 99%), it is recommended to add an external electron donor compound.

[0029] Furthermore, in the above technical solution, the external electron donor may be selected to have the general formula R″′ n Si(OR″″) 4-n An organosilicon compound, wherein 0≤n≤3 is an integer; R″′ and R″″ are the same or different alkyl, cycloalkyl or aryl groups, optionally containing heteroatoms; R″′ may also be a halogen or a hydrogen atom. Diphenyldimethoxysilane is preferred.

[0030] Furthermore, in the above technical solution, the usage ratio of each component in the catalyst is preferably 1:25-100:25-300, calculated on the molar ratio of titanium:aluminum:external electron donor compound.

[0031] The catalyst of the present invention can be used for olefin polymerization, especially homopolymerization of propylene or copolymerization of propylene with other olefins to obtain polymers with very high isotactic index. At the same time, it is not excluded that the catalyst is suitable for the production of polyethylene and copolymerization of ethylene with α-olefins such as propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene or 1-octene.

[0032] When used for propylene polymerization, various methods in the prior art can be used, which can be carried out in liquid phase or gas phase, or in a combination of liquid phase and gas phase polymerization stages. The polymerization is usually carried out at 0 to 150°C, preferably 40 to 90°C. The polymerization pressure is 0.01 to 10 MPa. Hydrogen or other compounds that can act as chain transfer agents can be used to control the molecular weight of the polymer.

[0033] Since the present invention adopts succinate compound as internal electron donor, its unique electronic geometric effect makes the comprehensive performance of the catalyst excellent. When used for propylene (co)polymerization, a satisfactory polymerization yield can be obtained, and the stereospecificity of the polymer is high. At the same time, the catalyst is also very sensitive to hydrogen regulation. The molecular weight distribution of the obtained polymer is relatively wide, which is conducive to the development of different grades of polymers. DETAILED DESCRIPTION

[0034] The following embodiments are used to further illustrate the present invention, but not to limit the present invention.

[0035] 1. Synthesis of succinate

[0036] The synthesis of succinate esters can be obtained by reacting maleate esters with the corresponding cyclic dienes via DA reaction. Diisobutyl phthalate (99%) and di-n-butyl succinate (99%) were purchased from TCI (Shanghai).

[0037] Example 1

[0038] Synthesis of dimethyl bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylate. Add 28.8g dimethyl maleate and 40.0g 1,3-cyclohexadiene into a 150mL flask and stir and reflux overnight. Column chromatography separation was performed to obtain 44.8g of dimethyl bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylate, a colorless and transparent liquid product, with a yield of 99%. 1 The H NMR results are shown in Table 1.

[0039] Example 2

[0040] Synthesis of diethyl bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylate The synthesis method is the same as that of Example 1, except that 34.4 g of diethyl maleate and 40.0 g of 1,3-cyclohexadiene are used instead of 28.8 g of dimethyl maleate and 40.0 g of 1,3-cyclohexadiene, and the yield is 99%. 1 The H NMR results are shown in Table 1.

[0041] Example 3

[0042] Synthesis of 7-methyl-bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylic acid diisopropyl ester. The synthesis method is the same as that of Example 1, except that 40.0 g of diisopropyl maleate and 47.0 g of 5-methyl-1,3-cyclohexadiene are used to replace 28.8 g of dimethyl maleate and 40.0 g of 1,3-cyclohexadiene, with a yield of 99%. 1 The H NMR results are shown in Table 1.

[0043] Example 4

[0044] Synthesis of 7-methoxy-bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylic acid di-n-butyl ester. The synthesis method is the same as that of Example 1, except that 45.7 g of di-n-butyl maleate and 55.0 g of 5-methoxy-1,3-cyclohexadiene are used to replace 28.8 g of dimethyl maleate and 40.0 g of 1,3-cyclohexadiene, with a yield of 99%. 1 The H NMR results are shown in Table 1.

[0045] Example 5

[0046] Synthesis of 1-methyl-bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylic acid diisobutyl ester. The synthesis method is the same as that of Example 1, except that 45.7 g of diisobutyl maleate and 47.0 g of 1-methyl-1,3-cyclohexadiene are used to replace 28.8 g of dimethyl maleate and 40.0 g of 1,3-cyclohexadiene, with a yield of 99%. 1 The H NMR results are shown in Table 1.

[0047] Example 6

[0048] Synthesis of 1,4-dimethyl-bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylic acid diisobutyl ester. The synthesis method is the same as that of Example 1, except that 45.7 g of diisobutyl maleate and 54.0 g of 1,4-dimethyl-1,3-cyclohexadiene are used to replace 28.8 g of dimethyl maleate and 40.0 g of 1,3-cyclohexadiene, with a yield of 99%. 1 The H NMR results are shown in Table 1.

[0049] Example 7

[0050] Synthesis of 5,6-dimethyl-bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylic acid neopentyl alcohol ester. The synthesis method is the same as that of Example 1, except that 51.2 g of dineopentyl maleate and 54.0 g of 2,3-dimethyl-1,3-cyclohexadiene are used to replace 28.8 g of dimethyl maleate and 40.0 g of 1,3-cyclohexadiene, with a yield of 99%. 1 The H NMR results are shown in Table 1.

[0051] Example 8

[0052] Synthesis of 1,4,5,6-tetramethyl-bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylic acid diisobutyl ester. The synthesis method is the same as that of Example 1, except that 45.7 g of diisobutyl maleate and 68.0 g of 1,2,3,4-tetramethyl-1,3-cyclohexadiene are used to replace 28.8 g of dimethyl maleate and 40.0 g of 1,3-cyclohexadiene, with a yield of 99%. 1 The H NMR results are shown in Table 1.

[0053] Example 9

[0054] Synthesis of diisobutyl bicyclo[3.2.2.]non-8-ene-6,7-dicarboxylate The synthesis method is the same as that of Example 1, except that 45.7 g of diisobutyl maleate and 47.0 g of 1,3-cycloheptadiene are used instead of 28.8 g of dimethyl maleate and 40.0 g of 1,3-cyclohexadiene, with a yield of 99%. 1 The H NMR results are shown in Table 1.

[0055] Example 10

[0056] Synthesis of dineopentyl bicyclo[4.2.2.]dec-9-ene-7,8-dicarboxylate The synthesis method is the same as that of Example 1, except that 51.2 g of dineopentyl maleate and 54.0 g of 1,3-cyclooctadiene are used instead of 28.8 g of dimethyl maleate and 40.0 g of 1,3-cyclohexadiene, with a yield of 99%. 1 The H NMR results are shown in Table 1.

[0057] Table 1. Internal electron donors 1 HNMR results

[0058]

[0059] 2. Preparation of Catalytic Component A

[0060] Add TiCl into a dry glass reactor protected by nitrogen. 4 The mixture was cooled to -20°C and a microspherical magnesium chloride alcoholate (magnesium alcohol ratio of 2.9:1) carrier was added under stirring. The carrier and TiCl 4The mixing ratio is 1g:20mL, the reaction mixture is heated uniformly from -20℃ to 0℃, and then to 70℃, the internal electron donor is added to the reactor, the reaction mixture is heated to 110℃, and the reaction is continued for 2h; filter, add fresh equal amount of TiCl 4 , the temperature was raised to 120℃ and the reaction was continued for 2h, then filtered, the filter cake was washed with hexane, and vacuum dried to obtain the catalyst component. The loading amount of the internal electron donor was determined by Angent 8890A gas chromatograph; the loading amount of titanium was determined by spectrophotometer.

[0061] 3. Propylene polymerization

[0062] 0.2 mL of external electron donor diphenyldimethoxysilane, 8.0 mL of a hexane solution of a co-catalyst triethylaluminum with a concentration of 1 mol / L, and 0.01 mmol (calculated as titanium) of the catalyst component a prepared by the present invention were added to a 5 L autoclave in sequence, 2.5 L of liquid propylene and 0.2 MPa of hydrogen were introduced, stirred and mixed uniformly at room temperature, heated to 70° C., stirred for reaction for 2 h, the autoclave was opened to take out the polypropylene, and the polymer was cooled to room temperature and weighed after the propylene was completely volatilized, the activity of the catalyst was calculated, and the isotacticity, bulk density, melt index, particle size distribution and other properties of the polypropylene were measured.

[0063] In Examples 11-20, propylene polymerization was carried out using the Ziegler-Natta catalyst synthesized by the internal electron donor in Examples 1-10 and the above-mentioned polymerization steps. The polymerization results are shown in Table 2.

[0064] Table 2. Aggregation results

[0065]

[0066]

[0067] From the above results, it can be seen that the activity and isotacticity of the synthesized catalyst with succinate as internal electron donor are significantly better than those of the commercial di-n-butyl phthalate and di-n-butyl succinate supported catalysts.

Claims

1. A solid catalyst for olefin polymerization, comprising, by weight percentage, 10% to 25% magnesium, 1% to 10% titanium, 40% to 60% halogen and 1% to 30% internal electron donor, characterized in that The internal electron donor compound is selected from at least one succinate ester in the general formula (I): Wherein n≥2 and is a positive integer, the groups R1 and R2 are the same or different from each other and are selected from C1 to C 20 a linear or branched alkyl, alkenyl, cycloalkyl, aryl, arylalkyl or alkylaryl group, optionally containing heteroatoms; the groups R3, R4, R5, R6 are identical or different and are selected from hydrogen or C1-C 20 A linear or branched alkyl, alkenyl, cycloalkyl, aryl, arylalkyl or alkylaryl group, optionally containing heteroatoms, and two or more groups among R3, R4, R5 and R6 can be bonded to each other to form one or more condensed ring structures.

2. The catalyst according to claim 1, characterized in that In the general formula (I) of the internal electron donor compound, R1 and R2 are ethyl, isopropyl, n-butyl, isobutyl or neopentyl.

3. The catalyst according to claim 1, characterized in that In the general formula (I) of the internal electron donor compound, at least one of the two groups of R3 and R4; R5 and R6 is hydrogen.

4. The catalyst according to claim 1, characterized in that The internal electron donor compound of general formula (I) is dimethyl bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylate, diethyl bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylate, diisopropyl 7-methyl-bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylate, di-n-butyl 7-methoxy-bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylate, diisobutyl 1-methyl-bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylate, diisopropyl 1-methyl-bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylate, di-n-butyl 1-methyl-bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylate, diisopropyl ... ,4-dimethyl-bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylic acid diisobutyl ester, 5,6-dimethyl-bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylic acid neopentyl alcohol ester, 1,4,5,6-tetramethyl-bicyclo[2.2.2]oct-5-ene-2,3-dicarboxylic acid diisobutyl ester, bicyclo[3.2.2.]non-8-ene-6,7-dicarboxylic acid diisobutyl ester, bicyclo[4.2.2.]dec-9-ene-7,8-dicarboxylic acid dineopentyl alcohol ester.

5. The catalyst according to claim 1, characterized in that The particle size distribution of magnesium in the catalyst component is 20 to 250 μm, and the general formula is Mg(OR')mM (2-m) ·nROH is provided by a magnesium halide alcoholate, wherein R' is C1~C 20 alkyl, arylalkyl or aryl; M is halogen; m is an integer where 0 ≤ m ≤ 2; n is a decimal or an integer where 0 < n < 6; R is an alkyl or arylalkyl having C1 to C 20 alkyl; The titanium in the catalytic component is represented by the general formula TiA n (OR”) 4-n A compound is provided, wherein R is a hydrocarbon group having 1 to 20 carbon atoms; A is a halogen; and n=1 to 4.

6. The catalyst according to claim 5, characterized in that A magnesium halide alcoholate of magnesium is provided, wherein the magnesium halide is one of magnesium dichloride, magnesium dibromide, chloromethoxymagnesium or chloroethoxymagnesium; and the alcohol in the magnesium halide alcoholate is one of methanol, ethanol, n-propanol, isopropanol, n-butanol or isobutanol; The titanium in the catalytic component is provided by titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, titanium tetrabutoxide, titanium tetraethoxide, titanium triethoxide monochloride, titanium diethoxide dichloride or titanium triethoxide monochloride.

7. A catalyst characterized in that Catalysts include: (a) the catalyst according to any one of claims 1 to 6; (b) an alkylaluminum compound; (c) optionally, an external electron donor component; The usage of each component is 1:5-1000:0-500 based on the molar ratio of titanium:aluminum:external electron donor compound.

8. The catalyst according to claim 7, characterized in that The alkylaluminum compound is a trialkylaluminum compound; The external electron donor is of the general formula R' n Si(OR””) 4-n An organosilicon compound, wherein 0≤n≤3 is an integer; R'' and R"" are the same or different alkyl, cycloalkyl or aryl groups.

9. The catalyst according to claim 8, characterized in that The alkylaluminum compound is triethylaluminum, triisobutylaluminum, tri-n-butylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, a mixture of a trialkylaluminum and an alkylaluminum halide or an alkylaluminum hydride, or an alkylaluminumoxane.

10. The catalyst according to claim 8, characterized in that The external electron donor is diphenyldimethoxysilane.

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