Ethylene oligomerization catalyst composition and application thereof

Abstract

The present invention discloses an ethylene polymerization catalyst composition and its application. The ethylene polymerization catalyst composition comprises a main catalyst and a co-catalyst, wherein the main catalyst comprises a metal complex of AMBn of general formula (I), and the co-catalyst is an organic aluminum compound; wherein A is an organic ligand of general formula (II), and general formula (II) is (Ar1)(Ar2)PN(R)P(Ar3)(Ar4), wherein Ar1, Ar2, Ar3, Ar4 are each independently a phenyl group or a halogen-substituted phenyl group; wherein M is selected from a transition metal of chromium, molybdenum or tungsten; wherein B is selected from acetylacetone, tetrahydrofuran, isooctanoic acid; wherein n=1 to 3. The catalyst composition of the invention has the characteristics of high catalytic activity, high selectivity, mild reaction conditions, etc., and has good industrial application prospects and economic value.

Description

Technical Field

[0001] The invention relates to the field of ethylene polymerization, specifically to the field of ethylene oligomerization, ethylene trimerization or ethylene tetramerization, and more specifically to an ethylene oligomerization catalyst composition and application thereof. Background Art

[0002] Ethylene oligomerization is one of the most important reactions in the olefin polymerization industry. Through oligomerization, cheap small molecule ethylene can be converted into high value-added products, namely α-olefins of different length chains. Since the 1970s, the research on olefin polymerization and oligomerization catalyzed by transition metal complexes has gradually attracted the attention of scientists. People have begun to study new catalysts and improve existing catalysts to improve the activity of catalysts and the selectivity of catalytic products. Among the many explorations, the earliest, fastest-growing and most concentrated one is the nickel-based cationic catalytic system, such as the long-reported US patents US3686351A and US3676523A, and the Shell SHOP process based on the patented technology. The Shell SHOP process involves OP bridging ligands, but the catalyst contains toxic organic phosphorus groups, and the synthesis steps are complicated and the stability is poor. Later, many patents such as OO, PN, PP and NN type coordinated nickel catalysts were developed, such as JP11060627, WO9923096A1, CN1401666A, CN1769270A, etc. However, the catalysts obtained from the above patents generally have the disadvantage that the preparation method is relatively complicated.

[0003] Sasol's patent WO2004056478A1 discloses a PNP skeleton catalyst. In the ethylene tetramerization reaction, the selectivity of the C8 component is about 66wt%, the selectivity of the C6 component is about 21wt%, of which the content of 1-hexene in the C6 component is only 82%, and the total selectivity of 1-hexene and 1-octene is about 84%. The US20100137669A1 patent discloses a PCCP symmetric skeleton catalyst. In the ethylene tetramerization reaction, the catalyst is more stable than the PNP system, and the total selectivity of 1-hexene and 1-octene does not exceed 85%.

[0004] In the above reaction systems, although the byproducts such as cycloolefins and cyclized products in the C6 product can be removed by separation and purification, it is not conducive to the economic efficiency of the entire process. Therefore, how to increase the content of 1-hexene in the C6 component while maintaining a high 1-octene content in the reaction product, thereby improving the economic efficiency of the process, is of certain challenge. Summary of the invention

[0005] In view of the above problems existing in the prior art, the present invention provides a new ethylene polymerization catalyst composition. The catalyst composition of the present invention has the characteristics of high catalytic activity, high selectivity and mild reaction conditions for ethylene polymerization, and has good industrial application prospects and economic value.

[0006] The first aspect of the present invention provides an ethylene polymerization catalyst composition, comprising a main catalyst and a co-catalyst, wherein the main catalyst comprises a metal complex of AMBn of general formula (I), and the co-catalyst is an organic aluminum compound.

[0007] wherein A is an organic ligand of the general formula (II), the general formula (II) is (Ar1)(Ar2)PN(R)P(Ar3)(Ar4), wherein Ar1, Ar2, Ar3, Ar4 are each independently a phenyl group or a halogen-substituted phenyl group;

[0008] wherein M is a transition metal selected from chromium, molybdenum or tungsten;

[0009] Wherein B is selected from acetylacetone, tetrahydrofuran, isooctanoic acid; wherein n=1-3.

[0010] According to some embodiments of the present invention, in the general formula (II), Ar1, Ar2, Ar3, Ar4 connected to P have one or more phenyl groups with fluorine atoms or fluorinated substituents at the ortho position.

[0011] According to some embodiments of the present invention, in the general formula (II), R is selected from substituted or unsubstituted C1-C 20 Alkyl, substituted or unsubstituted C3-C 20 Cycloalkyl and substituted or unsubstituted C6-C 30 Preferably, R is selected from substituted or unsubstituted C1-C 10 Alkyl, substituted or unsubstituted C3-C 10 Cycloalkyl and substituted or unsubstituted C6-C 20 More preferably, R is selected from at least one of methyl, ethyl, propyl, isopropyl, butyl, isobutyl, cyclopropyl, cyclopentyl, cyclohexyl, phenyl and substituted phenyl.

[0012] According to some embodiments of the present invention, preferably, the general formula (II) is selected from (Ph)2PN( i Pr)P(Ph)(2-F-Ph) 、 (Ph)2PN( i Pr)P(2-F-Ph)2, (2-F-Ph)(Ph)PN( i Pr)P(Ph)(2-F-Ph) , (2-F-Ph)(Ph)PN( iPr)P(2-F-Ph)2, (Ph)2PN( t Bu)P(Ph)(2-F-Ph), (Ph)2PN(C y )P(Ph)(2-F-Ph), (Ph)2PN(Ph)P(Ph)(2-F-Ph).

[0013] According to some embodiments of the present invention, in the general formula (I), M is a transition metal selected from chromium.

[0014] According to some embodiments of the present invention, in the general formula (I), B is selected from acetylacetone.

[0015] According to some embodiments of the present invention, in the general formula (I), n represents the number of molecules satisfying the valence state of M, for example, n is selected from 1, 2 or 3, and preferably, n is 3.

[0016] According to some embodiments of the present invention, the organoaluminum compound is selected from at least one of an alkylaluminum compound, an alkoxyaluminum compound, and an alkylaluminum chloride compound, and more preferably selected from at least one of methylaluminoxane, trimethylaluminum, triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, diethylaluminum monochloride, ethylaluminum dichloride, ethylaluminumoxane, and modified methylaluminoxane. In the present invention, the modified methylaluminoxane may be an alkyl-modified methylaluminoxane, such as the conventional alkyl-modified methylaluminoxane MMAO in the art.

[0017] According to some embodiments of the present invention, the molar ratio of the main catalyst to the co-catalyst is 1:1-3000, preferably 1:10-2000, and more preferably 1:100-1000.

[0018] The second aspect of the present invention provides a method for ethylene oligomerization, comprising: carrying out ethylene oligomerization reaction in an organic solvent in the presence of the above-mentioned catalyst composition.

[0019] According to some embodiments of the present invention, based on the volume of the organic solvent, the concentration of the catalyst composition is 0.1-10 μmol / L in terms of metal.

[0020] According to some embodiments of the present invention, the reaction conditions may be the reaction conditions commonly used in the art. Preferably, the reaction temperature of the ethylene oligomerization reaction is 0-75° C., preferably 30-75° C., more preferably 40-65° C. The catalyst composition of the present invention can be used to react at a relatively mild temperature, and the oligomerization effect is good.

[0021] According to some embodiments of the present invention, the reaction conditions may be the reaction conditions commonly used in the art. Preferably, the ethylene pressure of the ethylene oligomerization reaction is 0.1-20.0 MPa, preferably 0.5-5.0 MPa, more preferably 2.0-5.0 MPa.

[0022] According to some embodiments of the present invention, the organic solvent includes aliphatic hydrocarbon compounds and / or aromatic hydrocarbon compounds.

[0023] According to some embodiments of the present invention, the aliphatic hydrocarbon compound is selected from at least one of straight-chain alkanes, branched-chain alkanes and cycloalkanes; more preferably at least one of pentane, heptane, hexane, cyclohexane and methylcyclohexane.

[0024] According to some embodiments of the present invention, the aromatic hydrocarbon compound is selected from at least one of benzene, toluene, xylene, monochlorobenzene, dichlorobenzene, trichlorobenzene, monochlorotoluene and derivatives thereof.

[0025] According to some embodiments of the present invention, in the above reaction, the main catalyst and the co-catalyst in the catalyst composition can be pre-mixed and then added to the reaction system together, or the two components of the main catalyst and the co-catalyst can be added to the reaction system separately.

[0026] The third aspect of the present invention provides a method for ethylene trimerization or ethylene tetramerization, comprising: carrying out ethylene trimerization or ethylene tetramerization reaction in an organic solvent in the presence of the above-mentioned catalyst composition.

[0027] According to some embodiments of the present invention, based on the volume of the organic solvent, the concentration of the catalyst composition is 0.1-10 μmol / L in terms of metal.

[0028] According to some embodiments of the present invention, the reaction conditions may be the reaction conditions commonly used in the art. Preferably, the reaction temperature of the ethylene trimerization or ethylene tetramerization reaction is 0-75° C., preferably the reaction temperature is 30-75° C., and more preferably 40-65° C. The catalyst composition of the present invention can be used to react at a relatively mild temperature, and the polymerization effect is good.

[0029] According to some embodiments of the present invention, the reaction conditions may be the reaction conditions commonly used in the art. Preferably, the ethylene pressure of the ethylene trimerization or ethylene tetramerization reaction is 0.1-20.0 MPa, preferably 0.5-5.0 MPa, more preferably 2.0-5.0 MPa.

[0030] According to some embodiments of the present invention, in the above reaction, the main catalyst and the co-catalyst in the catalyst composition can be pre-mixed and then added to the reaction system together, or the two components of the main catalyst and the co-catalyst can be added to the reaction system separately.

[0031] Beneficial effects of the present invention:

[0032] (1) The ethylene polymerization catalyst composition of the present invention has a novel structure, is simple to prepare and has a low cost.

[0033] (2) The catalyst composition of the present invention can effectively catalyze the polymerization (including trimerization, tetramerization, and oligomerization) of ethylene, with high catalyst activity, good product selectivity, and mild reaction conditions; and by-products such as cycloolefins and cyclized products in the C6 product are significantly reduced.

[0034] (3) The catalyst composition described in the present invention has the characteristics of high catalytic activity and high selectivity, and has good industrial application prospects and economic value. DETAILED DESCRIPTION

[0035] In order to make the present invention easier to understand, the present invention will be described in detail below with reference to embodiments. These embodiments are only for illustration and are not intended to limit the application scope of the present invention.

[0036] The test method of the present invention and the equipment used in the test are as follows:

[0037] (1) In the embodiments of the present invention, nuclear magnetic resonance is detected using a Bruker AV400 nuclear magnetic resonance instrument, wherein the detection conditions of the nuclear magnetic resonance are: deuterated chloroform is used as the solvent.

[0038] (2) Room temperature test The gas chromatography was tested using an Agilent 7890 chromatograph, wherein the detection conditions of the gas chromatography were: chromatographic column SE-54, high-purity nitrogen carrier gas, FID detector; and the column temperature was raised using a two-step program.

[0039] In the present invention, t Bu is tert-butyl, i Pr is isopropyl, Cy is cyclohexyl, Ph is phenyl, Ar is substituted aryl, acac is acetylacetone, 2-EHA is isooctanoic acid, and THF is tetrahydrofuran.

[0040] [Preparation Example 1]

[0041] Preparation of organic ligand A 1 :(Ph)2PN( i Pr)P(Ph)(2-F-Ph)

[0042] At 0°C, (o-fluorophenyl)phenylphosphonium chloride (10 mmol) was added dropwise to a solution of isopropylamine (12.5 mmol) and triethylamine (5 mL) in dichloromethane (10 mL), and stirred for 30 minutes. The mixture was then heated to room temperature and stirred overnight. The solvent was drained from the mixture, and anhydrous ether (20 mL) was added to form a suspension. The filtrate was filtered and dried under reduced pressure to obtain an oily substance. The oily substance (2.0 g) was dissolved in dichloromethane (10 mL), triethylamine (0.5 mL) was added, and then diphenylphosphonium chloride (3.3 g, 15.2 mmol) was added dropwise. After the addition was complete, the mixture was heated to room temperature and stirred overnight. The solvent of the mixture was drained, and a white solid powder A was obtained by basic alumina column chromatography. 1 . 1 H NMR (400MHz, CDCl3) δ=7.52-7.41(m,1H),7.42-7.22(m,16H),7.11(t,1H),6.99(td,1H),3.87-3.69(m,1H),1.30(d,3H),1.02(d,3H).

[0043] [Preparation Example 2]

[0044] Preparation of organic ligand A 2 :(Ph)2PN( i Pr)P(2-F-Ph)2

[0045] Di(o-fluorophenyl)phosphine chloride (10 mmol) was added dropwise to a solution of isopropylamine (12.5 mmol) and triethylamine (5 mL) in dichloromethane (10 mL) at 0°C and stirred for 30 minutes, then heated to room temperature and stirred overnight, the mixture was drained of solvent, and then anhydrous ether (20 mL) was added to form a suspension, and the filtrate was filtered and decompressed to obtain an oily crude product. 0.5 g of the crude product was dissolved in dichloromethane (10 mL), triethylamine (0.5 mL) was added, and then diphenylphosphine chloride (0.8 g, 3.6 mmol) was added dropwise. After the addition was complete, the mixture was heated to room temperature and stirred overnight, the mixture solvent was drained, and white solid powder A was obtained by basic alumina column chromatography. 2 . 1 H NMR (400MHz, CDCl3) δ=7.42-7.27(m,14H),7.09(t,2H),6.99(td,2H),3.93-3.77(m,1H),1.18(d,6H).

[0046] [Preparation Example 3]

[0047] Preparation of organic ligand A 3 :(2-F-Ph)(Ph)PN( i Pr)P(Ph)(2-F-Ph)

[0048] (o-Fluorophenyl)phenylphosphonium chloride (10 mmol) was added dropwise to a solution of isopropylamine (4 mmol) and triethylamine (5 mL) in dichloromethane (10 mL) at 0°C and stirred for 30 minutes, then heated to room temperature and stirred overnight. The mixture was drained of solvent and purified by basic alumina column chromatography to obtain a white solid powder ligand A. 3 . 1 H NMR (400MHz, CDCl3) δ7.45(m,1H),7.39-7.20(m,13H),7.10(m,2H),6.97(m,2H),3.91-3.70(m,1H),1.40(d,1.5H),1.17(d,3H),0.90(d,1.5H).

[0049] [Preparation Example 4]

[0050] Preparation of organic ligand A 4 :(2-F-Ph)(Ph)PN( i Pr)P(2-F-Ph)2

[0051] Di(o-fluorophenyl)phosphonium chloride (10 mmol) was added dropwise to a dichloromethane (10 mL) solution of isopropylamine (12.5 mmol) and triethylamine (5 mL) at 0°C and stirred for 30 minutes, then heated to room temperature and stirred overnight, the mixture was drained of solvent, and then anhydrous ether (20 mL) was added to form a suspension, and the filtrate was filtered and decompressed to obtain an oily substance. The oily substance (1.8 g) was dissolved in n-hexane, cooled to -60°C, and n-butyl lithium (6.3 mmol) was added. After the addition, the temperature was slowly raised to room temperature, stirred for 30 minutes, cooled to -60°C again, (o-fluorophenyl)phenylphosphonium chloride (1.7 g, 7.0 mmol) was added dropwise, stirred for 30 minutes, and then moved to room temperature, reacted overnight, the mixture solvent was drained, and white solid powder A was obtained by basic alumina column chromatography. 4 . 1 H NMR (400MHz, CDCl3) δ7.33(m,11H),7.18-7.04(m,3H),7.05-6.87(m,3H),3.86(m,1H),1.33(d,6H).

[0052] [Preparation Example 5]

[0053] Preparation of organic ligand A 5 :(Ph)2PN( t Bu)P(Ph)(2-F-Ph)

[0054] The preparation method is the same as that of Preparation Example 1, except that isopropylamine is replaced by tert-butylamine. 1H NMR (400MHz, CDCl3) δ = 7.49-7.40 (m, 1H), 7.38-7.20 (m, 16H), 7.09 (t, 1H), 6.98 (td, 1H), 1.20 (s, 9H).

[0055] [Preparation Example 6]

[0056] Preparation of organic ligand A 6 :(Ph)2PN(C y )P(Ph)(2-F-Ph)

[0057] The preparation method is the same as that of Preparation Example 1, except that isopropylamine is replaced by cyclohexylamine. 1 H NMR (400MHz, CDCl3) δ=7.50-7.43(m,1H),7.40-7.25(m,16H),7.11(t,1H),7.00(td,1H),2.90(m,1H),1.60-1.40(m,10H).

[0058] [Preparation Example 7]

[0059] Preparation of organic ligand A 7 :(Ph)2PN(Ph)P(Ph)(2-F-Ph)

[0060] The preparation method is the same as that of Preparation Example 1, except that isopropylamine is replaced by aniline. 1 H NMR (400MHz, CDCl3) δ = 7.35-6.90 (m, 24H).

[0061] [Preparation Example 8]

[0062] Preparation of organic ligand A 8 :(Ph)2PN(Ph)P(Ph)2, (i.e., phenyl group without fluorine atom or fluorinated substituent at the ortho position)

[0063] Diphenylphosphine chloride (10 mmol) was added dropwise to a solution of aniline (5 mmol) and triethylamine (5 mL) in dichloromethane (10 mL) at 0°C and stirred for 30 minutes, then heated to room temperature and stirred overnight. The mixture was drained of solvent, and then anhydrous ether (20 mL) was added to form a suspension. The filtrate was filtered and dried under reduced pressure to obtain an oily substance. The oily substance was subjected to basic alumina column chromatography to obtain a white solid powder A. 8 . 1 H NMR (400MHz, CDCl3) δ = 7.40-6.85 (m, 25H).

[0064]

Synthesis Example 1-10

[0065] The preparation method of the metal complex AMBn is as follows: 5 mmol of organic ligand A 1 -A 8 (prepared in Preparation Examples 1-8, respectively) and 5 mmol of chromium acetylacetonate were transferred to a Schlenk tube, 50 mL of toluene solution was added, and then the temperature was raised to 80°C and stirred for 8 hours. The reaction solution was cooled to room temperature and filtered, and the obtained solid was washed with toluene and n-hexane, respectively, and vacuum dried to obtain the corresponding metal complex AMBn, i.e., C 1 -C 8 .

[0066] Metal Complex C 9 The preparation method is the same as that of Synthesis Example 7, except that chromium acetylacetonate is replaced by chromium isooctanoate.

[0067] Metal Complex C 10 The preparation method is the same as that of Synthesis Example 1, except that chromium acetylacetonate is replaced by tetrahydrofuran chromium chloride.

[0068] [Example 1]

[0069] Using metal complex C 1 (AMBn, where A is (Ph)2PN( i Pr)P(Ph)(2-F-Ph), M is Cr, Bn is (acac)3) for ethylene polymerization reaction.

[0070] A 300 mL stainless steel polymerization autoclave was used. The autoclave was heated to 80°C, evacuated and replaced with nitrogen several times, then filled with ethylene for replacement, and then cooled to the set temperature. Methylcyclohexane was then added at 40°C, and 0.1 μmol of metal complex C was added at the same time. 1 and co-catalyst modified methylaluminoxane (MMAO), the total volume of the mixed solution is 100 mL, wherein the metal complex C 1 The molar ratio of the catalyst to the co-catalyst is 1:2000, the reaction pressure is controlled at 3MPa, ethylene is introduced, and the ethylene polymerization reaction is carried out at 40°C.

[0071] After half an hour, the reaction was completed, the system was cooled to room temperature, the gas phase product was collected in a gas metering tank, the liquid phase product was collected in a conical flask, and 1 mL of ethanol was added as a terminator to terminate the reaction. The gas and liquid phase products were measured and analyzed by gas chromatography (the chromatograph was HP 5890). The data results are shown in Table 1.

[0072] [Example 2]

[0073] Using metal complex C 2 (AMBn, where A is (Ph)2PN( iPr)P(2-F-Ph)2, M is Cr, Bn is (acac)3) to carry out ethylene polymerization reaction.

[0074] Same as Example 1, except that the metal complex C 1 Replaced by metal complex C 2 The data results are shown in Table 1.

[0075] [Example 3]

[0076] Using metal complex C 3 (AMBn, where A is (2-F-Ph)(Ph)PN( i Pr)P(Ph)(2-F-Ph), M is Cr, Bn is (acac)3) for ethylene polymerization reaction.

[0077] Same as Example 1, except that the metal complex C 1 Replaced by metal complex C 3 The data results are shown in Table 1.

[0078] [Example 4]

[0079] Using metal complex C 4 (AMBn, where A is (2-F-Ph)(Ph)PN( i Pr)P(2-F-Ph)2, M is Cr, Bn is (acac)3) to carry out ethylene polymerization reaction.

[0080] Same as Example 1, except that the metal complex C 1 Replaced by metal complex C 4 The data results are shown in Table 1.

[0081] [Example 5]

[0082] Using metal complex C 5 (AMBn, where A is (Ph)2PN( t Bu)P(Ph)(2-F-Ph), M is Cr, Bn is (acac)3) for ethylene polymerization.

[0083] Same as Example 1, except that the metal complex C 1 Replaced by metal complex C 5 The data results are shown in Table 1.

[0084] [Example 6]

[0085] Using metal complex C 6 (AMBn, where A is (Ph)2PN(C y)P(Ph)(2-F-Ph), M is Cr, Bn is (acac)3) to carry out ethylene polymerization reaction.

[0086] Same as Example 1, except that the metal complex C 1 Replaced by metal complex C 6 The data results are shown in Table 1.

[0087] [Example 7]

[0088] Using metal complex C 7 (AMBn, wherein A is (Ph)2PN(Ph)P(Ph)(2-F-Ph), M is Cr, and Bn is (acac)3) for ethylene polymerization.

[0089] Same as Example 1, except that the metal complex C 1 Replaced by metal complex C 7 The data results are shown in Table 1.

[0090] [Example 8]

[0091] Using metal complex C 9 (AMBn, wherein A is (Ph)2PN(Ph)P(Ph)(2-F-Ph), M is Cr, and Bn is (2-EHA)3) for ethylene polymerization.

[0092] Same as Example 1, except that the metal complex C 1 Replaced by metal complex C 9 The data results are shown in Table 1.

[0093] [Example 9]

[0094] Using metal complex C 10 (AMBn, wherein A is (Ph)2PN(Ph)P(Ph)2, M is Cr, and Bn is (THF)3) for ethylene polymerization.

[0095] Same as Example 1, except that the metal complex C 1 Replaced by metal complex C 10 The data results are shown in Table 1.

[0096] [Example 10]

[0097] Using metal complex C 1 (AMBn, where A is (Ph)2PN( i Pr)P(Ph)(2-F-Ph), M is Cr, Bn is (acac)3) for ethylene polymerization reaction.

[0098] Same as Example 1, except that the modified methylaluminoxane is replaced by triethylaluminum. The data results are shown in Table 1.

[0099] [Example 11]

[0100] Using metal complex C 1 (AMBn, where A is (Ph)2PN( i Pr)P(Ph)(2-F-Ph), M is Cr, Bn is (acac)3) for ethylene polymerization reaction.

[0101] Same as Example 1, except that the reaction temperature was changed from 40° C. to 30° C. The data results are shown in Table 1.

[0102] [Example 12]

[0103] Using metal complex C 1 (AMBn, where A is (Ph)2PN( i Pr)P(Ph)(2-F-Ph), M is Cr, Bn is (acac)3) for ethylene polymerization reaction.

[0104] Same as Example 1, except that the reaction temperature was changed from 40° C. to 50° C. The data results are shown in Table 1.

[0105] [Example 13]

[0106] Using metal complex C 1 (AMBn, where A is (Ph)2PN( i Pr)P(Ph)(2-F-Ph), M is Cr, Bn is (acac)3) for ethylene polymerization.

[0107] Same as Example 1, except that the reaction temperature was changed from 40° C. to 60° C. The data results are shown in Table 1.

[0108] [Example 14]

[0109] Using metal complex C 1 (AMBn, where A is (Ph)2PN( i Pr)P(Ph)(2-F-Ph), M is Cr, Bn is (acac)3) for ethylene polymerization.

[0110] Same as Example 1, except that the reaction temperature was changed from 40° C. to 75° C. The data results are shown in Table 1.

[0111] [Example 15]

[0112] Using metal complex C 1 (AMBn, where A is (Ph)2PN(i Pr)P(Ph)(2-F-Ph), M is Cr, Bn is (acac)3) for ethylene polymerization reaction.

[0113] Same as Example 1, except that the reaction pressure was changed from 3 MPa to 5 MPa. The data results are shown in Table 1.

[0114] [Example 16]

[0115] Same as Example 1, except that the metal complex C 1 The molar ratio of the catalyst to the co-catalyst is 1: 1000. The data results are shown in Table 1.

[0116] [Example 17]

[0117] Same as Example 1, except that the metal complex C 1 The molar ratio of the catalyst to the co-catalyst is 1:3000. The data results are shown in Table 1.

[0118] [Example 18]

[0119] Using metal complex C 1 (AMBn, where A is (Ph)2PN( i Pr)P(Ph)(2-F-Ph), M is Cr, Bn is (acac)3) for ethylene polymerization reaction.

[0120] Same as Example 1, except that the reaction temperature was changed from 40° C. to 100° C. The data results are shown in Table 1.

[0121] [Example 19]

[0122] Using metal complex C 1 (AMBn, where A is (Ph)2PN( i Pr)P(Ph)(2-F-Ph), M is Cr, Bn is (acac)3) for ethylene polymerization reaction.

[0123] Same as Example 1, except that the reaction temperature was changed from 40° C. to 80° C. The data results are shown in Table 1.

[0124] [Example 20]

[0125] Using metal complex C 8 (AMBn, where A is (Ph)2PN(Ph)P(Ph)2, M is Cr, and Bn is (acac)3) for ethylene polymerization.

[0126] Same as Example 1, except that the metal complex C 1 Replaced by metal complex C 8 The data results are shown in Table 1.

[0127] [Comparative Example 1]

[0128] The compound bis[(S,S)-(phenyl)2PCH(Me)CH(Me)P(phenyl)2dichloro(μ-chloro)chromium] was used to carry out the polymerization of ethylene.

[0129] The implementation method is as described in Comparative Example 2 in CN104169003A. The data results are shown in Table 1.

[0130] [Comparative Example 2]

[0131] The compound bis[(S,S)-(o-fluoro-phenyl)2PCH(Me)CH(Me)P(o-fluoro-phenyl)2dichloro(μ-chloro)chromium] was used to carry out the polymerization of ethylene.

[0132] The implementation method is as described in Example 4 of CN104169003A. The data results are shown in Table 1.

[0133] [Comparative Example 3]

[0134] The same basic raw materials as in Example 1 were used, except that the metal complex of AMBn was not used, namely:

[0135] A 300 mL stainless steel polymerization reactor was used. The autoclave was heated to 80°C, evacuated and replaced with nitrogen several times, then filled with ethylene for replacement, and then cooled to the set temperature. Methylcyclohexane was then added at 40°C, and 0.1 μmol of chromium acetylacetonate, 0.1 μmol of (Ph)2PN ( i Pr)P(Ph)(2-F-Ph) and co-catalyst modified methylaluminoxane (MMAO), the total volume of the mixed solution is 100mL, of which the metal complex C 1 The molar ratio of the catalyst to the co-catalyst is 1:2000, the reaction pressure is controlled at 3MPa, ethylene is introduced, and the ethylene polymerization reaction is carried out at 40°C.

[0136] After half an hour, the reaction was completed, the system was cooled to room temperature, the gas phase product was collected in a gas metering tank, the liquid phase product was collected in a conical flask, and 1 mL of ethanol was added as a terminator to terminate the reaction. The gas and liquid phase products were measured and analyzed by gas chromatography. The data results are shown in Table 1.

[0137] Table 1

[0138]

[0139]

[0140] From the data in Table 1, it can be seen that the preferred catalyst composition provided by the present invention has a catalytic activity of more than 3.8×108 g·mol(Cr) -1 ·h -1 , up to 9.5×10 8 g·mol(Cr) -1 ·h -1 , under different conditions, the total selectivity of 1-hexene and 1-octene is above 93% by weight, and can be as high as over 98% by weight. Compared with Examples 18 and 19, the catalyst compositions provided by Examples 1-17 of the present invention have significantly higher catalyst activity and selectivity for 1-octene at lower reaction temperatures (below 75°C). Compared with Comparative Examples 1 to 2, the catalyst compositions provided by the present invention have catalyst activity several times or even more than 10 times higher. While maintaining high selectivity for 1-octene, the content of 1-hexene in C6 is greatly increased, and by-products such as cycloolefins and cyclized products are significantly reduced. This shows that the catalyst described in the present invention has better performance. Changes in the structure of the catalyst ligand affect the coordination ability and electronic effect of the ligand, and the complex formed with the metal is more suitable for ethylene oligomerization, which has a very obvious effect on the catalytic performance and effect.

[0141] The selectivity of 1-octene in the present invention is significantly improved. Since the polyolefin field, especially POE, C8-LLDPE, PAO new materials, etc., urgently needs copolymerization grade high-purity 1-octene, which is in short supply in the market and is completely dependent on imports in China, and its price is significantly higher than other long-chain α-olefins; therefore, the process technology with higher 1-octene selectivity has obvious economic benefits and social value.

[0142] The catalyst composition of the present invention can effectively catalyze ethylene polymerization reactions, especially ethylene oligomerization, ethylene trimerization and tetramerization reactions, has high catalyst activity, rapid reaction initiation, stable operation, good repeatability, strong practicability and broad industrial prospects.

[0143] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this field, under the technical enlightenment provided by the present invention, as common knowledge in the field, other equivalent variations and improvements can also be made, which should also be regarded as the protection scope of the present invention.

Claims

1. An ethylene oligomerization catalyst composition, comprising a main catalyst and a co-catalyst, wherein: The main catalyst comprises a metal complex of AMBn of general formula (I), and the co-catalyst is an organic aluminum compound; Where A is (Ph)2PN(C y )P(Ph)(2-F-Ph); wherein M is a transition metal selected from chromium, molybdenum or tungsten; Wherein B is selected from acetylacetone, tetrahydrofuran, isooctanoic acid; wherein n=1-3.

2. The composition according to claim 1, characterized in that In the general formula (I), M is selected from a transition metal of chromium; and / or B is selected from acetylacetone; and / or n is selected from 1, 2 or 3.

3. The composition according to claim 1, characterized in that The organic aluminum compound is at least one selected from an alkyl aluminum compound, an alkoxy aluminum compound, and an alkyl aluminum chloride compound.

4. The composition according to claim 3, characterized in that The organoaluminum compound is at least one selected from methylaluminoxane, trimethylaluminum, triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, diethylaluminum monochloride, ethylaluminum dichloride, ethylaluminumoxane and alkyl-modified methylaluminumoxane.

5. The composition according to any one of claims 1 to 3, characterized in that The molar ratio of the main catalyst to the co-catalyst is 1:1-3000.

6. The composition according to claim 5, characterized in that The molar ratio of the main catalyst to the co-catalyst is 1:100-1000.

7. A method for the polymerization of ethylene, comprising: An ethylene oligomerization reaction is carried out in an organic solvent in the presence of the catalyst composition according to any one of claims 1 to 6.

8. The method according to claim 7, characterized in that Based on the volume of the organic solvent, the concentration of the catalyst composition is 0.1-10 μmol / L in terms of metal; and / or, The reaction temperature of the ethylene oligomerization reaction is 0-75°C; and / or, The ethylene pressure of the ethylene polymerization reaction is 0.1-20.0 MPa.

9. The method according to claim 8, characterized in that The reaction temperature of the ethylene oligomerization reaction is 40-65°C; and / or, The ethylene pressure of the ethylene polymerization reaction is 2.0-5.0 MPa.

10. A method for ethylene trimerization or ethylene tetramerization, comprising: In the presence of the catalyst composition according to any one of claims 1 to 6, an ethylene trimerization or ethylene tetramerization reaction is carried out in an organic solvent.

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