Biphenyl diphosphine type catalyst ligand, catalyst composition and application thereof

Abstract

The invention relates to the technical field of ethylene polymerization, and provides a biphenyl diphosphine type catalyst ligand, a catalyst composition and application of the biphenyl diphosphine type catalyst ligand and the catalyst composition. The structure of the biphenyl diphosphine type catalyst ligand is shown as a formula (I), in the # imgabs0 # formula (I), R1, R2 and R3 are the same or different and are respectively and independently selected from naphthenic base and aryl; hydrogen on carbon of the naphthenic base and the aryl is optionally substituted by one or more substituent groups. The biphenyl diphosphine type catalyst ligand provided by the invention is novel in structure, simple to prepare and relatively low in cost; the catalyst composition can effectively catalyze the ethylene oligomerization reaction, is high in catalytic activity, high in 1-octene selectivity, mild and stable in reaction, good in repeatability and good in 1-hexene selectivity in C6 products, and has good industrial application prospects and economic values.

Description

Technical Field

[0001] The present invention relates to the technical field of ethylene polymerization, and more specifically to a biphenyldiphosphine type catalyst ligand, a catalyst composition and application thereof. Background Art

[0002] 1-Hexene or 1-octene is an important organic raw material and chemical intermediate, mainly used to produce high-quality polyethylene (PE), lubricant base oil, plasticizer, detergent, etc. Linear low-density polyethylene (LLDPE) produced by copolymerization of 1-hexene or 1-octene with ethylene can significantly improve the various properties of PE, especially the mechanical properties, optical properties, tear strength and impact strength of polyethylene. The product is very suitable for packaging film and agricultural covering film such as greenhouses and sheds. The polyolefin plastomers and polyolefin elastomers produced by copolymerization of 1-octene and ethylene currently have a large market consumption and demand. With the continuous development of the polyolefin industry, the demand for high-carbon chain α-olefins such as 1-hexene or 1-octene is growing rapidly worldwide.

[0003] Through the ethylene polymerization reaction, cheap small molecule ethylene can be converted into α-olefins of different long chains, thereby increasing the added value of the product. Since the 1970s, the research on olefin polymerization and polymerization catalyzed by transition metal complexes has gradually attracted the attention of scientists, and people have begun to work hard to study new catalysts and improve existing catalysts to improve the activity of catalysts and the selectivity of catalytic products. For example, 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%, 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, but the total selectivity of 1-hexene and 1-octene does not exceed 85%.

[0004] Copolymer grade high purity 1-octene is in short supply in the market. The Chinese market basically relies on imports, and its price is significantly higher than other long-chain α-olefins. Therefore, the development of process technology with higher selectivity for 1-octene has obvious economic benefits and social value. In addition, in the existing technology, there are more by-products such as cycloolefins and cyclized products in the C6 product, which is unfavorable to the economic efficiency of the entire process.

[0005] Therefore, it is of great significance 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. Summary of the invention

[0006] The object of the present invention is to provide a biphenylbisphosphine type catalyst ligand and a catalyst composition to solve the technical problem that the total selectivity of 1-hexene and 1-octene in the ethylene polymerization product in the prior art is not ideal.

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] In a first aspect, the present invention provides a biphenylbisphosphine-type catalyst ligand, the structure of which is shown in formula (I):

[0009]

[0010] In formula (I), R1, R2, and R3 are the same or different and are independently selected from cycloalkyl and aryl groups; the hydrogen on the carbon of the cycloalkyl and aryl groups is optionally substituted by one or more substituents.

[0011] According to some embodiments of the present invention, the cycloalkyl group is C3 to C 20 Cycloalkyl, preferably C3~C 10 The cycloalkyl group is more preferably a C3-C6 cycloalkyl group.

[0012] According to some embodiments of the present invention, the aryl group is C6 to C 20 Aryl, preferably C6~C 10 The aryl group is more preferably a C6-C8 aryl group.

[0013] According to some embodiments of the present invention, the substituent is selected from C1 to C 20 Alkyl, C3~C 20 Cycloalkyl, C1~C 20 Alkoxy, C6~C 20 Aryl, halogen.

[0014] According to some embodiments of the present invention, the substituent is selected from C1 to C 10 Alkyl, C3~C 10 Cycloalkyl, C1~C 10 Alkoxy, C6~C 12 Aryl, halogen.

[0015] According to some embodiments of the present invention, the substituent is selected from C1-C6 alkyl, C3-C6 cycloalkyl, C1-C6 alkoxy, C6-C 12 Aryl, halogen.

[0016] According to some embodiments of the invention, the substituent is selected from at least one of methyl, ethyl, propyl, butyl, isobutyl, pentyl, isopentyl, hexyl, cyclopropyl, cyclopentyl, cyclohexyl, methoxy, ethoxy, propoxy, butoxy, phenyl, tolyl, ethylphenyl, propylphenyl, biphenyl, naphthyl, fluorine, chlorine, bromine and iodine.

[0017] In a second aspect, the present invention provides a method for preparing the biphenylbisphosphine-type catalyst ligand described in the first aspect, comprising:

[0018]

[0019] S1: a first reaction is carried out with o-aminobiphenyl and PCl3 in a first solvent to obtain compound a;

[0020] S2: Compound a and AlCl3 undergo a second reaction to obtain compound b;

[0021] S3: Compound b and compound c undergo a third reaction in a second solvent to obtain compound d;

[0022] S4: Compound d and compound e undergo a fourth reaction in the presence of triethylamine in a third solvent to obtain a biphenyldiphosphine-type catalyst ligand having a structure as shown in formula (I);

[0023] Wherein, R1, R2, and R3 are the same or different, and are independently selected from cycloalkyl and aryl; the hydrogen on the carbon of the cycloalkyl and aryl is optionally substituted by one or more substituents.

[0024] According to some embodiments of the present invention, in step S1, the molar ratio of o-aminobiphenyl to PCl3 is 1:0.01-10, preferably 1:1-3.

[0025] According to some embodiments of the present invention, in step S2, the molar ratio of compound a to AlCl3 is 1:0.01-10, preferably 1:1-3.

[0026] According to some embodiments of the present invention, in step S3, the molar ratio of compound b to compound c is 1:0.01-10, preferably 1:1-3.

[0027] According to some embodiments of the present invention, in step S4, the molar ratio of compound d, compound e and triethylamine is 1:0.01-10:0.01-10, preferably 1:1-3:1-3.

[0028] According to some embodiments of the invention, the first solvent comprises benzene.

[0029] According to some embodiments of the invention, the second solvent comprises tetrahydrofuran (THF).

[0030] According to some embodiments of the invention, the third solvent comprises acetonitrile.

[0031] In a third aspect, the present invention provides a catalyst composition comprising the biphenyldiphosphine-type catalyst ligand described in the first aspect, a transition metal compound and an aluminum-containing co-catalyst.

[0032] According to some embodiments of the present invention, the transition metal compound is selected from at least one of compounds of chromium, molybdenum, iron, titanium, zirconium and nickel.

[0033] According to some embodiments of the present invention, the transition metal compound is selected from at least one of chromium acetylacetonate, chromium isooctanoate, tri(tetrahydrofuran)chromium trichloride and di(tetrahydrofuran)chromium dichloride.

[0034] According to some embodiments of the present invention, the aluminum-containing co-catalyst is an organic aluminum compound.

[0035] According to some embodiments of the present invention, the aluminum-containing co-catalyst is selected from at least one of an alkyl aluminum compound, an alkoxy aluminum compound, and an alkyl aluminum chloride compound.

[0036] According to some embodiments of the present invention, the aluminum-containing co-catalyst is selected from at least one of methylaluminoxane, trimethylaluminum, triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, diethylaluminum monochloride, ethylaluminum dichloride, ethylaluminumoxane and modified methylaluminumoxane.

[0037] According to some embodiments of the present invention, the aluminum-containing co-catalyst is selected from at least one of methylaluminoxane, triethylaluminum, and modified methylaluminoxane.

[0038] In the present invention, the modified methylaluminoxane may be an alkyl-modified methylaluminoxane, such as the conventional alkyl-modified methylaluminoxane MMAO in the art.

[0039] According to some embodiments of the present invention, the molar ratio of the transition metal compound, the biphenyl diphosphine-type catalyst ligand shown in formula (I), and the aluminum-containing co-catalyst, calculated as the transition metal, is 1:(0.1-10):(1-1000), preferably 1:(0.25-2):(10-700), and more preferably 1:(0.5-2):(100-500).

[0040] In a fourth aspect, the present invention provides use of the catalyst composition described in the third aspect in an ethylene oligomerization reaction.

[0041] In a fifth aspect, the present invention provides a method for ethylene polymerization, comprising: in the presence of the catalyst composition described in the third aspect, continuously adding ethylene, hydrogen and an organic solvent into a reactor to carry out an ethylene polymerization reaction.

[0042] According to some embodiments of the present invention, in the ethylene polymerization reaction, the concentration of the catalyst composition is 0.1-10 μmol / L in terms of transition metal, based on the volume of the organic solvent. For example, when the transition metal is Cr, the concentration of the catalyst composition is 0.1-10 μmol / L in terms of Cr.

[0043] In the present invention, the reactor used for the ethylene polymerization reaction can be a hybrid reactor commonly used in the art, such as a tank reactor, a tubular reactor, a loop reactor, etc. containing an agitator or a mixing system.

[0044] According to some embodiments of the present invention, the organic solvent comprises an aliphatic hydrocarbon compound and / or an aromatic hydrocarbon compound.

[0045] 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; preferably at least one of pentane, heptane, hexane, cyclohexane and methylcyclohexane.

[0046] 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.

[0047] According to some embodiments of the present invention, in the above reaction, one or more of the catalyst compositions may be pre-mixed and then added to the reaction system together, or each component may be added to the reaction system separately.

[0048] According to some embodiments of the present invention, in the ethylene polymerization reaction, the volume ratio of hydrogen to ethylene is 1:(1-10000), preferably 1:(10-2000).

[0049] According to some embodiments of the present invention, the reaction temperature of the ethylene oligomerization reaction is 0 to 200°C, preferably 0 to 100°C, more preferably 30 to 100°C, and further preferably 40 to 75°C.

[0050] According to some embodiments of the present invention, the ethylene pressure of the ethylene oligomerization reaction is 0.1 to 20.0 MPa, preferably 0.5 to 10.0 MPa, and more preferably 2.0 to 6.0 MPa.

[0051] According to some embodiments of the present invention, the ethylene oligomerization reaction includes ethylene trimerization reaction and ethylene tetramerization reaction.

[0052] The beneficial effects of the present invention are at least:

[0053] (1) The biphenyl diphosphine-type catalyst provided by the present invention has a novel ligand structure, is simple to prepare, and has low cost.

[0054] (2) The catalyst composition provided by the present invention includes a biphenyl diphosphine-type catalyst ligand, which can effectively catalyze the polymerization reaction of ethylene, has high selectivity for 1-octene, a mild and stable reaction, good repeatability, and good selectivity for 1-hexene in the C6 product, and significantly reduces by-products such as cycloolefins and cyclized products, and has good industrial application prospects and economic value. DETAILED DESCRIPTION

[0055] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain this patent in detail and do not limit the scope of protection of the present invention in any way.

[0056] Unless otherwise defined, the technical terms used in the following examples have the same meanings as those generally understood by those skilled in the art to which the present invention belongs. The reagents used in the following examples, unless otherwise specified, are all conventional biochemical reagents; the raw materials, instruments and equipment used in the following examples, etc., can all be purchased on the market or can be obtained by existing methods; the reagent amounts, unless otherwise specified, are the reagent amounts used in conventional experimental operations; the experimental methods, unless otherwise specified, are all conventional methods.

[0057] In each embodiment and comparative example of the present invention, each performance data is tested according to the following test method:

[0058] (1) Nuclear magnetic resonance: The detection was performed using a Bruker AV400 nuclear magnetic resonance instrument; the detection conditions were: deuterated chloroform as the solvent.

[0059] (2) Room temperature test gas chromatography: Agilent 7890 chromatograph was used for detection; the detection conditions were: chromatographic column SE-54, high-purity nitrogen carrier gas, FID detector; the column temperature was raised using a two-step program.

[0060] It should be noted that, in the present invention, Cy is a cyclohexyl group, Cp is a cyclopentyl group, Ph is a phenyl group, and Me is a methyl group.

[0061] Preparation Example 1

[0062] Preparation of catalyst ligand I 1 (R1=R2=R3=Ph)

[0063]

[0064] (1) dissolving o-aminobiphenyl (10 mmol) and phosphorus trichloride (10 mmol) in benzene and reacting them under reflux conditions to obtain a phosphine amine compound;

[0065] (2) reacting a phosphine amine compound (10 mmol) with AlCl3 (20 mmol) at 180°C to generate a phosphine amine ring compound;

[0066] (3) reacting a phosphine amine ring compound (10 mmol) with a Grignard reagent PhMgBr (20 mmol) in tetrahydrofuran (THF) at room temperature to obtain a phenyl-containing phosphine amine;

[0067] (4) At room temperature, a phenyl-containing phosphine amine (10 mmol) and Ph2PCl (15 mmol) were dissolved in acetonitrile and reacted in the presence of triethylamine to obtain catalyst ligand I. 1 .

[0068] Preparation Example 2

[0069] Preparation of catalyst ligand I 2 (R1=R2=Cy,R3=Ph)

[0070] The preparation method is the same as that of Preparation Example 1, except that Ph2PCl is replaced by Cy2PCl.

[0071] Preparation Example 3

[0072] Preparation of catalyst ligand I 3 (R1=R2=4-Me-Ph, R3=2-F-Ph)

[0073] The preparation method is the same as that of Preparation Example 1, except that PhMgBr is replaced by 2-F-PhMgBr, and Ph2PCl is replaced by (4-Me-Ph)2PCl.

[0074] Preparation Example 4

[0075] Preparation of catalyst ligand I 4 (R1=R2=Ph, R3=2-biphenyl)

[0076] The preparation method is the same as that of Preparation Example 1, except that PhMgBr is replaced by 2-biphenyl magnesium bromide.

[0077] Preparation Example 5

[0078] Preparation of catalyst ligand I 5 (R1=R2=3,5-di-tert-butyl-4-methoxyphenyl, R3=Cp)

[0079] The preparation method is the same as that of Preparation Example 1, except that PhMgBr is replaced by CpMgBr, and Ph2PCl is replaced by di(3,5-di-tert-butyl-4-methoxyphenyl)phosphine chloride.

[0080] Example 1

[0081] 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 45°C, along with 0.5 μmol of chromium acetylacetonate and 0.5 μmol of catalyst ligand I. 1 and co-catalyst modified methylaluminoxane (MMAO), the total volume of the mixed solution is 100 mL, wherein chromium acetylacetonate, catalyst ligand I 1 The molar ratio of ethylene to MMAO is 1:1:1000, the reaction pressure is controlled at 4MPa, a mixed gas of ethylene and hydrogen (the volume ratio of hydrogen to ethylene is 1:1000) is introduced, and ethylene polymerization is carried out at 45°C.

[0082] 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 test results are shown in Table 1.

[0083] Example 2

[0084] The preparation method is similar to that of Example 1, except that the catalyst ligand I 1 Replaced with catalyst ligand I 2 The test results are shown in Table 1.

[0085] Example 3

[0086] The preparation method is similar to that of Example 1, except that the catalyst ligand I 1 Replaced with catalyst ligand I 3 The test results are shown in Table 1.

[0087] Example 4

[0088] The preparation method is similar to that of Example 1, except that the catalyst ligand I 1 Replaced with catalyst ligand I 4 The test results are shown in Table 1.

[0089] Example 5

[0090] The preparation method is similar to that of Example 1, except that the catalyst ligand I 1 Replaced with catalyst ligand I 5 The test results are shown in Table 1.

[0091] Table 1

[0092]

[0093] As can be seen from the data in Table 1, the catalytic activity of the catalyst composition provided by the present invention is high, and the content of 1-octene in C8 and the content of 1-hexene in C6 are both very high, and the total selectivity of 1-hexene and 1-octene exceeds 90wt%. Compared with existing PNP ligands or PCCP ligands, the catalyst composition including the biphenyl diphosphine type catalyst ligand provided by the present invention has a higher total selectivity of 1-hexene and 1-octene, and a better catalytic performance. The change in the catalyst ligand structure affects the coordination ability and electronic effect of the ligand, and the complex formed with the metal is more suitable for ethylene polymerization reaction, thereby having a very obvious effect on the catalytic performance and effect.

[0094] It can be seen from the above test results that the catalyst composition provided by the present invention is used for ethylene oligomerization reaction, and the selectivity of 1-octene and 1-hexene in the product is very high. Since the polyolefin field, especially POE, C8-LLDPE, PAO new materials, etc., is in urgent need of copolymerization grade high-purity 1-octene or 1-hexene; therefore, the process technology with higher total selectivity of 1-octene and 1-hexene has obvious economic benefits and social value.

[0095] It should be noted that the embodiments described above are only used to explain the present invention and do not constitute any limitation to the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than restrictive words. The present invention may be modified as specified within the scope of the claims of the present invention, and the present invention may be revised without departing from the scope and spirit of the present invention. Although the present invention described therein relates to specific methods, materials and embodiments, it does not mean that the present invention is limited to the specific examples disclosed therein, on the contrary, the present invention can be extended to all other methods and applications with the same functions.

Claims

1. A biphenyldiphosphine type catalyst ligand, the structure of which is shown in formula (I), In formula (I), R1, R2, and R3 are the same or different and are independently selected from cycloalkyl and aryl groups; the hydrogen on the carbon of the cycloalkyl and aryl groups is optionally substituted by one or more substituents.

2. The biphenylbisphosphine type catalyst ligand according to claim 1, characterized in that: The cycloalkyl group is C3~C 20 Cycloalkyl, preferably C3~C 10 Cycloalkyl, more preferably C3-C6 cycloalkyl; And / or, the aryl group is C6~C 20 Aryl, preferably C6~C 12 Aryl, more preferably C6-C8 aryl; And / or, the substituent is selected from C1 to C 20 Alkyl, C3~C 20 Cycloalkyl, C1~C 20 Alkoxy, C6~C 20 Aryl, halogen; preferably selected from C1 to C 10 Alkyl, C3~C 10 Cycloalkyl, C1~C 10 Alkoxy, C6~C 12 Aryl, halogen; more preferably selected from C1-C6 alkyl, C3-C6 cycloalkyl, C1-C6 alkoxy, C6-C 12 Aryl, halogen; further selected from at least one of methyl, ethyl, propyl, butyl, isobutyl, pentyl, isopentyl, hexyl, cyclopropyl, cyclopentyl, cyclohexyl, methoxy, ethoxy, propoxy, butoxy, phenyl, tolyl, ethylphenyl, propylphenyl, biphenyl, naphthyl, fluorine, chlorine, bromine and iodine.

3. The method for preparing the biphenylbisphosphine type catalyst ligand according to claim 1 or 2, characterized in that: include: S1: a first reaction is carried out with o-aminobiphenyl and PCl3 in a first solvent to obtain compound a; S2: Compound a and AlCl3 undergo a second reaction to obtain compound b; S3: Compound b and compound c undergo a third reaction in a second solvent to obtain compound d; S4: Compound d and compound e undergo a fourth reaction in the presence of triethylamine in a third solvent to obtain a biphenyldiphosphine-type catalyst ligand having a structure as shown in formula (I); Wherein, R1, R2, and R3 are the same or different, and are independently selected from cycloalkyl and aryl; the hydrogen on the carbon of the cycloalkyl and aryl is optionally substituted by one or more substituents.

4. The preparation method according to claim 3, characterized in that: In the step S1, the molar ratio of o-aminobiphenyl to PCl3 is 1:0.01-10, preferably 1:1-3; And / or, in step S2, the molar ratio of compound a to AlCl3 is 1:0.01 to 10, preferably 1:1 to 3; And / or, in step S3, the molar ratio of compound b to compound c is 1:0.01-10, preferably 1:1-3; And / or, in step S4, the molar ratio of compound d, compound e and triethylamine is 1:0.01-10:0.01-10, preferably 1:1-3:1-3.

5. The preparation method according to claim 3 or 4, characterized in that: The first solvent includes benzene; and / or, the second solvent comprises tetrahydrofuran; And / or, the third solvent comprises acetonitrile.

6. A catalyst composition, characterized in that It comprises the biphenyl diphosphine type catalyst ligand as claimed in claim 1 or 2, a transition metal compound and an aluminum-containing co-catalyst.

7. The catalyst composition according to claim 6, characterized in that The transition metal compound is selected from at least one of compounds of chromium, molybdenum, iron, titanium, zirconium and nickel, and is preferably selected from at least one of chromium acetylacetonate, chromium isooctanoate, tri(tetrahydrofuran)chromium trichloride and di(tetrahydrofuran)chromium dichloride.

8. The catalyst composition according to claim 6 or 7, characterized in that The aluminum-containing co-catalyst is an organic aluminum compound, preferably at least one selected from an alkyl aluminum compound, an alkoxy aluminum compound and an alkyl aluminum chloride compound, more preferably at least one selected from methylaluminoxane, trimethylaluminum, triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, diethylaluminum monochloride, ethylaluminum dichloride, ethylaluminumoxane and modified methylaluminumoxane, further preferably at least one selected from methylaluminumoxane, triethylaluminum and modified methylaluminumoxane.

9. The catalyst composition according to any one of claims 6 to 8, characterized in that The molar ratio of the transition metal compound, the biphenyl diphosphine type catalyst ligand represented by formula (I) and the aluminum-containing co-catalyst calculated as transition metal is 1: (0.1-10): (1-1000), preferably 1: (0.25-2): (10-700), and more preferably 1: (0.5-2): (100-500).

10. Use of the catalyst composition according to any one of claims 6 to 9 in ethylene oligomerization reaction.

11. A method for the polymerization of ethylene, comprising: In the presence of the catalyst composition according to any one of claims 6 to 9, ethylene, hydrogen and an organic solvent are continuously added to a reactor to carry out an ethylene oligomerization reaction; Preferably, the volume ratio of hydrogen to ethylene is 1:(1-10000), preferably 1:(10-2000).

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