CN111434667B

CN111434667B - Fluorine-containing compound and application thereof, ethylene oligomerization catalyst composition, ethylene oligomerization method, ethylene trimerization method and ethylene tetramerization method

Info

Publication number: CN111434667B
Application number: CN201910036065.4A
Authority: CN
Inventors: 吴红飞; 郑明芳; 韩春卉; 刘珺; 栗同林
Original assignee: Sinopec Beijing Research Institute of Chemical Industry; China Petroleum and Chemical Corp
Current assignee: Sinopec Beijing Research Institute of Chemical Industry; China Petroleum and Chemical Corp
Priority date: 2019-01-15
Filing date: 2019-01-15
Publication date: 2021-07-30
Anticipated expiration: 2039-01-15
Also published as: CN111434667A

Abstract

The invention discloses a fluorine-containing compound shown in formula I and application thereof as a ligand of an ethylene oligomerization catalyst composition; the invention also discloses an ethylene oligomerization catalyst composition containing the fluorine-containing compound, and an ethylene oligomerization method, an ethylene trimerization method and an ethylene tetramerization method which adopt the catalyst composition. The fluorine-containing polymer as the ligand of the catalyst for ethylene oligomerization can effectively improve the catalytic performance of the catalyst system, particularly shows obviously improved catalytic performance in ethylene oligomerization reaction, and has the highest catalyst activity of more than 4 multiplied by 10⁸g·mol(Cr)^‑1·h^‑1The total selectivity of 1-hexene and 1-octene is over 92 wt%, and in the C6 product, the content of 1-hexene can reach about 98%, and in the C8 product, the content of 1-octene can reach more than 98%. The catalyst composition has good industrial application prospect and economic value.

Description

Fluorine-containing compound and application thereof, ethylene oligomerization catalyst composition, ethylene oligomerization method, ethylene trimerization method and ethylene tetramerization method

Technical Field

The invention relates to a fluorine-containing compound, and also relates to the application of the fluorine-containing compound as a ligand of an ethylene oligomerization catalyst composition; the invention further relates to an ethylene oligomerization catalyst composition, and an ethylene oligomerization process, an ethylene trimerization process and an ethylene tetramerization process employing the catalyst composition.

Background

Ethylene oligomerization, which is one of the most important reactions in the olefin polymerization industry, can convert cheap small-molecule olefins into products with high added value, such as: 1-octene and 1-hexene. 1-octene and 1-hexene are used as important organic raw materials and chemical intermediates, and are mainly applied to the field of producing high-quality Polyethylene (PE). The Linear Low Density Polyethylene (LLDPE) produced by copolymerizing 1-hexene or 1-octene with ethylene can obviously improve various properties of PE, especially mechanical property, optical property, tear strength and impact strength of polyethylene, and the product is very suitable for the fields of packaging films, agricultural covering films such as greenhouses and sheds, etc.

In recent years, with the continuous development of the polyolefin industry, the worldwide demand for alpha-olefins has rapidly increased, wherein the majority of the alpha-olefins are produced by oligomerization of ethylene.

Since the last 70 s, the research on the polymerization and oligomerization of olefins catalyzed by transition metal complexes has been receiving the attention of scientists, and researchers have made efforts to research novel catalysts, improve the existing catalysts, and improve the activity of the catalysts and the selectivity of catalytic products.

Among the most developed and concentrated researches on the nickel-based cationic catalytic systems, such as US3686351 and US3676523, and the shell SHOP process based on the patent technology are the earliest and fastest. In the Shell SHOP SHOP process, O-P bridging ligand is involved, but the catalyst contains toxic organophosphorus group, and the synthesis steps are complicated and the stability is poor.

Subsequently, researchers developed O-O, P-N, P-P and N-N type complex nickel catalysts, such as JP11060627, WO9923096, WO991550, CN1401666 and CN 1769270. However, the catalysts obtained from the above patents suffer from the general disadvantage of relatively complicated preparation processes.

Patent WO04056478 by Sasol company discloses a PNP framework type catalyst, in which the selectivity of C8 component is about 66 wt% and the selectivity of C6 component is about 21 wt%, wherein the content of 1-hexene in C6 component is only 82% and the total selectivity of 1-hexene and 1-octene is about 84%, in ethylene tetramerization.

US20100137669 discloses a PCCP symmetric framework type catalyst which is more stable than a PNP system in ethylene tetramerisation reactions, but the total selectivity to 1-hexene and 1-octene does not exceed 85%.

In these reaction systems, by-products such as cycloolefins and cyclized products present in the product of C6 can be removed by separation and purification, but they are disadvantageous in terms of the economy of the overall process.

Disclosure of Invention

In view of the above-mentioned deficiencies of the prior art, the inventors of the present invention conducted an intensive study on a phosphorus-containing catalyst for ethylene oligomerization, and found that introduction of a ligand having a vinyl-bridged bisphosphine ligand and an ortho-fluoro substituent into a catalyst system can effectively improve the catalytic performance of the catalyst system, especially the catalytic performance in ethylene trimerization and tetramerization reactions, show significantly improved activity and selectivity, and significantly reduce the production of by-products such as cyclic olefins and cyclized products.

According to a first aspect of the present invention, there is provided a fluorine-containing compound, which is a compound represented by formula I,

in the formula I, R¹And R²Identical or different, each independently C₁-C₁₂Chain alkyl radical, C₃-C₁₂Cycloalkyl or C₆-C₂₀And (4) an aryl group.

According to a second aspect of the present invention there is provided the use of a fluorine-containing compound according to the first aspect of the present invention as a ligand for an ethylene oligomerization catalyst composition.

According to a third aspect of the present invention, there is provided an ethylene oligomerization catalyst composition comprising a fluorine-containing compound represented by formula I, a transition metal compound, and a cocatalyst;

According to a fourth aspect of the present invention there is provided a process for the oligomerization of ethylene which comprises contacting ethylene with a catalyst composition according to the third aspect of the present invention.

According to a fifth aspect of the present invention there is provided an ethylene trimerisation process which comprises contacting ethylene with a catalyst composition according to the third aspect of the present invention at a temperature of from 60 to 90 ℃.

According to a sixth aspect of the present invention there is provided a process for the tetramerisation of ethylene which comprises contacting ethylene with a catalyst composition according to the third aspect of the present invention at a temperature of from 30 to 50 ℃.

The fluorine-containing polymer as the ligand of the catalyst for ethylene oligomerization can effectively improve the catalytic performance of the catalyst system, particularly shows obviously improved catalytic performance in ethylene oligomerization reaction, and has the highest catalyst activity of more than 4 multiplied by 10⁸g·mol(Cr)^-1·h^-1The total selectivity of 1-hexene and 1-octene is over 92 wt%, and in the C6 product, the content of 1-hexene can reach about 98%, and in the C8 product, the content of 1-octene can reach more than 98%.

In addition, when the catalyst composition of the present invention is used for oligomerization of ethylene, the initiation rate is high, the absorption amount of ethylene can reach the maximum value in a short time, and the catalyst composition can be maintained for a long time. It is shown that the catalyst composition according to the invention initiates rapidly and has a higher stability during the polymerization.

Therefore, the catalyst composition has the characteristics of high catalytic activity, high selectivity and stable catalytic performance, and has better industrial application prospect and economic value.

Detailed Description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

In the present invention, the term "C₁-C₁₂Alkanyl radical "comprising C₁-C₁₂Straight chain alkyl of (2) and C₃-C₁₂Specific examples of the branched alkyl group of (1) may include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, 2-methylbutyl, 3-methylbutyl, 2-dimethylpropyl, n-hexyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 2, 3-dimethylbutyl, 2-dimethylbutyl, 3-dimethylbutyl, 2-ethylbutyl, n-heptyl, 2-methylhexyl, 3-methylhexyl, 4-methylhexyl, 5-methylhexyl, 2-dimethylpentyl, 2, 3-dimethylpentyl, 2, 4-dimethylpentyl, 3-dimethylpentyl, 3, 4-dimethylpentyl, 2-methylpentyl, 2, 3-dimethylpentyl, 2-methylpentyl, 2-dimethylbutyl, 3-methylbutyl, 2-dimethylbutyl, 2-methylbutyl, 3-methylbutyl, 2-dimethylbutyl, 3-methylbutyl, 3-methylpentyl, 2-dimethylbutyl, 2-methylbutyl, 3-dimethylbutyl, 2-methylbutyl, 3-methylbutyl, 2-methylpentyl, 3-dimethylpentyl, 3, 2-dimethylpentyl, 3-butyl, 2-dimethylpentyl, 2-butyl, 3-dimethylpentyl, 2-butyl, 3, 2-butyl, 2-dimethylpentyl, 2-butyl, 3-butyl, 2-butyl, 3-butyl, 2-pentyl, 3-butyl, 2-pentyl, 3-butyl, 2-pentyl, 2-butyl, 2-pentyl, 3-butyl, 2-pentyl, 3-pentyl, and the same, 2-pentyl, 3-pentyl, 2,4, 4-dimethylpentyl group, 2-ethylpentyl group, 3-ethylpentyl group, n-octyl group, 2-methylheptyl group, 3-methylheptyl group, 4-methylheptyl group, 5-methylheptyl group, 6-methylheptyl group, 2-dimethylhexyl group, 2, 3-dimethylhexyl group, 2, 4-dimethylhexyl group, 2, 5-dimethylhexyl group, 3-dimethylhexyl group, 3, 4-dimethylhexyl group, 3, 5-dimethylhexyl group, 4-dimethylhexyl group, 4, 5-dimethylhexyl group, 5-dimethylhexyl group, 2-ethylhexyl group, 3-ethylhexyl group, 4-ethylhexyl group, 2-n-propylpentyl group, 2-ethylhexyl group, 2-dimethylhexyl group, 3-ethylhexyl group, 2-dimethylhexyl group, and 3-dimethylhexyl group,2-isopropylpentyl, octyl (including various isomers of octyl), decyl (including various isomers of decyl), undecyl (including various isomers of undecyl), and dodecyl (including various isomers of dodecyl).

In the present invention, the term "C₃-C₁₂Cycloalkyl "includes substituted or unsubstituted cycloalkyl. Substituted cycloalkyl means that at least one hydrogen atom bonded to a carbon atom on the ring is substituted with a substituent which may be C₁-C₆A chain alkyl group, specific examples of which may include, but are not limited to: methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, tert-pentyl, neopentyl and hexyl (including the various isomers of hexyl). Said C is₃-C₁₂Specific examples of cycloalkyl groups may include, but are not limited to: cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, methylcyclohexyl, ethylcyclohexyl, propylcyclohexyl, and butylcyclohexyl.

In the present invention, the term "C₆-C₂₀Aryl "includes substituted or unsubstituted aryl. Substituted aryl means that at least one hydrogen atom on the aromatic ring is substituted with a substituent, which may be C₁-C₆Alkyl and/or halogen groups, specific examples of which may include, but are not limited to: methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, tert-pentyl, neopentyl, hexyl (including various isomers of hexyl), chlorine, bromine and iodine. Said C is₆-C₂₀Specific examples of aryl groups may include, but are not limited to: phenyl, naphthyl, tolyl, ethylphenyl, chlorophenyl, or naphthyl.

in the formula I, R¹And R²The same or differentEach independently is C₁-C₁₂Chain alkyl radical, C₃-C₁₂Cycloalkyl or C₆-C₂₀And (4) an aryl group.

In a preferred embodiment, in formula I, R¹And R²Each independently is C₁-C₈Chain alkyl radical, C₃-C₈Cycloalkyl or C₆-C₁₆And (4) an aryl group.

In a more preferred embodiment, in formula I, R¹And R²Each independently is C₁-C₆Chain alkyl radical, C₃-C₆Cycloalkyl or C₆-C₁₂And (4) an aryl group.

In a further preferred embodiment, in formula I, R¹And R²Each independently is methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, isobutyl, n-pentyl, isopentyl, tert-pentyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, phenyl, methylphenyl, ethylphenyl, chlorophenyl or naphthyl.

In a further preferred embodiment, in formula I, R¹And R²Each independently is tert-butyl, cyclohexyl, phenyl, isopropyl or methyl.

In a particularly preferred embodiment, in formula I, R¹And R²Each independently is tert-butyl, cyclohexyl or methyl.

The fluorine-containing compounds according to the present invention can be prepared by literature methods: J.am.chem.Soc,2007, 129, 4009-; ACS Catalysis,2013,3, 2311-2317. The preparation method specifically comprises the following steps:

the fluorine-containing compound of formula I can be isolated from the reaction mixture resulting from the first contacting of the alkyne compound of formula II with a first portion of difluorophenylphosphine chloride and an organolithium compound at a first temperature, followed by the addition of copper iodide, an alkali metal carbonate, and a second portion of difluorophenylphosphine chloride for a second contacting at a second temperature.

In the formula II, R¹And R²Is defined as in formula I¹And R²Are as defined above and are each independently C₁-C₁₂Chain alkyl radical, C₃-C₁₂Cycloalkyl or C₆-C₂₀And (4) an aryl group.

In a preferred embodiment, in formula II, R¹And R²Each independently is C₁-C₈Chain alkyl radical, C₃-C₈Cycloalkyl or C₆-C₁₆And (4) an aryl group. In a more preferred embodiment, in formula II, R¹And R²Each independently is C₁-C₆Chain alkyl radical, C₃-C₆Cycloalkyl or C₆-C₁₂And (4) an aryl group. In a further preferred embodiment, in formula II, R¹And R²Each independently is methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, isobutyl, n-pentyl, isopentyl, tert-pentyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, phenyl, methylphenyl, ethylphenyl, chlorophenyl or naphthyl. In a further preferred embodiment, in formula II, R¹And R²Each independently is tert-butyl, cyclohexyl, phenyl, isopropyl or methyl. In a particularly preferred embodiment, in formula II, R¹And R²Each independently is tert-butyl, cyclohexyl or methyl.

The organolithium compound may be a compound represented by formula III,

R³li (formula III)

In the formula III, R³Is C₁-C₆Alkyl of (C)₃-C₁₂Cycloalkyl of, C₇-C₁₄Aralkyl or C₆-C₁₂Aryl group of (1). R³Specific examples of (a) may include, but are not limited to: methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, tert-butylPentyl, neopentyl, n-hexyl, cyclopropyl, cyclopentyl, cyclohexyl, 4-methylcyclohexyl, 4-ethylcyclohexyl, 4-n-propylcyclohexyl, 4-n-butylcyclohexyl, phenylmethyl, phenylethyl, phenyl-n-propyl, phenyl-n-butyl, phenyl-tert-butyl, phenylisopropyl, phenyl-n-pentyl, phenyl-n-butyl, phenyl, naphthyl, 4-methylphenyl and 4-ethylphenyl.

Specific examples of the organolithium compound may include, but are not limited to: one or more of ethyllithium, n-propyllithium, isopropyllithium, n-butyllithium, sec-butyllithium, tert-butyllithium, phenyllithium, 2-naphthyllithium, 4-butylphenyl lithium, 4-tolyllithium, cyclohexyllithium, and 4-butylcyclohexyllithium.

Preferably, the organolithium compound is n-butyllithium and/or sec-butyllithium. More preferably, the organolithium compound is n-butyllithium.

The molar ratio of the organolithium compound to the alkyne compound of formula II may be 0.8 to 1.2: 1.

the acetylene compound represented by the formula II may be mixed with the organolithium compound first, and difluorophenylphosphine chloride may be added to the resulting mixture. In mixing the acetylene compound and the organolithium compound, the organolithium compound is preferably added dropwise to the acetylene compound.

The first contacting may be carried out at a temperature of-10 ℃ to 10 ℃, preferably at a temperature of-5 ℃ to 5 ℃. The duration of the first contact may be 10 to 60 minutes, preferably 20 to 40 minutes. The first contact may be carried out in an oxygen-containing heterocyclic compound as a solvent, preferably in tetrahydrofuran.

The alkali metal carbonate is preferably cesium carbonate. The copper iodide and the alkali metal carbonate are used as catalysts, and the dosage of the copper iodide and the alkali metal carbonate is based on the catalytic function, and can be catalytic amount.

The molar ratio of the first portion of difluorophenylphosphonium chloride to the second portion of difluorophenylphosphonium chloride can be 1: 0.9 to 1.1, preferably 1: 1.

the reaction mixture from the first contacting may be first mixed with copper iodide and an alkali metal carbonate and then mixed with a second portion of difluorophenylphosphine chloride.

The second contacting is conducted at a higher temperature than the first contacting. In particular, the second contacting may be carried out at a temperature of 60 to 120 ℃, preferably at a temperature of 80 to 100 ℃.

The fluorine-containing compound represented by formula I can be isolated from the reaction mixture obtained by the second contacting by a conventional method. For example: the reaction mixture obtained by the second contact may be subjected to solid-liquid separation, the solvent in the liquid phase obtained by the solid-liquid separation is removed, and the residue is subjected to column separation to obtain the fluorine-containing compound represented by formula I.

The reaction scheme for preparing the fluorochemical compound of formula I is shown below for illustrative purposes:

the fluorine-containing compound is particularly suitable for serving as a ligand of a catalyst for ethylene oligomerization, and when the ligand of the catalyst contains the fluorine-containing compound, the catalytic performance of the catalyst is obviously improved.

The fluorine-containing compound according to the present invention can be used in combination with a transition metal compound and a cocatalyst which are generally used for oligomerization of ethylene.

In a preferred embodiment, the catalyst composition comprises a transition metal compound, a cocatalyst and the fluorine-containing compound.

The transition metal element in the transition metal compound may be chromium, molybdenum, iron, titanium, zirconium, or nickel. Accordingly, the transition metal compound may be at least one selected from the group consisting of a chromium compound, a molybdenum compound, an iron compound, a titanium compound, a zirconium compound, and a nickel compound. The transition metal compound may be at least one selected from the group consisting of a transition metal salt of acetylacetone, a transition metal salt of carboxylic acid, and a transition metal complex of tetrahydrofuran. The transition metal compound is preferably at least one selected from the group consisting of chromium acetylacetonate, chromium isooctanoate, chromium tris (tetrahydrofuran) trichloride and chromium bis (tetrahydrofuran) dichloride. The transition metal compound is more preferably chromium acetylacetonate.

The molar ratio of the fluorine-containing compound to the transition metal compound may be 1: 0.1 to 10, for example: 1: 0.1, 1: 0.2, 1: 0.3, 1: 0.4, 1: 0.5, 1: 0.6, 1: 0.7, 1: 0.8, 1: 0.9, 1: 1. 1: 1.1, 1: 1.2, 1: 1.3, 1: 1.4, 1: 1.5, 1: 1.6, 1: 1.7, 1: 1.8, 1: 1.9, 1: 2. 1: 2.1, 1: 2.2, 1: 2.3, 1: 2.4, 1: 2.5, 1: 2.6, 1: 2.7, 1: 2.8, 1: 2.9, 1: 3. 1: 3.1, 1: 3.2, 1: 3.3, 1: 3.4, 1: 3.5, 1: 3.6, 1: 3.7, 1: 3.8, 1: 3.9, 1: 4. 1: 4.1, 1: 4.2, 1: 4.3, 1: 4.4, 1: 4.5, 1: 4.6, 1: 4.7, 1: 4.8, 1: 4.9, 1: 5. 1: 5.1, 1: 5.2, 1: 5.3, 1: 5.4, 1: 5.5, 1: 5.6, 1: 5.7, 1: 5.8, 1: 5.9, 1: 6. 1: 6.1, 1: 6.2, 1: 6.3, 1: 6.4, 1: 6.5, 1: 6.6, 1: 6.7, 1: 6.8, 1: 6.9, 1: 7. 1: 7.1, 1: 7.2, 1: 7.3, 1: 7.4, 1: 7.5, 1: 7.6, 1: 7.7, 1: 7.8, 1: 7.9, 1: 8. 1: 8.1, 1: 8.2, 1: 8.3, 1: 8.4, 1: 8.5, 1: 8.6, 1: 8.7, 1: 8.8, 1: 8.9, 1: 9. 1: 9.1, 1: 9.2, 1: 9.3, 1: 9.4, 1: 9.5, 1: 9.6, 1: 9.7, 1: 9.8, 1: 9.9 or 1: 10.

preferably, the molar ratio of the fluorine-containing compound to the transition metal compound is 1: 0.25-2. More preferably, the molar ratio of the fluorine-containing compound to the transition metal compound is 1: 0.5-2. Further preferably, the molar ratio of the fluorine-containing compound to the transition metal compound is 1: 0.5-1. Still more preferably, the molar ratio of the fluorine-containing compound to the transition metal compound is 1: 0.5-0.8.

The cocatalyst may be an aluminum-containing cocatalyst. Preferably, the cocatalyst is an organoaluminum compound. More preferably, the co-catalyst is at least one selected from the group consisting of alkylaluminum, alkylaluminum alkoxide, and alkylaluminum halide. Further preferably, the cocatalyst is at least one selected from methylaluminoxane, trimethylaluminum, triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, diethylaluminum monochloride, ethylaluminum dichloride, ethylaluminoxane and modified methylaluminoxane. Still more preferably, the cocatalyst is at least one selected from the group consisting of modified methylaluminoxane, methylaluminoxane and triethylaluminum. Particularly preferably, the cocatalyst is modified methylaluminoxane. In the present invention, "modified methylaluminoxane" means methylaluminoxane modified with an alkyl group, for example, methylaluminoxane modified with a butyl group. The modified methylaluminoxane may be a modified methylaluminoxane available from aksunobel corporation.

The molar ratio of the fluorine-containing compound to the co-catalyst may be 1: 1-1000. Preferably, the molar ratio of the fluorine-containing compound to the co-catalyst is 1: 10-700. More preferably, the molar ratio of the fluorine-containing compound to the co-catalyst is 1: 100- & lt500 & gt, for example: 1: 100. 1: 105. 1: 110. 1: 115. 1: 120. 1: 125. 1: 130. 1: 135. 1: 140. 1: 145. 1: 150. 1: 155. 1: 160. 1: 165. 1: 170. 1: 175. 1: 180. 1: 185. 1: 190. 1: 195. 1: 200. 1: 205. 1: 210. 1: 215. 1: 220. 1: 225. 1: 230. 1: 235. 1: 240. 1: 245. 1: 250. 1: 255. 1: 260. 1: 265. 1: 270. 1: 275. 1: 280. 1: 285. 1: 290. 1: 295. 1: 300. 1: 305. 1: 310. 1: 315. 1: 320. 1: 325. 1: 330. 1: 335. 1: 340. 1: 345. 1: 350. 1: 355. 1: 360. 1: 365. 1: 370. 1: 375. 1: 380. 1: 385. 1: 390. 1: 395. 1: 400. 1: 405. 1: 410. 1: 415. 1: 420. 1: 425. 1: 430. 1: 435. 1: 440. 1: 445. 1: 450. 1: 455. 1: 460. 1: 465. 1: 470. 1: 475. 1: 480. 1: 485. 1: 490. 1: 495 or 1: 500.

further preferably, the molar ratio of the fluorine-containing compound to the co-catalyst is 1: 150-300. Still more preferably, the molar ratio of the fluorine-containing compound to the co-catalyst is 1: 200-280.

in the formula I, R¹And R²Identical or different, each independently C₁-C₁₂Chain alkyl radical, C₃-C₁₂Cycloalkyl or C₆-C₂₀And (4) an aryl group. In a preferred embodiment, in formula I, R¹And R²Identical or different, each independently C₁-C₈Chain alkyl radical, C₃-C₈Cycloalkyl or C₆-C₁₆And (4) an aryl group. In a more preferred embodiment, in formula I, R¹And R²Identical or different, each independently C₁-C₆Chain alkyl radical, C₃-C₆Cycloalkyl or C₆-C₁₂And (4) an aryl group. In a further preferred embodiment, in formula I, R¹And R²Identical or different, each independently of the others, is methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, isobutyl, n-pentyl, isopentyl, tert-pentyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, phenyl, methylphenyl, ethylphenyl, chlorophenyl or naphthyl. In a further preferred embodiment, in formula I, R¹And R²Each independently is tert-butyl, cyclohexyl, phenyl, isopropyl or methyl. In a particularly preferred embodiment, in formula I, R¹And R²Each independently is tert-butyl, cyclohexyl or methyl.

The transition metal element in the transition metal compound may be chromium, molybdenum, iron, titanium, zirconium, or nickel. Accordingly, the transition metal compound may be at least one selected from the group consisting of a chromium compound, a molybdenum compound, an iron compound, a titanium compound, a zirconium compound, and a nickel compound.

The transition metal compound may be at least one selected from the group consisting of a transition metal salt of acetylacetone, a transition metal salt of carboxylic acid, and a transition metal complex of tetrahydrofuran.

The transition metal compound is preferably at least one selected from the group consisting of chromium acetylacetonate, chromium isooctanoate, chromium tris (tetrahydrofuran) trichloride and chromium bis (tetrahydrofuran) dichloride. The transition metal compound is more preferably chromium acetylacetonate.

The cocatalyst may be an aluminum-containing cocatalyst. Preferably, the cocatalyst is an organoaluminum compound. More preferably, the co-catalyst is at least one selected from the group consisting of alkylaluminum, alkylaluminum alkoxide, and alkylaluminum halide. Further preferably, the cocatalyst is at least one selected from methylaluminoxane, trimethylaluminum, triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, diethylaluminum monochloride, ethylaluminum dichloride, ethylaluminoxane and modified methylaluminoxane. Still more preferably, the cocatalyst is at least one of modified methylaluminoxane, methylaluminoxane and triethylaluminum. Particularly preferably, the cocatalyst is modified methylaluminoxane.

According to the ethylene oligomerization process of the present invention, the contacting is preferably carried out in at least one organic solvent. The organic solvent is a solvent capable of dissolving the oligomerization products, can be at least one selected from paraffin, naphthene and aromatic hydrocarbon, and is preferably selected from C₆-C₁₂Alkane of (C)₆-C₁₂Cycloalkane of (2)₆-C₁₂At least one aromatic hydrocarbon of (1). Specific examples of the organic solvent may include, but are not limited to: hexane, 2-methylpentane, 3-methylpentane, 2, 3-dimethylbutane, cyclohexane, methylcyclopentane, heptane, 2-methylhexane, 3-methylhexane, methylcyclohexane, 2-ethylpentane, 3-ethylpentane, 2, 3-dimethylpentane, 2, 4-dimethylpentane, octane, 2-methylheptane, 3-methylheptane, 4-methylheptane, 2, 3-dimethylhexane, 2, 4-dimethylhexane, 2, 5-dimethylhexane, 3-ethylhexane, 2, 3-trimethylpentane, 2,3, 3-trimethylpentane, 2,4, 4-trimethylpentane, 2-methyl-3-ethylpentane, nonane, 2-methyloctane, cyclohexane, methylcyclopentane, heptane, 2-methylhexane, 3-methylheptane, 4-methylheptane, 2, 4-dimethylhexane, 2, 3-trimethylpentane, 2-methylhexane, 2, 3-methylpentane, 2-dimethylpentane, 2-dimethylpentane, 4-dimethylhexane, 2-dimethylpentane, 2, 3-dimethylpentane, 2, 3-dimethylpentane, 2, 3-dimethylpentane, 2, 3-dimethylpentane, 2,3, 2,3, 2, and/3, 2 '-dimethylpentane, 2' -dimethylpentane, 2, 3-methyloctane, 4-methyloctane, 2, 3-dimethylheptane, 2, 4-dimethylheptane, 3-ethylheptane, 4-ethylheptane, 2,3, 4-trimethylhexane, 2,3, 5-trimethylhexane, 2,4, 5-trimethylhexane, 2, 3-trimethylhexane, 2, 4-trimethylhexane, 2, 5-trimethylhexane, 2,3, 3-trimethylhexane, 2,4, 4-trimethylhexane, 2-methyl-3-ethylhexane, 2-methyl-4-ethylhexane, 3-methyl-3-ethylhexane, 3-methyl-4-ethylhexane, 3, 3-diethylpentane, 1-methyl-2-ethylcyclohexane, 1-methyl-3-ethylcyclohexane, 1-methyl-4-ethylcyclohexane, n-propylcyclohexane, isopropylcyclohexane, trimethylcyclohexane (including various isomers of trimethylcyclohexane, such as 1,2, 3-trimethylcyclohexane, 1,2, 4-trimethylcyclohexane, 1,2, 5-trimethylcyclohexane, 1,3, 5-trimethylcyclohexane), decane, 2-methylnonane, 3-methylnonane, 4-methylnonane, 5-methylnonane, 2, 3-dimethyloctane, 2, 4-dimethyloctane, 3-ethyloctane, 4-ethyloctane, 2,3, 4-trimethylheptane, 2,3, 5-trimethylheptane, 2,3, 6-trimethylheptane, trimethylheptane, 2,4, 5-trimethylheptane, 2,4, 6-trisMethylheptane, 2, 3-trimethylheptane, 2, 4-trimethylheptane, 2, 5-trimethylheptane, 2, 6-trimethylheptane, 2,3, 3-trimethylheptane, 2,4, 4-trimethylheptane, 2-methyl-3-ethylheptane, 2-methyl-4-ethylheptane, 2-methyl-5-ethylheptane, 3-methyl-3-ethylheptane, 4-methyl-3-ethylheptane, 5-methyl-3-ethylheptane, 4-methyl-4-ethylheptane, 4-propylheptane, 3, 3-diethylhexane, 3, 4-diethylhexane, 2-methyl-3, 3-diethylpentane, 1, 2-diethylcyclohexane, 1, 3-diethylcyclohexane, 1, 4-diethylcyclohexane, n-butylcyclohexane, isobutylcyclohexane, tert-butylcyclohexane, tetramethylcyclohexane (including various isomers of tetramethylcyclohexane, such as 1,2,3, 4-tetramethylcyclohexane, 1,2,4, 5-tetramethylcyclohexane, 1,2,3, 5-tetramethylcyclohexane), toluene, ethylbenzene, and xylenes (including o-xylene, m-xylene, and p-xylene). The organic solvent is more preferably at least one selected from the group consisting of methylcyclohexane, heptane, cyclohexane, toluene, and xylene.

The amount of the organic solvent used in the present invention is not particularly limited, and may be selected conventionally. Generally, the organic solvent is used in an amount such that the concentration of the catalyst composition is 1 to 20. mu. mol/L, based on the transition metal element in the transition metal compound. Specifically, the organic solvent is used in an amount such that the concentration of the catalyst composition is 1. mu. mol/L, 2. mu. mol/L, 3. mu. mol/L, 4. mu. mol/L, 5. mu. mol/L, 6. mu. mol/L, 7. mu. mol/L, 8. mu. mol/L, 9. mu. mol/L, 10. mu. mol/L, 11. mu. mol/L, 12. mu. mol/L, 13. mu. mol/L, 14. mu. mol/L, 15. mu. mol/L, 16. mu. mol/L, 17. mu. mol/L, 18. mu. mol/L, 19. mu. mol/L or 20. mu. mol/L, based on the transition metal element in the transition metal compound. Preferably, the organic solvent is used in an amount such that the concentration of the catalyst composition is 5 to 10. mu. mol/L, based on the transition metal element in the transition metal compound.

According to the ethylene oligomerization process of the invention, the contact may be carried out at a temperature of from 0 to 200 ℃, for example: 0 ℃, 1 ℃,2 ℃,3 ℃,4 ℃,5 ℃,6 ℃, 7 ℃, 8 ℃, 9 ℃, 10 ℃, 11 ℃, 12 ℃, 13 ℃, 14 ℃, 15 ℃, 16 ℃, 17 ℃, 18 ℃, 19 ℃,20 ℃, 21 ℃, 22 ℃,23 ℃, 24 ℃, 25 ℃, 26 ℃, 27 ℃, 28 ℃, 29 ℃, 30 ℃, 31 ℃, 32 ℃, 33 ℃, 34 ℃, 35 ℃, 36 ℃, 37 ℃, 38 ℃, 39 ℃,40 ℃, 41 ℃, 42 ℃, 43 ℃, 44 ℃, 45 ℃, 46 ℃, 47 ℃, 48 ℃, 49 ℃, 50 ℃, 51 ℃, 52 ℃, 53 ℃, 54 ℃, 56 ℃, 57 ℃, 58 ℃, 59 ℃, 60 ℃, 61 ℃, 62 ℃, 63 ℃, 64 ℃, 66 ℃, 67 ℃, 68 ℃, 69 ℃, 70 ℃, 72 ℃, 73 ℃, 74 ℃, 75 ℃, 76 ℃, 77 ℃, 78 ℃, 79 ℃, 80 ℃, 81 ℃, 82 ℃, 83 ℃, 84 ℃, 85 ℃, 86 ℃, 87 ℃, 88 ℃, 89 ℃, 90 ℃, 91 ℃, 92 ℃, 93 ℃, 94 ℃, 95 ℃, 96 ℃, 97 ℃, 98 ℃, 99 ℃, 100 ℃, 101 ℃, 102 ℃, 103 ℃, 104 ℃, 105 ℃, 106 ℃, 107 ℃, 108 ℃, 109 ℃, 110 ℃, 111 ℃, 112 ℃, 113 ℃, 114 ℃, 115 ℃, 116 ℃, 117 ℃, 118 ℃, 119 ℃, 120 ℃, 121 ℃, 122 ℃, 123 ℃, 124 ℃, 125 ℃, 126 ℃, 127 ℃, 128 ℃, 129 ℃, 130 ℃, 131 ℃, 132 ℃, 133 ℃, 134 ℃, 135 ℃, 136 ℃, 137 ℃, 138 ℃, 140 ℃, 141 ℃, 142 ℃, 143 ℃, 144 ℃, 145 ℃, 146 ℃, 147 ℃, 148 ℃, 149 ℃, 150 ℃, 151 ℃, 152 ℃, 153 ℃, 154 ℃, 155 ℃, 156 ℃, 157 ℃, 158 ℃, 159 ℃, 160 ℃, 162 ℃, 163 ℃, 164 ℃, 165 ℃, 166 ℃, 167 ℃, ° f, 168 deg.C, 169 deg.C, 170 deg.C, 171 deg.C, 172 deg.C, 173 deg.C, 174 deg.C, 175 deg.C, 176 deg.C, 177 deg.C, 178 deg.C, 179 deg.C, 180 deg.C, 181 deg.C, 182 deg.C, 183 deg.C, 184 deg.C, 185 deg.C, 186 deg.C, 187 deg.C, 188 deg.C, 189 deg.C, 190 deg.C, 191 deg.C, 192 deg.C, 193 deg.C, 194 deg.C, 195 deg.C, 197 deg.C, 198 deg.C, 199 deg.C or 200 deg.C.

Preferably, the contacting is carried out at a temperature of 0-100 ℃. More preferably, the contacting is carried out at a temperature of 30-90 ℃.

According to the ethylene oligomerization process of the invention, the ethylene pressure may be between 0.1 and 20MPa, for example: 0.1MPa, 0.2MPa, 0.3MPa, 0.4MPa, 0.5MPa, 0.6MPa, 0.7MPa, 0.8MPa, 0.9MPa, 1MPa, 1.1MPa, 1.2MPa, 1.3MPa, 1.4MPa, 1.5MPa, 1.6MPa, 1.7MPa, 1.8MPa, 1.9MPa, 2MPa, 2.1MPa, 2.2MPa, 2.3MPa, 2.4MPa, 2.5MPa, 2.6MPa, 2.7MPa, 2.8MPa, 2.9MPa, 3MPa, 3.1MPa, 3.2MPa, 3.3MPa, 3.4MPa, 3.5MPa, 3.6MPa, 3.7MPa, 3.8MPa, 3.9MPa, 4.1MPa, 4.2MPa, 4.3MPa, 4.4MPa, 4.5MPa, 4.6MPa, 7.7MPa, 6.6MPa, 6.7MPa, 6.8MPa, 6.6MPa, 6.7.7 MPa, 6MPa, 6.6.7 MPa, 6MPa, 6.7.7 MPa, 6MPa, 6.7.7.8 MPa, 6.7MPa, 6MPa, 6.7.7.7.7 MPa, 6MPa, 6.7.7.7.7.7.7 MPa, 6MPa, 6.7.7.7.7.8 MPa, 6MPa, 6.9MPa, 6MPa, 6.9MPa, 6.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7 MPa, 6.7.7.6, 6MPa, 6.7.7.7.7 MPa, 6MPa, 6MPa, 6.7.7.7.7.7.7.7.7.7.7 MPa, 6MPa, 6.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.6, 6MPa, 6, 6.6, 6MPa, 6, 6.7.7.7.7.7.7.7.7.7.7.7.7.7.7 MPa, 6MPa, 6.7.7.6.6, 6, 6.6, 6MPa, 6, 6.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7 MPa, 6MPa, 7.7.7.7.7 MPa, 6MPa, 7.7.7.7.7.7.7.7.7.7.7 MPa, 6MPa, 6.6, 6MPa, 6, 6.7.7.6, 6, 7.7., 8.3MPa, 8.4MPa, 8.5MPa, 8.6MPa, 8.7MPa, 8.8MPa, 8.9MPa, 9MPa, 9.1MPa, 9.2MPa, 9.3MPa, 9.4MPa, 9.5MPa, 9.6MPa, 9.7MPa, 9.8MPa, 9.9MPa, 10MPa, 10.1MPa, 10.2MPa, 10.3MPa, 10.4MPa, 10.5MPa, 10.6MPa, 10.7MPa, 10.8MPa, 10.9MPa, 11MPa, 11.1MPa, 11.2MPa, 11.3MPa, 11.4MPa, 11.5MPa, 11.6MPa, 11.7MPa, 11.8MPa, 11.9MPa, 12MPa, 12.1MPa, 12.2MPa, 12.3MPa, 12.4MPa, 12.5MPa, 12.6MPa, 12.7MPa, 12.8MPa, 13.6MPa, 14.6MPa, 13.6MPa, 14.6MPa, 13.6MPa, 14.6MPa, 13.6MPa, 14.6MPa, 13.6MPa, 14.6MPa, 13.6MPa, 13.7MPa, 13.6MPa, 14.6MPa, 13.6MPa, 14.6MPa, 13.6MPa, 14.6MPa, 13.6MPa, 14.7MPa, 14.6MPa, 13.6MPa, 14.6MPa, 16.6MPa, 16.7MPa, 16.8MPa, 16.9MPa, 17MPa, 17.1MPa, 17.2MPa, 17.3MPa, 17.4MPa, 17.5MPa, 17.6MPa, 17.7MPa, 17.8MPa, 17.9MPa, 18MPa, 18.1MPa, 18.2MPa, 18.3MPa, 18.4MPa, 18.5MPa, 18.6MPa, 18.7MPa, 18.8MPa, 18.9MPa, 19MPa, 19.1MPa, 19.2MPa, 19.3MPa, 19.4MPa, 19.5MPa, 19.6MPa, 19.7MPa, 19.8MPa, 19.9MPa or 20 MPa.

Preferably, the pressure of the ethylene is from 0.5 to 10 MPa. More preferably, the pressure of the ethylene is from 2 to 8 MPa.

The ethylene oligomerization process according to the present invention can be carried out by a conventional method. In one embodiment, the fluorine-containing compound, the transition metal compound and the cocatalyst are mixed and then added to the reactor to contact ethylene in the presence of an optional organic solvent to carry out oligomerization. In another embodiment, the fluorine-containing compound, the transition metal compound and the cocatalyst can be added into the reactor separately and contacted with ethylene in the presence of an optional organic solvent to carry out oligomerization.

According to the ethylene trimerization method of the present invention, the temperature of the contact may be, for example, 60 ℃, 61 ℃, 62 ℃, 63 ℃, 64 ℃, 65 ℃, 66 ℃, 67 ℃, 68 ℃, 69 ℃, 70 ℃, 71 ℃, 72 ℃, 73 ℃, 74 ℃, 75 ℃, 76 ℃, 77 ℃, 78 ℃, 79 ℃, 80 ℃, 81 ℃, 82 ℃, 83 ℃, 84 ℃, 85 ℃, 86 ℃, 87 ℃, 88 ℃, 89 ℃ or 90 ℃. Preferably, the temperature of said contacting is 70-90 ℃.

According to the ethylene trimerization process of the present invention, said contacting is preferably carried out in at least one organic solvent. The organic solvent is a solvent capable of dissolving the oligomerization products, can be at least one selected from paraffin, naphthene and aromatic hydrocarbon, and is preferably selected from C₆-C₁₂Alkane of (C)₆-C₁₂Cycloalkane of (2)₆-C₁₂At least one aromatic hydrocarbon of (1). Specific examples of the organic solvent may include, but are not limited to: hexane, 2-methylpentane, 3-methylpentane, 2, 3-dimethylbutane, cyclohexane, methylcyclopentane, heptane, 2-methylhexane, 3-methylhexane, methylcyclohexane, 2-ethylpentane, 3-ethylpentane, 2, 3-dimethylpentane, 2, 4-dimethylpentane, octane, 2-methylheptane, 3-methylheptane, 4-methylheptane, 2, 3-dimethylhexane, 2, 4-dimethylhexane, 2, 5-dimethylhexane, 3-ethylhexane, 2, 3-trimethylpentane, 2,3, 3-trimethylpentane, 2,4, 4-trimethylpentane, 2-methyl-3-ethylpentane, nonane, 2-methyloctane, cyclohexane, methylcyclopentane, heptane, 2-methylhexane, 3-methylheptane, 4-methylheptane, 2, 4-dimethylhexane, 2, 3-trimethylpentane, 2-methylhexane, 2, 3-methylpentane, 2-dimethylpentane, 2-dimethylpentane, 4-dimethylhexane, 2-dimethylpentane, 2, 3-dimethylpentane, 2, 3-dimethylpentane, 2, 3-dimethylpentane, 2, 3-dimethylpentane, 2,3, 2,3, 2, and/3, 2 '-dimethylpentane, 2' -dimethylpentane, 2, 3-methyloctane, 4-methyloctane, 2, 3-dimethylheptane, 2, 4-dimethylheptane, 3-ethylheptane, 4-ethylheptane, 2,3, 4-trimethylhexane, 2,3, 5-trimethylhexane, 2, 4-trimethylhexane5-trimethylhexane, 2, 3-trimethylhexane, 2, 4-trimethylhexane, 2, 5-trimethylhexane, 2,3, 3-trimethylhexane, 2,4, 4-trimethylhexane, 2-methyl-3-ethylhexane, 2-methyl-4-ethylhexane, 3-methyl-3-ethylhexane, 3-methyl-4-ethylhexane, 3, 3-diethylpentane, 1-methyl-2-ethylcyclohexane, 1-methyl-3-ethylcyclohexane, 1-methyl-4-ethylcyclohexane, n-propylcyclohexane, isopropylcyclohexane, trimethylcyclohexane (including various isomers of trimethylcyclohexane, such as 1,2, 3-trimethylcyclohexane, 1,2, 4-trimethylcyclohexane, 1,2, 5-trimethylcyclohexane, 1,3, 5-trimethylcyclohexane), decane, 2-methylnonane, 3-methylnonane, 4-methylnonane, 5-methylnonane, 2, 3-dimethyloctane, 2, 4-dimethyloctane, 3-ethyloctane, 4-ethyloctane, 2,3, 4-trimethylheptane, 2,3, 5-trimethylheptane, 2,3, 6-trimethylheptane, 2,4, 5-trimethylheptane, 2,4, 6-trimethylheptane, 2, 3-trimethylheptane, 2, 4-trimethylheptane, 2, 5-trimethylheptane, 2,2, 6-trimethylheptane, 2,3, 3-trimethylheptane, 2,4, 4-trimethylheptane, 2-methyl-3-ethylheptane, 2-methyl-4-ethylheptane, 2-methyl-5-ethylheptane, 3-methyl-3-ethylheptane, 4-methyl-3-ethylheptane, 5-methyl-3-ethylheptane, 4-methyl-4-ethylheptane, 4-propylheptane, 3, 3-diethylhexane, 3, 4-diethylhexane, 2-methyl-3, 3-diethylpentane, 1, 2-diethylcyclohexane, 1, 3-diethylcyclohexane, 1, 4-diethylcyclohexane, 1, 3-diethylheptane, 2-methyl-3-ethylheptane, 3-methyl-3-diethylheptane, 4-ethylheptane, 3-diethylhexane, 3-diethylheptane, 4-diethylheptane, 1, 4-diethylcyclohexane, 1, 2-diethylheptane, 4-diethylheptane, 2-ethylheptane, 2-methyl-3-ethyl-heptane, 4-ethylheptane, 4-diethylheptane, 1, 4-diethylheptane, 1, 4-diethylheptane, ethyl-ethylheptane, 4-diethylheptane, 4-ethylheptane, 4-diethylheptane, ethyl-heptane, 4-ethyl-heptane, 2-ethyl-heptane, 4-ethyl-heptane, 4-ethyl-heptane, 4-ethyl-heptane, or-ethyl-, N-butylcyclohexane, isobutylcyclohexane, tert-butylcyclohexane, tetramethylcyclohexane (including various isomers of tetramethylcyclohexane, such as 1,2,3, 4-tetramethylcyclohexane, 1,2,4, 5-tetramethylcyclohexane, 1,2,3, 5-tetramethylcyclohexane), toluene, ethylbenzene, and xylene (including o-xylene, m-xylene, and p-xylene). The organic solvent is more preferably at least one of methylcyclohexane, heptane, cyclohexane, toluene, and xylene.

The amount of the organic solvent used in the present invention is not particularly limited, and may be selected conventionally. Generally, the organic solvent is used in an amount such that the concentration of the catalyst composition is 1 to 20. mu. mol/L, based on the transition metal element in the transition metal compound. Specifically, the organic solvent is used in an amount such that the concentration of the catalyst composition is 1. mu. mol/L, 2. mu. mol/L, 3. mu. mol/L, 4. mu. mol/L, 5. mu. mol/L, 6. mu. mol/L, 7. mu. mol/L, 8. mu. mol/L, 9. mu. mol/L, 10. mu. mol/L, 11. mu. mol/L, 12. mu. mol/L, 13. mu. mol/L, 14. mu. mol/L, 15. mu. mol/L, 16. mu. mol/L, 17. mu. mol/L, 18. mu. mol/L, 19. mu. mol/L or 20. mu. mol Cr/L, based on the transition metal element in the transition metal compound. Preferably, the organic solvent is used in an amount such that the concentration of the catalyst composition is 5 to 10. mu. mol/L, based on the transition metal element in the transition metal compound.

According to the ethylene trimerization process of the present invention, the pressure of the ethylene may be from 0.1 to 20MPa, for example: 0.1MPa, 0.2MPa, 0.3MPa, 0.4MPa, 0.5MPa, 0.6MPa, 0.7MPa, 0.8MPa, 0.9MPa, 1MPa, 1.1MPa, 1.2MPa, 1.3MPa, 1.4MPa, 1.5MPa, 1.6MPa, 1.7MPa, 1.8MPa, 1.9MPa, 2MPa, 2.1MPa, 2.2MPa, 2.3MPa, 2.4MPa, 2.5MPa, 2.6MPa, 2.7MPa, 2.8MPa, 2.9MPa, 3MPa, 3.1MPa, 3.2MPa, 3.3MPa, 3.4MPa, 3.5MPa, 3.6MPa, 3.7MPa, 3.8MPa, 3.9MPa, 4.1MPa, 4.2MPa, 4.3MPa, 4.4MPa, 4.5MPa, 4.6MPa, 7.7MPa, 6.6MPa, 6.7MPa, 6.8MPa, 6.7.6 MPa, 6MPa, 6.7MPa, 6.6.7 MPa, 6MPa, 6.7.7 MPa, 6MPa, 6.7.7.8 MPa, 6MPa, 6.7.7.7.7.7 MPa, 6MPa, 6.7.7 MPa, 6MPa, 6.9MPa, 6MPa, 6.7.7.7.7.7.7.7.7.7.7.7.7.7.7 MPa, 6.7.7.7.7.7.7 MPa, 6MPa, 6, 6.7MPa, 6, 6.7.7.7.9 MPa, 6MPa, 6MPa, 6.7.7 MPa, 6MPa, 6.7.7.7.7.7.7.7.7 MPa, 6MPa, 6.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7 MPa, 6, 6.7.7.7.7.7.7.7.7.7.7 MPa, 6, 6.7.7.7.6, 6MPa, 6, 6.9MPa, 6MPa, 6, 6.7.7.7.7.7.7.7.7.7.7.7 MPa, 6MPa, 7.7.7.7.7 MPa, 6, 7.7.7.7.7.7.7.7.7.7.7 MPa, 6, 6.7.7.9 MPa, 6, 7.7.7.7.7., 8.4MPa, 8.5MPa, 8.6MPa, 8.7MPa, 8.8MPa, 8.9MPa, 9MPa, 9.1MPa, 9.2MPa, 9.3MPa, 9.4MPa, 9.5MPa, 9.6MPa, 9.7MPa, 9.8MPa, 9.9MPa, 10MPa, 10.1MPa, 10.2MPa, 10.3MPa, 10.4MPa, 10.5MPa, 10.6MPa, 10.7MPa, 10.8MPa, 10.9MPa, 11MPa, 11.1MPa, 11.2MPa, 11.3MPa, 11.4MPa, 11.5MPa, 11.6MPa, 11.7MPa, 11.8MPa, 11.9MPa, 12MPa, 12.1MPa, 12.2MPa, 12.3MPa, 12.4MPa, 12.5MPa, 12.6MPa, 12.7MPa, 12.8MPa, 12.9MPa, 13.9MPa, 13.6MPa, 13.1MPa, 14.6MPa, 14.7MPa, 14.6MPa, 13.6MPa, 14.6MPa, 15.6MPa, 13.6MPa, 13.7MPa, 13.6MPa, 15.6MPa, 13.6MPa, 14.6MPa, 15.6MPa, 13.6MPa, 13.7MPa, 13.6MPa, 15.6MPa, 13.6MPa, 13.7MPa, 13.6MPa, 13.7MPa, 13.6MPa, 15.6MPa, 13.6MPa, 13.7MPa, 13.6MPa, 15.6MPa, 13.6MPa, 13.7MPa, 13.6MPa, 15.6MPa, 13.6MPa, 15.6MPa, 13.6MPa, 13, 16.7MPa, 16.8MPa, 16.9MPa, 17MPa, 17.1MPa, 17.2MPa, 17.3MPa, 17.4MPa, 17.5MPa, 17.6MPa, 17.7MPa, 17.8MPa, 17.9MPa, 18MPa, 18.1MPa, 18.2MPa, 18.3MPa, 18.4MPa, 18.5MPa, 18.6MPa, 18.7MPa, 18.8MPa, 18.9MPa, 19MPa, 19.1MPa, 19.2MPa, 19.3MPa, 19.4MPa, 19.5MPa, 19.6MPa, 19.7MPa, 19.8MPa, 19.9MPa or 20 MPa.

Preferably, the pressure of the ethylene is from 0.5 to 5 MPa. More preferably, the pressure of the ethylene is from 1 to 4 MPa. Further preferably, the pressure of the ethylene is 2-3 MPa.

The ethylene trimerization process according to the present invention can be carried out by conventional methods. In one embodiment, the fluorine-containing compound, the transition metal compound and the cocatalyst are mixed and then added to the reactor to contact ethylene in the presence of an optional organic solvent to carry out oligomerization. In another embodiment, the fluorine-containing compound, the transition metal compound and the cocatalyst can be added into the reactor separately and contacted with ethylene in the presence of an optional organic solvent to carry out oligomerization.

According to a fourth aspect of the present invention there is provided a process for the tetramerisation of ethylene which comprises contacting ethylene with a catalyst composition according to the third aspect of the present invention at a temperature of from 30 to 50 ℃.

According to the ethylene tetramerization method of the present invention, the contact temperature may be, for example, 30 ℃, 31 ℃, 32 ℃, 33 ℃, 34 ℃, 35 ℃, 36 ℃, 37 ℃, 38 ℃, 39 ℃,40 ℃, 41 ℃, 42 ℃, 43 ℃, 44 ℃, 45 ℃, 46 ℃, 47 ℃, 48 ℃, 49 ℃ or 50 ℃.

According to the ethylene tetramerisation process of the present invention, the contacting is preferably carried out in at least one organic solvent. The organic solvent is a solvent capable of dissolving the tetramerization product, and may be at least one selected from paraffin, naphthene and aromatic hydrocarbon, preferably selected from C₆-C₁₂Alkane of (C)₆-C₁₂Cycloalkane of (2)₆-C₁₂At least one aromatic hydrocarbon of (1). Specific examples of the organic solvent may include, but are not limited to: hexane, 2-methylpentane, 3-methylpentane, 2, 3-dimethylbutane, cyclohexane, methylcyclopentane, heptane, 2-methylhexane, 3-methylhexane, methylcyclohexane, 2-ethylpentane, 3-ethylpentane, 2, 3-dimethylpentane, 2, 4-dimethylpentane, octane, 2-methylheptane, 3-methylheptane, 4-methylheptane, 2, 3-dimethylhexane, 2, 4-dimethylhexane, 2, 5-dimethylhexane, 3-ethylhexane, 2, 3-trimethylpentane, 2,3, 3-trimethylpentane, 2,4, 4-trimethylpentane, 2-methyl-3-ethylpentane, nonane, 2-methyloctane, cyclohexane, methylcyclopentane, heptane, 2-methylhexane, 3-methylheptane, 4-methylheptane, 2, 4-dimethylhexane, 2, 3-trimethylpentane, 2-methylhexane, 2, 3-methylpentane, 2-dimethylpentane, 2-dimethylpentane, 4-dimethylhexane, 2-dimethylpentane, 2, 3-dimethylpentane, 2, 3-dimethylpentane, 2, 3-dimethylpentane, 2, 3-dimethylpentane, 2,3, 2,3, 2, and/3, 2 '-dimethylpentane, 2' -dimethylpentane, 2, 3-methyloctane, 4-methyloctane, 2, 3-dimethylheptane, 2, 4-dimethylheptane, 3-ethylheptane, 4-ethylheptane, 2,3, 4-trimethylhexane, 2,3, 5-trimethylhexane, 2,4, 5-trimethylhexane, 2, 3-trimethylhexane, 2, 4-trimethylhexane, 2, 5-trimethylhexane, 2,3, 3-trimethylhexane, 2,4, 4-trimethylhexane, 2-methyl-3-ethylhexane, 2-methyl-4-ethylhexane, 3-methyl-3-ethylhexane, 3-methyl-4-ethylhexane, 3, 3-diethylpentane, 1-methyl-2-ethylcyclohexane, 1-methyl-3-ethylcyclohexane, 1-methyl-4-ethylcyclohexane, n-propylcyclohexane, isopropylcyclohexane, trimethylcyclohexane (including various isomers of trimethylcyclohexane, such as 1,2, 3-trimethylcyclohexane, 1,2, 4-trimethylcyclohexane, 1,2, 5-trimethylcyclohexane, 1,3, 5-trimethylcyclohexane), decane, 2-methylnonane, 3-methylnonane, 4-methylnonane, 5-methylnonane, 2, 3-dimethyloctane, 2, 4-dimethyloctane, 3-ethyloctane, 4-ethyloctane, 2,3, 4-trimethylheptane, 2,3, 5-trimethylheptane, 2,3, 6-trimethylheptane, trimethylheptane, 2,4, 5-trimethylheptane, 2,4, 6-trimethylheptane, 2, 3-trimethylheptane, 2, 4-trimethylheptane, 2, 5-trimethylheptane, 2, 6-trimethylheptane, 2,3, 3-trimethylheptane, 2,4, 4-trimethylheptane, 2-methyl-3-ethylheptane, 2-methyl-4-ethylheptane, 2-methyl-5-ethylheptane, 3-methyl-3-ethylheptane, 4-methyl-3-ethylheptane, 5-methyl-3-ethylheptane, 4-methyl-4-ethylheptane, 4-propylheptane, 3, 3-diethylhexane, diethylheptane, ethylheptane, diethylheptane, ethylheptane, diethylheptane, or mixtures thereof, and mixtures thereof, 3, 4-diethylhexane,2-methyl-3, 3-diethylpentane, 1, 2-diethylcyclohexane, 1, 3-diethylcyclohexane, 1, 4-diethylcyclohexane, n-butylcyclohexane, isobutylcyclohexane, tert-butylcyclohexane, tetramethylcyclohexane (including various isomers of tetramethylcyclohexane, such as 1,2,3, 4-tetramethylcyclohexane, 1,2,4, 5-tetramethylcyclohexane, 1,2,3, 5-tetramethylcyclohexane), toluene, ethylbenzene, and xylenes (including o-xylene, m-xylene, and p-xylene). The organic solvent is more preferably at least one of methylcyclohexane, heptane, cyclohexane, toluene, and xylene.

According to the ethylene tetramerisation process of the present invention, the pressure of the ethylene may be in the range of 0.1 to 20MPa, for example: 0.1MPa, 0.2MPa, 0.3MPa, 0.4MPa, 0.5MPa, 0.6MPa, 0.7MPa, 0.8MPa, 0.9MPa, 1MPa, 1.1MPa, 1.2MPa, 1.3MPa, 1.4MPa, 1.5MPa, 1.6MPa, 1.7MPa, 1.8MPa, 1.9MPa, 2MPa, 2.1MPa, 2.2MPa, 2.3MPa, 2.4MPa, 2.5MPa, 2.6MPa, 2.7MPa, 2.8MPa, 2.9MPa, 3MPa, 3.1MPa, 3.2MPa, 3.3MPa, 3.4MPa, 3.5MPa, 3.6MPa, 3.7MPa, 3.8MPa, 3.9MPa, 4.1MPa, 4.2MPa, 4.3MPa, 4.4MPa, 4.5MPa, 4.6MPa, 7.7MPa, 6.6MPa, 6.7MPa, 6.8MPa, 6.7.6 MPa, 6MPa, 6.7MPa, 6.6.7 MPa, 6MPa, 6.7.7 MPa, 6MPa, 6.7.7.8 MPa, 6MPa, 6.7.7.7.7.7 MPa, 6MPa, 6.7.7 MPa, 6MPa, 6.9MPa, 6MPa, 6.7.7.7.7.7.7.7.7.7.7.7.7.7.7 MPa, 6.7.7.7.7.7.7 MPa, 6MPa, 6, 6.7MPa, 6, 6.7.7.7.9 MPa, 6MPa, 6MPa, 6.7.7 MPa, 6MPa, 6.7.7.7.7.7.7.7.7 MPa, 6MPa, 6.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7.7 MPa, 6, 6.7.7.7.7.7.7.7.7.7.7 MPa, 6, 6.7.7.7.6, 6MPa, 6, 6.9MPa, 6MPa, 6, 6.7.7.7.7.7.7.7.7.7.7.7 MPa, 6MPa, 7.7.7.7.7 MPa, 6, 7.7.7.7.7.7.7.7.7.7.7 MPa, 6, 6.7.7.9 MPa, 6, 7.7.7.7.7., 8.4MPa, 8.5MPa, 8.6MPa, 8.7MPa, 8.8MPa, 8.9MPa, 9MPa, 9.1MPa, 9.2MPa, 9.3MPa, 9.4MPa, 9.5MPa, 9.6MPa, 9.7MPa, 9.8MPa, 9.9MPa, 10MPa, 10.1MPa, 10.2MPa, 10.3MPa, 10.4MPa, 10.5MPa, 10.6MPa, 10.7MPa, 10.8MPa, 10.9MPa, 11MPa, 11.1MPa, 11.2MPa, 11.3MPa, 11.4MPa, 11.5MPa, 11.6MPa, 11.7MPa, 11.8MPa, 11.9MPa, 12MPa, 12.1MPa, 12.2MPa, 12.3MPa, 12.4MPa, 12.5MPa, 12.6MPa, 12.7MPa, 12.8MPa, 12.9MPa, 13.9MPa, 13.6MPa, 13.1MPa, 14.6MPa, 14.7MPa, 14.6MPa, 13.6MPa, 14.6MPa, 15.6MPa, 13.6MPa, 13.7MPa, 13.6MPa, 15.6MPa, 13.6MPa, 14.6MPa, 15.6MPa, 13.6MPa, 13.7MPa, 13.6MPa, 15.6MPa, 13.6MPa, 13.7MPa, 13.6MPa, 13.7MPa, 13.6MPa, 15.6MPa, 13.6MPa, 13.7MPa, 13.6MPa, 15.6MPa, 13.6MPa, 13.7MPa, 13.6MPa, 15.6MPa, 13.6MPa, 15.6MPa, 13.6MPa, 13, 16.7MPa, 16.8MPa, 16.9MPa, 17MPa, 17.1MPa, 17.2MPa, 17.3MPa, 17.4MPa, 17.5MPa, 17.6MPa, 17.7MPa, 17.8MPa, 17.9MPa, 18MPa, 18.1MPa, 18.2MPa, 18.3MPa, 18.4MPa, 18.5MPa, 18.6MPa, 18.7MPa, 18.8MPa, 18.9MPa, 19MPa, 19.1MPa, 19.2MPa, 19.3MPa, 19.4MPa, 19.5MPa, 19.6MPa, 19.7MPa, 19.8MPa, 19.9MPa or 20 MPa.

Preferably, the pressure of the ethylene is from 0.5 to 8 MPa. More preferably, the pressure of the ethylene is from 3 to 6 MPa. Further preferably, the pressure of the ethylene is 4-5 MPa.

The ethylene tetramerisation process according to the present invention can be carried out by conventional methods. In one embodiment, the fluorine-containing compound, the transition metal compound and the cocatalyst are mixed and then added to the reactor to contact ethylene in the presence of an optional organic solvent to carry out oligomerization. In another embodiment, the fluorine-containing compound, the transition metal compound and the cocatalyst can be added into the reactor separately and contacted with ethylene in the presence of an optional organic solvent to carry out oligomerization.

The present invention will be described in detail with reference to examples, but the scope of the present invention is not limited thereto.

In the following examples and comparative examples, NMR spectroscopy was carried out using a Bruker AV400 NMR spectrometer, in which NMR was measured under the following conditions: deuterated chloroform is used as a solvent, and the test is carried out at room temperature (25 ℃). The gas chromatography is detected by adopting a Hewlett packard 5890 chromatograph, wherein the detection conditions of the gas chromatography are as follows: the chromatographic column is an SE-54 chromatographic column, high-purity nitrogen is used as carrier gas, and an FID detector is adopted; the column temperature adopts two-step temperature programming.

The abbreviations referred to in the following examples and comparative examples have the following meanings:

^tbu is tert-butyl;ⁱpr is isopropyl;

cy is cyclohexyl; ph is phenyl;

me is methyl; THF is tetrahydrofuran;

acac is acetylacetone.

Preparation examples 1 to 5 were used for the fluorine-containing compound according to the present invention.

Preparation example 1

Preparation example 1 preparation of fluorine-containing Compound I¹。

Fluorine-containing compound I¹The preparation method refers to the reaction formula, and the specific steps are as follows.

Under nitrogen protection, 15mL of dried tetrahydrofuran and 2-butyne (11mmol) were charged in a 50mL reaction flask, followed by dropwise addition of n-butyllithium (11mmol) (6.6mL of a hexane solution of n-butyllithium at a concentration of 1.6M) at 0 ℃. After the addition, stirring was continued at 0 ℃ for 30min, then 2.2g (10mmol) of difluorophenylphosphonium chloride was added dropwise, and after the addition, the temperature was raised to room temperature (25 ℃ C., the same applies hereinafter), and stirring was continued for 2 h. Catalytic amounts of CuI and cesium carbonate were added, followed by 2.2g (10mmol) of difluorophenylphosphine chloride, the temperature was raised to 90 ℃ and stirred at 90 ℃ for 4 h. After the reaction was completed, the reaction mixture was cooled to room temperatureFiltering, vacuum-drying the filtrate, passing the residue through a silica gel column (petroleum ether (PE)/Ethyl Acetate (EA) ═ 20: 1) to give a fluorine-containing compound I¹。

Performing nuclear magnetic resonance analysis on the prepared compound to determine that the prepared compound is a fluorine-containing compound shown as a formula I, wherein R¹And R²Is Me.

H¹NMR(400MHz,CDCl₃):δ＝7.30-7.00(m,16H),1.68(s,6H)。

Preparation example 2

Preparation example 2 for preparing fluorine-containing Compound I²。

This preparation example was used to prepare a fluorine-containing compound in the same manner as in preparation example 1, except that 2-butyne was replaced with 2, 5-dimethyl-3-hexyne. Performing nuclear magnetic resonance analysis on the prepared compound to determine that the prepared compound is a fluorine-containing compound shown as a formula I, wherein R¹And R²Is composed ofⁱPr。

H¹NMR(400MHz,CDCl₃):δ＝7.35-7.00(m,16H),2.70(m,2H), 1.15-1.10(m,12H)。

Preparation example 3

Preparation example 3 preparation of fluorine-containing Compound I³。

This preparation example prepared a fluorine-containing compound in the same manner as in preparation example 1 except that 2-butyne was replaced with dicyclohexylacetylene. Performing nuclear magnetic resonance analysis on the prepared compound to determine that the prepared compound is a fluorine-containing compound shown as a formula I, wherein R¹And R²Is Cy.

H¹NMR(400MHz,CDCl₃):δ＝7.35-6.99(m,16H),2.15(m,2H), 1.30-1.60(m,20H)。

Preparation example 4

Preparation example 4 preparation of fluorine-containing Compound I⁴。

This preparation example prepared a fluorine-containing compound in the same manner as in preparation example 1 except that 2-butyne was replaced with diphenylacetylene. Performing nuclear magnetic resonance analysis on the prepared compound to determine that the prepared compound is a fluorine-containing compound shown as a formula I, wherein R¹And R²Is Ph。

H¹NMR(400MHz,CDCl₃):δ＝7.45-7.00(m,26H)。

Preparation example 5

Preparation example 5 preparation of fluorine-containing Compound I⁵。

This preparation example was used to prepare a fluorine-containing compound in the same manner as in preparation example 1, except that 2-butyne was replaced with 2,2,5, 5-tetramethyl-3-hexyne. Performing nuclear magnetic resonance analysis on the prepared compound to determine that the prepared compound is a fluorine-containing compound shown as a formula I, wherein R¹And R²Is composed of^tBu。

H¹NMR(400MHz,CDCl₃):δ＝7.25-6.97(m,16H),1.20(s,18H)。

Examples 1-15 are intended to illustrate the invention.

Example 1

A300 mL stainless polymerization autoclave was heated to 80 ℃ and evacuated, then the inside of the autoclave was purged with nitrogen and purged with ethylene, and then the temperature of the autoclave was lowered to 40 ℃. To the autoclave were added methylcyclohexane (available from carbofuran chemical Co., Beijing), 0.5. mu. mol of chromium acetylacetonate (available from carbofuran chemical Co., Beijing), and a fluorine-containing compound I as a ligand¹(wherein, R¹And R²Me), and modified methylaluminoxane (MMAO, available from aksonobel corporation) as a cocatalyst, and mixed uniformly, wherein the total volume of the mixed solution was 100mL, chromium acetylacetonate: fluorine-containing compound: the molar ratio of the cocatalyst is 1: 2: 400, i.e. fluorine-containing compounds I¹The amount of MMAO added was 1. mu. mol and the amount of MMAO added was 200. mu. mol. Ethylene is introduced, the pressure of the ethylene is controlled to be 3MPa, and the ethylene oligomerization reaction is carried out at the temperature of 40 ℃. After 30 minutes, 1mL of ethanol was added as a terminator to terminate the reaction. The temperature in the autoclave was lowered to room temperature (25 c), the gas phase product was collected in a gas metering tank, the liquid phase product was collected in a conical flask, the gas phase product was separately metered and subjected to gas chromatography analysis to calculate the catalyst activity and product composition, the results of which are listed in table 1.

Example 2

By usingEthylene oligomerization was carried out in the same manner as in example 1 except that the fluorine-containing compound as the ligand was replaced with the fluorine-containing compound I²(wherein, R¹And R²Is composed ofⁱPr), the results of the experiments are listed in table 1.

Example 3

Ethylene oligomerization was carried out in the same manner as in example 1 except that the fluorine-containing compound as the ligand was replaced with the fluorine-containing compound I³(wherein, R¹And R²For Cy), the results are listed in table 1.

Example 4

Ethylene oligomerization was carried out in the same manner as in example 1 except that the fluorine-containing compound as the ligand was replaced with the fluorine-containing compound I⁴(wherein, R¹And R²Ph), the results are listed in table 1.

Example 5

Ethylene oligomerization was carried out in the same manner as in example 1 except that the fluorine-containing compound as the ligand was replaced with the fluorine-containing compound I⁵(wherein, R¹And R²Is composed of^tBu), the experimental results are listed in table 1.

Example 6

Ethylene oligomerization was carried out in the same manner as in example 1, except that the modified methylaluminoxane as a cocatalyst was replaced with triethylaluminum (available from carbofuran chemical reagent company, beijing), and the experimental results were as shown in table 1.

Example 7

Ethylene oligomerization was carried out in the same manner as in example 1 except that chromium acetylacetonate was replaced with tris (tetrahydrofuran) chromium trichloride (available from carbofuran chemical reagent company, beijing) and the experimental results are shown in table 1.

Example 8

Ethylene oligomerization was carried out in the same manner as in example 1, except that the ethylene oligomerization was carried out at a temperature of 50 deg.C, and the experimental results are shown in Table 1.

Example 9

Ethylene oligomerization was carried out in the same manner as in example 1, except that the ethylene oligomerization was carried out at a temperature of 60 deg.C, and the experimental results are shown in Table 1.

Example 10

Ethylene oligomerization was carried out in the same manner as in example 1, except that the ethylene oligomerization was carried out at a temperature of 70 deg.C, and the experimental results are shown in Table 1.

Example 11

Ethylene oligomerization was carried out in the same manner as in example 1, except that the ethylene oligomerization was carried out at a temperature of 90 deg.C, and the experimental results are shown in Table 1.

Example 12

Ethylene oligomerization was carried out in the same manner as in example 1, except that the ethylene oligomerization was carried out at a temperature of 30 deg.C, and the experimental results are shown in Table 1.

Example 13

Ethylene oligomerization was carried out in the same manner as in example 1, except that the reaction pressure was controlled to 5MPa, and the experimental results were as shown in Table 1.

Comparative example 1

Ethylene oligomerization was carried out in the same manner as in example 1 except that the fluorine-containing compound was replaced with (S, S) - (phenyl)₂PCH (Me) CH (Me) P (phenyl)₂(labeled D1), the results are listed in Table 1.

Comparative example 2

Ethylene oligomerization was carried out in the same manner as in example 1 except that the fluorine-containing compound was replaced with (S, S) - (o-fluoro-phenyl)₂PCH (Me) CH (Me) P (o-fluoro-phenyl)₂(labeled D2), the results are listed in Table 1.

Example 14

A300 mL stainless polymerization autoclave was heated to 80 ℃ and evacuated, then the inside of the autoclave was purged with nitrogen and purged with ethylene, and then the temperature of the autoclave was lowered to 50 ℃. To the autoclave were added heptane (available from carbofuran chemical Co., Beijing), 0.5. mu. mol of chromium acetylacetonate (available from carbofuran, Beijing)Chemical Co.), fluorine-containing compound I as ligand⁵(wherein, R¹And R²Is composed of^tBu), and modified methylaluminoxane (MMAO, available from aksonobel corporation) as a cocatalyst, and mixed uniformly, wherein the total volume of the mixed solution was 100mL, chromium acetylacetonate: fluorine-containing compound: the molar ratio of the cocatalyst is 1: 2: 500, i.e. fluorine-containing compounds I⁵The amount of addition of (3) was 1. mu. mol and the amount of addition of MMAO was 250. mu. mol. Ethylene is introduced, the pressure of the ethylene is controlled to be 4MPa, and the ethylene oligomerization reaction is carried out at the temperature of 50 ℃. After 60 minutes, 1mL of ethanol was added as a terminator to terminate the reaction. The temperature in the autoclave was lowered to room temperature (25 c), the gas phase product was collected in a gas metering tank, the liquid phase product was collected in a conical flask, the gas phase product was separately metered and subjected to gas chromatography analysis to calculate the catalyst activity and product composition, the results of which are listed in table 1.

Example 15

A300 mL stainless steel polymerization autoclave was heated to 80 ℃ and evacuated to be substituted with nitrogen, followed by charging ethylene to be substituted, and toluene (available from Bailingwei chemical Co., Beijing), 1.0. mu. mol of chromium acetylacetonate (available from Bailingwei chemical Co., Ltd.), and a fluorine-containing compound I as a ligand were added to the autoclave⁴(wherein, R¹And R²Ph), and methylalumoxane (MAO, available from aksonobel corporation) as a co-catalyst, wherein the total volume of the mixture was 100mL, chromium acetylacetonate: fluorine-containing compound: the molar ratio of the cocatalyst is 1: 1.5: 300, i.e. fluorine-containing compounds I⁴The amount of MAO added was 1.5. mu. mol and the amount of MAO added was 300. mu. mol. Ethylene is introduced, the pressure of the ethylene is controlled to be 2MPa, and the ethylene oligomerization reaction is carried out at the temperature of 80 ℃. After 30 minutes, 1mL of ethanol was added as a terminator to terminate the reaction. The temperature in the autoclave was lowered to room temperature (25 c), the gas phase product was collected in a gas metering tank, the liquid phase product was collected in a conical flask, the gas phase product was separately metered and subjected to gas chromatography analysis to calculate the catalyst activity and product composition, the results of which are listed in table 1.

TABLE 1

From the data in Table 1 it can be seen that the catalytic activity of the symmetrical vinyl-bridged bisphosphine-type catalysts according to the invention is at 0.9X 10⁸g·mol(Cr)^-1·h^-1Above, up to 4 × 10⁸g·mol(Cr)^-1·h^-1Under different conditions, the total selectivity of 1-hexene to 1-octene is more than 92 wt%, and can exceed 94 wt% at most.

From the results in table 1, it can be seen that the change of the ligand structure of the catalyst has a very significant effect on the catalytic performance. Compared with the catalysts of comparative examples 1-2, the catalyst composition of the invention has obviously improved catalyst activity, can obtain good balance between the catalytic activity and the product selectivity, reduces the generation of byproducts such as cycloolefins and cyclized products, and shows that the catalyst of the invention has better performance.

In addition, when the polymerization reaction is carried out, the catalyst system of the catalyst composition disclosed by the invention is quick in initiation and stable in operation, and can be used for more effectively catalyzing ethylene trimerization and tetramerization, wherein the catalyst composition disclosed by the invention only needs a plurality of minutes, the ethylene absorption can reach the maximum value, and the ethylene absorption can be kept for more than half an hour. This shows that the catalyst composition according to the invention has strong practicability and wide industrialization prospect.

The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.

Claims

1. A fluorine-containing compound is a compound shown in a formula I,

2. The fluorochemical of claim 1, wherein R¹And R²Each independently is C₁-C₈Chain alkyl radical, C₃-C₈Cycloalkyl or C₆-C₁₆And (4) an aryl group.

3. The fluorochemical of claim 1, wherein R¹And R²Each independently is C₁-C₆Chain alkyl radical, C₃-C₆Cycloalkyl or C₆-C₁₂And (4) an aryl group.

4. The fluorochemical of claim 1, wherein R¹And R²Each independently is methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, isobutyl, n-pentyl, isopentyl, tert-pentyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, phenyl, methylphenyl, ethylphenyl, chlorophenyl or naphthyl.

5. The fluorochemical of claim 1, wherein R¹And R²Each independently is tert-butyl, cyclohexyl, phenyl, isopropyl or methyl.

6. The fluorochemical of claim 1, wherein R¹And R²Each independently is tert-butyl, cyclohexyl or methyl.

7. Use of a fluorine-containing compound according to any one of claims 1 to 6 as a ligand for an ethylene oligomerization catalyst composition.

8. Use according to claim 7, wherein the catalyst composition comprises a transition metal compound, a cocatalyst and the fluorine-containing compound.

9. Use according to claim 8, wherein the molar ratio of the fluorine-containing compound and the transition metal compound is 1: 0.1-10.

10. Use according to claim 9, wherein the molar ratio of the fluorine-containing compound and the transition metal compound is 1: 0.25-2.

11. Use according to claim 10, wherein the molar ratio of the fluorine-containing compound and the transition metal compound is 1: 0.5-2.

12. Use according to claim 8, wherein the molar ratio of the fluorine-containing compound to the cocatalyst is 1: 1-1000.

13. Use according to claim 12, wherein the molar ratio of the fluorine-containing compound to the cocatalyst is 1: 10-700.

14. Use according to claim 13, wherein the molar ratio of the fluorine-containing compound to the cocatalyst is 1: 100-500.

15. The use according to any one of claims 8 to 14, wherein the transition metal compound is at least one selected from a compound of chromium, a compound of molybdenum, a compound of iron, a compound of titanium, a compound of zirconium and a compound of nickel.

16. The use according to claim 15, wherein the transition metal compound is at least one selected from chromium acetylacetonate, chromium isooctanoate, chromium tris (tetrahydrofuran) trichloride and chromium bis (tetrahydrofuran) dichloride.

17. Use according to any one of claims 8 to 14, wherein the cocatalyst is an aluminium-containing cocatalyst.

18. Use according to claim 17, wherein the cocatalyst is an organoaluminium compound.

19. The use according to claim 17, wherein the co-catalyst is at least one selected from the group consisting of an aluminum alkyl, an aluminum alkoxy and an aluminum alkyl halide.

20. The use according to claim 17, wherein the cocatalyst is at least one selected from methylaluminoxane, trimethylaluminum, triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, diethylaluminum monochloride, ethylaluminum dichloride, ethylaluminoxane and modified methylaluminoxane.

21. The use of claim 17, wherein the cocatalyst is at least one selected from modified methylaluminoxane, and triethylaluminum.

22. An ethylene oligomerization catalyst composition, which contains a fluorine-containing compound shown as a formula I, a transition metal compound and a cocatalyst;

23. According to claim22 wherein R¹And R²Each independently is C₁-C₈Chain alkyl radical, C₃-C₈Cycloalkyl or C₆-C₁₆And (4) an aryl group.

24. The composition of claim 22, wherein R¹And R²Each independently is C₁-C₆Chain alkyl radical, C₃-C₆Cycloalkyl or C₆-C₁₂And (4) an aryl group.

25. The composition of claim 22, wherein R¹And R²Each independently is methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, isobutyl, n-pentyl, isopentyl, tert-pentyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, phenyl, methylphenyl, ethylphenyl, chlorophenyl or naphthyl.

26. The composition of claim 22, wherein R¹And R²Each independently is tert-butyl, cyclohexyl, phenyl, isopropyl or methyl.

27. The composition of claim 22, wherein R¹And R²Each independently is tert-butyl, cyclohexyl or methyl.

28. The composition of any of claims 22-27, wherein the molar ratio of the fluorine-containing compound to the transition metal compound is 1: 0.1-10.

29. The composition of claim 28, wherein the molar ratio of the fluorine-containing compound to the transition metal compound is 1: 0.25-2.

30. The composition of claim 29, wherein the molar ratio of the fluorine-containing compound to the transition metal compound is 1: 0.5-2.

31. The composition of any of claims 22-27, wherein the molar ratio of the fluorochemical compound to the co-catalyst is 1: 1-1000.

32. The composition of claim 31, wherein the molar ratio of the fluorine-containing compound to the co-catalyst is 1: 10-700.

33. The composition of claim 32, wherein the molar ratio of the fluorine-containing compound to the co-catalyst is 1: 100-500.

34. The composition of any of claims 22-27, wherein the transition metal compound is at least one selected from a compound of chromium, a compound of molybdenum, a compound of iron, a compound of titanium, a compound of zirconium, and a compound of nickel.

35. The composition of claim 34, wherein the transition metal compound is at least one selected from the group consisting of chromium acetylacetonate, chromium isooctanoate, chromium tris (tetrahydrofuran) trichloride, and chromium bis (tetrahydrofuran) dichloride.

36. The composition of any of claims 22-27, wherein the cocatalyst is an aluminum-containing cocatalyst.

37. The composition of claim 36, wherein the co-catalyst is an organoaluminum compound.

38. The composition of claim 36, wherein the co-catalyst is at least one selected from the group consisting of aluminum alkyls, aluminum alkoxides, and aluminum alkyl halides.

39. The composition of claim 36, wherein the cocatalyst is at least one selected from methylaluminoxane, trimethylaluminum, triethylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, diethylaluminum monochloride, ethylaluminum dichloride, ethylaluminoxane, and modified methylaluminoxane.

40. The composition of claim 36, wherein the cocatalyst is at least one selected from modified methylaluminoxane, and triethylaluminum.

41. A process for the oligomerization of ethylene, comprising contacting ethylene with the catalyst composition of any of claims 22-40.

42. The method of claim 41, wherein the contacting is performed in at least one organic solvent.

43. The method of claim 42, wherein the organic solvent is selected from C₆-C₁₂Alkane of (C)₆-C₁₂Cycloalkane of (2)₆-C₁₂At least one aromatic hydrocarbon of (1).

44. The method according to claim 43, wherein the organic solvent is at least one selected from the group consisting of methylcyclohexane, heptane, cyclohexane, toluene, and xylene.

45. The process of any one of claims 42 to 44, wherein the organic solvent is used in an amount such that the concentration of the catalyst composition in the solvent is from 1 to 20 μmol/L, based on the transition metal element in the transition metal compound.

46. The method of any one of claims 41-44, wherein the contacting is performed at a temperature of 0-200 ℃.

47. The method of claim 46, wherein the contacting is performed at a temperature of 0-100 ℃.

48. The method of claim 47, wherein the contacting is performed at a temperature of 30-90 ℃.

49. The process of any one of claims 41 to 44, wherein the ethylene pressure is from 0.1 to 20 MPa.

50. The process of claim 49, wherein the ethylene pressure is from 0.5 to 10 MPa.

51. The process of claim 50, wherein the ethylene pressure is from 2 to 8 MPa.

52. An ethylene trimerization process comprising contacting ethylene with the catalyst composition of any one of claims 22-40 at a temperature of from 60 to 90 ℃.

53. The trimerization process of claim 52, wherein said contacting is carried out in at least one organic solvent.

54. The trimerization process of claim 53, wherein the organic solvent is selected from C₆-C₁₂Alkane of (C)₆-C₁₂Cycloalkane of (2)₆-C₁₂At least one aromatic hydrocarbon of (1).

55. The trimerization process of claim 54, wherein the organic solvent is at least one selected from the group consisting of methylcyclohexane, heptane, cyclohexane, toluene and xylene.

56. The trimerization process of any of claims 53-55, wherein the organic solvent is used in an amount such that the concentration of the catalyst composition, calculated as transition metal element in the transition metal compound, is from 1 to 20 μmol/L.

57. The trimerization process of any of claims 52-55, wherein the pressure of the ethylene is from 0.1 to 20 MPa.

58. The trimerization process of claim 57, wherein the pressure of the ethylene is from 0.5 to 5 MPa.

59. The trimerization process of claim 58, wherein the pressure of the ethylene is from 1 to 4 MPa.

60. The trimerization process of claim 59, wherein the pressure of the ethylene is from 2 to 3 MPa.

61. A process for the tetramerisation of ethylene, which comprises contacting ethylene with a catalyst composition according to any one of claims 22 to 40 at a temperature of from 30 to 50 ℃.

62. The tetramerization process according to claim 61, wherein the contacting is carried out in at least one organic solvent.

63. The tetramerization process of claim 62, wherein the organic solvent is selected from C₆-C₁₂Alkane of (C)₆-C₁₂Cycloalkane of (2)₆-C₁₂At least one aromatic hydrocarbon of (1).

64. The tetramerization process according to claim 63, wherein the organic solvent is at least one selected from the group consisting of methylcyclohexane, heptane, cyclohexane, toluene, and xylene.

65. The tetramerization process according to any one of claims 62 to 64, wherein the organic solvent is used in an amount such that a concentration of a catalyst composition is 1 to 20 μmol/L, based on the transition metal element in the transition metal compound.

66. The tetramerisation process of any one of claims 61 to 64, wherein the pressure of ethylene is from 0.1 to 20 MPa.

67. The tetramerisation process of claim 66, wherein the pressure of ethylene is 0.5-8 MPa.

68. The tetramerisation process of claim 67, wherein the pressure of ethylene is 3-6 MPa.

69. The tetramerisation process of claim 68, wherein the pressure of ethylene is 4-5 MPa.