Multi-center supported catalyst and preparation method and application thereof
阅读说明：本技术 一种多中心负载型催化剂及其制备方法与应用 (Multi-center supported catalyst and preparation method and application thereof ) 是由 王立娟 张瑞 任鹤 王文燕 孙彬彬 杨琦 和树立 王�华 牛娜 李冬霞 宋磊 于 2019-09-25 设计创作，主要内容包括：本发明公开了一种多中心负载型催化剂及其制备方法与应用,该多中心负载型催化剂包括载体和活性组分,活性组分为钒的氧化物、含铬有机化合物和吡咯茂杂环化合物,钒的氧化物、含铬有机化合物和吡咯茂杂环化合物负载于所述载体上；含铬有机化合物包括如下结构：Cr-R,其中,R为取代或非取代的环戊二烯基、茚基或芴基；吡咯茂杂环化合物具有如下式Ⅰ结构：其中,R～1、R～2和R～3分别独立选自H、CH-3-、饱和的或含有双键的直链或支链C-2-C-(10)烃基中的一种；R～4为直链或支链的C-1-C-5烷基；M为Ti或Zr。本发明催化剂共聚性能优异,能够用于生产乙烯均聚物和乙烯/α-烯烃共聚物。(The invention discloses a multi-center supported catalyst and a preparation method and application thereof, wherein the multi-center supported catalyst comprises a carrier and active components, wherein the active components are vanadium oxide, chromium-containing organic compound and pyrrole heterocyclic compound; the chromium-containing organic compound comprises the following structure: Cr-R, wherein R is substituted or unsubstituted cyclopentadienyl, indenyl or fluorenyl; the pyrrole heterocyclic compound has the following structure as shown in the formula I: wherein R is 1 、R 2 And R 3 Each independently selected from H, CH 3 -, saturated or containing double bonds, straight-chain or branched C 2 ‑C 10 One of the hydrocarbon groups; r 4 Is straight-chain or branched C 1 ‑C 5 An alkyl group; m is Ti or Zr. The catalyst has excellent copolymerization performance and can be used for producing ethylene homopolymer and ethylene/alpha-olefin copolymer.)
1. A multi-center supported catalyst is characterized by comprising a carrier and active components, wherein the active components are vanadium oxide, a chromium-containing organic compound and a pyrrole metallocene heterocyclic compound, and the vanadium oxide, the chromium-containing organic compound and the pyrrole metallocene heterocyclic compound are supported on the carrier;
the chromium-containing organic compound comprises the following structure:
Cr-R
wherein R is substituted or unsubstituted cyclopentadienyl, indenyl or fluorenyl;
the pyrrole heterocyclic compound has the following structure as shown in the formula I:
wherein R is1、R2And R3Each independently selected from H, CH3-, saturated or containing double bonds, straight-chain or branched C2-C10One of the hydrocarbon groups; r4Is straight-chain or branched C1-C5An alkyl group; m is Ti or Zr.
2. The multi-center supported catalyst according to claim 1, wherein the content of the vanadium oxide is 0.01 to 10 wt% in terms of vanadium, the content of the chromium-containing organic compound is 0.01 to 10 wt% in terms of chromium, and the content of the azole heterocyclic compound is 0.01 to 5 wt% in terms of M, based on the total mass of the multi-center supported catalyst.
3. The multi-center supported catalyst according to claim 1, wherein the carrier is one or more selected from the group consisting of silica, alumina, titania, zirconia, magnesia, calcia and inorganic clay; and/or the carrier is obtained by dehydration, deoxidation and modification.
4. The multi-center supported catalyst according to claim 3, wherein the modifier for modifying the support is one or more selected from the group consisting of methylaluminoxane, trimethylaluminum, triethylaluminum and triisobutylaluminum.
5. The multi-center supported catalyst of claim 1, wherein R is1、R2And R3Each independently selected from H, CH3-, saturated or containing double bonds, straight-chain or branched C2-C5One of the hydrocarbon groups; the R is4Is CH3-or CH3CH2-。
6. The multi-site supported catalyst according to claim 5, wherein the azole metallocene heterocyclic compound is:
[(η5-C9H6)CH2(2-C4H3N)]Zr(NMe2)2、
[(η5-C9H6)CH2(2-(3-CH3-C4H2N))]Zr(NMe2)2、
[(η5-C9H6)CH2(2-(4-CH3-C4H2N))]Zr(NMe2)2、
[(η5-C9H6)CH2(2-(5-CH3-C4H2N))]Zr(NMe2)2、
[(η5-C9H6)CH2(2-(3-CH3-4-CH3-C4HN))]Zr(NMe2)2、
[(η5-C9H6)CH2(2-(3-CH3-5-CH3-C4HN))]Zr(NMe2)2、
[(η5-C9H6)CH2(2-(4-CH3-5-CH3-C4HN))]Zr(NMe2)2、
[(η5-C9H6)CH2(2-(3-CH3-4-CH3-5-CH3-C4N))]Zr(NMe2)2、
[(η5-C9H6)CH2(2-C4H3N)]Zr(NEt2)2、
[(η5-C9H6)CH2(2-(3-CH3-C4H2N))]Zr(NEt2)2、
[(η5-C9H6)CH2(2-(4-CH3-C4H2N))]Zr(NEt2)2、
[(η5-C9H6)CH2(2-(5-CH3-C4H2N))]Zr(NEt2)2、
[(η5-C9H6)CH2(2-(3-CH3-4-CH3-C4HN))]Zr(NEt2)2、
[(η5-C9H6)CH2(2-(3-CH3-5-CH3-C4HN))]Zr(NEt2)2、
[(η5-C9H6)CH2(2-(4-CH3-5-CH3-C4HN))]Zr(NEt2)2、
[(η5-C9H6)CH2(2-(3-CH3-4-CH3-5-CH3-C4N))]Zr(NEt2)2、
[(η5-C9H6)CH2(2-C4H3N)]Ti(NMe2)2、
[(η5-C9H6)CH2(2-(3-CH3-C4H2N))]Ti(NMe2)2、
[(η5-C9H6)CH2(2-(4-CH3-C4H2N))]Ti(NMe2)2、
[(η5-C9H6)CH2(2-(5-CH3-C4H2N))]Ti(NMe2)2、
[(η5-C9H6)CH2(2-(3-CH3-4-CH3-C4HN))]Ti(NMe2)2、
[(η5-C9H6)CH2(2-(3-CH3-5-CH3-C4HN))]Ti(NMe2)2、
[(η5-C9H6)CH2(2-(4-CH3-5-CH3-C4HN))]Ti(NMe2)2、
[(η5-C9H6)CH2(2-(3-CH3-4-CH3-5-CH3-C4N))]Ti(NMe2)2、
[(η5-C9H6)CH2(2-C4H3N)]Ti(NEt2)2、
[(η5-C9H6)CH2(2-(3-CH3-C4H2N))]Ti(NEt2)2、
[(η5-C9H6)CH2(2-(4-CH3-C4H2N))]Ti(NEt2)2、
[(η5-C9H6)CH2(2-(5-CH3-C4H2N))]Ti(NEt2)2、
[(η5-C9H6)CH2(2-(3-CH3-4-CH3-C4HN))]Ti(NEt2)2、
[(η5-C9H6)CH2(2-(3-CH3-5-CH3-C4HN))]Ti(NEt2)2、
[(η5-C9H6)CH2(2-(4-CH3-5-CH3-C4HN))]Ti(NEt2)2and
[(η5-C9H6)CH2(2-(3-CH3-4-CH3-5-CH3-C4N))]Ti(NEt2)2one or more of the group.
7. The multi-site supported catalyst of claim 1, wherein the substituted or unsubstituted cyclopentadienyl group has the structure:
wherein, R is3、R4、R5、R6And R7Each independently hydrogen, aliphatic hydrocarbyl of 1-20 carbon atoms;
the substituted or unsubstituted indenyl group has the following structure:
wherein, R is8、R9、R10And R11Each independently is hydrogen, aliphatic hydrocarbyl of 1-10 carbon atoms; the R is12、R13And R14Each independently is hydrogen, aliphatic hydrocarbyl of 1-10 carbon atoms;
the substituted or unsubstituted fluorenyl group has the following structure:
wherein, R is15、R16、R17、R18、R19、R20、R21、R22And R23Each independently hydrogen, an aliphatic hydrocarbon group of 1 to 10 carbon atoms.
8. The multi-center supported catalyst of claim 7, wherein R is3、R4、R5、R6And R7Each independently is one of hydrogen, methyl, ethyl, propyl, butyl, amyl and allyl; the R is8、R9、R10、R11、R12、R13And R14Independently of one another are hydrogen, methyl, ethyl, propyl, butyl, pentyl and allylOne of (1); the R is15、R16、R17、R18、R19、R20、R21、R22And R23Each independently is one of hydrogen, methyl, ethyl, propyl, butyl, pentyl and allyl.
9. A preparation method of a multi-center supported catalyst is characterized by comprising the following steps:
step 1, dipping a carrier into a solution containing a vanadium source, drying and roasting;
step 2, carrying out dehydration, deoxidation and activation treatment on the carrier obtained in the step 1; and
step 3, dipping the activated carrier obtained in the step 2 into a solution containing an organic chromium source and a pyrrole metallocene heterocyclic compound to obtain a multi-center supported catalyst;
the organic chromium source comprises the following structure:
R'-Cr-R
wherein R and R' are each independently substituted or unsubstituted cyclopentadienyl, indenyl, or fluorenyl;
the pyrrole heterocyclic compound has the following structure as shown in the formula I:
wherein R is1、R2And R3Each independently selected from H, CH3-, saturated or containing double bonds, straight-chain or branched C2-C10One of the hydrocarbon groups; r4Is straight-chain or branched C1-C5An alkyl group; m is Ti or Zr.
10. The method for preparing a multi-center supported catalyst according to claim 9, wherein the vanadium source is a water-soluble vanadium-containing salt or a water-insoluble vanadium-containing salt; the water-soluble vanadium-containing salt is nitrate, phosphate, sulfate, acetate or metavanadate of vanadium, and the water-insoluble vanadium-containing salt is vanadium bisacetylacetonate oxide, vanadium triisopropoxide, vanadium tripropanolate oxide, vanadium acetylacetonate, vanadium triethoxide, vanadyl chloride or vanadium trisilicide.
11. The method of claim 10, wherein the water-soluble vanadium-containing salt is ammonium hexafluorovanadate, vanadium nitrate, vanadyl oxalate, ammonium metavanadate, vanadyl sulfate, vanadium (iv) oxide sulfate hydrate, vanadium (iii) sulfate, vanadium oxide trichloride, sodium orthovanadate, sodium metavanadate, or vanadium acetate present in an acid solution.
12. The method for preparing the multi-center supported catalyst according to claim 9, wherein the organic chromium source is one or more selected from the group consisting of bis (cyclopentadiene) chromium (II), bis (ethylcyclopentadiene) chromium (II), bis (pentamethylcyclopentadiene) chromium (II), bis (tetramethylcyclopentadiene) chromium (II), and bis (isopropylcyclopentadiene) chromium (II).
13. The method for preparing a multi-site supported catalyst according to claim 9, wherein the method for preparing the heterocyclic azole compound comprises the steps of:
step a, reacting 2-pyrrole-carbaldehyde shown in formula II or a derivative thereof with indene to prepare nitrogen-containing fulvene shown in formula III R1、R2And R3Each independently selected from H, CH3-, saturated or containing double bonds, straight-chain or branched C2-C10One of the hydrocarbon groups;
b, reducing nitrogen-containing fulvene in a formula III to generate a pyrrole N heterocyclic-containing ligand in a formula IV; and
step c, ligand of formula IV containing pyrrole N heterocyclic ring and M [ N (R)4)2]4A complexation reaction occurs to produce a metallocene catalyst, R4Is straight-chain or branched C1-C5Alkyl, M is Ti or Zr;
14. the method for preparing a multi-site supported catalyst according to claim 13, wherein the step a is: dissolving 2-pyrrole formaldehyde shown in the formula II or a derivative thereof and indene in an organic solvent, cooling to-10-5 ℃, dropwise adding pyrrolidine, heating to room temperature, and stirring for reaction for 0.5-20 hours to obtain nitrogen-containing fulvene shown in the formula III;
wherein, the mass ratio of 2-pyrrole formaldehyde or its derivative, indene and tetrahydropyrrole in formula II is 1: 1-5: 1 to 5.
15. The method for preparing a multi-site supported catalyst according to claim 13, wherein the step b is: dissolving the nitrogen-containing fulvene in the formula III obtained in the step a in an organic solvent, cooling to-10-5 ℃, dropwise adding lithium aluminum hydride dissolved in the organic solvent, heating to 40-70 ℃, and stirring for reaction for 5-50h to obtain a pyrrole N heterocyclic ring-containing ligand in the formula IV;
wherein, the molar ratio of the nitrogen-containing fulvene in the formula III to the lithium aluminum hydride is 1: 0.5 to 5.
16. The method for preparing a multi-site supported catalyst according to claim 13, wherein the step c is: dissolving the pyrrole N heterocyclic ring-containing ligand of the formula IV obtained in the step b in an organic solvent, cooling to-10-5 ℃, and then dropwise adding M [ N (R) dissolved in the organic solvent4)2]4Heating to 50-100 ℃, and stirring for reaction for 1-30 h to obtain a metallocene catalyst;
wherein, formula IV contains pyrrole N heterocyclic ligand and M [ N (R)4)2]4In a molar ratio of 1: 0.5 to 5.
17. A process for the polymerization of olefins carried out under the action of a multi-site supported catalyst according to any of claims 1 to 8.
18. The method of claim 17, wherein the olefin is one or more selected from the group consisting of ethylene, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-eicosene, dicyclopentadiene, 1, 4-butadiene, 1, 5-pentadiene, 1, 6-hexadiene, styrene, alpha-methylstyrene, divinylbenzene, and 3-chloromethylstyrene.
19. The olefin polymerization reaction process of claim 17, wherein the multi-center supported catalyst of any one of claims 1 to 8 is a main catalyst, the aluminum alkyl or aluminoxane compound is a cocatalyst, and the molar ratio of the main catalyst to the cocatalyst is 1: 500-2000.
Technical Field
The invention relates to an inorganic carrier loaded organic metal multi-center composite polyethylene catalyst and a preparation method and application thereof.
Background
Polyethylene is a variety with the largest yield in general synthetic resin, and has the characteristics of chemical resistance, good mechanical strength, electrical insulation property and the like; polypropylene is a thermoplastic synthetic resin with excellent performance, has the advantages of no toxicity, stable chemical properties, easy processing and the like, and is the product with the best heat resistance in general resins. Polyethylene and polypropylene are widely applied to various aspects of human daily life, medical treatment and health, industry and agriculture and the like, and polyolefin products with excellent performance are closely related to used catalysts.
Currently, the widely used industrial polyethylene catalysts are mainly Ziegler-Natta (Z-N) type catalysts, metallocene catalysts and chromium-based catalysts. Among them, the chromium-based catalyst is favored by the market due to its outstanding contribution to HDPE production and its irreplaceability of the product, producing about 50% of HDPE worldwide.
J.P Hogan and R.L. Bank both reported in patent US2825721 a silica gel supported chromium oxide catalyst, the latter well known Phillips inorganic chromium catalyst. Leonard m. baker and Wayne l. carrick disclose an organochromium polyethylene catalyst, i.e., an S-2 organochromium catalyst from Union Carbide, in US3324101, US3324095 and CA 759121. George L.Karapinka discloses in U.S. Pat. Nos. 3709853 and FR1591425 an organochromium polyethylene catalyst, the S-9 organochromium catalyst by Union Carbide. Although the three catalysts are very similar in structure, there are large differences in the catalytic and polymerization behavior. The Phillips inorganic chromium catalyst has high polymerization activity and short induction period, and the produced polyethylene product has wider molecular weight distribution, higher comonomer insertion amount and higher catalyst efficiency; the S-2 organic chromium catalyst has lower polymerization activity and longer induction period, and the produced polyethylene product has wider molecular weight distribution and higher density; the S-9 organic chromium catalyst has relatively high polymerization activity, short induction period and poor copolymerization, and the produced polyethylene product has narrow molecular weight distribution, high density and good hydrogen regulation sensitivity, can produce various melt index products and can meet different market requirements. For many years, the literature mainly reports more about the modification of Phillips chromium-based catalysts, and the research on the modification of S-2 and S-9 catalysts reports less, particularly the research on the modification of the S-9 catalyst reports less.
Although a number of different polyethylene catalysts already exist, there is still a need in the market for catalysts with new properties and polyethylene products thereof.
Disclosure of Invention
The invention mainly aims to provide a multi-center supported catalyst, a preparation method and application thereof, wherein the catalyst has higher activity and can develop a polyethylene product with higher performance.
In order to achieve the above object, the present invention provides a multi-center supported catalyst comprising a support and active components, wherein the active components are vanadium oxide, a chromium-containing organic compound and a pyrrole metallocene heterocyclic compound, and the vanadium oxide, the chromium-containing organic compound and the pyrrole metallocene heterocyclic compound are supported on the support;
the chromium-containing organic compound comprises the following structure:
Cr-R
wherein R is substituted or unsubstituted cyclopentadienyl, indenyl or fluorenyl;
the pyrrole heterocyclic compound has the following structure as shown in the formula I:
wherein R is1、R2And R3Each independently selected from H, CH3-, saturated or containing double bonds, straight-chain or branched C2-C10One of the hydrocarbon groups; r4Is straight-chain or branched C1-C5An alkyl group; m is Ti or Zr.
The multicenter supported catalyst of the invention is characterized in that the content of vanadium oxide is 0.01-10 wt% calculated by vanadium, the content of chromium-containing organic compound is 0.01-10 wt% calculated by chromium, and the content of pyrrole heterocyclic compound is 0.01-5 wt% calculated by M based on the total mass of the multicenter supported catalyst.
The multi-center supported catalyst provided by the invention is characterized in that the carrier is one or more of the group consisting of silicon dioxide, aluminum oxide, titanium dioxide, zirconium oxide, magnesium oxide, calcium oxide and inorganic clay; and/or the carrier is obtained by dehydration, deoxidation and modification.
The multi-center supported catalyst provided by the invention has the advantages that the modifier for modifying the carrier is one or more of the group consisting of methylaluminoxane, trimethylaluminum, triethylaluminum and triisobutylaluminum.
The multi-center supported catalyst of the invention, wherein R is1、R2And R3Each independently selected from H, CH3-, saturated or containing double bonds, straight-chain or branched C2-C5One of the hydrocarbon groups; the R is4Is CH3-or CH3CH2-。
The multi-center supported catalyst provided by the invention is characterized in that the pyrrole metallocene heterocyclic compound is:
[(η5-C9H6)CH2(2-C4H3N)]Zr(NMe2)2、
[(η5-C9H6)CH2(2-(3-CH3-C4H2N))]Zr(NMe2)2、
[(η5-C9H6)CH2(2-(4-CH3-C4H2N))]Zr(NMe2)2、
[(η5-C9H6)CH2(2-(5-CH3-C4H2N))]Zr(NMe2)2、
[(η5-C9H6)CH2(2-(3-CH3-4-CH3-C4HN))]Zr(NMe2)2、
[(η5-C9H6)CH2(2-(3-CH3-5-CH3-C4HN))]Zr(NMe2)2、
[(η5-C9H6)CH2(2-(4-CH3-5-CH3-C4HN))]Zr(NMe2)2、
[(η5-C9H6)CH2(2-(3-CH3-4-CH3-5-CH3-C4N))]Zr(NMe2)2、
[(η5-C9H6)CH2(2-C4H3N)]Zr(NEt2)2、
[(η5-C9H6)CH2(2-(3-CH3-C4H2N))]Zr(NEt2)2、
[(η5-C9H6)CH2(2-(4-CH3-C4H2N))]Zr(NEt2)2、
[(η5-C9H6)CH2(2-(5-CH3-C4H2N))]Zr(NEt2)2、
[(η5-C9H6)CH2(2-(3-CH3-4-CH3-C4HN))]Zr(NEt2)2、
[(η5-C9H6)CH2(2-(3-CH3-5-CH3-C4HN))]Zr(NEt2)2、
[(η5-C9H6)CH2(2-(4-CH3-5-CH3-C4HN))]Zr(NEt2)2、
[(η5-C9H6)CH2(2-(3-CH3-4-CH3-5-CH3-C4N))]Zr(NEt2)2、
[(η5-C9H6)CH2(2-C4H3N)]Ti(NMe2)2、
[(η5-C9H6)CH2(2-(3-CH3-C4H2N))]Ti(NMe2)2、
[(η5-C9H6)CH2(2-(4-CH3-C4H2N))]Ti(NMe2)2、
[(η5-C9H6)CH2(2-(5-CH3-C4H2N))]Ti(NMe2)2、
[(η5-C9H6)CH2(2-(3-CH3-4-CH3-C4HN))]Ti(NMe2)2、
[(η5-C9H6)CH2(2-(3-CH3-5-CH3-C4HN))]Ti(NMe2)2、
[(η5-C9H6)CH2(2-(4-CH3-5-CH3-C4HN))]Ti(NMe2)2、
[(η5-C9H6)CH2(2-(3-CH3-4-CH3-5-CH3-C4N))]Ti(NMe2)2、
[(η5-C9H6)CH2(2-C4H3N)]Ti(NEt2)2、
[(η5-C9H6)CH2(2-(3-CH3-C4H2N))]Ti(NEt2)2、
[(η5-C9H6)CH2(2-(4-CH3-C4H2N))]Ti(NEt2)2、
[(η5-C9H6)CH2(2-(5-CH3-C4H2N))]Ti(NEt2)2、
[(η5-C9H6)CH2(2-(3-CH3-4-CH3-C4HN))]Ti(NEt2)2、
[(η5-C9H6)CH2(2-(3-CH3-5-CH3-C4HN))]Ti(NEt2)2、
[(η5-C9H6)CH2(2-(4-CH3-5-CH3-C4HN))]Ti(NEt2)2and
[(η5-C9H6)CH2(2-(3-CH3-4-CH3-5-CH3-C4N))]Ti(NEt2)2one or more of the group.
The multi-center supported catalyst provided by the invention is characterized in that the substituted or unsubstituted cyclopentadienyl has the following structure:
wherein, R is3、R4、R5、R6And R7Each independently hydrogen, aliphatic hydrocarbyl of 1-20 carbon atoms;
the substituted or unsubstituted indenyl group has the following structure:
wherein, R is8、R9、R10And R11Each independently is hydrogen, aliphatic hydrocarbyl of 1-10 carbon atoms; the R is12、R13And R14Each independently is hydrogen, aliphatic hydrocarbyl of 1-10 carbon atoms;
the substituted or unsubstituted fluorenyl group has the following structure:
wherein, R is15、R16、R17、R18、R19、R20、R21、R22And R23Each independently hydrogen, an aliphatic hydrocarbon group of 1 to 10 carbon atoms.
The multi-center supported catalyst of the invention, wherein R is3、R4、R5、R6And R7Each independently is one of hydrogen, methyl, ethyl, propyl, butyl, amyl and allyl; the R is8、R9、R10、R11、R12、R13And R14Each independently is one of hydrogen, methyl, ethyl, propyl, butyl, amyl and allyl; the R is15、R16、R17、R18、R19、R20、R21、R22And R23Each independently is one of hydrogen, methyl, ethyl, propyl, butyl, pentyl and allyl.
In order to achieve the above object, the present invention also provides a preparation method of a multi-site supported catalyst, comprising the steps of:
step 1, dipping a carrier into a solution containing a vanadium source, drying and roasting;
step 2, carrying out dehydration, deoxidation and activation treatment on the carrier obtained in the step 1; and
step 3, dipping the activated carrier obtained in the step 2 into a solution containing an organic chromium source and a pyrrole metallocene heterocyclic compound to obtain a multi-center supported catalyst;
the organic chromium source comprises the following structure:
R'-Cr-R
wherein R and R' are each independently substituted or unsubstituted cyclopentadienyl, indenyl, or fluorenyl;
the pyrrole heterocyclic compound has the following structure as shown in the formula I:
wherein R is1、R2And R3Each independently selected from H, CH3-, saturated or containing double bonds, straight-chain or branched C2-C10One of the hydrocarbon groups; r4Is straight-chain or branched C1-C5An alkyl group; m is Ti or Zr.
The preparation method of the multi-center supported catalyst comprises the following steps of (1) preparing a vanadium source from water-soluble vanadium-containing salt or water-insoluble vanadium-containing salt; the water-soluble vanadium-containing salt is nitrate, phosphate, sulfate, acetate or metavanadate of vanadium, and the water-insoluble vanadium-containing salt is vanadium bisacetylacetonate oxide, vanadium triisopropoxide, vanadium tripropanolate oxide, vanadium acetylacetonate, vanadium triethoxide, vanadyl chloride or vanadium trisilicide.
The preparation method of the multi-center supported catalyst comprises the following step of preparing a water-soluble vanadium-containing salt from ammonium hexafluorovanadate, vanadium nitrate, vanadyl oxalate, ammonium metavanadate, vanadyl sulfate oxide (IV) hydrate, vanadium sulfate (III), vanadyl trichloride oxide, sodium orthovanadate, sodium metavanadate or vanadium acetate existing in an acid solution.
The preparation method of the multi-center supported catalyst comprises the step of preparing an organic chromium source, wherein the organic chromium source is one or more of the group consisting of bis (cyclopentadiene) chromium (II), bis (ethylcyclopentadiene) chromium (II), bis (pentamethylcyclopentadiene) chromium (II), bis (tetramethylcyclopentadiene) chromium (II) and bis (isopropylcyclopentadiene) chromium (II).
The preparation method of the multi-center supported catalyst comprises the following steps:
step a, reacting 2-pyrrole-carbaldehyde shown in formula II or a derivative thereof with indene to prepare nitrogen-containing fulvene shown in formula III R1、R2And R3Each independently selected from H, CH3-, saturated or containing double bonds, straight-chain or branched C2-C10One of the hydrocarbon groups;
b, reducing nitrogen-containing fulvene in a formula III to generate a pyrrole N heterocyclic-containing ligand in a formula IV; and
step c, ligand of formula IV containing pyrrole N heterocyclic ring and M [ N (R)4)2]4A complexation reaction occurs to produce a metallocene catalyst, R4Is straight-chain or branched C1-C5Alkyl, M is Ti or Zr;
the invention relates to a preparation method of a multi-center supported catalyst, wherein the step a is as follows: dissolving 2-pyrrole formaldehyde shown in the formula II or a derivative thereof and indene in an organic solvent, cooling to-10-5 ℃, dropwise adding pyrrolidine, heating to room temperature, and stirring for reaction for 0.5-20 hours to obtain nitrogen-containing fulvene shown in the formula III;
wherein, the mass ratio of 2-pyrrole formaldehyde or its derivative, indene and tetrahydropyrrole in formula II is 1: 1-5: 1 to 5.
The preparation method of the multi-center supported catalyst comprises the following steps: dissolving the nitrogen-containing fulvene in the formula III obtained in the step a in an organic solvent, cooling to-10-5 ℃, dropwise adding lithium aluminum hydride dissolved in the organic solvent, heating to 40-70 ℃, and stirring for reaction for 5-50h to obtain a pyrrole N heterocyclic ring-containing ligand in the formula IV;
wherein, the molar ratio of the nitrogen-containing fulvene in the formula III to the lithium aluminum hydride is 1: 0.5 to 5.
The preparation method of the multi-center supported catalyst comprises the following steps: subjecting the product obtained in step bDissolving a pyrrole N heterocyclic ring-containing ligand in a formula IV in an organic solvent, cooling to-10-5 ℃, and then dropwise adding M [ N (R) dissolved in the organic solvent4)2]4Heating to 50-100 ℃, and stirring for reaction for 1-30 h to obtain a metallocene catalyst;
wherein, formula IV contains pyrrole N heterocyclic ligand and M [ N (R)4)2]4In a molar ratio of 1: 0.5 to 5.
In order to achieve the above object, the present invention further provides an olefin polymerization process, which is carried out under the action of the above-mentioned multi-site supported catalyst.
The olefin polymerization reaction method is characterized in that the olefin is one or more of a group consisting of ethylene, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-eicosene, dicyclopentadiene, 1, 4-butadiene, 1, 5-pentadiene, 1, 6-hexadiene, styrene, alpha-methylstyrene, divinylbenzene and 3-chloromethylstyrene.
The olefin polymerization reaction method of the invention is characterized in that the multi-center supported catalyst is a main catalyst, the alkylaluminium or aluminoxane compound is a cocatalyst, and the molar ratio of the main catalyst to the cocatalyst is 1: 500-2000.
The invention has the beneficial effects that:
according to the multi-center supported catalyst provided by the invention, organic chromium and a metallocene active component are loaded on an inorganic carrier supported inorganic vanadium catalyst to form the multi-active center catalyst, so that the copolymerization performance of the catalyst can be improved, the content and distribution of a comonomer are optimized, the amount of the comonomer inserted into a low molecular weight end is reduced, the amount of the comonomer inserted into a high molecular weight end is increased, more tie molecules are easily formed, a polyethylene product with higher performance is developed, and the catalyst also has higher activity.
Detailed Description
The following examples illustrate the invention in detail: the present example is carried out on the premise of the technical scheme of the present invention, and detailed embodiments and processes are given, but the scope of the present invention is not limited to the following examples, and the experimental methods without specific conditions noted in the following examples are generally performed according to conventional conditions.
The invention discloses a multi-center supported catalyst which comprises a carrier and active components, wherein the active components are vanadium oxide, chromium-containing organic compound and pyrrole heterocyclic compound;
the chromium-containing organic compound comprises the following structure:
Cr-R
wherein R is substituted or unsubstituted cyclopentadienyl, indenyl or fluorenyl;
the pyrrole heterocyclic compound has the following structure as shown in the formula I:
wherein R is1、R2And R3Each independently selected from H, CH3-, saturated or containing double bonds, straight-chain or branched C2-C10One of the hydrocarbon groups; r4Is straight-chain or branched C1-C5An alkyl group; m is Ti or Zr.
In the technical scheme of the invention, the carrier is generally an inorganic carrier, for example, selected from silicon dioxide, aluminum oxide, titanium dioxide, zirconium oxide, magnesium oxide, calcium oxide, inorganic clay and the combination thereof; preferably, the support is an amorphous porous silica gel modified with Ti, Al, F, or the like. In another embodiment, the pore volume is 0.5-5.0 cm3A surface area of 50 to 800m2/g。
The active component vanadium of the invention is loaded on the carrier in the form of inorganic oxide, such as vanadium trioxide, vanadium dioxide, vanadium pentoxide and the like.
The chromium-containing organic compounds of the present invention generally comprise the following structure:
Cr-R
wherein R is substituted or unsubstituted cyclopentadienyl, indenyl or fluorenyl.
In detail, the substituted or unsubstituted cyclopentadienyl group has the following structure:
wherein, R is3、R4、R5、R6And R7Each independently hydrogen, aliphatic hydrocarbyl of 1-20 carbon atoms; preferably one of hydrogen, methyl, ethyl, propyl, butyl, pentyl and allyl.
The substituted or unsubstituted indenyl group has the following structure:
wherein, R is8、R9、R10And R11Each independently is hydrogen, aliphatic hydrocarbyl of 1-10 carbon atoms; the R is12、R13And R14Each independently is hydrogen, aliphatic hydrocarbyl of 1-10 carbon atoms; r8、R9、R10、R11、R12、R13And R14Each independently is preferably one of hydrogen, methyl, ethyl, propyl, butyl, pentyl and allyl.
The substituted or unsubstituted fluorenyl group has the following structure:
wherein, R is15、R16、R17、R18、R19、R20、R21、R22And R23Each independently hydrogen, an aliphatic hydrocarbon group of 1 to 10 carbon atoms, preferably one of hydrogen, methyl, ethyl, propyl, butyl, pentyl and allyl.
The pyrrole cyclopentadiene heterocyclic compound has the following structure as shown in the formula I:
wherein R is1、R2And R3Each independently selected from H, CH3-, saturated or containing double bonds, straight-chain or branched C2-C10One of the hydrocarbon groups, preferably H, CH3-, saturated or containing double bonds, straight-chain or branched C2-C5One of the hydrocarbon groups; r4Is straight-chain or branched C1-C5Alkyl, preferably CH3-or CH3CH2-; m is Ti or Zr.
The azole metallocene heterocyclic compound of the present invention may further preferably be:
[(η5-C9H6)CH2(2-C4H3N)]Zr(NMe2)2、
[(η5-C9H6)CH2(2-(3-CH3-C4H2N))]Zr(NMe2)2、
[(η5-C9H6)CH2(2-(4-CH3-C4H2N))]Zr(NMe2)2、
[(η5-C9H6)CH2(2-(5-CH3-C4H2N))]Zr(NMe2)2、
[(η5-C9H6)CH2(2-(3-CH3-4-CH3-C4HN))]Zr(NMe2)2、
[(η5-C9H6)CH2(2-(3-CH3-5-CH3-C4HN))]Zr(NMe2)2、
[(η5-C9H6)CH2(2-(4-CH3-5-CH3-C4HN))]Zr(NMe2)2、
[(η5-C9H6)CH2(2-(3-CH3-4-CH3-5-CH3-C4N))]Zr(NMe2)2、
[(η5-C9H6)CH2(2-C4H3N)]Zr(NEt2)2、
[(η5-C9H6)CH2(2-(3-CH3-C4H2N))]Zr(NEt2)2、
[(η5-C9H6)CH2(2-(4-CH3-C4H2N))]Zr(NEt2)2、
[(η5-C9H6)CH2(2-(5-CH3-C4H2N))]Zr(NEt2)2、
[(η5-C9H6)CH2(2-(3-CH3-4-CH3-C4HN))]Zr(NEt2)2、
[(η5-C9H6)CH2(2-(3-CH3-5-CH3-C4HN))]Zr(NEt2)2、
[(η5-C9H6)CH2(2-(4-CH3-5-CH3-C4HN))]Zr(NEt2)2、
[(η5-C9H6)CH2(2-(3-CH3-4-CH3-5-CH3-C4N))]Zr(NEt2)2、
[(η5-C9H6)CH2(2-C4H3N)]Ti(NMe2)2、
[(η5-C9H6)CH2(2-(3-CH3-C4H2N))]Ti(NMe2)2、
[(η5-C9H6)CH2(2-(4-CH3-C4H2N))]Ti(NMe2)2、
[(η5-C9H6)CH2(2-(5-CH3-C4H2N))]Ti(NMe2)2、
[(η5-C9H6)CH2(2-(3-CH3-4-CH3-C4HN))]Ti(NMe2)2、
[(η5-C9H6)CH2(2-(3-CH3-5-CH3-C4HN))]Ti(NMe2)2、
[(η5-C9H6)CH2(2-(4-CH3-5-CH3-C4HN))]Ti(NMe2)2、
[(η5-C9H6)CH2(2-(3-CH3-4-CH3-5-CH3-C4N))]Ti(NMe2)2、
[(η5-C9H6)CH2(2-C4H3N)]Ti(NEt2)2、
[(η5-C9H6)CH2(2-(3-CH3-C4H2N))]Ti(NEt2)2、
[(η5-C9H6)CH2(2-(4-CH3-C4H2N))]Ti(NEt2)2、
[(η5-C9H6)CH2(2-(5-CH3-C4H2N))]Ti(NEt2)2、
[(η5-C9H6)CH2(2-(3-CH3-4-CH3-C4HN))]Ti(NEt2)2、
[(η5-C9H6)CH2(2-(3-CH3-5-CH3-C4HN))]Ti(NEt2)2、
[(η5-C9H6)CH2(2-(4-CH3-5-CH3-C4HN))]Ti(NEt2)2and
[(η5-C9H6)CH2(2-(3-CH3-4-CH3-5-CH3-C4N))]Ti(NEt2)2one or more of the group.
In the multi-center supported catalyst, the loading amount of the Cr active center on the inorganic carrier is calculated by Cr, and is preferably 0.01-10 wt% of the total weight of the catalyst. The V active center loading amount is calculated by V, and is preferably 0.01-10 wt% of the total weight of the catalyst. The M active center loading amount is calculated by M, and preferably 0.01-5 wt% of the total weight of the catalyst.
The invention also provides a preparation method of the supported multi-center composite catalyst, which comprises the following steps:
step 1, dipping a carrier into a solution containing a vanadium source, drying and roasting;
step 2, carrying out dehydration, deoxidation and activation treatment on the carrier obtained in the step 1; and
step 3, dipping the activated carrier obtained in the step 2 into a solution containing an organic chromium source and a pyrrole metallocene heterocyclic compound to obtain a multi-center supported catalyst;
the organic chromium source comprises the following structure:
R'-Cr-R
wherein R and R' are each independently substituted or unsubstituted cyclopentadienyl, indenyl, or fluorenyl;
the pyrrole heterocyclic compound has the following structure as shown in the formula I:
wherein R is1、R2And R3Each independently selected from H, CH3-、Saturated or containing double bonds, straight or branched C2-C10One of the hydrocarbon groups; r4Is straight-chain or branched C1-C5An alkyl group; m is Ti or Zr.
In a preferred embodiment, in step 1, the inorganic carrier is immersed in an aqueous solution of an inorganic vanadium source, kept at room temperature to 60 ℃ for 1 to 12 hours, and then dried at 100 to 200 ℃ for 1 to 18 hours, in which case the drying speed may be increased by forced air drying, and then calcined at 150 to 1000 ℃ in oxygen or air for 1 to 10 hours, and then cooled, wherein the air is replaced with an inert gas such as nitrogen or argon when cooled to 300 to 400 ℃.
Wherein the inorganic vanadium source is selected from water-soluble vanadium-containing salts and water-insoluble vanadium-containing salts; the water-soluble vanadium-containing salt is selected from the group consisting of nitrate, phosphate, sulfate, acetate of vanadium, and various salts of metavanadate, and the water-insoluble vanadium-containing salt is selected from the group consisting of vanadium bisacetylacetonate oxide, vanadium triisopropoxide, vanadium tripropanolate oxide, vanadium acetylacetonate, vanadium triethoxide, vanadyl chloride, trivanadium silicide, and the like.
The concentration and the amount of the vanadium source aqueous solution are not particularly limited in the present invention, as long as the loading amount of vanadium in the catalyst is 0.01 wt% to 10 wt% in terms of vanadium.
In a preferred embodiment, in the step 2, the catalyst precursor obtained in the step 1 is immersed in an organic metal promoter solution in an inert gas atmosphere, and is reacted at room temperature to 200 ℃ for 1 to 30 hours, and then dried at 60 to 200 ℃ for 1 to 12 hours to complete the modification of the catalyst precursor, and in this case, the drying speed can be increased by vacuum drying.
Wherein, the organic metal cocatalyst is used as a modifier to modify the carrier so as to remove the moisture and oxygen in the catalyst precursor. The organometallic cocatalyst can be one of methylaluminoxane, trimethylaluminum, triethylaluminum and triisobutylaluminum or a mixture of the methylaluminoxane, the trimethylaluminum, the triethylaluminum and the triisobutylaluminum. The amount of the organometallic cocatalyst may be generally 2 to 30 wt% based on the total weight of the catalyst, but the present invention is not particularly limited.
In a preferred embodiment, in the step 3, the catalyst precursor obtained in the step 2 is immersed in an organic solution of an organic chromium source and a heterocyclic pyrrole-metallocene compound in an inert gas atmosphere, the reaction is carried out for 1 to 10 hours at a temperature ranging from room temperature to 100 ℃, then a solvent is added, the reaction solution is stirred and washed for several times, the reaction solution is washed for 0.5 to 5 hours at a temperature ranging from room temperature to 100 ℃, and then the reaction solution is dried for 2 to 8 hours at a temperature ranging from 60 to 120 ℃, and at this time, the drying speed can also be accelerated by vacuum drying.
Wherein, the organic chromium source comprises the following structure:
R'-Cr-R
wherein R and R' are independently substituted or unsubstituted cyclopentadienyl, indenyl or fluorenyl, and the substituted or unsubstituted cyclopentadienyl, indenyl or fluorenyl is described in detail above and will not be described herein again. As a preferred embodiment, the organic chromium source is selected from bis (cyclopentadiene) chromium (II), bis (ethylcyclopentadiene) chromium (II), bis (pentamethylcyclopentadiene) chromium (II), bis (tetramethylcyclopentadiene) chromium (II), bis (isopropylcyclopentadiene) chromium (II), and the like, and combinations thereof.
The structure of the heterocyclic azole compounds is also described in detail above and will not be described further. The concentration of the organic chromium source in the impregnation solution and the concentration of the heterocyclic pyrrole-metallocene compound in the impregnation solution are not particularly limited, as long as the loading of chromium on the catalyst is 0.01 to 10 wt% in terms of chromium and the loading of the heterocyclic pyrrole-metallocene compound on the catalyst is 0.01 to 5 wt% in terms of M.
The preparation method of the pyrrole metallocene heterocyclic compound provided by the invention comprises the following steps:
step a, reacting 2-pyrrole-carbaldehyde shown in formula II or a derivative thereof with indene to prepare nitrogen-containing fulvene shown in formula III R1、R2And R3Each independently selected from H, CH3-, saturated or containing double bonds, straight-chain or branched C2-C10One of the hydrocarbon groups;
b, reducing nitrogen-containing fulvene in a formula III to generate a pyrrole N heterocyclic-containing ligand in a formula IV; and
step c, ligand of formula IV containing pyrrole N heterocyclic ring and M [ N (R)4)2]4A complexation reaction occurs to produce a metallocene catalyst, R4Is straight-chain or branched C1-C5Alkyl, M is Ti or Zr;
in detail, the preparation method of the pyrrole metallocene heterocyclic compound comprises the following steps:
step a, dissolving 2-pyrrole-carbaldehyde or a derivative thereof and indene in a formula II in a Schlenk bottle in an organic solvent, cooling to-10-5 ℃, for example, placing in an ice water bath, and then slowly dropwise adding pyrrolidine, wherein the ratio of the amount of the 2-pyrrole-carbaldehyde or the derivative thereof to the amount of the indene to the amount of the pyrrolidine is 1: 1-5: 1-5; after the dropwise addition, the temperature is raised to the room temperature, and the mixture is stirred for 0.5 to 20 hours to react; and after the reaction is finished, carrying out liquid separation extraction and washing by using an organic solvent, taking an organic phase, drying the organic phase, and carrying out rotary evaporation to obtain the nitrogen-containing fulvene in the formula III. Wherein the organic solvent can be one or more of methanol, ethanol, formaldehyde, acetaldehyde, diethyl ether, toluene and ethylbenzene.
B, dissolving the nitrogen-containing fulvene of the formula III prepared in the step a in an organic solvent such as tetrahydrofuran in a Schlenk bottle, cooling to-10-5 ℃, for example, placing in an ice water bath, then dropwise adding lithium aluminum hydride dissolved in the solvent (such as tetrahydrofuran), withdrawing the ice water bath, slowly heating to 40-70 ℃, reacting for 5-50h, adding the organic solvent, separating, extracting, washing, drying the organic phase, and then performing rotary evaporation to obtain a ligand containing pyrrole N heterocycle of the formula IV; wherein, the molar ratio of the nitrogen-containing fulvene in the formula III to the lithium aluminum hydride is 1: 0.5 to 5. Wherein the organic solvent is one or more of ethanol, acetaldehyde, diethyl ether, toluene and ethylbenzene.
Step c, mixing M (N (R) in Schlenk flask4)2)4Dissolving in an organic solvent, cooling to-10-5 ℃, for example, placing in an ice-water bath, dissolving the pyrrole N heterocycle-containing ligand of formula IV prepared in the step b in the organic solvent, slowly adding into a Schlenk bottle, removing the ice-water bath, heating to 50-100 ℃, and reacting for 1-30 h.
OrOr dissolving the pyrrole N heterocyclic ring-containing ligand of the formula IV obtained in the step b in an organic solvent, cooling to-10-5 ℃, and then dropwise adding Zr [ N (R) dissolved in the organic solvent4)2]4After the dripping is finished, the temperature is raised to 50-100 ℃, and the stirring reaction is carried out for 1-30 h.
Wherein, formula IV contains pyrrole N heterocyclic ligand and M [ N (R)4)2]4In a molar ratio of 1: 0.5 to 5.
And after the reaction is finished, pumping the solvent, and finally recrystallizing in an organic solvent at a low temperature to obtain the product. Wherein the organic solvent is one or more of methane, ethane, ethanol, acetaldehyde, diethyl ether, toluene and ethylbenzene.
The whole reaction process of the preparation method of the pyrrole metallocene heterocyclic compound is always carried out under the protection of inert gas, and the inert gas can be one of hydrogen, nitrogen, helium and argon.
In summary, the invention uses inorganic compound as carrier, firstly, the vanadium source is dipped on the carrier, and then the carrier is roasted at high temperature to prepare the catalyst parent body loaded with inorganic vanadium; and adding an organic metal cocatalyst into the solution containing the catalyst precursor to modify the carrier, and finally adding an organic solution of an organic chromium source and a pyrrole heterocyclic compound into the solution containing the catalyst precursor to carry out loading, thereby preparing the multi-center supported catalyst.
The multi-site supported catalyst of the present invention as described above can be used for producing ethylene homopolymers and ethylene/α -olefin copolymers.
The present invention is not particularly limited in the manner of olefin polymerization, and for example, the polymerization is carried out by a conventional slurry polymerization method, and the specific operations are as follows: firstly, heating a polymerization reaction kettle in vacuum (100 ℃), then replacing the polymerization reaction kettle with high-purity nitrogen, repeatedly operating for three times, then replacing the polymerization reaction kettle with a small amount of ethylene monomer once, and finally filling the reaction kettle with ethylene to a micro-positive pressure (0.12 MPa); adding a refined solvent subjected to dehydration and deoxidation treatment into a reaction kettle, taking a certain amount of alkyl aluminum as a cocatalyst, respectively adding a certain amount of hydrogen and a comonomer in a hydrogen blending copolymerization experiment, and finally adding the multi-center supported catalyst to start a polymerization reaction; the instantaneous consumption of monomer ethylene is collected on line in the reaction process (by connecting a high-precision ethylene mass flow meter with a computer) and recorded by the computer, and the reaction is stopped after the reaction is carried out for a certain time (for example, 1 hour) at a certain temperature (for example, 35 ℃ to 100 ℃); the polymer was washed, dried in vacuo, weighed and analyzed.
The catalyst of the present invention can produce ethylene homopolymers and ethylene/alpha-olefin copolymers (part of the product having a bimodal distribution) having a broad molecular weight distribution (MWD ═ 10 to 60) in a single reactor or a combination of reactors. By using the catalyst of the present invention, the molecular weight and distribution of ethylene homopolymer and ethylene and α -olefin copolymer and the comonomer content and distribution thereof can be conveniently and easily adjusted by changing the amount of co-catalyst used, polymerization temperature, molecular weight regulator and the like, so that a polymer product having desired properties can be conveniently and easily obtained.
The supported multi-center composite catalyst provided by the invention is characterized in that an organic chromium system and a metallocene active component are supported on an inorganic carrier supported inorganic vanadium catalyst to form a multi-active-center catalyst, the copolymerization performance of the catalyst can be improved, the content and the distribution of a comonomer are optimized, the amount of the comonomer inserted into a low molecular weight end is reduced, and the amount of the comonomer inserted into a high molecular weight end is increased, so that more tie molecules are easily formed, a polyethylene product with higher performance is developed, and the catalyst also has higher activity.
The present invention is explained in more detail with reference to the following examples, which do not limit the scope of the present invention.
The silica gel employed in the examples was commercially available as Davison 955.
Various polymer properties in the examples were measured according to the following methods:
example 1:
inorganic carrier supported multi-center composite catalyst, wherein the inorganic carrier is silicon dioxide (pore volume is 0.8 cm)3(ii)/g; the surface area of the inorganic carrier is 380m2(iv)/g); the inorganic vanadium source is vanadium nitrate, the organic chromium source is bis (cyclopentadiene) chromium (II), and the pyrrole heterocyclic compound is [ (. eta. ])5-C9H6)CH2(2-(3-CH3-4-CH3-5-CH3-C4N))]Zr(NMe2)2。
The preparation method of the pyrrole heterocyclic compound comprises the following steps: reacting 3-CH3-4-CH3-5-CH3Cooling the-2-pyrrole-carbaldehyde and indene to-10 ℃, and dropwise adding the pyrrolidine, wherein the mass ratio of the substances of the-2-pyrrole-carbaldehyde to the indene is 1: 2: 1, heating to room temperature, stirring and reacting for 10 hours to obtain nitrogen-containing fulvene; then cooling to-4 ℃, and dropwise adding lithium aluminum hydride, wherein the molar ratio of the nitrogen-containing fulvene to the lithium aluminum hydride is 1: 2, heating to 70 ℃, and stirring for reaction for 10 hours to obtain a pyrrole N heterocyclic ring-containing ligand; cooling to-1 deg.C, and adding Zr (NMe) dissolved in organic solvent2)4And heating to 70 ℃, and stirring for reaction for 13h to obtain the pyrrole heterocyclic compound.
The preparation method of the catalyst comprises the following steps: step 1, dipping a carrier into a solution containing a vanadium source, drying and roasting; step 2, carrying out dehydration, deoxidation and activation treatment on the carrier obtained in the step 1; and 3, dipping the activated carrier obtained in the step 2 into a solution containing an organic chromium source and a pyrrole metallocene heterocyclic compound to obtain the multi-center supported catalyst. The catalyst prepared by the preparation method has the advantages that the Cr active center loading capacity is 3.2 wt% of the total weight of the catalyst, the V active center loading capacity is 3.9 wt% of the total weight of the catalyst, the Zr active center loading capacity is 0.8 wt% of the total weight of the catalyst, the organic metal cocatalyst is methylaluminoxane, and the dosage of the organic metal cocatalyst accounts for 8 wt% of the total weight of the catalyst. The copolymerisation of ethylene and 1-hexene was carried out using a conventional slurry polymerisation process with a 1-hexene/ethylene ratio of 0.2. The catalyst activity was found to be 8230g PE/g Cat and the product density was found to be 0.940g/cm3。
Example 2:
inorganic carrier supported multi-center composite catalyst, wherein the inorganic carrier is silicon dioxide (pore volume is 1.3 cm)3(ii)/g; the surface area of the inorganic carrier is 590m2(iv)/g); the inorganic vanadium source is vanadium sulfate, the organic chromium source is bis (ethylcyclopentadiene) chromium (II), and the pyrrole heterocyclic compound is [ (. eta. ])5-C9H6)CH2(2-(3-CH3-4-CH3-C4HN))]Zr(NMe2)2。
The preparation method of the pyrrole heterocyclic compound comprises the following steps: reacting 3-CH3-4-CH3Cooling the-2-pyrrole-carbaldehyde and indene to-5 ℃, and dropwise adding the pyrrolidine, wherein the mass ratio of the substances of the-2-pyrrole-carbaldehyde to the indene is 1: 2: 2, heating to room temperature, stirring and reacting for 5 hours to obtain nitrogen-containing fulvene; then cooling to-6 ℃, and dropwise adding lithium aluminum hydride, wherein the molar ratio of the nitrogen-containing fulvene to the lithium aluminum hydride is 1: 0.5, heating to 60 ℃, stirring and reacting for 15h to obtain a ligand containing pyrrole N heterocycle; cooling to-3 deg.C, and adding Zr (NMe) dissolved in organic solvent2)4And heating to 60 ℃, and stirring for reaction for 7 hours to obtain the pyrrole cyclopentadiene heterocyclic compound.
The preparation method of the catalyst comprises the following steps: step 1, dipping a carrier into a solution containing a vanadium source, drying and roasting; step 2, carrying out dehydration, deoxidation and activation treatment on the carrier obtained in the step 1; and 3, dipping the activated carrier obtained in the step 2 into a solution containing an organic chromium source and a pyrrole metallocene heterocyclic compound to obtain the multi-center supported catalyst. According to the catalyst prepared by the preparation method, the loading of a Cr active center is 1.2 wt% of the total weight of the catalyst, the loading of a V active center is 0.06 wt% of the total weight of the catalyst, the loading of a Zr active center is 0.15 wt% of the total weight of the catalyst, an organic metal cocatalyst is trimethylaluminum, and the dosage of the organic metal cocatalyst accounts for 22 wt% of the total weight of the catalyst. The copolymerisation of ethylene and 1-hexene was carried out using a conventional slurry polymerisation process with a 1-hexene/ethylene ratio of 0.2. The catalyst activity was found to be 5300g PE/g Cat, and the product density was found to be 0.948g/cm3。
Example 3:
inorganic carrier supported multi-center composite catalyst, wherein the inorganic carrier is silicon dioxide (pore volume is 2.8 cm)3(ii)/g; the surface area of the inorganic carrier was 720m2(iv)/g); the inorganic vanadium source is vanadium acetate, the organic chromium source is bis (pentamethylcyclopentadienyl) chromium (II), and the pyrrole heterocyclic compound is [ (. eta. ])5-C9H6)CH2(2-(3-CH3-4-CH3-C4HN))]Ti(NMe2)2。
The preparation method of the pyrrole heterocyclic compound comprises the following steps:reacting 3-CH3-4-CH3Cooling the-2-pyrrole-carbaldehyde and indene to 0 ℃, and dropwise adding the pyrrolidine, wherein the mass ratio of the substances of the-2-pyrrole-carbaldehyde to the indene is 1: 2: 3, heating to room temperature, stirring and reacting for 1 hour to obtain nitrogen-containing fulvene; then cooling to-10 ℃, and dropwise adding lithium aluminum hydride, wherein the molar ratio of the nitrogen-containing fulvene to the lithium aluminum hydride is 1:1, heating to 65 ℃, and stirring for reaction for 5 hours to obtain a pyrrole N heterocyclic ring-containing ligand; cooling to-7 deg.C, and adding Ti (NMe) dissolved in organic solvent2)4And heating to 80 ℃, and stirring for reacting for 19h to obtain the pyrrole heterocyclic compound.
The preparation method of the catalyst comprises the following steps: step 1, dipping a carrier into a solution containing a vanadium source, drying and roasting; step 2, carrying out dehydration, deoxidation and activation treatment on the carrier obtained in the step 1; and 3, dipping the activated carrier obtained in the step 2 into a solution containing an organic chromium source and a pyrrole metallocene heterocyclic compound to obtain the multi-center supported catalyst. The catalyst prepared by the preparation method has the advantages that the Cr active center loading amount is 1.8 wt% of the total weight of the catalyst, the V active center loading amount is 1.2 wt% of the total weight of the catalyst, the Ti active center loading amount is 0.25 wt% of the total weight of the catalyst, the organometallic cocatalyst is triethyl aluminum, and the dosage of the organometallic cocatalyst accounts for 28 wt% of the total weight of the catalyst. The copolymerisation of ethylene and 1-hexene was carried out using a conventional slurry polymerisation process with a 1-hexene/ethylene ratio of 0.2. The catalyst activity was found to be 8850g PE/g Cat, the product density was found to be 0.946g/cm3。
Example 4:
inorganic carrier supported multi-center composite catalyst, wherein the inorganic carrier is silicon dioxide (pore volume is 3.9 cm)3(ii)/g; the surface area of the inorganic carrier is 638m2(iv)/g); the inorganic vanadium source is triisopropoxytrianisum, the organic chromium source is bis (pentamethylcyclopentadienyl) chromium (II), and the pyrrole heterocyclic compound is [ (. eta. ])5-C9H6)CH2(2-(5-CH3-C4H2N))]Ti(NEt2)2。
The preparation method of the pyrrole heterocyclic compound comprises the following steps: reacting 5-CH3Cooling the-2-pyrrole-carbaldehyde and indene to 5 ℃, and dropwise adding the pyrrolidine, wherein the mass ratio of the substances of the-2-pyrrole-carbaldehyde to the indene is 1: 3: 3, thenThen heating to room temperature, stirring and reacting for 0.5 hour to obtain nitrogen-containing fulvene; then cooling to-2 ℃, and dropwise adding lithium aluminum hydride, wherein the molar ratio of the nitrogen-containing fulvene to the lithium aluminum hydride is 1: 4, heating to 55 ℃, and stirring for reaction for 20 hours to obtain a pyrrole N heterocyclic ring-containing ligand; cooling to 5 deg.C, and adding Ti (NEt) dissolved in organic solvent2)4Heating to 100 ℃, and stirring for reaction for 30 hours to obtain the pyrrole heterocyclic compound.
The preparation method of the catalyst comprises the following steps: step 1, dipping a carrier into a solution containing a vanadium source, drying and roasting; step 2, carrying out dehydration, deoxidation and activation treatment on the carrier obtained in the step 1; and 3, dipping the activated carrier obtained in the step 2 into a solution containing an organic chromium source and a pyrrole metallocene heterocyclic compound to obtain the multi-center supported catalyst. The catalyst prepared by the preparation method has the advantages that the Cr active center loading amount is 0.9 wt% of the total weight of the catalyst, the V active center loading amount is 0.5 wt% of the total weight of the catalyst, the Ti active center loading amount is 1.6 wt% of the total weight of the catalyst, the organic metal cocatalyst is triisobutylaluminum, and the dosage of the organic metal cocatalyst accounts for 20 wt% of the total weight of the catalyst. The copolymerisation of ethylene and 1-hexene was carried out using a conventional slurry polymerisation process with a 1-hexene/ethylene ratio of 0.2. The catalyst activity was found to be 5950g PE/g Cat, the product density was found to be 0.938g/cm3。
Example 5:
inorganic carrier supported multi-center composite catalyst, wherein the inorganic carrier is silicon dioxide (pore volume is 5.0 cm)3(ii)/g; the surface area of the inorganic carrier was 650m2(iv)/g); the inorganic vanadium source is vanadium acetylacetonate, the organic chromium source is bis (isopropylcyclopentadiene) chromium (II), and the pyrrole heterocyclic compound is [ (. eta. ])5-C9H6)CH2(2-(3-CH3-4-CH3-5-CH3-C4N))]Ti(NEt2)2。
The preparation method of the pyrrole heterocyclic compound comprises the following steps: reacting 3-CH3-4-CH3-5-CH3Cooling the-2-pyrrole-carbaldehyde and indene to-3 ℃, and dropwise adding the pyrrolidine, wherein the mass ratio of the substances of the-2-pyrrole-carbaldehyde to the indene is 1: 3: 2, heating to room temperature, stirring and reacting for 20 hours to obtain nitrogen-containing fulvene; cooling to 0 deg.C, and drippingAnd (3) adding aluminum lithium hydride, wherein the molar ratio of the nitrogen-containing fulvene to the aluminum lithium hydride is 1: 5, heating to 40 ℃, and stirring for reacting for 1h to obtain a pyrrole N heterocyclic ring-containing ligand; cooling to-10 deg.C, and adding Ti (NEt) dissolved in organic solvent2)4And heating to 90 ℃, and stirring for reaction for 25 hours to obtain the pyrrole cyclopentadiene heterocyclic compound.
The preparation method of the catalyst comprises the following steps: step 1, dipping a carrier into a solution containing a vanadium source, drying and roasting; step 2, carrying out dehydration, deoxidation and activation treatment on the carrier obtained in the step 1; and 3, dipping the activated carrier obtained in the step 2 into a solution containing an organic chromium source and a pyrrole metallocene heterocyclic compound to obtain the multi-center supported catalyst. The catalyst prepared by the preparation method has the advantages that the Cr active center loading capacity is 0.6 wt% of the total weight of the catalyst, the V active center loading capacity is 1.4 wt% of the total weight of the catalyst, the Ti active center loading capacity is 2.2 wt% of the total weight of the catalyst, the organic metal cocatalyst is methylaluminoxane, and the dosage of the organic metal cocatalyst accounts for 18 wt% of the total weight of the catalyst. The copolymerisation of ethylene and 1-hexene was carried out using a conventional slurry polymerisation process with a 1-hexene/ethylene ratio of 0.2. The catalyst activity was found to be 9500g PE/g Cat, the product density was found to be 0.936g/cm3。
Example 6:
inorganic carrier supported multi-center composite catalyst, wherein the inorganic carrier is silicon dioxide (pore volume is 4.2 cm)3(ii)/g; the surface area of the inorganic carrier is 800m2(iv)/g); the inorganic vanadium source is acetylacetone vanadium oxide, the organic chromium source is bis (tetramethylcyclopentadiene) chromium (II), and the pyrrole heterocyclic compound is [ (. eta. ])5-C9H6)CH2(2-(4-CH3-C4H2N))]Ti(NMe2)2。
The preparation method of the pyrrole heterocyclic compound comprises the following steps: 4-CH is added3Cooling the-2-pyrrole-carbaldehyde and indene to 3 ℃, and dropwise adding the pyrrolidine, wherein the mass ratio of the substances of the-2-pyrrole-carbaldehyde to the indene is 1: 1:1, then heating to room temperature, stirring and reacting for 8 hours to obtain nitrogen-containing fulvene; then cooling to 4 ℃, and dropwise adding lithium aluminum hydride, wherein the molar ratio of the nitrogen-containing fulvene to the lithium aluminum hydride is 1: 3, heating to 50 ℃, stirring and reacting for 30 hours to obtain the pyrrole N heterocyclic ring-containing ligand(ii) a Cooling to-7 deg.C, and adding Ti (NMe) dissolved in organic solvent2)4And heating to 50 ℃, and stirring for reaction for 1h to obtain the pyrrole heterocyclic compound.
The preparation method of the catalyst comprises the following steps: step 1, dipping a carrier into a solution containing a vanadium source, drying and roasting; step 2, carrying out dehydration, deoxidation and activation treatment on the carrier obtained in the step 1; and 3, dipping the activated carrier obtained in the step 2 into a solution containing an organic chromium source and a pyrrole metallocene heterocyclic compound to obtain the multi-center supported catalyst. The catalyst prepared by the preparation method has the advantages that the Cr active center loading capacity is 2.5 wt% of the total weight of the catalyst, the V active center loading capacity is 2.1 wt% of the total weight of the catalyst, the Ti active center loading capacity is 1.1 wt% of the total weight of the catalyst, the organic metal cocatalyst is methylaluminoxane, and the dosage of the organic metal cocatalyst accounts for 30 wt% of the total weight of the catalyst. The copolymerisation of ethylene and 1-hexene was carried out using a conventional slurry polymerisation process with a 1-hexene/ethylene ratio of 0.2. The catalyst activity was found to be 8500g PE/g Cat, and the product density was found to be 0.942g/cm3。
The present invention is capable of other embodiments, and various changes and modifications may be made by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.
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