Assistant for olefin polymerization reaction, olefin catalyst system, prepolymerization catalyst composition and olefin polymerization reaction method

Abstract

The present invention provides an olefin polymerization auxiliary agent, an olefin catalyst system, a prepolymerization catalyst composition and an olefin polymerization method, a 3-pyrroline-1-formate compound as an auxiliary agent is added into a Ziegler-Natta type polyolefin catalyst system of which an internal electron donor comprises a diether or succinate compound, and the polymerization activity is maintained at a high level. The activity attenuation is slowed down, and the isotactic index, the molecular weight and the adjustable range of molecular weight distribution of a polymerization product are widened; when applied to random copolymerization, the copolymer has improved polymerization activity, increased ethylene content of the obtained product and reduced melting point of the polymerization product. # imgabs0 #

Description

Technical Field

[0001] The invention belongs to the field of petrochemical industry, and specifically relates to an auxiliary agent for olefin polymerization reaction, an olefin catalyst system, a prepolymerization catalyst composition and an olefin polymerization reaction method. Background Art

[0002] With the advancement of technology and economic development, the demand for polyolefins has gradually shown differentiated and high-end characteristics. Catalyst technology is the core of polyolefin development. Developing catalyst technology with better performance for different polyolefin production processes is necessary to ensure normal production and continuously meet new demands. Olefin polymerization that realizes multiple reaction stages (such as double-loop plus gas phase reaction) is an important way to develop high-end polyolefins, which has higher requirements for catalyst performance including life.

[0003] As we all know, Ziegler-Natta catalysts still dominate the industrial production of polyolefins. Many companies have developed and industrially applied catalysts with diethers as internal electron donors, which have the characteristics of high polymerization activity, high stereospecificity, high hydrogen adjustment sensitivity, and narrow product molecular weight distribution. Without the addition of external electron donors, the isotactic index of the product is still at a high level; while the catalyst with succinate as internal electron donor has the characteristics of large molecular weight and wide molecular weight distribution. Summary of the invention

[0004] In view of the problems existing in the above-mentioned prior art, one of the objects of the present invention is to provide an application of a 3-pyrroline-1-carboxylate compound as an auxiliary agent for olefin polymerization. When the 3-pyrroline-1-carboxylate compound is added as an auxiliary agent to a Ziegler-Natta type polyolefin catalyst system in which an internal electron donor includes a diether or a succinate compound, the polymerization activity is maintained at a high level, the activity decay slows down, the molecular weight distribution of the polymerization product is significantly narrowed, and the adjustable range of the isotactic index of the polymerization product is widened; when applied in random copolymerization, the polymerization activity is improved, the ethylene content of the obtained product is significantly improved, and the melting point of the polymerization product is reduced.

[0005] In a first aspect, the present invention provides an auxiliary agent for olefin polymerization reaction, comprising a 3-pyrroline-1-carboxylate compound represented by formula (I),

[0006]

[0007] In formula (I),

[0008] M1 and M2 are the same or different and are independently selected from hydrogen, C1-C 20alkyl, keto, halogen, M3 and M4 are the same or different and are independently selected from hydrogen and halogen; M1, M2, M3, and M4 optionally contain a substituent I; the substituent I is selected from hydroxyl, halogen, cyano, nitro, amino, mono-C1-C 10 Alkylamino, di-C1-C 10 One or more of an alkylamino group, an aldehyde group, a carboxyl group and a heteroatom;

[0009] R is selected from C1-C 10 Alkyl, C2-C 10 Alkenyl, C2-C 10 Alkynyl, C3-C 12 Cycloalkyl, C6-C 20 Aryl, C7-C 20 Arylalkyl, 4-12 membered heterocycloalkyl and C5-C 20 Heteroaryl; R optionally contains a substituent II selected from hydroxy, halogen, cyano, nitro, amino, mono-C1-C 10 Alkylamino, di-C1-C 10 One or more of an alkylamino group, an aldehyde group, a carboxyl group and a heteroatom.

[0010] As a preferred technical solution, in formula (I), M1 and M2 are each independently selected from hydrogen, methyl, ethyl, isopropyl, n-butyl, tert-butyl, isobutyl, pentyl, hexyl, phenyl, keto, halogen or C1-C6 alkyl substituted phenyl.

[0011] As a preferred technical solution, the 3-pyrroline-1-carboxylate compound is selected from benzyl 3-pyrroline-1-carboxylate, tert-butyl 2,5-dihydropyrrole-1-carboxylate, methyl 2,5-dioxopyrrole-1-carboxylate, tert-butyl 2-oxo-5-dihydropyrrole-1-carboxylate, ethyl 2-chloro-5-dihydropyrrole-1-carboxylate, ethyl 2-methyl-3-pyrroline-1-carboxylate or ethyl 2,3-dimethyl-3-pyrroline-1-carboxylate.

[0012] In a second aspect, the present invention provides a catalyst system for olefin polymerization containing the above-mentioned auxiliary agent.

[0013] According to some preferred embodiments of the present invention, the catalyst system includes component A and / or the reaction product of component A; component A includes a main catalyst component (which is usually solid), a co-catalyst component and a 3-pyrroline-1-carboxylate compound shown in formula (I); the main catalyst component contains magnesium, titanium, halogen and an internal electron donor; the internal electron donor is selected from diether compound I and / or succinate compound; the co-catalyst component is selected from alkyl aluminum compounds.

[0014] According to the present invention, the content of the compound represented by formula (I) can vary within a wide range.

[0015] According to a preferred embodiment of the catalyst system of the present invention, the molar ratio of the compound represented by formula (I) to the main catalyst component calculated as titanium element is (0.1-1000):1, preferably (1-200):1, and more preferably (1-80):1.

[0016] The inventors of the present application have discovered through research that the introduction of a 3-pyrroline-1-carboxylate compound of formula (I) into a Ziegler-Natta type polyolefin catalyst system in which an internal electron donor includes a diether compound I and / or a succinate compound can effectively improve the polymerization activity, slow down the activity decay, significantly narrow the molecular weight distribution of the polymerization product, and widen the adjustable range of the isotactic index of the polymerization product; in random copolymerization, the activity is improved, the ethylene content of the obtained product is significantly increased, and the melting point of the polymerization product is decreased.

[0017] According to a preferred embodiment of the catalyst system of the present invention, the internal electron donor further comprises a second internal electron donor, and the second internal electron donor is selected from one or more of a diether compound II, a succinate compound II, an alcohol ester compound I, and an aromatic carboxylate compound I; the molar ratio of the first internal electron donor to the second internal electron donor is (100-1):(1-100).

[0018] According to a preferred embodiment of the catalyst system of the present invention, the catalyst system further comprises an external electron donor, and the external electron donor is selected from one or more of silane compounds, alcohol ester compounds II, aromatic carboxylic acid ester compounds II, diether compounds III and succinate compounds III.

[0019] According to some embodiments of the catalyst system of the present invention, the molar ratio of the external electron donor to the titanium element in the main catalyst component is (0-500):1, preferably (0.01-200):1, and more preferably (0.1-100):1.

[0020] According to some embodiments of the catalyst system of the present invention, the structure of the silane compound is as shown in formula (IV):

[0021]

[0022] In formula (IV), R1 to R4 are the same or different and are independently selected from hydrogen, C1-C 10 Alkyl, C2-C 10 Alkenyl, C1-C 10 Alkoxy, C2-C 10 Alkenyloxy, C2-C 10 Alkynyl, C2-C10 Alkynyloxy, C3-C 10 Cycloalkyl, C6-C 15 Aryl and amino, preferably hydrogen, C1-C6 alkyl, C3-C6 cycloalkyl, C6-C 10 The alkyl, alkenyl, alkynyl, alkoxy, alkenyloxy, alkynyloxy, cycloalkyl, aryl and amino groups may be optionally selected from halogen, C1-C6 alkyl, C3-C6 cycloalkyl, C6-C 10 The aryl group and the amino group are substituted with one or more substituents.

[0023] Preferably, the silane compound is selected from tetramethoxysilane, tetraethoxysilane, diisopropyldimethoxysilane, isopropyltrimethoxysilane, di-n-propyldimethoxysilane, n-propyltrimethoxysilane, di-n-butyldimethoxysilane, di-tert-butyldimethoxysilane, diisobutyldimethoxysilane, cyclopentyltrimethoxysilane, dicyclopentyldimethoxysilane, cyclohexylmethyldimethoxysilane, cyclohexyldimethoxysilane, cyclohexylethyldimethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, phenyltriethoxysilane, vinylmethoxysilane, vinylethoxysilane, vinylpropoxysilane, vinyldimethoxysilane, vinyldiethoxysilane, vinyldipropoxysilane, vinyltrimethoxysilane, vinyl At least one of triethoxysilane, vinyltripropoxysilane, allylmethoxysilane, allylethoxysilane, allylpropoxysilane, allyldimethoxysilane, allyldiethoxysilane, allyldipropoxysilane, allyltrimethoxysilane, allyltriethoxysilane, allyltripropoxysilane, aminotrimethylsilane, aminotriethylsilane, aminotripropylsilane, aminotri-n-butylsilane, aminotriisobutylsilane, methylaminotrimethylsilane, methylaminotriethylsilane, methylaminotripropylsilane, methylaminotri-n-butylsilane, methylaminotriisobutylsilane, ethylaminotrimethylsilane, ethylaminotriethylsilane, ethylaminotripropylsilane, ethylaminotri-n-butylsilane and ethylaminotriisobutylsilane.

[0024] According to some embodiments of the catalyst system provided by the present invention, the diether compound I, the diether compound II, and the diether compound III are independently selected from 1,3-diether compounds represented by formula (II),

[0025]

[0026] In formula (II), R Ⅰ , R Ⅱ , R Ⅲ , R Ⅳ , R Ⅴ and R Ⅵare the same or different, each independently selected from hydrogen, halogen, C1-C 20 Alkyl, C3-C 20 Cycloalkyl, C6-C 20 Aryl, C7-C 20 Arylalkyl and C7-C 20 Alkaryl; R Ⅶ and R Ⅷ The same or different, each independently selected from C1-C 20 Alkyl, C3-C 20 Cycloalkyl, C6-C 20 Aryl, C7-C 20 Arylalkyl and C7-C 20 Alkaryl, wherein any one of the alkyl, alkenyl, alkynyl, cycloalkyl, aryl, aralkyl and alkaryl groups may be optionally substituted with one or more substituents selected from C1-C 10 Alkyl, C1-C 10 Alkoxy, hydroxy, halogen, cyano, nitro, amino, mono-C1-C 10 Alkylamino, di-C1-C 10 alkylamino, aldehyde, carboxyl and heteroatom; or, R Ⅰ , R Ⅱ , R Ⅲ , R Ⅳ , R Ⅴ and R Ⅵ Two or more of the fluorene rings are bonded to each other to form a saturated or unsaturated monocyclic or polycyclic ring, such as a fluorene ring.

[0027] According to a preferred embodiment of the present invention, in formula (II), R Ⅰ , R Ⅱ , R Ⅲ , R Ⅳ , R Ⅴ and R Ⅵ are the same or different, each independently selected from hydrogen, halogen, C1-C 18 Alkyl, C3-C 18 Cycloalkyl, C6-C 18 Aryl, C7-C 18 Arylalkyl and C7-C 18 Alkyl.

[0028] According to a preferred embodiment of the present invention, in formula (II), R Ⅰ , R Ⅱ , R Ⅲ , R Ⅳ , R Ⅴ and R Ⅵ are the same or different, each independently selected from hydrogen, halogen, C1-C 10Alkyl, C3-C 10 Cycloalkyl, C6-C 10 Aryl, C7-C 10 Arylalkyl and C7-C 10 Alkyl.

[0029] According to a preferred embodiment of the present invention, in formula (II), R Ⅶ and R Ⅷ are the same or different, each independently selected from hydrogen, halogen, C1-C 10 Alkyl, C3-C 10 Cycloalkyl, C6-C 10 Aryl, C7-C 10 Arylalkyl and C7-C 10 Alkyl.

[0030] According to a preferred embodiment of the present invention, in formula (II), R Ⅶ and R Ⅷ are independently selected from hydrogen, halogen, C1-C 10 Alkyl, C3-C 10 Cycloalkyl, C6-C 10 Aryl, C7-C 10 Arylalkyl and C7-C 10 Alkyl.

[0031] According to a preferred embodiment of the present invention, in formula (II), R Ⅲ and R Ⅳ They are bonded to each other to form a saturated or unsaturated monocyclic or polycyclic ring.

[0032] According to a preferred embodiment of the present invention, in formula (II), R Ⅶ and R Ⅷ Each independently is C1-C 10 alkyl.

[0033] According to a preferred embodiment of the present invention, the 1,3-diether compound represented by formula (II) is selected from 2-isopropyl-2-isopentyl-1,3-dimethoxypropane, 2-(2-ethylhexyl)-1,3-dimethoxypropane, 2-isopropyl-1,3-dimethoxypropane, 2-butyl-1,3-dimethoxypropane, 2-sec-butyl-1,3-dimethoxypropane, 2-cyclohexyl-1,3-dimethoxypropane, 2-phenyl-1,3-dimethoxypropane, 2-(2-phenylethyl)-1,3-dimethoxypropane, 2-(2-cyclohexylethyl)-1,3-dimethoxypropane, 2-(p-chlorophenyl)-1,3-dimethoxypropane, 2-(diphenylmethyl)-1,3-dimethoxypropane 1,3-dimethoxypropane, 2-(1-naphthyl)-1,3-dimethoxypropane, 2-(2-fluorophenyl)-1,3-dimethoxypropane, 2,2-dicyclohexyl-1,3-dimethoxypropane, 2,2-dicyclopentyl-1,3-dimethoxypropane, 2,2-diethyl-1,3-dimethoxypropane, 2,2-dipropyl-1,3-dimethoxypropane, 2,2-diisopropyl-1,3-dimethoxypropane, 2,2-dibutyl-1,3-dimethoxypropane, 2-methyl-2-propyl-1,3-dimethoxypropane, 2-methyl-2-benzyl-1,3-dimethoxypropane, 2-methyl-2-ethyl-1,3-dimethoxypropane, 2-methyl-2-isopropyl-1,3-dimethoxypropane 2-Methyl-2-phenyl-1,3-dimethoxypropane, 2-methyl-2-cyclohexyl-1,3-dimethoxypropane, 2,2-bis(p-chlorophenyl)-1,3-dimethoxypropane, 2,2-bis(2-cyclohexylethyl)-1,3-dimethoxypropane, 2-methyl-2-isobutyl-1,3-dimethoxypropane, 2-methyl-2-(2-ethylhexyl)-1,3-dimethoxypropane, 2,2-diisobutyl-1,3-dimethoxypropane, 2,2-diphenyl-1,3-dimethoxypropane, 2,2-dibenzyl-1,3-dimethoxypropane, 2,2-bis(cyclohexylmethyl)-1,3-dimethoxypropane, 2-isobutyl-2-isopropyl-1,3-dimethoxypropane 2-(1-methylbutyl)-2-isopropyl-1,3-dimethoxypropane, 2-(1-methylbutyl)-2-sec-butyl-1,3-dimethoxypropane, 2,2-di-sec-butyl-1,3-dimethoxypropane, 2,2-di-tert-butyl-1,3-dimethoxypropane, 2,2-di-neopentyl-1,3-dimethoxypropane, 2-isopropyl-2-isopentyl-1,3-dimethoxypropane, 2-isopropyl-2-phenyl-1,3-dimethoxypropane, 2-phenyl-2-sec-butyl-1,3-dimethoxypropane, 2-isopropyl-2-benzyl-1,3-dimethoxypropane, 2-isopropyl-2-cyclopentyl-1,3-dimethoxypropane, 2-cyclopentyl-2-sec-butyl-1,3-dimethoxypropane, 2-cyclohexyl-2-isopropyl-1,3-dimethoxypropane, 2-sec-butyl-2-cyclohexyl-1,3-dimethoxypropane, 2-isopropyl-2-sec-butyl-1,3-dimethoxypropane, 2-cyclohexyl-2-cyclohexylmethyl-1,3-dimethoxypropane, 1,1-bis(methoxymethyl)-cyclopentadiene, 1,1-bis(methoxymethyl)-2,3,4,5,-tetramethylcyclopentadiene, 1,1-bis(methoxymethyl)-2,3,4,5,-tetramethylcyclopentadiene, 1,1-bis(methoxymethyl)-2,3,4,5,-tetraphenylcyclopentadiene, 1,1-bis(methoxymethyl)-2,3,4,5,-tetrafluorocyclopentadiene, 1,1-bis(methoxymethyl) 1,1-bis(methoxymethyl)-3,4-dicyclopentylcyclopentadiene, 1,1-bis(methoxymethyl)-indene, 1,1-bis(methoxymethyl)-2,3-dimethoxyindene, 1,1-bis(methoxymethyl)-2,3,6,7-tetrafluoroindene, 1,1-bis(methoxymethyl)-4,5,6,7-tetrafluoroindene, 1,1-bis(methoxymethyl)-4,7-dimethylindene, 1,1-bis(methoxymethyl)-3,6-dimethylindene, 1,1-bis(methoxymethyl)-4-phenylindene, 1,1-bis(methoxymethyl)-4-phenyl-2-methylindene, 1,1-bis(methoxymethyl)-4-tetracyclohexylindene, 1,1-bis(methoxymethyl)-7-(3,3,3-trifluoropropyl)phenylindene, 1,1-bis(methoxymethyl)- 1,1-bis(methoxymethyl)-7-cyclopentylindene, 1,1-bis(methoxymethyl)-7-isopropylindene, 1,1-bis(methoxymethyl)-7-cyclohexylindene, 1,1-bis(methoxymethyl)-7-tert-butylindene, 1,1-bis(methoxymethyl)-7-tert-butyl-2-methylindene, 1,1-bis(methoxymethyl)-7-phenylindene, 1,1-bis(methoxymethyl)-7-tert-butylindene (Methoxymethyl)-2-phenylindene, 9,9-bis(methoxymethyl)fluorene, 9,9-bis(methoxymethyl)-2,7-dicyclopentylfluorene, 9,9-bis(methoxymethyl)-1,8-dichlorofluorene, 9,9-bis(methoxymethyl)-1,8-difluorofluorene, 9,9-bis(methoxymethyl)-1,2,3,4-tetrahydrofluorene, 9,9-bis(methoxymethyl)- At least one of 1,1-bis-(methoxymethyl)-4-tert-butylfluorene, 1,1-bis-(methoxymethyl)-2,5-cyclohexadiene, 1,1-bis-(methoxymethyl)-benzonaphthalene, 7,7-bis-(methoxymethyl)-2,5-norbornadiene, 9,9-bis-(methoxymethyl)-1,4-methanedihydronaphthalene, 9,9-bis-(methoxymethyl)-1,4-methanedihydroanthracene, 4,4-bis-(methoxymethyl)-1-phenyl-1,4-dihydronaphthalene, 4,4-bis-(methoxymethyl)-1-phenyl-3,4-dihydronaphthalene, 5,5-bis-(methoxymethyl)-1,3,6-cycloheptatriene and 1-methoxymethyl-1-(1'-methoxyethyl)-2,3,4,5-tetramethylcyclopentadiene.

[0034] In some preferred embodiments of the present invention, the succinate compound I, the succinate compound II, and the succinate compound III are each independently selected from the succinate compounds represented by formula (III):

[0035]

[0036] In formula (III), R1, R2, R3, R4, R5 and R6 are the same or different and are independently selected from C1-C 20 Alkyl, C3-C 20 Cycloalkyl, C6-C 20 Aryl, C7-C 20 Arylalkyl or C7-C 20Alkaryl, R"1, R"2, R"3, R"4, R"5 and R"6 optionally contain halogen or heteroatom; R"3, R"4, R"5 and R"6 groups may be optionally connected to form a ring. According to the present invention, the succinate compound represented by formula (III) is selected from 2,3-bis(2-ethylbutyl)succinic acid diethyl ester, 2,3-diethyl-2-isopropylsuccinic acid diethyl ester, 2,3-diisopropylsuccinic acid diethyl ester, 2,3-di-tert-butylsuccinic acid diethyl ester, 2,3-diisobutylsuccinic acid diethyl ester, 2,3-(bistrimethylsilyl)succinic acid diethyl ester, 2-(3,3,3-trifluoropropyl)-3-methylsuccinic acid diethyl ester, 2,3-dineopentylsuccinic acid diethyl ester, 2,3-diisopentylsuccinic acid diethyl ester, 2,3-(1-trifluoromethyl- diethyl 2-isopropyl-3-isobutylsuccinate, diethyl 2-tert-butyl-3-isopropylsuccinate, diethyl 2-isopropyl-3-cyclohexylsuccinate, diethyl 2-isopentyl-3-cyclohexylsuccinate, diethyl 2,2,3,3-tetramethylsuccinate, diethyl 2,2,3,3-tetraethylsuccinate, diethyl 2,2,3,3-tetrapropylsuccinate, diethyl 2,3-diethyl-2,3-diisopropyldisuccinate, diisobutyl 2,3-bis(2-ethylbutyl)succinate, diisobutyl 2,3-diethyl-2-isopropylsuccinate Ester, diisobutyl 2,3-diisopropylsuccinate, diisobutyl 2,3-di-tert-butylsuccinate, diisobutyl 2,3-diisobutylsuccinate, diisobutyl 2,3-(bistrimethylsilyl)succinate, diisobutyl 2-(3,3,3-trifluoropropyl)-3-methylsuccinate, diisobutyl 2,3-dineopentylsuccinate, diisobutyl 2,3-diisopentylsuccinate, diisobutyl 2,3-(1-trifluoromethyl-ethyl)succinate, diisobutyl 2-isopropyl-3-isobutylsuccinate, diisobutyl 2-tert-butyl-3-isopropylsuccinate, 2-isopropyl-3-cyclopentylsuccinate Hexyl succinic acid diisobutyl ester, 2,3-diisopropyl 2-cyanosuccinic acid diethyl ester, 2-isopentyl-3-cyclohexyl succinic acid diisobutyl ester, 2,2,3,3-tetramethyl succinic acid diisobutyl ester, 2,2,3,3-tetraethyl succinic acid diisobutyl ester, 2,2,3,3-tetrapropyl succinic acid diisobutyl ester, 2,3-diethyl-2,3-diisopropyl disuccinic acid diisobutyl ester; preferably one or more selected from 2,3-diisopropyl succinic acid diethyl ester, 2,3-di-tert-butyl succinic acid diethyl ester, 2,3-diisobutyl succinic acid diethyl ester and 2,3-diisopropyl succinic acid diisobutyl ester.

[0037] In some preferred embodiments of the present invention, the alcohol ester compound I and the alcohol ester compound II are each independently selected from the diol ester compound represented by formula (VI) or the diol ester compound represented by formula (VI),

[0038]

[0039] In formula (VI), R 1 and R 2 The same or different, each independently selected from C1-C 20 Alkyl, C2-C 20 Alkenyl, C2-C 20 Alkynyl, C3-C 20 Cycloalkyl, C6-C 20 Aryl, C7-C 20 Alkyl, C7-C 20 Arylalkyl and C with or without substituents 10 -C 20 The fused ring aromatic groups are preferably independently selected from C1-C 10 Alkyl, C2-C 10 Alkenyl, C3-C 10 Cycloalkyl, C6-C 10 Aryl, C7-C 10 Alkyl, C7-C 10 Arylalkyl and C with or without substituents 10 -C 15 The condensed ring aromatic group, wherein the substituent is selected from one or more of a hydroxyl group, a halogen atom, a cyano group, a nitro group, an amino group, a mono-C1-C6 alkylamino group, a di-C1-C6 alkylamino group, an aldehyde group, a carboxyl group and a heteroatom; M is a divalent linking group, preferably selected from a C1-C6 alkylamino group with or without a substituent. 20 Alkylene, C3-C 20 Cycloalkylene and C6-C 20 Arylene, the substituent is selected from nitrogen, oxygen, sulfur, silicon, phosphorus, halogen atoms and C1-C 20 Alkyl, when the substituent is multiple C1-C 20 When alkyl, the substituents are optionally bonded to form one or more rings;

[0040]

[0041] In formula (a), R'1 and R'2 are the same or different and are independently selected from C1-C 10 Alkyl, C2-C 10 Alkenyl, C2-C 10 Alkynyl, C3-C 20 Cycloalkyl, C6-C20 Aryl, C7-C 20 Arylalkyl and C7-C 20 Alkaryl is preferably selected from C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C3-C 10 Cycloalkyl, C6-C 10 Aryl, C7-C 10 Arylalkyl and C7-C 10 Alkaryl, wherein the alkyl, alkenyl, cycloalkyl, aryl, aralkyl or alkaryl is optionally substituted with one or more substituents selected from halogen, C1-C6 alkyl and C1-C6 alkoxy; R'3, R'4, R'5, R'6 and R' 1 -'R' 2n are the same or different, each independently selected from hydrogen, halogen, C1-C 20 Alkyl, C2-C 10 Alkenyl, C2-C 10 Alkynyl, C3-C 20 Cycloalkyl, C6-C 20 Aryl, C7-C 20 Alkyl, C7-C 20 Aralkyl and C 10 -C 20 The fused ring aromatic group is preferably selected from hydrogen, halogen, C1-C 10 Alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C3-C 10 Cycloalkyl, C6-C 10 Aryl, C7-C 10 Alkyl, C7-C 10 Aralkyl and C 10 -C 15 The alkyl, alkenyl, alkynyl, cycloalkyl, aryl, alkaryl, aralkyl and condensed ring aryl are optionally substituted by one or more substituents selected from halogen, C1-C6 alkyl and C1-C6 alkoxy; R'3, R'4, R'5, R'6 and R' 1 -R' 2n Optionally contain heteroatoms, the heteroatoms are one or more of nitrogen, oxygen, sulfur, silicon, halogen and phosphorus; or, R'3, R'4, R'5, R'6 and R' 1 -R' 2nTwo or more of the substituents are bonded to each other to form a saturated or unsaturated monocyclic ring or a saturated or unsaturated polycyclic ring; wherein n is an integer of 0 to 10, preferably an integer of 1 to 8, and more preferably an integer of 2 to 6. When n is 0, the carbon atoms of the substituents R'3 and R'4 are bonded to the carbon atoms of the substituents R'5 and R'6. According to the present invention, in formula (a), the bracket part indicates that there are n carbon atoms bonded in sequence, and each carbon atom is also bonded to two substituents, that is, there are n carbon atoms and R' in the bracket. 1 , R' 2 , R' 3 …R' 2n And so on 2n substituents.

[0042] According to the present invention, the diol ester compound represented by formula (a) or the diol ester compound represented by formula (VI) is selected from 2,4-pentanediol dibenzoate, 3-methyl-2,4-pentanediol dibenzoate, 3,5-heptanediol dibenzoate, 4-ethyl-3,5-heptanediol dibenzoate, 3,5-heptanediol di-p-methylbenzoate, 3,5-heptanediol di-o-methylbenzoate, 3,5-heptanediol di-p-chlorobenzoate, 3,5-heptanediol di-o-chlorobenzoate, 3,5-heptanediol di-p-methoxybenzoate, 3,5-heptanediol di-o-methoxybenzoate, 3,5-heptanediol di-m-methoxybenzoate, 2-methyl-3,5-heptanediol dibenzoate, 4-methyl-3,5-heptanediol dibenzoate, 6-Methyl-3,5-heptanediol dibenzoate, 4-ethyl-3,5-heptanediol dibenzoate, 5-ethyl-3,5-heptanediol dibenzoate, 4-propyl-3,5-heptanediol dibenzoate, 4-butyl-3,5-heptanediol dibenzoate, 2,4-dimethyl-3,5-heptanediol dibenzoate, 2,6-dimethyl-3,5-heptanediol dibenzoate, 4,4-dimethyl-3,5-heptanediol dibenzoate, 6,6-dimethyl-3,5-heptanediol dibenzoate, 4,6-dimethyl-3,5-heptanediol dibenzoate, 4,4-dimethyl-3,5-heptanediol dibenzoate, 6,6-dimethyl-3,5-heptanediol dibenzoate, 2-methyl-4-ethyl-3 ,5-heptanediol dibenzoate, 4-methyl-4-ethyl-3,5-heptanediol dibenzoate, 2-methyl-4-propyl-3,5-heptanediol dibenzoate, 4-methyl-4-propyl-3,5-heptanediol dibenzoate, 6-methyl-2,4-heptanediol di(p-chlorobenzoate), 6-methyl-2,4-heptanediol di(p-methylbenzoate), 6-methyl-2,4-heptanediol di(m-methylbenzoate), 2,2,6,6-tetramethyl-3,5-heptanediol dibenzoate, 4-methyl-3,5-octanediol dibenzoate, 4-ethyl-3,5-octanediol dibenzoate, 4-propyl-3,5-octanediol dibenzoate, 4-butyl-3,5-octanediol dibenzoate, 4, 4-Dimethyl-3,5-octanediol dibenzoate, 4-methyl-4-ethyl-3,5-octanediol dibenzoate, 2-methyl-4-ethyl-3,5-octanediol dibenzoate, 2-methyl-6-ethyl-3,5-octanediol dibenzoate, 5-methyl-4,6-nonanediol dibenzoate, 5-ethyl-4,6-nonanediol dibenzoate, 5-propyl-4,6-nonanediol dibenzoate, 5-butyl-4,6-nonanediol dibenzoate, 5,5-dimethyl-4,6-nonanediol dibenzoate, 5-methyl-4-ethyl-4,6-nonanediol dibenzoate, 5-phenyl-4,6-nonanediol dibenzoate, 4,6-nonanediol dibenzoate and 4-butyl-3,5-heptanediol dibenzoate, 1,2-phenylene dibenzoate, 3-methyl-5-tert-butyl-1,2-phenylene dibenzoate, 3,5-diisopropyl-1,2-phenylene dibenzoate, 3,6-dimethyl-1,2-phenylene dibenzoate, 4-tert-butyl-1,2-phenylene dibenzoate, 1,2-naphthalene dibenzoate, 2,3-naphthalene dibenzoate, 1,8-naphthyl dibenzoate, 1,8-naphthyl dibenzoate, 1,8-naphthyl dibenzoate, 1,3-naphthyl dibenzoate, 1,2-naphthyl dibenzoate, 1,8-naphthyl dibenzoate, 1,2-naphthyl dibenzoate, 1,8-naphthyl dibenzoate, 1,2-naphthyl dibenzoate, 1,2-naphthyl dibenzoate, 1,2-naphthyl dibenzoate, 1,8-naphthyl dibenzoate, 1,2-naphthyl dibenzoate 8-naphthyl ester, di-4-ethylbenzoic acid-1,8-naphthyl ester, di-4-n-propylbenzoic acid-1,8-naphthyl ester, di-4-isopropylbenzoic acid-1,8-naphthyl ester, di-4-n-butylbenzoic acid-1,8-naphthyl ester, di-4-isobutylbenzoic acid-1,8-naphthyl ester, di-4-tert-butylbenzoic acid-1,8-naphthyl ester, di-4-phenylbenzoic acid-1,8-naphthyl ester, di-4-fluorobenzoic acid-1,8-naphthyl ester, di-3-fluorobenzoic acid-1,8-naphthyl ester and di-2-fluorobenzoic acid-1,8-naphthyl ester.

[0043] In some preferred embodiments of the present invention, the aromatic carboxylate compound I and the aromatic carboxylate compound II are each independently a compound represented by formula (VII),

[0044]

[0045] In formula (VII), each R 3 the same or different, each independently selected from C1-C8 alkyl groups which may or may not contain substituents selected from C1-C6 alkyl groups and halogen atoms, C5-C6 alkyl groups which may or may not contain substituents selected from C1-C6 alkyl groups and halogen atoms 10 Cycloalkyl, C6-C6 alkyl or C1-C6 alkyl substituents selected from C1-C6 alkyl and halogen atoms 15 an aryl group, a C7-C6 alkyl group which may or may not contain a substituent selected from a C1-C6 alkyl group and a halogen atom; 15 an alkylaryl group or a C7-C6 alkyl group which may or may not contain a substituent selected from a C1-C6 alkyl group and a halogen atom; 15 R4-R7 may be the same or different and are independently selected from hydrogen, halogen, C1-C8 alkyl containing or not containing substituents selected from C1-C6 alkyl and halogen atoms, C5-C 10 Cycloalkyl, C6-C6 alkyl or C1-C6 alkyl substituents selected from C1-C6 alkyl and halogen atoms 20 an aryl group, a C7-C6 alkyl group which may or may not contain a substituent selected from a C1-C6 alkyl group and a halogen atom; 20 an alkylaryl group or a C7-C6 alkyl group which may or may not contain a substituent selected from a C1-C6 alkyl group and a halogen atom; 20Aralkyl. According to the present invention, the aromatic carboxylate compound represented by formula (VII) is preferably phthalic acid carboxylate; more preferably, the aromatic carboxylate compound is selected from at least one of diethyl phthalate, dipropyl phthalate, diisobutyl phthalate, di-n-butyl phthalate, dipentyl phthalate, dihexyl phthalate, diheptyl phthalate and dioctyl phthalate, and further preferably, the aromatic carboxylate compound is diisobutyl phthalate.

[0046] According to an embodiment of the present invention, the main catalyst component includes titanium element, magnesium element and internal electron donor, and is the reaction product of titanium compound, magnesium compound and internal electron donor. Since the present invention improves the performance of olefin polymerization catalyst system by adding auxiliary agent, therefore, in the present invention, the method for preparing the main catalyst component can be carried out according to the conventional method used in the art, for example, the method disclosed in CN1506384A, CN1091748A, CN85100997A, CN102399326A, US4540679A, CN109096415B, etc. can be referred to, and the disclosed contents are incorporated herein by reference.

[0047] The preparation method of the main catalyst component in the present invention includes but is not limited to the following method:

[0048] Method 1: A magnesium compound is added to an inert solvent, and then an organic epoxy compound and an organic phosphorus compound are added, and after dissolving, a precipitation aid and a titanium compound are added to precipitate a solid; an internal electron donor is added to be carried on the solid, and then treated with titanium tetrahalide and an inert diluent to obtain a solid;

[0049] Method 2: In an inert solvent such as decane or toluene, a solid magnesium compound is dissolved in an organic alcohol compound such as 2-ethylhexanol, and after dissolution, a precipitation aid and a titanium compound are added to precipitate a solid; an internal electron donor is added to be carried on the solid, and then treated with a titanium compound and an inert diluent to obtain;

[0050] Method 3: dispersing the magnesium halide alcoholate into a low temperature (e.g., below -5°C) titanium compound, then heating it to a high temperature (e.g., above 50°C), adding an internal electron donor compound during the heating process, filtering, treating the obtained precipitate with a titanium compound, washing the precipitate, and obtaining the main catalyst component;

[0051] Method 4: preparing an alkoxy magnesium carrier and an inert diluent into a suspension, then reacting the suspension with a mixture of a titanium compound and an inert diluent, filtering the suspension, contacting the obtained precipitate with the titanium compound and an internal electron donor compound, washing the precipitate, and obtaining the main catalyst component;

[0052] Method 5: In a reaction kettle that has been repeatedly replaced with high-purity nitrogen, anhydrous magnesium chloride, toluene, decane epichlorohydrin, tributyl phosphate and a surfactant are added in sequence, and the reaction is carried out at a temperature of 30 to 100°C for 0.1 to 6 hours. Then the internal electron donor is added and stirring is continued for 0.1 to 3 hours. The solution is cooled to -30 to 60°C, titanium tetrachloride is added, and the temperature is gradually raised to 85 to 100°C. The electron donor compound is added during the heating process. After the mixture is filtered, the solid matter is washed with toluene, a mixture of toluene and titanium tetrachloride, and hexane, respectively, to obtain the main catalyst component.

[0053] According to a preferred embodiment of the present invention, a titanium compound or a mixture of a titanium compound and an inert solvent (an inert solvent such as hexane, heptane, octane, decane, toluene, etc.) precooled to -15°C to -40°C is mixed with a magnesium compound, and the temperature of the mixture is raised to 90-110°C in stages and maintained for 0.1-2 hours, and an internal electron donor is added during the heating process. Then the solid-liquid separation is performed, and the obtained solid phase is treated at least twice with the titanium compound again, washed with a solvent, and finally vacuum dried to obtain the main catalyst component.

[0054] According to the present invention, the magnesium compound can be various magnesium compounds conventionally used in the preparation of olefin polymerization catalysts in the art, for example, the magnesium compound can be selected from at least one of magnesium dihalide, alkoxymagnesium, alkylmagnesium, hydrates of magnesium dihalide, alcoholates of magnesium dihalide, and derivatives in which one halogen atom in the magnesium dihalide molecule is replaced by a hydrocarbonoxy group or a halogenated hydrocarbonoxy group. According to a preferred embodiment of the present invention, the magnesium compound is an alcoholate of magnesium dihalide.

[0055] According to a preferred embodiment of the present invention, the alcoholate of magnesium dihalide has a spherical magnesium alcoholate represented by formula (VIII),

[0056] MgX2·m(R'OH)·nE·qH2O formula (VIII)

[0057] In formula (VIII): X is chlorine or bromine; R' is a C1-C4 alkyl group (for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl), m is 0.5-4.0; E is an ether or ester electron donor compound, n is 0-1.0, wherein the ether or ester can be an ether or ester that can be used as an electron donor as known in the art, and can also be an internal electron donor and / or external electron donor used in the present invention; q is 0-0.8.

[0058] According to a preferred embodiment of the present invention, in formula (VIII), X is chlorine or bromine; R' is a C1-C4 alkyl group, m is 1.5 to 3.5; and n and q are both 0.

[0059] According to a preferred embodiment of the present invention, the magnesium compound is MgCl2·m(CH3CH2OH), where m is 1.5 to 3.5.

[0060] According to some embodiments of the present invention, the preparation method of the alcoholate of magnesium dihalide can be prepared according to methods known in the art, for example, it can be prepared by referring to the method disclosed in CN1330086A.

[0061] According to a preferred embodiment of the present invention, the preparation method of the alcoholate of magnesium dihalide comprises: (1) mixing anhydrous magnesium dihalide with an alcohol compound (R'OH), and reacting at 90-140°C to obtain an alcoholate of magnesium halide; (2) shearing the alcoholate of magnesium halide in a dispersion medium, and cooling in an inert medium after shearing to obtain the alcoholate of spherical magnesium halide. Wherein, the ratio of the anhydrous magnesium dihalide and the alcohol compound can be determined according to the actual need to load the alcohol compound in the anhydrous magnesium dihalide. Wherein, the dispersion medium can be a hydrocarbon inert solvent, such as kerosene, white oil, silicone oil, paraffin oil, vaseline oil, etc. The inert medium can be selected from pentane, hexane, heptane, petroleum ether, raffinate oil, etc. The shearing refers to shearing the magnesium halide alcoholate by external shear force, for example, high-speed stirring method (such as CN1330086A), spray method (such as US6020279 A), high-gravity rotating bed (such as CN1580136A) and emulsifier method (CN1463990A).

[0062] According to a preferred embodiment of the present invention, in order to further improve the purity of the magnesium compound, the obtained spherical magnesium halide alcoholate is further subjected to washing and drying steps.

[0063] According to the present invention, the alkoxy magnesium is prepared by reacting metal magnesium, ethanol, isooctyl alcohol (2-ethylhexanol) and a mixed halogenating agent under an inert atmosphere. The mixed halogenating agent is a combination of halogens and halogen compounds, and the non-limiting selection of the halogens and halogen compounds is: iodine, bromine, chlorine, magnesium chloride, magnesium bromide, magnesium iodide, potassium chloride, potassium bromide, potassium iodide, calcium chloride, calcium bromide, calcium iodide, mercuric chloride, mercuric bromide, mercuric iodide, ethoxymagnesium iodide, methoxymagnesium iodide, isopropylmagnesium iodide, hydrogen chloride, chloroacetyl chloride, etc.

[0064] According to the present invention, the titanium compound can be various titanium compounds conventionally used in the preparation of olefin polymerization catalysts in the art. According to a preferred embodiment of the present invention, the titanium compound has a structure shown in formula (IX),

[0065] Ti(OR”) 4-k X k Formula (IX)

[0066] In formula (IX), R" is a C1-C20 alkyl group, X is F, Cl or Br; and k is an integer of 0-4.

[0067] According to a preferred embodiment of the present invention, in formula (IX): R" is a C1-C10 alkyl group.

[0068] According to a preferred embodiment of the present invention, in formula (IX): R" is a C1-C5 alkyl group.

[0069] According to a preferred embodiment of the present invention, for example, in formula (IX): R" is methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, or neopentyl.

[0070] According to a preferred embodiment of the present invention, in formula (IX): X is Cl.

[0071] According to a preferred embodiment of the present invention, the titanium compound is selected from at least one of titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, tetrabutoxytitanium, tetraethoxytitanium, monochlorotributoxytitanium, dichlorodibutoxytitanium, trichloromonobutoxytitanium, monochlorotriethoxytitanium, dichlorodiethoxytitanium, trichloromonoethoxytitanium and titanium trichloride.

[0072] According to a preferred embodiment of the present invention, the titanium compound is titanium tetrachloride.

[0073] According to some embodiments of the present invention, the weight ratio of the titanium element, the magnesium element, and the internal electron donor in the main catalyst component is 1:(5-25):(2-15).

[0074] In some preferred embodiments of the present invention, the alkyl aluminum compound is selected from the compound represented by formula (b),

[0075] AlR3 formula (b),

[0076] In formula (b), R is a C1-C 20 The alkyl group is preferably a C1-C6 alkyl group which may be substituted by a halogen atom.

[0077] In some preferred embodiments of the present invention, the alkyl aluminum compound is selected from triethylaluminum, tripropylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, triisobutylaluminum, diethylaluminum monohydrogen, diisobutylaluminum monohydrogen, diethylaluminum monochloride, diisobutylaluminum monochloride, ethylaluminum dichloride, Al(n-C6H 13 )3 and Al(n-C8H 17 )3 or more.

[0078] In some preferred embodiments of the present invention, the molar ratio of the external electron donor to the aluminum element in the alkyl aluminum compound is 1:(0.1-1000), preferably 1:(1-500).

[0079] According to the present invention, in the catalyst system, the molar ratio of the main catalyst component calculated as titanium element to the alkyl aluminum compound calculated as aluminum element is 1:(5-5000), preferably 1:(20-2000).

[0080] In a third aspect, the present invention provides a prepolymerized catalyst composition for olefin polymerization, comprising a prepolymer obtained by polymerizing an olefin using the catalyst system described in the second aspect of the present invention.

[0081] In some preferred embodiments of the present invention, the prepolymerization multiple of the prepolymer is 0.1-1000 g prepolymer / g main catalyst component, preferably 0.2-500 g prepolymer / g main catalyst component, and more preferably 0.5-20 g prepolymer / g main catalyst component.

[0082] According to the present invention, the term "prepolymerized catalyst" refers to a catalyst which has been subjected to a polymerization step at a relatively low conversion degree. In the present invention, the prepolymerization may be carried out using the same olefin as the olefin used for the polymerization.

[0083] According to some preferred embodiments of the present invention, the general formula of the olefin is CH2=CHR, wherein R is hydrogen or a C1-C7 alkyl group.

[0084] According to some preferred embodiments of the present invention, the olefin to be prepolymerized is propylene.

[0085] According to some preferred embodiments of the present invention, propylene or a mixture thereof with up to 20% by mole of one or more α-olefins is used for prepolymerization.

[0086] According to some embodiments of the present invention, the temperature of the prepolymerization reaction is -20 to 80° C., and the polymerization pressure is preferably 0 to 5 MPa.

[0087] According to some preferred embodiments of the present invention, the temperature of the prepolymerization reaction is 0-50°C.

[0088] According to some embodiments of the present invention, the prepolymerization reaction is carried out in liquid or gas phase.

[0089] According to some embodiments of the present invention, the prepolymerization step can be performed in-line as part of a continuous polymerization process, or independently in a batch operation.

[0090] According to some preferred embodiments of the present invention, to prepare 0.1-1000 g olefin prepolymer / g polymer of the main catalyst component, the prepolymerization of the catalyst of the present invention and olefin is independently carried out in a batch operation at a polymerization pressure of 0-5 MPa.

[0091] In a fourth aspect, the present invention provides a use of the above catalyst system or the above prepolymerized catalyst composition in the field of olefin polymerization, especially in the field of propylene polymerization.

[0092] According to the present invention, the general formula of the olefin is CH2=CHR, wherein R is hydrogen or a C1-C7 alkyl group, and the olefin polymerization can be the homopolymerization of a single olefin or the copolymerization of multiple olefins, or it can be a combination of a single olefin homopolymerization process and multiple olefin copolymerization processes.

[0093] According to some preferred embodiments of the present invention, the olefin is selected from at least one of ethylene, propylene, 1-butene, 4-methyl-1-pentene and 1-hexene.

[0094] According to some preferred embodiments of the present invention, the olefin is ethylene, propylene and / or 1-butene.

[0095] In a fifth aspect, the present invention provides a use of the catalyst system according to the second aspect and / or the prepolymerized catalyst composition according to the third aspect in an olefin polymerization reaction.

[0096] In some preferred embodiments of the present invention, the polymerization reaction conditions include: temperature of 0°C to 150°C, preferably 50°C to 90°C; pressure of 0.01MPa to 10MPa, preferably 0.1MPa to 5MPa; time of 0.1h to 5h, preferably 0.2h to 3h.

[0097] According to some embodiments of the present invention, both the catalyst system and the prepolymerized catalyst composition can be used for the polymerization reaction of olefins.

[0098] According to some preferred embodiments of the present invention, the catalyst system and the prepolymerized catalyst composition can be used in homopolymerization of propylene or copolymerization with other olefins.

[0099] Preferably, the olefin contains ethylene and propylene, and the volume ratio of ethylene:propylene is (0.1-20):100.

[0100] According to the present invention, the catalyst system of the present invention can be directly added to the reactor for use in the polymerization process, or the catalyst system and the prepolymerized catalyst composition obtained by prepolymerizing olefins can be added to the reactor for polymerization reaction.

[0101] According to the present invention, the olefin polymerization reaction can be carried out according to a known polymerization method, can be carried out in liquid phase or gas phase, can also be carried out in a combination of liquid phase and gas phase polymerization stages, and can also adopt conventional techniques such as slurry process, gas phase fluidized bed, etc.

[0102] According to the present invention, the polymerization can be carried out in the presence of a solvent. Wherein, based on the titanium element in the main catalyst component, the concentration of the catalyst system in the solvent can be 0.1×10 -5 ~5×10 -5 mol / L.

[0103] According to some preferred embodiments of the present invention, the concentration of the catalyst system in the solvent can be 0.2×10 -5 ~2×10 -5 mol / L.

[0104] In the present invention, the hydrocarbon group may be selected from an alkyl group, a cycloalkyl group, an alkenyl group, an alkynyl group, an aryl group, an aralkyl group and an alkaryl group.

[0105] In the present invention, alkyl refers to a straight chain alkyl or a branched chain alkyl, and non-limiting examples thereof include: methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, 1-ethylpropyl, 2-methylbutyl, 3-methylbutyl, 2,2-dimethylpropyl, n-hexyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, n-heptyl, 2-methylhexyl, 3-methylhexyl, 4-methylhexyl, 5-methylhexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, tetrahydrogeranyl, n-dodecyl, n-tridecyl, n-tetradecyl, n-pentadecyl, n-hexadecyl, n-octadecyl, n-nonadecyl and n-eicosyl.

[0106] In the present invention, examples of alkenyl may include, but are not limited to, ethenyl, propenyl, butenyl, pentenyl, and octenyl.

[0107] In the present invention, examples of the alkynyl group may include, but are not limited to, ethynyl and propargyl.

[0108] In the present invention, examples of cycloalkyl may include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, 4-methylcyclohexyl, 4-ethylcyclohexyl, 4-n-propylcyclohexyl, 4-n-butylcyclohexyl, cycloundecyl, and cyclododecyl.

[0109] In the present invention, examples of halogen include, but are not limited to, fluorine, chlorine, bromine and iodine.

[0110] In the present invention, examples of aryl groups may include, but are not limited to, phenyl, methylphenyl, ethylphenyl, 4-tert-butylphenyl, and naphthyl.

[0111] In the present invention, aralkyl refers to an alkyl group having an aryl substituent, and examples may include, but are not limited to, phenylmethyl, phenylethyl, phenyl-n-propyl, phenyl-n-butyl, phenyl-t-butyl, and phenyl-isopropyl.

[0112] In the present invention, the alkylaryl group refers to an aryl group having 7 to 20 carbon atoms and having an alkyl substituent, and examples thereof may include but are not limited to: methylphenyl and ethylphenyl.

[0113] In the present invention, examples of alkoxy groups may include, but are not limited to, methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, isobutoxy, isopropoxy, n-butoxy, sec-butoxy, isobutoxy, tert-butoxy, n-pentoxy, isopentyl, tert-pentyloxy and hexyloxy.

[0114] In the present invention, the heteroatom refers to an atom usually contained in a molecular structure except a halogen atom, a carbon atom and a hydrogen atom, such as O, N, S, P, Si and B.

[0115] The present invention adopts a 3-pyrroline-1-carboxylate compound shown in formula (I) as an auxiliary agent and an alkyl aluminum as a co-catalyst component, which are used in combination with a main catalyst component. The catalyst system can improve the hydrogen adjustment sensitivity of the catalyst system while maintaining a relatively high activity, expand the adjustable range of the isotactic index of the polymerization product, and narrow the molecular weight of the polymerization product, so that a high isotactic and high melt index polyolefin product can be prepared; it has a certain significance for optimizing the performance of the catalyst and expanding the use of the catalyst; the addition of the auxiliary agent can also slow down the activity decay of the polymerization system, which is conducive to realizing olefin polymerization in multiple reaction stages (such as double-loop pipe plus gas phase reaction); the catalyst system can simultaneously increase the output and the ethylene content of the product during the random copolymerization of ethylene and propylene, and effectively reduce the melting point of the polymerization product. DETAILED DESCRIPTION

[0116] The present invention is described in detail below by way of examples, but the protection scope of the present invention is not limited to the following description.

[0117] A catalyst system for olefin polymerization, comprising the following components or the reaction product of the following components:

[0118] 1) A main catalyst component comprising magnesium, titanium, halogen and an internal electron donor;

[0119] 2) a co-catalytic component selected from alkyl aluminum compounds;

[0120] 3) additives;

[0121] The auxiliary agent comprises a 3-pyrroline-1-carboxylate compound represented by formula (I), and the internal electron donor comprises a diether and / or a succinate compound.

[0122] The method for determining the polymerization activity of the catalyst in the Examples and Comparative Examples is as follows: the amount of polymer obtained within a certain period of time (in kg) is divided by the amount of catalyst added (in g).

[0123] The performance test of the polymer prepared in the embodiment and comparative example is as follows:

[0124] (1) Determination of polymer weight average molecular weight and molecular weight distribution: high temperature gel permeation chromatography, measured in accordance with standard GB / T 36214.4-2018.

[0125] (2) Determination method of isotactic index of polymer: Determine according to standard GB / T 2412-2008.

[0126] (3) Determination of ethylene content in polymer: measured by infrared spectrometer.

[0127] (4) Determination method of polymer melting point: Determined in accordance with standard GB / T 28724-2012.

[0128] In the examples and comparative examples, the titanium content of the catalyst was measured colorimetrically using a UV-Visible Spectrophotometer Model 722.

[0129] Preparation Example 1

[0130] This preparation example is used to illustrate the preparation of a magnesium compound.

[0131] Anhydrous magnesium chloride and ethanol are mixed in a molar ratio of 1:2.6, and the temperature is raised to 120° C. to react for 2 to 4 hours to generate a magnesium chloride alcoholate melt. The magnesium chloride alcoholate melt is mixed with a dispersion medium of white oil and silicone oil (volume ratio 1:1), and after high-speed stirring (500 to 2000 rpm), the mixture is placed in cooled hexane to form spherical magnesium chloride alcoholate particles, which are washed and dried to obtain a spherical carrier.

[0132] Preparation Example 2

[0133] This preparation example is used to illustrate the preparation of the main catalyst component.

[0134] In a 300mL stirred glass reaction bottle fully replaced with high-purity nitrogen, add 100mL of titanium tetrachloride, cool to -20°C, add 8g of the spherical carrier prepared in Preparation Example 1, slowly heat to 110°C, add 6mmol of 2-isopropyl-2-isopentyl-1,3-dimethoxypropane as an internal electron donor during the heating process, keep constant temperature at 110°C for 0.5h, obtain a solid-liquid mixture, filter out the liquid to obtain a solid, mix and filter the solid twice with titanium tetrachloride, then wash five times with hexane, and vacuum dry to obtain a titanium-containing solid catalyst component Z1, the titanium content in Z1 is 2.4wt%.

[0135] Preparation Example 3

[0136] This preparation example is used to illustrate the preparation of the main catalyst component.

[0137] In a reactor that has been repeatedly replaced with high-purity nitrogen, add 7.2g of anhydrous magnesium chloride, 60mL of toluene, 6.0mL of epichlorohydrin, and 36mL of tributyl phosphate in sequence, and stir at 350rpm for 2 hours at 60°C. Then add 2.0g of phthalic anhydride and continue stirring at 60°C for 1 hour to obtain a solution. Cool the solution to 5°C and increase the stirring speed to 400rpm. Add 3.5g of T602 and 20g of food-grade No. 100 white oil (kinematic viscosity (40°C) at 100mm 2 / s), 73mL of titanium tetrachloride was dripped into the solution within 60min. After the addition was completed, it was maintained for 1 hour and the temperature was gradually raised to 80°C. During the heating process, 6mmol of 9,9-dimethoxymethylfluorene was added, and the temperature was raised to 85°C and maintained for 1 hour to obtain a solid-liquid mixture I. After filtering the clear liquid, a solid I was obtained. The solid I was washed 2 times with 200mL of toluene. The solid I was mixed with 120mL of toluene and 80mL of titanium tetrachloride, and treated at 110°C for 0.5 hours to obtain a solid-liquid mixture II. The filtrate was removed to obtain a solid II. The solid II was mixed with 120mL of toluene and 80mL of titanium tetrachloride, and treated at 110°C for 0.5 hours to obtain a solid-liquid mixture III. The filtrate was removed to obtain a solid III. After the solid III was washed 4 times with 200mL of hexane, a titanium-containing solid catalyst component Z2 was obtained after drying. The titanium content in Z2 was 2.5wt%.

[0138] Preparation Example 4

[0139] This preparation example is used to illustrate the preparation of the main catalyst component.

[0140] In a 300mL stirred glass reaction bottle fully replaced with high-purity nitrogen, add 100mL of titanium tetrachloride, cool to -20°C, add 8g of the spherical carrier prepared in Preparation Example 1, slowly heat to 110°C, add 6mmol of 2,3-diisopropylsuccinic acid diethyl ester as an internal electron donor during the heating process, and keep the temperature at 110°C for 0.5h to obtain a solid-liquid mixture. Filter the liquid to obtain a solid, then mix and filter the solid twice with titanium tetrachloride, then wash five times with hexane, and vacuum dry to obtain a titanium-containing solid catalyst component Z3. The titanium content in Z3 is 4.1wt%.

[0141] Preparation Example 5

[0142] This preparation example is used to illustrate the preparation of the main catalyst component.

[0143] In a 300mL stirred glass reaction bottle fully replaced with high-purity nitrogen, add 100mL of titanium tetrachloride, cool to -20°C, add 8g of the spherical carrier prepared in Preparation Example 1, slowly heat to 110°C, add 3mmol of 2,3-diisopropylsuccinic acid diethyl ester and 3mmol of 2-isopropyl-2-isopentyl-1,3-dimethoxypropane as internal electron donors during the heating process, and keep at 110°C for 0.5h to obtain a solid-liquid mixture. Filter out the liquid to obtain a solid, treat the mixed solid with titanium tetrachloride twice, then wash it with hexane five times, and obtain a titanium-containing solid catalyst component Z4 after vacuum drying. The titanium content in Z4 is 3.3wt%.

[0144] Preparation Example 6

[0145] This preparation example is used to illustrate the preparation of the main catalyst component.

[0146] In a reactor fully replaced with high-purity nitrogen, 6.0 g of magnesium chloride, 119 ml of toluene, 5 ml of epichlorohydrin, and 15.6 ml of tributyl phosphate (TBP) were added in sequence, and the temperature was raised to 50°C under stirring and maintained for 2.5 hours, and the solid was completely dissolved; 1.7 g of phthalic anhydride was added and maintained for 1 hour to obtain a solution; the solution was cooled to below -25°C, 70 ml of TiCl4 was added dropwise within 1 hour, and the temperature was slowly raised to 80°C. Solid matter was gradually precipitated during the heating process, 6 mmol of 3-methyl-2,4-pentanediol dibenzoate was added to the reactor as an internal electron donor, and the temperature was maintained for 1 hour to obtain a solid-liquid mixture I. After filtration, a solid matter I was obtained, and the solid matter was mixed with 80 ml of toluene and washed twice to obtain a solid precipitate. The solid precipitate is mixed with 60 ml of toluene and 40 ml of TiCl4, the temperature is raised to 100°C, and the mixture is treated for 2 hours to obtain a solid-liquid mixture II. After the filtrate is removed, a solid II is obtained. The solid II is then mixed with 60 ml of toluene and 40 ml of TiCl4, the temperature is raised to 100°C, and the mixture is treated for 2 hours to obtain a solid-liquid mixture III. After the filtrate is removed, a solid III is obtained. The solid III is then mixed with 60 ml of toluene, and the mixture is washed three times in a boiling state. Then 60 ml of hexane is added, and the mixture is washed twice in a boiling state. Then 60 ml of hexane is added, and the mixture is washed twice at room temperature to obtain a solid catalyst component Z5. The titanium content in Z5 is 2.6 wt%.

[0147] Examples 1-11 and Comparative Examples 1-9

[0148] Examples 1-21 and Comparative Examples 1-12 are used to illustrate the catalyst system and application thereof provided by the present invention.

[0149] In a 48-channel parallel pressure reactor (reaction volume 20 mL), a certain amount of hydrogen was filled; propylene gas was filled to about 1 MPa, and 5 mL of liquid propylene was added; triethylaluminum (calculated as aluminum element): external electron donor: main catalyst component (calculated as titanium element) was added in a molar ratio of 500:20:1 to prepare a mixed solution, and a certain amount of auxiliary agent was added to the mixed solution (the amount added is shown in Table 1); a certain amount of the mixed solution (containing 0.02 mg of the main catalyst component) was injected into the reactor; the reaction was carried out at 70°C for 1 hour to obtain a polymer, and the catalyst activity was calculated; the isotactic index, weight average molecular weight and molecular weight distribution of the polymer were determined at the same time, and the results are shown in Table 1.

[0150] Table 1

[0151]

[0152] In Table 1: D1: cyclohexylmethyldimethoxysilane; D2: 2-isopropyl-2-isopentyl-1,3-dimethoxypropane; NE1: 3-pyrroline-1-carboxylic acid benzyl ester;

[0153] NE2: tert-butyl 3-pyrroline-1-carboxylate;

[0154] NE3: methyl 2,5-dioxo-3-pyrroline-1-carboxylate;

[0155] NE4: tert-butyl 2-oxo-3-pyrroline-1-carboxylate;

[0156] NE5: 2-chloro-3-pyrroline-1-carboxylic acid ethyl ester;

[0157] NE6: 2-methyl-3-pyrroline-1-carboxylic acid ethyl ester;

[0158] It can be seen from Table 1 that after the 3-pyrroline-1-carboxylate compound provided by the present invention is added as an auxiliary agent to olefin polymerization, especially propylene polymerization system, the polymerization activity remains at a high level, the molecular weight distribution of the polymer becomes narrower, and the isotactic index decreases.

[0159] The Z1 catalyst has the characteristics of high stereospecificity and narrow polymer molecular weight distribution. It can be seen from Example 4 and Comparative Example 3 that the addition of 3-pyrroline-1-carboxylate compound can reduce the isotactic index of the polymer to below the level without adding an external electron donor, thereby expanding the adjustable range of the isotactic index of the Z1 catalyst; at the same time, the molecular weight distribution is further narrowed, maintaining and improving the narrow distribution characteristics of the polymerization product of the Z1 catalyst.

[0160] The Z3 catalyst is insensitive to hydrogen regulation and has a wide molecular weight distribution of the polymerization product. It can be seen from Example 9 and Comparative Example 6 that the addition of 3-pyrroline-1-carboxylate compound narrows the molecular weight distribution of the polymer while maintaining a high weight average molecular weight of the polymer, that is, the Z3 catalyst is insensitive to hydrogen regulation and the adjustable range of the molecular weight distribution of the polymerization product is expanded.

[0161] It can be seen from Comparative Examples 8-9 that when the internal electron donor is changed to a diol ester, the addition of a 3-pyrroline-1-carboxylate compound can increase the isotactic index of the polymer product, and the molecular weight distribution of the polymer product becomes wider. This shows that the 3-pyrroline-1-carboxylate compound, as an auxiliary agent, has different effects on the polymer product in different catalyst systems. The addition of a 3-pyrroline-1-carboxylate compound can expand the application range of the catalyst system in which the internal electron donor includes a diether or a succinate.

[0162] Examples 12-13 and Comparative Example 10

[0163] This example is used to illustrate that adding 3-pyrroline-1-carboxylate compound to the polymerization system can slow down the activity decay.

[0164] In a 48-channel parallel pressure reactor (reaction volume 20 mL), a certain amount of hydrogen was filled; propylene gas was filled to about 1 MPa, and 5 mL of liquid propylene was added; triethylaluminum (in terms of aluminum element): external electron donor in Table 2: main catalyst component (in terms of titanium element) was added in a molar ratio of 500:20:1 to prepare a mixed solution, and a certain amount of auxiliary agent was added to the mixed solution (the amount added is shown in Table 2); a certain amount of the mixed solution (containing 0.02 mg of the main catalyst component) was injected into the reactor; the reaction was carried out at 70°C for 30 minutes, 60 minutes or 90 minutes to obtain a polymer, and the mass of the polymer product was weighed.

[0165] Table 2

[0166]

[0167] In Table 2, Y30, Y60 and Y90 represent the mass of the polymerization product after polymerization for 30 minutes, 60 minutes and 90 minutes, respectively; D1: cyclohexylmethyldimethoxysilane; NE2: tert-butyl 3-pyrroline-1-carboxylate; NE4: tert-butyl 2-oxo-3-pyrroline-1-carboxylate.

[0168] It can be seen from Table 2 that after the 3-pyrroline-1-carboxylate compound provided by the present invention is added as an auxiliary agent to olefin polymerization, especially to a propylene polymerization system, the decay of the polymerization activity is significantly slowed down, and high activity can be maintained over a longer period of time, which is beneficial to brand development and industrial production.

[0169] Examples 14-17 and Comparative Example 11

[0170] This example is used to illustrate the application of 3-pyrroline-1-carboxylate compound in random copolymerization.

[0171] In a 48-channel parallel pressure reactor (reaction volume 20 ml), a hydrogen / ethylene / propylene mixed gas (the volume ratio of hydrogen:ethylene:propylene is 2:3:60) was filled, and the pressure was controlled at 0.7 MPa at 70°C; triethyl aluminum (in terms of aluminum element): external electron donor in Table 3: main catalyst component (in terms of titanium element) was added in a molar ratio of 100:4:1 to prepare a mixed solution, and a certain amount of auxiliary agent was added to the mixed solution (the amount added is shown in Table 3); a certain amount of the mixed solution (containing 0.04 mg of the main catalyst component) was injected into the reactor; and the reaction was carried out at 70°C for 40 minutes.

[0172] The material was discharged, the polymer weight was weighed, and the catalyst activity was calculated; at the same time, the ethylene content and melting point of the polymer were determined. The results are shown in Table 3.

[0173] Table 3

[0174]

[0175] In Table 3, D1: cyclohexylmethyldimethoxysilane;

[0176] NE1: benzyl 3-pyrroline-1-carboxylate;

[0177] NE2: tert-butyl 3-pyrroline-1-carboxylate;

[0178] NE3: methyl 2,5-dioxo-3-pyrroline-1-carboxylate;

[0179] NE4: tert-Butyl 2-oxo-3-pyrroline-1-carboxylate.

[0180] It can be seen from Table 3 that after the 3-pyrroline-1-carboxylate compound provided by the present invention is added as an auxiliary agent to the olefin copolymerization system, the polymerization activity is improved, the ethylene content of the polymerization product is increased, the melting point is reduced, and the copolymerization capacity and copolymer performance can be improved.

[0181] It should be noted that the embodiments described above are only used to explain the present invention and do not constitute any limitation to the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory words, rather than restrictive words. The present invention may be modified as specified within the scope of the claims of the present invention, and the present invention may be revised without departing from the scope and spirit of the present invention. Although the present invention described therein relates to specific methods, materials and embodiments, it does not mean that the present invention is limited to the specific examples disclosed therein, on the contrary, the present invention can be extended to all other methods and applications with the same functions.

Claims

1. An auxiliary agent for olefin polymerization, characterized in that: Containing a 3-pyrroline-1-carboxylate compound represented by formula (I), In formula (I), M1 and M2 are the same or different and are independently selected from hydrogen, C1-C 20 Alkyl, keto, halogen; M3 and M4 are the same or different and are independently selected from hydrogen and halogen; M1, M2, M3, M4 optionally contain substituent I; R is selected from C1-C 10 Alkyl, C2-C 10 Alkenyl, C2-C 10 Alkynyl, C3-C 12 Cycloalkyl, C6-C 20 Aryl, C7-C 20 Arylalkyl, 4-12 membered heterocycloalkyl or C5-C 20 heteroaryl; R optionally contains a substituent II, The substituent I and the substituent II are each independently selected from hydroxyl, halogen, cyano, nitro, amino, mono-C1-C 10 Alkylamino, di-C1-C 10 One or more of an alkylamino group, an aldehyde group, a carboxyl group and a heteroatom.

2. The auxiliary agent for olefin polymerization according to claim 1, characterized in that In formula (I), M1 and M2 are each independently selected from hydrogen, methyl, ethyl, isopropyl, n-butyl, tert-butyl, isobutyl, pentyl, hexyl, phenyl, keto, halogen or C1-C6 alkyl-substituted phenyl, And / or, the 3-pyrroline-1-carboxylate compound is selected from benzyl 3-pyrroline-1-carboxylate, tert-butyl 2,5-dihydropyrrole-1-carboxylate, methyl 2,5-dioxopyrrole-1-carboxylate, tert-butyl 2-oxo-5-dihydropyrrole-1-carboxylate, ethyl 2-chloro-5-dihydropyrrole-1-carboxylate, ethyl 2-methyl-3-pyrroline-1-carboxylate or ethyl 2,3-dimethyl-3-pyrroline-1-carboxylate.

3. A catalyst system for olefin polymerization containing the auxiliary agent according to claim 1 or 2.

4. The catalyst system according to claim 3, characterized in that The catalyst system includes component A and / or a reaction product of component A; The component A comprises a main catalyst component, a co-catalyst component and a 3-pyrroline-1-carboxylate compound represented by formula (I); the main catalyst component comprises magnesium, titanium, halogen and an internal electron donor; the internal electron donor is selected from a diether compound I and / or a succinate compound I; The co-catalytic component is selected from alkyl aluminum compounds.

5. The catalyst system according to claim 4, characterized in that The weight ratio of titanium element, magnesium element and internal electron donor in the main catalyst component is 1:(5-25):(2-15); And / or, the molar ratio of the 3-pyrroline-1-carboxylate compound represented by formula (I) to the main catalyst component calculated as titanium element is (0.1-1000):1, preferably (1-200):1, and more preferably (1-80):

1.

6. The catalyst system according to claim 4, characterized in that The alkyl aluminum compound is selected from the compounds represented by formula (b), AlR3 formula (b), In formula (b), R is a C1-C 20 Alkyl, preferably C1-C6 alkyl which may contain halogen atom substituents; Preferably, the alkyl aluminum compound is selected from triethylaluminum, tripropylaluminum, tri-n-butylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, triisobutylaluminum, diethylaluminum monohydrogen, diisobutylaluminum monohydrogen, diethylaluminum monochloride, diisobutylaluminum monochloride, ethylaluminum dichloride, Al(n-C6H 13 )3 and Al(n-C8H 17 )3 or more; Preferably, in the catalyst system, the molar ratio of the main catalyst component calculated as titanium element to the alkyl aluminum compound calculated as aluminum element is 1:(5-5000), preferably 1:(20-2000).

7. The catalyst system according to claim 4, 5 or 6, characterized in that The internal electron donor further comprises a second internal electron donor, and the second internal electron donor is selected from one or more of a diether compound II, a succinate compound II, an alcohol ester compound I, and an aromatic carboxylic acid ester compound I; the molar ratio of the first internal electron donor to the second internal electron donor is (100-1):(1-100); And / or, the catalyst system further comprises an external electron donor, and the external electron donor is selected from one or more of a silane compound, an alcohol ester compound II, an aromatic carboxylic acid ester compound II, a diether compound III and a succinate compound III; preferably, the molar ratio of the external electron donor to the titanium element in the main catalyst component is (0-500):1, preferably (0.01-200):1, and more preferably (0.1-100):1; Preferably, the structure of the silane compound is as shown in formula (IV): In formula (IV), R1 to R4 are the same or different and are independently selected from hydrogen, C1-C 10 Alkyl, C2-C 10 Alkenyl, C1-C 10 Alkoxy, C2-C 10 Alkenyloxy, C2-C 10 Alkynyl, C2-C 10 Alkynyloxy, C3-C 10 Cycloalkyl, C6-C 15 Aryl and amino, preferably hydrogen, C1-C6 alkyl, C3-C6 cycloalkyl, C6-C 10 The alkyl, alkenyl, alkynyl, alkoxy, alkenyloxy, alkynyloxy, cycloalkyl, aryl and amino groups may be optionally selected from halogen, C1-C6 alkyl, C3-C6 cycloalkyl, C6-C 10 The silane compound is substituted with one or more substituents of the aromatic group and the amino group; preferably, the silane compound is selected from tetramethoxysilane, tetraethoxysilane, diisopropyldimethoxysilane, isopropyltrimethoxysilane, di-n-propyldimethoxysilane, n-propyltrimethoxysilane, di-n-butyldimethoxysilane, di-tert-butyldimethoxysilane, diisobutyldimethoxysilane, cyclopentyltrimethoxysilane, dicyclopentyldimethoxysilane, cyclohexylmethyldimethoxysilane, cyclohexyldimethoxysilane, cyclohexylethyldimethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, phenyltriethoxysilane, vinylmethoxysilane, vinylethoxysilane, vinylpropoxysilane, vinyldimethoxysilane, vinyldiethoxysilane, vinyldipropoxysilane, vinyltrimethoxysilane At least one of methoxysilane, vinyltriethoxysilane, vinyltripropoxysilane, allylmethoxysilane, allylethoxysilane, allylpropoxysilane, allyldimethoxysilane, allyldiethoxysilane, allyldipropoxysilane, allyltrimethoxysilane, allyltriethoxysilane, allyltripropoxysilane, aminotrimethylsilane, aminotriethylsilane, aminotripropylsilane, aminotri-n-butylsilane, aminotriisobutylsilane, methylaminotrimethylsilane, methylaminotriethylsilane, methylaminotripropylsilane, methylaminotri-n-butylsilane, methylaminotriisobutylsilane, ethylaminotrimethylsilane, ethylaminotriethylsilane, ethylaminotripropylsilane, ethylaminotri-n-butylsilane and ethylaminotriisobutylsilane.

8. The catalyst system according to claim 7, characterized in that The diether compound I, diether compound II and diether compound III are independently selected from 1,3-diether compounds represented by formula (II). In formula (II), R Ⅰ , R Ⅱ , R Ⅲ , R Ⅳ , R Ⅴ and R Ⅵ are the same or different, each independently selected from hydrogen, halogen, C1-C 20 Alkyl, C3-C 20 Cycloalkyl, C6-C 20 Aryl, C7-C 20 Arylalkyl and C7-C 20 Alkaryl; R Ⅶ and R Ⅷ The same or different, each independently selected from C1-C 20 Alkyl, C3-C 20 Cycloalkyl, C6-C 20 Aryl, C7-C 20 Arylalkyl and C7-C 20 Alkaryl; R Ⅰ , R Ⅱ , R Ⅲ , R Ⅳ , R Ⅴ , R Ⅵ , R Ⅶ and R Ⅷ Optionally contain one or more substituents III; the one or more substituents III are each independently selected from C1-C 10 Alkyl, C1-C 10 Alkoxy, hydroxy, halogen, cyano, nitro, amino, mono-C1-C 10 Alkylamino, di-C1-C 10 Alkylamino, aldehyde, carboxyl and heteroatoms; and / or, R Ⅰ , R Ⅱ , R Ⅲ , R Ⅳ , R Ⅴ and R Ⅵ Two or more of them are bonded to each other to form a saturated or unsaturated monocyclic or polycyclic ring; Preferably, R Ⅰ , R Ⅱ , R Ⅲ , R Ⅳ , R Ⅴ and R Ⅵ are the same or different, each independently selected from hydrogen, halogen, C1-C 18 Alkyl, C3-C 18 Cycloalkyl, C6-C 18 Aryl, C7-C 18 Arylalkyl and C7-C 18 Alkaryl; Preferably, R Ⅰ , R Ⅱ , R Ⅲ , R Ⅳ , R Ⅴ and R Ⅵ are the same or different, each independently selected from hydrogen, halogen, C1-C 10 Alkyl, C3-C 10 Cycloalkyl, C6-C 10 Aryl, C7-C 10 Arylalkyl and C7-C 10 Alkaryl; Preferably, R Ⅶ and R Ⅷ are the same or different, each independently selected from hydrogen, halogen, C1-C 10 Alkyl, C3-C 10 Cycloalkyl, C6-C 10 Aryl, C7-C 10 Arylalkyl and C7-C 10 Alkaryl; Preferably, R Ⅶ and R Ⅷ are independently selected from hydrogen, halogen, C1-C 10 Alkyl, C3-C 10 Cycloalkyl, C6-C 10 Aryl, C7-C 10 Arylalkyl and C7-C 10 Alkaryl; Preferably, the 1,3-diether compound represented by formula (II) is selected from 2-isopropyl-2-isopentyl-1,3-dimethoxypropane, 2-(2-ethylhexyl)-1,3-dimethoxypropane, 2-isopropyl-1,3-dimethoxypropane, 2-butyl-1,3-dimethoxypropane, 2-sec-butyl-1,3-dimethoxypropane, 2-cyclohexyl-1,3-dimethoxypropane, 2-phenyl-1,3-dimethoxypropane, 2-(2-phenylethyl)-1,3-dimethoxypropane, 2-(2-cyclohexylethyl)-1,3-dimethoxypropane, 2-(p-chlorophenyl)-1,3-dimethoxypropane, 2-(diphenylmethyl)-1,3-dimethoxypropane, 2-(1-naphthyl)- 1,3-dimethoxypropane, 2-(2-fluorophenyl)-1,3-dimethoxypropane, 2,2-dicyclohexyl-1,3-dimethoxypropane, 2,2-dicyclopentyl-1,3-dimethoxypropane, 2,2-diethyl-1,3-dimethoxypropane, 2,2-dipropyl-1,3-dimethoxypropane, 2,2-diisopropyl-1,3-dimethoxypropane, 2,2-dibutyl-1,3-dimethoxypropane, 2-methyl-2-propyl-1,3-dimethoxypropane, 2-methyl-2-benzyl-1,3-dimethoxypropane, 2-methyl-2-ethyl-1,3-dimethoxypropane, 2-methyl-2-isopropyl-1,3-dimethoxypropane, 2-methyl-2-phenyl-1,3-dimethoxypropane Methoxypropane, 2-methyl-2-cyclohexyl-1,3-dimethoxypropane, 2,2-bis(p-chlorophenyl)-1,3-dimethoxypropane, 2,2-bis(2-cyclohexylethyl)-1,3-dimethoxypropane, 2-methyl-2-isobutyl-1,3-dimethoxypropane, 2-methyl-2-(2-ethylhexyl)-1,3-dimethoxypropane, 2,2-diisobutyl-1,3-dimethoxypropane, 2,2-diphenyl-1,3-dimethoxypropane, 2,2-dibenzyl-1,3-dimethoxypropane, 2,2-bis(cyclohexylmethyl)-1,3-dimethoxypropane, 2-isobutyl-2-isopropyl-1,3-dimethoxypropane, 2-(1-methylbutyl)-2-isopropyl -1,3-dimethoxypropane, 2-(1-methylbutyl)-2-sec-butyl-1,3-dimethoxypropane, 2,2-di-sec-butyl-1,3-dimethoxypropane, 2,2-di-tert-butyl-1,3-dimethoxypropane, 2,2-dineopentyl-1,3-dimethoxypropane, 2-isopropyl-2-isopentyl-1,3-dimethoxypropane, 2-isopropyl-2-phenyl-1,3-dimethoxypropane, 2-phenyl-2-sec-butyl-1,3-dimethoxypropane, 2-isopropyl-2-benzyl-1,3-dimethoxypropane, 2-isopropyl-2-cyclopentyl-1,3-dimethoxypropane, 2-cyclopentyl-2-sec-butyl-1,3-dimethoxypropane, 2-cyclohexyl-2-isopropyl-1,3-dimethoxypropane, 2-sec-butyl-2-cyclohexyl-1,3-dimethoxypropane, 2-isopropyl-2-sec-butyl-1,3-dimethoxypropane, 2-cyclohexyl-2-cyclohexylmethyl-1,3-dimethoxypropane, 1,1-bis(methoxymethyl)-cyclopentadiene, 1,1-bis(methoxymethyl)-2,3,4,5,-tetramethylcyclopentadiene, 1,1-bis(methoxymethyl)-2,3,4,5,-tetramethylcyclopentadiene, 1,1-bis(methoxymethyl)-2,3,4,5,-tetraphenylcyclopentadiene, 1,1-bis(methoxymethyl)-2,3,4,5,-tetrafluorocyclopentadiene, 1,1-bis(methoxymethyl)-3,4-dicyclopentylcyclopentadiene, 1,1-bis(methoxymethyl)indene, 1,1-bis(methoxymethyl)-2,3-dimethoxyindene, 1,1-bis(methoxymethyl)-2,3,6,7-tetrafluoroindene, 1,1-bis(methoxymethyl)-4,5,6,7-tetrafluoroindene, 1,1-bis(methoxymethyl)-4,7-dimethylindene, 1,1-bis(methoxymethyl)-3,6-dimethylindene, 1,1-bis(methoxymethyl)-4-phenylindene, 1,1-bis(methoxymethyl)-4-phenyl-2-methylindene, 1,1-bis(methoxymethyl)-4-tetracyclohexylindene, 1,1-bis(methoxymethyl)-7-(3,3,3-trifluoropropyl)phenylindene, 1,1-bis(methoxymethyl)-7-cyclopentylindene , 1,1-bis(methoxymethyl)-7-isopropylindene, 1,1-bis(methoxymethyl)-7-cyclohexylindene, 1,1-bis(methoxymethyl)-7-tert-butylindene, 1,1-bis(methoxymethyl)-7-tert-butyl-2-methylindene, 1,1-bis(methoxymethyl)-7-phenylindene, 1,1-bis(methoxymethyl)-2-phenylindene, 9,9-bis(methoxymethyl)fluorene, 9,9-bis(methoxymethyl)-2,7-dicyclopentylfluorene, 9,9-bis(methoxymethyl)-1,8-dichlorofluorene, 9,9-bis(methoxymethyl)-1,8-difluorofluorene, 9,9-bis(methoxymethyl)-1,2,3,4-tetrahydrofluorene, 9,9-bis(methoxymethyl)- at least one of 4-tert-butylfluorene, 1,1-bis-(methoxymethyl)-2,5-cyclohexadiene, 1,1-bis-(methoxymethyl)-benzonaphthalene, 7,7-bis-(methoxymethyl)-2,5-norbornadiene, 9,9-bis-(methoxymethyl)-1,4-methanedihydronaphthalene, 9,9-bis-(methoxymethyl)-1,4-methanedihydroanthracene, 4,4-bis-(methoxymethyl)-1-phenyl-1,4-dihydronaphthalene, 4,4-bis-(methoxymethyl)-1-phenyl-3,4-dihydronaphthalene, 5,5-bis-(methoxymethyl)-1,3,6-cycloheptatriene and 1-methoxymethyl-1-(1'-methoxyethyl)-2,3,4,5-tetramethylcyclopentadiene; and / or, the alcohol ester compound I and the alcohol ester compound II are each independently selected from the diol ester compound represented by formula (a) or the diol ester compound represented by formula (VI), In formula (a), R'1 and R'2 are the same or different and are independently selected from C1-C 10 Alkyl, C2-C 10 Alkenyl, C2-C 10 Alkynyl, C3-C 20 Cycloalkyl, C6-C 20 Aryl, C7-C 20 Arylalkyl and C7-C 20 Alkaryl is preferably selected from C1-C6 alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C3-C 10 Cycloalkyl, C6-C 10 Aryl, C7-C 10 Arylalkyl and C7-C 10 Alkaryl, wherein the alkyl, alkenyl, cycloalkyl, aryl, aralkyl or alkaryl is optionally substituted with one or more substituents selected from halogen, C1-C6 alkyl and C1-C6 alkoxy; R'3, R'4, R'5, R'6 and R' 1 -R' 2n are the same or different, each independently selected from hydrogen, halogen, C1-C 20 Alkyl, C2-C 10 Alkenyl, C2-C 10 Alkynyl, C3-C 20 Cycloalkyl, C6-C 20 Aryl, C7-C 20 Alkyl, C7-C 20 Aralkyl and C 10 -C 20 The fused ring aromatic group is preferably selected from hydrogen, halogen, C1-C 10 Alkyl, C2-C6 alkenyl, C2-C6 alkynyl, C3-C 10 Cycloalkyl, C6-C 10 Aryl, C7-C 10 Alkyl, C7-C 10 Aralkyl and C 10 -C 15 The alkyl, alkenyl, alkynyl, cycloalkyl, aryl, alkaryl, aralkyl and condensed ring aryl are optionally substituted by one or more substituents selected from halogen, C1-C6 alkyl and C1-C6 alkoxy; R'3, R'4, R'5, R'6 and R' 1 -R' 2n Optionally contain heteroatoms, the heteroatoms are one or more of nitrogen, oxygen, sulfur, silicon, halogen and phosphorus; or, R'3, R'4, R'5, R'6 and R' 1 -R' 2n wherein two or more of the substituents R'3 and R'4 are bonded to each other to form a saturated or unsaturated monocyclic ring or a saturated or unsaturated polycyclic ring; wherein n is an integer of 0 to 10, preferably an integer of 1 to 8, more preferably an integer of 2 to 6, and when n is 0, the carbon atoms of the substituents R'3 and R'4 are bonded to the carbon atoms of the substituents R'5 and R'6; the bracketed portion indicates that n carbon atoms are bonded in sequence, and each carbon atom is also bonded to two substituents, that is, there are n carbon atoms and R' in the brackets. 1 , R' 2 , R' 3 …R' 2n etc. 2n substituents; In formula (VI), R 1 and R 2 The same or different, each independently selected from C1-C 20 Alkyl, C2-C 20 Alkenyl, C2-C 20 Alkynyl, C3-C 20 Cycloalkyl, C6-C 20 Aryl, C7-C 20 Alkyl, C7-C 20 Arylalkyl and C with or without substituents 10 -C 20 The fused ring aromatic groups are preferably independently selected from C1-C 10 Alkyl, C2-C 10 Alkenyl, C3-C 10 Cycloalkyl, C6-C 10 Aryl, C7-C 10 Alkyl, C7-C 10 Arylalkyl and C with or without substituents 10 -C 15 The condensed ring aromatic group, wherein the substituent is selected from one or more of a hydroxyl group, a halogen atom, a cyano group, a nitro group, an amino group, a mono-C1-C6 alkylamino group, a di-C1-C6 alkylamino group, an aldehyde group, a carboxyl group and a heteroatom; M is a divalent linking group, preferably selected from a C1-C6 alkylamino group with or without a substituent. 20 Alkylene, C3-C 20 Cycloalkylene and C6-C 20 Arylene, the substituent is selected from nitrogen, oxygen, sulfur, silicon, phosphorus, halogen atoms and C1-C 20 Alkyl, when the substituent is multiple C1-C 20 When alkyl, the substituents are optionally bonded to form one or more rings; Preferably, the diol ester compound represented by formula (a) and the diol ester compound represented by formula (VI) are selected from 2,4-pentanediol dibenzoate, 3-methyl-2,4-pentanediol dibenzoate, 3,5-heptanediol dibenzoate, 4-ethyl-3,5-heptanediol dibenzoate, 3,5-heptanediol di-p-methylbenzoate, 3,5-heptanediol di-o-methylbenzoate, 3,5-heptanediol di-p-chlorobenzoate, 3,5-heptanediol di-o-chlorobenzoate, 3,5-heptanediol di-p-methoxybenzoate, 3,5-heptanediol di-o-methoxybenzoate, 3,5-heptanediol di-m-methoxybenzoate, 2-methyl-3,5-heptanediol dibenzoate, 4-methyl-3,5-heptanediol dibenzoate, 6- Methyl-3,5-heptanediol dibenzoate, 4-ethyl-3,5-heptanediol dibenzoate, 5-ethyl-3,5-heptanediol dibenzoate, 4-propyl-3,5-heptanediol dibenzoate, 4-butyl-3,5-heptanediol dibenzoate, 2,4-dimethyl-3,5-heptanediol dibenzoate, 2,6-dimethyl-3,5-heptanediol dibenzoate, 4,4-dimethyl-3,5-heptanediol dibenzoate, 6,6-dimethyl-3,5-heptanediol dibenzoate, 4,6-dimethyl-3,5-heptanediol dibenzoate, 4,4-dimethyl-3,5-heptanediol dibenzoate, 6,6-dimethyl-3,5-heptanediol dibenzoate, 2-methyl-4-ethyl-3, 5-heptanediol dibenzoate, 4-methyl-4-ethyl-3,5-heptanediol dibenzoate, 2-methyl-4-propyl-3,5-heptanediol dibenzoate, 4-methyl-4-propyl-3,5-heptanediol dibenzoate, 6-methyl-2,4-heptanediol di(p-chlorobenzoate), 6-methyl-2,4-heptanediol di(p-methylbenzoate), 6-methyl-2,4-heptanediol di(m-methylbenzoate), 2,2,6,6-tetramethyl-3,5-heptanediol dibenzoate, 4-methyl-3,5-octanediol dibenzoate, 4-ethyl-3,5-octanediol dibenzoate, 4-propyl-3,5-octanediol dibenzoate, 4-butyl-3,5-octanediol dibenzoate, 4-Dimethyl-3,5-octanediol dibenzoate, 4-methyl-4-ethyl-3,5-octanediol dibenzoate, 2-methyl-4-ethyl-3,5-octanediol dibenzoate, 2-methyl-6-ethyl-3,5-octanediol dibenzoate, 5-methyl-4,6-nonanediol dibenzoate, 5-ethyl-4,6-nonanediol dibenzoate, 5-propyl-4,6-nonanediol dibenzoate, 5-butyl-4,6-nonanediol dibenzoate, 5,5-dimethyl-4,6-nonanediol dibenzoate, 5-methyl-4-ethyl-4,6-nonanediol dibenzoate, 5-phenyl-4,6-nonanediol dibenzoate, 4,6-nonanediol dibenzoate and 4-butyl-3,5-heptanediol dibenzoate, 1,2-phenylene dibenzoate, 3-methyl-5-tert-butyl-1,2-phenylene dibenzoate, 3,5-diisopropyl-1,2-phenylene dibenzoate, 3,6-dimethyl-1,2-phenylene dibenzoate, 4-tert-butyl-1,2-phenylene dibenzoate, 1,2-naphthalene dibenzoate, 2,3-naphthalene dibenzoate, 1,8-naphthyl dibenzoate, 1,8-naphthyl dibenzoate, 1,8-naphthyl dibenzoate, 1,3-naphthyl dibenzoate, 1,2-naphthyl dibenzoate, 1,8-naphthyl dibenzoate, 1,2-naphthyl dibenzoate, 1,8-naphthyl dibenzoate, 1,2-naphthyl dibenzoate, 1,2-naphthyl dibenzoate, 1,2-naphthyl dibenzoate, 1,8-naphthyl dibenzoate, 1,2-naphthyl dibenzoate 8-naphthyl ester, di-4-ethylbenzoic acid-1,8-naphthyl ester, di-4-n-propylbenzoic acid-1,8-naphthyl ester, di-4-isopropylbenzoic acid-1,8-naphthyl ester, di-4-n-butylbenzoic acid-1,8-naphthyl ester, di-4-isobutylbenzoic acid-1,8-naphthyl ester, di-4-tert-butylbenzoic acid-1,8-naphthyl ester, di-4-phenylbenzoic acid-1,8-naphthyl ester, di-4-fluorobenzoic acid-1,8-naphthyl ester, di-3-fluorobenzoic acid-1,8-naphthyl ester and di-2-fluorobenzoic acid-1,8-naphthyl ester; and / or, the aromatic carboxylate compound I and the aromatic carboxylate compound II are each independently selected from the aromatic carboxylate compound represented by formula (VII), In formula (VII), each R 3 the same or different, each independently selected from C1-C8 alkyl groups which may or may not contain substituents selected from C1-C6 alkyl groups and halogen atoms, C5-C6 alkyl groups which may or may not contain substituents selected from C1-C6 alkyl groups and halogen atoms 10 Cycloalkyl, C6-C6 alkyl or C1-C6 alkyl substituents selected from C1-C6 alkyl and halogen atoms 15 an aryl group, a C7-C6 alkyl group which may or may not contain a substituent selected from a C1-C6 alkyl group and a halogen atom; 15 an alkylaryl group or a C7-C6 alkyl group which may or may not contain a substituent selected from a C1-C6 alkyl group and a halogen atom; 15 R4-R7 may be the same or different and are independently selected from hydrogen, halogen, C1-C8 alkyl containing or not containing substituents selected from C1-C6 alkyl and halogen atoms, C5-C 10 Cycloalkyl, C6-C6 alkyl or C1-C6 alkyl substituents selected from C1-C6 alkyl and halogen atoms 20 an aryl group, a C7-C6 alkyl group which may or may not contain a substituent selected from a C1-C6 alkyl group and a halogen atom; 20 an alkylaryl group or a C7-C6 alkyl group which may or may not contain a substituent selected from a C1-C6 alkyl group and a halogen atom; 20 Aralkyl; preferably, the aromatic carboxylate compound represented by formula (VII) is phthalic acid carboxylate; more preferably, at least one of diethyl phthalate, dipropyl phthalate, diisobutyl phthalate, di-n-butyl phthalate, dipentyl phthalate, dihexyl phthalate, diheptyl phthalate and dioctyl phthalate; And / or, the succinate compound I, the succinate compound II, and the succinate compound III are each independently selected from the succinate compounds represented by formula (III), In formula (III), R"1, R"2, R"3, R"4, R"5 and R"6 are the same or different and are each independently selected from C1-C 20 Alkyl, C3-C 20 Cycloalkyl, C6-C 20 Aryl, C7-C 20 Arylalkyl or C7-C 20 The alkylaryl group, R"1, R"2, R"3, R"4, R"5 and R"6 optionally contain halogen or heteroatom; R"3, R"4, R"5 and R"6 groups may be optionally connected to form a ring; preferably, the succinate compound represented by formula (III) is selected from 2,3-bis(2-ethylbutyl)succinic acid diethyl ester, 2,3-diethyl-2-isopropylsuccinic acid diethyl ester, 2,3-diisopropylsuccinic acid diethyl ester, 2,3-di-tert-butylsuccinic acid diethyl ester, 2,3-diisobutylsuccinic acid diethyl ester, 2,3-(bistrimethylsilyl)succinic acid diethyl ester, 2-(3,3,3-trifluoropropyl)-3-methylsuccinic acid diethyl ester, esters, 2,3-dineopentylsuccinic acid diethyl ester, 2,3-diisopentylsuccinic acid diethyl ester, 2,3-(1-trifluoromethyl-ethyl)succinic acid diethyl ester, 2-isopropyl-3-isobutylsuccinic acid diethyl ester, 2-tert-butyl-3-isopropylsuccinic acid diethyl ester, 2-isopropyl-3-cyclohexylsuccinic acid diethyl ester, 2-isopentyl-3-cyclohexylsuccinic acid diethyl ester, 2,2,3,3-tetramethylsuccinic acid diethyl ester, 2,2,3,3-tetraethylsuccinic acid diethyl ester, 2,2,3,3-tetrapropylsuccinic acid diethyl ester, 2,3-diethyl-2,3-diisopropyldisuccinic acid diethyl ester, 2,3-bis(2-ethyl diisobutyl 2,3-diethyl-2-isopropylsuccinate, diisobutyl 2,3-diisopropylsuccinate, diisobutyl 2,3-di-tert-butylsuccinate, diisobutyl 2,3-diisobutylsuccinate, diisobutyl 2,3-(bistrimethylsilyl)succinate, diisobutyl 2-(3,3,3-trifluoropropyl)-3-methylsuccinate, diisobutyl 2,3-dineopentylsuccinate, diisobutyl 2,3-diisopentylsuccinate, diisobutyl 2,3-(1-trifluoromethyl-ethyl)succinate, diisobutyl 2-isopropyl-3-isobutylsuccinate, 2-tert-butyl-3-isopropylsuccinate diisobutyl ester, diisobutyl 2-isopropyl-3-cyclohexylsuccinate, diethyl 2,3-diisopropyl 2-cyanosuccinate, diisobutyl 2-isopentyl-3-cyclohexylsuccinate, diisobutyl 2,2,3,3-tetramethylsuccinate, diisobutyl 2,2,3,3-tetraethylsuccinate, diisobutyl 2,2,3,3-tetrapropylsuccinate, diisobutyl 2,3-diethyl-2,3-diisopropyldisuccinate; preferably one or more selected from diethyl 2,3-diisopropylsuccinate, diethyl 2,3-di-tert-butylsuccinate, diethyl 2,3-diisobutylsuccinate and diisobutyl 2,3-diisopropylsuccinate.

9. A prepolymerized catalyst composition comprising a prepolymer obtained by polymerizing the catalyst system according to any one of claims 3 to 8 with an olefin; the prepolymer has a prepolymer multiple of 0.1 to 1000 g prepolymer / g of the main catalyst component, preferably 0.2 to 500 g prepolymer / g of the main catalyst component, and more preferably 0.5 to 20 g prepolymer / g of the main catalyst component; The general formula of the olefin is CH2=CHR, wherein R is hydrogen or C1-C7 alkyl; The olefin is preferably propylene; Prepolymerization with propylene or a mixture thereof with up to 20% by mole of one or more alpha-olefins; The temperature of the prepolymerization reaction is -20 to 80°C, and the polymerization pressure is preferably 0 to 5 MPa; Preferably, the temperature of the prepolymerization reaction is 0 to 50°C; Preferably, the prepolymerization of the catalyst and the olefin is carried out independently in a batch operation, and the polymerization pressure is 0 to 5 MPa.

10. An olefin polymerization method, wherein an olefin polymerization reaction occurs in the catalyst system according to any one of claims 3 to 8; preferably, the polymerization reaction conditions include: The temperature is 0°C to 150°C, preferably 50°C to 90°C; the pressure is 0.01MPa to 10MPa, preferably 0.1MPa to 5MPa; the time is 0.1h to 5h, preferably 0.2h to 3h; the general formula of the olefin is CH2=CHR, wherein R is hydrogen or a C1-C7 alkyl; preferably the olefin contains ethylene and propylene, and the volume ratio of ethylene:propylene is (0.1 to 20):100.

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