CN114478861A - Catalyst component for olefin polymerization, preparation method thereof, catalyst, method for preparing ultrahigh molecular weight polyolefin and application - Google Patents

Abstract

The invention belongs to the technical field of olefin polymerization catalysts, and discloses a catalyst component for olefin polymerization, a preparation method thereof, a catalyst, a method for preparing ultrahigh molecular weight polyolefin and application thereof. The catalyst component comprises a magnesium compound, an organic acid anhydride compound, an acetate compound, a titanium-containing compound, an electron donor a and a reaction product of an electron donor b, wherein the electron donor a is selected from at least one of compounds shown in a general formula (I) and a general formula (II), and the electron donor b is selected from at least one of compounds shown in a general formula (III) and a general formula (IV). The invention introduces organic acid anhydride compounds, acetate compounds, electron donors a and b as compound electron donors into an N-type polyolefin catalyst preparation system, and olefin polymerization can be carried out to obtain the productTo spherical/ellipsoidal ultrahigh molecular weight polyolefin having a viscosity average molecular weight of more than 700 ten thousand, and has a narrow particle size distribution and a high bulk density.

Description

Catalyst component for olefin polymerization, preparation method thereof, catalyst, method for preparing ultrahigh molecular weight polyolefin and application

Technical Field

The invention belongs to the technical field of olefin polymerization catalysts, and particularly relates to a catalyst component for olefin polymerization, a preparation method of the catalyst component, a catalyst for olefin polymerization, a method for preparing ultrahigh molecular weight polyolefin and application of the catalyst component.

Background

Ultra High Molecular Weight Polyethylene (UHMWPE) is a special polyethylene variety with molecular weight greater than 150 ten thousand. At present, most commercial UHMWPE is prepared by a Ziegler-Natta catalyst (Z-N catalyst for short), and has the comprehensive properties of wear resistance, impact resistance, self lubrication, corrosion resistance, low temperature resistance, sanitation, no toxicity, difficult adhesion, difficult water absorption, small density and the like which are incomparable with common polyethylene and other engineering plastics.

The compression molding process is one of the main processing methods of UHMWPE, and is to put the polymerized powder into the cavity of a mold, close the mold, raise the temperature and pressure to solidify and mold the polymerized powder, and can be used for producing filter press plates and products with various shapes. The UHMWPE filter press plate is a main accessory of a filter press, and the equipment is widely applied to the fields of coal dressing, metallurgy, sewage treatment and the like which need solid-liquid separation. The use effect of the filter press is directly related to the performance of the filter press plate, which depends on the aperture size and the aperture uniformity of the filter press plate, and the shape, the particle size and the particle size distribution of the UHMWPE powder directly influence the performance of the filter press plate. The polymer powder should therefore have a narrow particle size distribution and a good particle shape. For various shaped articles, the surface smoothness directly affects the appearance of the article, so it is necessary to control the content of large particles in the polymer powder to avoid the formation of projections on the surface of the article.

Furthermore, the bulk density and flowability of the UHMWPE powder particles directly influence the operation of the production plant. Therefore, it is required that the powder particles have a higher bulk density and a better flowability.

In view of the above, spherical/ellipsoidal ultra high molecular weight polyethylene powders with narrow particle size distribution and high bulk density have the best application value, and this requires the development of high performance Ziegler-Natta type polyethylene catalysts.

The Ziegler-Natta type olefin polymerization catalyst particles have the specific ability to replicate morphology to the polyolefin powder particles they produce. For example, spherical/ellipsoidal catalyst particles generally produce spherical/ellipsoidal frit particles, and high porosity catalyst particles generally produce high porosity frit particles. The spherical/ellipsoidal polyolefin powder particles have good fluidity, and if a simple method for preparing the powder particles can be found, the method has good industrial prospect. The dissolution precipitation type catalyst has short preparation process and strong controllability, thereby being a better choice. The N series polyolefin catalyst of Beijing chemical research institute is a typical representative of the dissolution precipitation type catalyst. Such catalyst particles are non-spherical (as shown in FIG. 1), and the particle size is usually less than 50 μm, and the powder particles obtained by ethylene polymerization are also non-spherical (as shown in FIGS. 2 and 3). If one wants to prepare narrow-distribution, spherical/ellipsoidal shaped N-type polyolefin-like catalyst particles, it is necessary to achieve precise control of the precipitation formation of the catalyst particles. For example, when an organic acid anhydride/acetic ester/cyclic ketone compound is introduced into a system as a complex electron donor in patent document CN201410531766.2, spherical/ellipsoidal N-type polyolefin catalyst particles are prepared for the first time. The catalyst can obtain spherical/ellipsoidal powder particles after ethylene slurry polymerization/copolymerization. However, the above spherical/ellipsoidal N-type polyethylene catalyst cannot prepare an ultrahigh molecular weight polyethylene powder having a viscosity average molecular weight of more than 500 ten thousand.

Disclosure of Invention

In view of the above situation, the inventors of the present invention have found through research that the addition of electron donors having specific structures, namely electron donor a and electron donor b having specific general formulas, can reduce the active sites of the low molecular weight PE component generated by the Z-N catalyst, thereby increasing the molecular weight of the polymerization product. The spherical/ellipsoidal N-type polyethylene catalyst introduced with the electron donor a and the electron donor b can produce spherical/ellipsoidal ultrahigh molecular weight polyethylene powder with viscosity average molecular weight of more than 700 ten thousand, narrow particle size distribution and high bulk density (the bulk density is more than or equal to 0.44g/mL and the span value is less than 0.8). Based on the above, the invention aims to provide a catalyst component for olefin polymerization, a preparation method thereof, a catalyst, a method for preparing ultrahigh molecular weight polyolefin and application thereof.

The first aspect of the present invention provides a catalyst component for olefin polymerization, which comprises a magnesium-containing compound, an organic acid anhydride compound, an acetate compound, a titanium-containing compound, an electron donor a and a reaction product of an electron donor b, wherein the electron donor a is at least one selected from compounds represented by general formulas (i) and (ii), and the electron donor b is at least one selected from compounds represented by general formulas (iii) and (iv):

in the formula (I), R₁And R₂Independently is methyl or ethyl, R₃And R₄Independently hydrogen or methyl;

in the formula (II), R₉And R₁₀Independently is methyl or ethyl, R₁₁、R₁₂、R₁₃And R₁₄Same or different, independently hydrogen, halogen, C₁-C₁₀Straight chain alkyl group of (1), C₁-C₁₀Branched alkyl or C₁-C₁₀Alkoxy group of (a);

in the formula (III), M₁、M₂、M₃、M₄、M₅And M₆The same or different, each being selected from hydrogen, hydroxyl, amino, aldehyde, carboxyl, acyl, halogen atom, -R₁' OR-OR₂', wherein R₁' and R₂' each is substituted or unsubstituted C₁-C₁₀A hydrocarbyl group, the substituent being selected from a hydroxyl group, an amino group, an aldehyde group, a carboxyl group, an acyl group, a halogen atom, an alkoxy group or a heteroatom;

in the formula (IV), N₁、N₂、N₃、N₄、N₅、N₆、N₇And N₈The same or different, each being selected from hydrogen, hydroxyl, amino, aldehyde, carboxyl, acyl, halogen atom, -R₃' OR-OR₄', wherein R₃' and R₄' each is substituted or unsubstituted C₁-C₁₀The substituent is selected from hydroxyl, amino, aldehyde group, carboxyl, acyl, halogen atom, alkoxy or hetero atom.

The second aspect of the present invention provides the above-mentioned method for preparing a catalyst component for olefin polymerization, comprising the steps of:

s1, dissolving magnesium halide in a solvent system containing an organic epoxy compound and an organic phosphorus compound to form a uniform solution;

s2, reacting the solution obtained in the step S1 with an organic acid anhydride compound and an acetate compound, then contacting with a titanium compound, and then heating to separate out magnesium/titanium-containing solid particles;

s3, adding an electron donor a and an electron donor b into the reaction system obtained in the step S2, and carrying out constant temperature treatment to obtain a mixture;

s4, removing unreacted substances and the solvent from the mixture obtained in the step S3, and washing to obtain the solid catalyst component.

A third aspect of the present invention provides a catalyst for olefin polymerization, the catalyst comprising the following components:

A) the method comprises the following steps The catalyst component described above or the catalyst component prepared by the above preparation method;

B) the method comprises the following steps The general formula is AlR'_dX’_3-dWherein R' is hydrogen or C_l-C₂₀A hydrocarbon group, X' is a halogen atom, preferably fluorine, chlorine or bromine, 0 < d.ltoreq.3.

A fourth aspect of the present invention provides a method for preparing an ultrahigh molecular weight polyolefin, the method comprising: reacting one or more olefins of the formula CH in the presence of the above-described catalyst₂Wherein R is hydrogen or C₁-C₆Alkyl group of (1).

The fifth aspect of the present invention provides the use of the above catalyst component or the catalyst component obtained by the above preparation method or the above catalyst or the above method for preparing an ultrahigh molecular weight polyolefin.

According to the invention, an organic acid anhydride compound, an acetate compound, an electron donor a and an electron donor b are introduced into an N-type polyolefin catalyst preparation system to serve as compound electron donors, so that magnesium and titanium-containing solid particles (solid catalyst components) can be prepared. The catalyst particles containing the catalyst component can obtain spherical/ellipsoidal ultrahigh molecular weight polyethylene powder with viscosity-average molecular weight of more than 700 ten thousand, narrow particle size distribution and high bulk density after being used for ethylene slurry polymerization/copolymerization (the bulk density is more than or equal to 0.44g/mL, and the span value is less than 0.8).

Additional features and advantages of the invention will be set forth in the detailed description which follows.

Drawings

FIG. 1 is an electron micrograph of a non-spherical N-series polyolefin catalyst of the prior art.

FIGS. 2 and 3 are electron micrographs of polymer powders obtained by olefin polymerization using the nonspherical N-series polyolefin catalyst shown in FIG. 1.

FIG. 4 is an electron micrograph of catalyst particles of example 1.

FIGS. 5 and 6 are electron micrographs of the polymer powder of example 1.

FIG. 7 is an electron micrograph of catalyst particles of example 2.

FIGS. 8 and 9 are electron micrographs of the polymer powder of example 2.

Fig. 10 is an electron micrograph of the catalyst particles of comparative example 1.

FIGS. 11 and 12 are electron micrographs of the polymer powder of comparative example 1.

Detailed Description

The following describes in detail specific embodiments of the present invention. It should be understood that the detailed description and specific examples, while indicating the present invention, are given by way of illustration and explanation only, not limitation.

According to a first aspect of the present invention, there is provided a catalyst component for olefin polymerization, the catalyst component comprising a magnesium compound, an organic acid anhydride compound, an acetate compound, a titanium-containing compound, an electron donor a and a reaction product of an electron donor b, wherein the electron donor a is at least one selected from compounds represented by general formulas (i) and (ii), and the electron donor b is at least one selected from compounds represented by general formulas (iii) and (iv):

in the formula (I), R₁And R₂Independently is methyl or ethyl, R₃And R₄Independently is hydrogen or methylA group;

in the formula (II), R₉And R₁₀Independently is methyl or ethyl, R₁₁、R₁₂、R₁₃And R₁₄Same or different, independently hydrogen, halogen, C₁-C₁₀Straight chain alkyl group of (1), C₁-C₁₀Branched alkyl or C₁-C₁₀Alkoxy group of (a);

in the formula (III), M₁、M₂、M₃、M₄、M₅And M₆The same or different, each being selected from hydrogen, hydroxyl, amino, aldehyde, carboxyl, acyl, halogen atom, -R₁' OR-OR₂', wherein R₁' and R₂' each is substituted or unsubstituted C₁-C₁₀A hydrocarbyl group, the substituent being selected from a hydroxyl group, an amino group, an aldehyde group, a carboxyl group, an acyl group, a halogen atom, an alkoxy group or a heteroatom;

in the formula (IV), N₁、N₂、N₃、N₄、N₅、N₆、N₇And N₈The same or different, each being selected from hydrogen, hydroxyl, amino, aldehyde, carboxyl, acyl, halogen atom, -R₃' OR-OR₄', wherein R₃' and R₄' each is substituted or unsubstituted C₁-C₁₀The substituent is selected from hydroxyl, amino, aldehyde group, carboxyl, acyl, halogen atom, alkoxy or hetero atom.

In the present invention, the organic acid anhydride compound may be used in an amount of 0.03 to 1.0 mol, preferably 0.1 to 0.5 mol, per mol of magnesium in the magnesium composite; the amount of the acetate compound may be 0.01 to 1 mol, preferably 0.03 to 0.2 mol; the titanium-containing compound may be used in an amount of 0.5 to 120 moles, preferably 5 to 20 moles; the dosage of the electron donor a can be 0.01-1.0 mol, and preferably 0.1-0.3 mol; the dosage of the electron donor b can be 0.001-1.0 mol, and preferably 0.002-0.3 mol.

According to the invention, the molar ratio of the electron donor a to the electron donor b may be from 0.1 to 100: 1.

Preferably, the compound represented by formula (i) is at least one selected from the group consisting of 2, 2-dimethyl-1, 3-diethoxy-propane, 2-dimethyl-1, 3-dimethoxy-propane, 2-dimethyl-1-ethoxy-3-methoxy-propane and 1-ethoxy-3-methoxy-propane.

Preferably, in formula (II), R₉And R₁₀Independently is methyl or ethyl, R₁₁、R₁₂、R₁₃And R₁₄The same or different, independently are hydrogen, fluorine, chlorine, bromine, iodine, C₁-C₆Straight chain alkyl group of (1), C₁-C₆Branched alkyl or C₁-C₆Alkoxy group of (2). More preferably, the compound represented by the formula (II) is at least one selected from the group consisting of o-dimethylether, o-diethylether and 1-ethoxy-2-methoxybenzene.

In the present invention, the compound represented by the formula (iii) may be selected from at least one of the following compounds:

a compound A: m₁＝M₂＝M₃＝M₄＝M₅＝M₆＝OCH₃；

Compound B: m₁＝M₂＝M₃＝M₄＝M₅＝M₆＝OCH₂CH₃；

Compound C: m₁＝M₂＝M₃＝M₄＝M₅＝M₆＝OCH₂CH₂CH₃；

Compound D: m₁＝M₂＝M₃＝M₄＝M₅＝M₆＝OCH(CH₃)₂；

Compound E: m₁＝M₂＝M₃＝M₄＝M₅＝M₆＝OCH₂CH₂CH₂CH₃；

Compound F: m₁＝M₃＝M₅＝OCH₃；M₂＝M₄＝M₆＝OCH₂CH₃；

Compound G: m₁＝M₃＝M₅＝OCH₃；M₂＝M₄＝M₆＝OCH₂CH₂CH₃；

Compound H: m is a group of₁＝M₃＝M₅＝OCH₃；M₂＝M₄＝M₆＝OCH₂CH₂CH₂CH₃；

A compound L: m₁＝M₃＝M₅＝OCH₃；M₂＝M₄＝M₆＝Cl；

Compound M: m₁＝M₃＝M₅＝OCH₃；M₂＝M₄＝M₆＝OH；

Compound N: m₁＝M₃＝M₅＝OCH₃；M₂＝M₄＝M₆＝OCH₂CH₂Br。

The compound represented by the formula (iv) may be selected from at least one of the following compounds:

compound O: n is a radical of₁＝N₂＝N₃＝N₄＝N₅＝N₆＝N₇＝N₈＝OCH₃；

Compound P: n is a radical of₁＝N₂＝N₃＝N₄＝N₅＝N₆＝N₇＝N₈＝OCH₂CH₃；

Compound Q: n is a radical of₁＝N₃＝N₅＝N₇＝OCH₃；N₂＝N₄＝N₆＝N₈＝OCH₂CH₃；

A compound R: n is a radical of₁＝N₃＝N₅＝N₇＝OCH₃；N₂＝N₄＝N₆＝N₈＝OCH₂CH₂CH₃；

A compound S: n is a radical of₁＝N₂＝N₃＝N₄＝N₅＝N₆＝N₇＝N₈＝OH；

A compound T: n is a radical of₁＝N₃＝N₅＝N₇＝OCH₃；N₂＝N₄＝N₆＝N₈＝OH；

Compound U: n is a radical of₁＝N₃＝N₅＝N₇＝OCH₃；N₂＝N₄＝N₆＝N₈＝NH₂；

Compound V: n is a radical of₁＝N₃＝N₅＝N₇＝OCH₃；N₂＝N₄＝N₆＝N₈＝Cl；

A compound W: n is a radical of₁＝N₃＝N₅＝N₇＝OCH₃；N₂＝N₄＝N₆＝N₈＝Br；

Compound X: n is a radical of₁＝N₃＝N₅＝N₇＝OCH₃；N₂＝N₄＝N₆＝N₈＝I；

Compound Y: n is a radical of₁＝N₃＝N₅＝N₇＝OCH₃；N₂＝N₄＝N₆＝N₈＝CHO；

Compound Z: n is a radical of₁＝N₃＝N₅＝N₇＝OCH₃；N₂＝N₄＝N₆＝N₈＝OCH₂CH₂Br。

In the present invention, the magnesium compound is a compound obtained by dissolving a magnesium halide in a solvent system containing an organic epoxy compound and an organic phosphorus compound.

The magnesium halide is selected from magnesium dihalide or a complex of magnesium dihalide and water, alcohol or an electron donor. The magnesium dihalide may be magnesium dichloride, magnesium dibromide, magnesium difluoride or magnesium diiodide, preferably magnesium dichloride. The complex of magnesium dihalide with water, alcohol or electron donor may be selected from the group consisting of complexes of magnesium dihalide with water, methanol, ethanol, propanol, butanol, pentanol, hexanol, isooctanol, ammonia, hydroxyamine, ethers, esters. The magnesium halides can be used individually or in admixture.

According to the invention, the organic epoxy compound may be C₂-C₁₈At least one of an oxide, glycidyl ether and internal ether of an aliphatic olefin, diolefin or halogenated aliphatic olefin or diolefin. Preferably, the organic epoxy compound is selected from at least one of ethylene oxide, propylene oxide, butylene oxide, butadiene oxide, epichlorohydrin, glycidyl methacrylate, ethyl glycidyl ether and butyl glycidyl ether.

In the present invention, the organophosphorus compound is a hydrocarbyl ester or a halogenated hydrocarbyl ester of orthophosphoric acid or phosphorous acid. Preferably at least one selected from the group consisting of trimethyl phosphate, triethyl phosphate, tri-n-propyl phosphate, triisopropyl phosphate, tri-n-butyl phosphate, triisobutyl phosphate, tri-t-butyl phosphate, tri-n-pentyl phosphate, triisopentyl phosphate, tri-n-hexyl phosphate, triisohexyl phosphate, tri-n-heptyl phosphate, triisoheptyl phosphate, tri-n-octyl phosphate, triisooctyl phosphate, triphenyl phosphate, trimethyl phosphite, triethyl phosphite, tri-n-propyl phosphite, triisopropyl phosphite, tri-n-butyl phosphite, triisobutyl phosphite, tri-t-butyl phosphite, tri-n-pentyl phosphite, triisopentyl phosphite, tri-n-hexyl phosphite, triisohexyl phosphite, tri-n-heptyl phosphite, triisoheptyl phosphite, tri-n-octyl phosphite, triisooctyl phosphite, triphenyl phosphite and di-n-butyl phosphite.

In order to fully dissolve, optionally, an inert diluent is contained in the solvent system, the inert diluent is an aromatic hydrocarbon compound or an alkane compound, and the aromatic hydrocarbon compound can be selected from at least one of benzene, toluene, xylene, monochlorobenzene, dichlorobenzene, trichlorobenzene, monochlorobenzene and derivatives thereof; the alkane compound is at least one selected from linear alkanes, branched alkanes and cyclic alkanes having 3 to 20 carbon atoms, and is preferably at least one selected from butane, pentane, hexane, cyclohexane and heptane, as long as it can contribute to the dissolution of the magnesium halide.

In the present invention, the organic epoxy compound is used in an amount of 0.2 to 10 moles, preferably 0.5 to 1.5 moles, per mole of magnesium in the magnesium composite; the organic phosphorus compound is used in an amount of 0.1 to 10 mol, preferably 0.5 to 1.5 mol.

According to the invention, the structure of the organic acid anhydride compound is shown as the formula (V):

in the formula (V), R₅And R₆Independently is hydrogen or C₁-C₁₀Alkyl radical, C₂-C₁₀Alkenyl radical, C₂-C₁₀Alkynyl, C₃-C₈Cycloalkyl or C₆-C₁₀Aromatic hydrocarbon radical, R₅And R₆Can be arbitrarily cyclized.

In the present invention, C₁-C₁₀Examples of alkyl groups include C₁、C₂、C₃、C₄、C₅、C₆、C₇、C₈、C₉、C₁₀The straight-chain or branched alkyl group of (1) is preferably methyl, ethyl, n-propyl, n-butyl, isobutyl, n-pentyl, n-hexyl, etc. C₂-C₁₀Alkenyl radicals comprising C₂、C₃、C₄、C₅、C₆、C₇、C₈、C₉、C₁₀Such as ethenyl, propenyl, butenyl and the like. C₃-C₈Examples of cycloalkyl groups include, but are not limited to, cyclopropyl, methylcyclopropyl, cyclopentyl, methylcyclopentyl, cyclohexyl, cycloheptyl, and the like. C₆-C₂₀Examples of aromatic hydrocarbon groups include, but are not limited to, phenyl, benzyl, dimethylphenyl, and the like.

Preferably, the organic acid anhydride-based compound is at least one selected from the group consisting of acetic anhydride, propionic anhydride, butyric anhydride, acrylic anhydride, phthalic anhydride, crotonic anhydride and maleic anhydride.

In the invention, the general formula of the acetate compound is CH₃COOR₇In the formula, R₇Is C₁-C₁₀Alkyl radical, C₂-C₁₀Alkenyl radical, C₃-C₈Cycloalkyl radical, C₂-C₁₀Alkynyl or C₆-C₁₀Aromatic hydrocarbon radical, R₇Preferably selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl, n-hexyl, n-octyl, cyclopropyl, methylcyclopropyl, n-pentyl, methylcyclopentyl, cyclohexyl, phenyl, benzyl or xylyl.

Preferably, the acetate-based compound is at least one selected from the group consisting of methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, n-pentyl acetate, n-hexyl acetate, and n-octyl acetate.

In the present invention, the titanium-containing compound has the general formula of Ti (OR)₈)_aX_bIn the formula, R₈Is C₁-C₁₀Aliphatic hydrocarbon radical of (C)₆-C₁₄X is halogen, preferably fluorine, chlorine or bromine, a is 0, 1 or 2, b is an integer from 1 to 4, and a + b is 3 or 4.

According to the present invention, the term "aliphatic hydrocarbon group" means a straight-chain or branched-chain hydrocarbon group composed of only carbon atoms and hydrogen atoms, and specific examples include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, vinyl, 1-propenyl, allyl, ethynyl, 1-propynyl, 2-propynyl, butynyl and the like. "aromatic hydrocarbon group" means a hydrocarbon group having a benzene ring, and includes an aryl group, an aryl-substituted hydrocarbon group or a hydrocarbon-substituted aryl group, such as a phenyl group, a benzyl group, an anthryl group, a naphthyl group and the like.

In the present invention, R₈Can be selected from C₁-C₆Alkyl radical, C₂-C₆Alkenyl radical, C₃-C₈Cycloalkyl or C₆-C₁₀An aromatic hydrocarbon group of (1). Preferably, R₈Selected from the group consisting of methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, cyclopropyl, methylcyclopropyl, n-pentyl, methylcyclopentyl, cyclohexyl, phenyl, benzyl, xylyl.

Preferably, the titanium-containing compound is at least one selected from the group consisting of titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, chlorotriethoxytitanium, titanium trichloride, dichlorodiethoxytitanium, and trichloromonoethoxytitanium.

According to a second aspect of the present invention, there is provided a process for the preparation of the above catalyst component for olefin polymerization, comprising the steps of:

s1, dissolving magnesium halide in a solvent system containing an organic epoxy compound and an organic phosphorus compound to form a uniform solution;

s2, reacting the solution obtained in the step S1 with an organic acid anhydride compound and an acetate compound, then contacting with a titanium compound, and then heating to separate out magnesium/titanium-containing solid particles;

s3, adding the electron donor a and the electron donor b into the system obtained in the step S2, and carrying out constant temperature treatment to obtain a mixture;

s4, removing unreacted substances and the solvent from the mixture obtained in the step S3, and washing to obtain the solid catalyst component.

Preferably, in step S1, the dissolving temperature is 50-70 deg.C and the time is 1-3 hours; more preferably, the dissolution temperature is 60 ℃ and the time is 2 h.

In step S2 of the present invention, the reaction temperature is the same as the dissolution temperature in step S1. The temperature of the reacted system is reduced to-60 ℃ to-20 ℃, and then the reacted system is contacted with the titanium compound. The temperature rise is preferably gradual temperature rise, the rate of the temperature rise is 0.2-2 ℃/min, and the temperature rise is up to 75-100 ℃.

Preferably, in step S3, the constant temperature is the same as the temperature raising temperature in step S2, and the time of the treatment is 0.5 to 3 hours, more preferably 1 to 2 hours.

According to a third aspect of the present invention, there is provided a catalyst for the polymerisation of olefins, the catalyst comprising the following components:

A) the method comprises the following steps The catalyst component described above or the catalyst component prepared by the above preparation method;

B) the method comprises the following steps The general formula is AlR'_dX’_3-dWherein R' may be hydrogen or C_l-C₂₀A hydrocarbon radical, X' isA halogen atom, preferably fluorine, chlorine or bromine, 0 < d.ltoreq.3.

In the present invention, R' is preferably C_l-C₂₀Alkyl of (C)_l-C₂₀Aralkyl or C_l-C₂₀Aryl group of (1). The organoaluminum compound may be Al (CH)₃)₃、Al(CH₂CH₃)₃、AlH(CH₂CH₃)₂、Al(i-Bu)₃、AlH(i-Bu)₂、AlCl(CH₂CH₃)₂、Al₂Cl₃(CH₂CH₃)₃、AlCl(CH₂CH₃)₂Or AlCl₂(CH₂CH₃) Preferably Al (CH)₂CH₃)₃Or Al (i-Bu)₃。

According to the invention, the molar ratio of aluminium in component B) to titanium in component A) is preferably 5: 1 to 500: 1, more preferably 20: 1 to 200: 1, most preferably 50: 1 to 100: 1.

According to a fourth aspect of the present invention, there is provided a process for producing an ultrahigh molecular weight polyolefin, the process comprising: one or more olefins are reacted in the presence of the catalyst described above.

According to the invention, the olefin has the general formula CH₂Wherein R is hydrogen or C₁-C₆Preferably ethylene, propylene and/or butylene. The catalyst of the present invention may be used in homopolymerization of ethylene and copolymerization of ethylene and alpha-olefin, and the comonomer may be propylene, butene, pentene, hexene, octene or 4-methyl-1-pentene.

In the present invention, the pressure of the reaction is 0.5 to 1.5MPa, preferably 1.0 MPa. The temperature of the reaction is 70-100 ℃, preferably 75-85 ℃. The reaction time is 1.5h-2.5h, preferably 2 h.

The olefin reaction may be carried out by slurry polymerization or gas phase polymerization. The catalyst has an activity in the homopolymerization of ethylene slurry of more than 6800 gPE/gCat.

The slurry polymerization medium comprises: and inert solvents such as saturated aliphatic hydrocarbons and aromatic hydrocarbons, such as isobutane, hexane, heptane, cyclohexane, naphtha, raffinate, hydrogenated gasoline, kerosene, benzene, toluene, and xylene.

The powder particles of the ultra-high molecular weight polyethylene prepared by the method are spherical or ellipsoidal, the viscosity-average molecular weight can be more than 700 ten thousand, the bulk density can be more than or equal to 0.44g/mL, and the span value of the powder particles is less than 0.8.

According to a fifth aspect of the present invention, there is provided the use of a catalyst component as described above or a catalyst component as prepared by the above-described method of preparation or a catalyst as described above or the above-described method of preparation for ultrahigh molecular weight polyolefins.

Preferably, the ultrahigh molecular weight polyolefin is ultrahigh molecular weight polyethylene, powder particles of the ultrahigh molecular weight polyethylene are spherical or ellipsoidal, the viscosity-average molecular weight is more than 700 ten thousand, the bulk density is more than or equal to 0.44g/mL, and the span value is less than 0.8.

The present invention will be further described with reference to the following examples. But is not limited by these examples.

In the following examples and comparative examples:

1. determination of morphology of catalyst/polymer powder: FEI XL-30/Hitachi S-4800 type scanning electron microscope is adopted.

2. Determination of the bulk Density of the Polymer: the measurements were carried out using (ASTM D1895) test methods for apparent density, bulk factor and pourability of plastics.

3. Testing of the polymer particle size distribution: a Microtrac laser particle size particle analyzer was used, where Span is defined as follows: [ (particle size of 10% cumulative particle size) - (particle size of 90% cumulative particle size) ]/(particle size of 50% cumulative particle size), where the term 10%/50%/90% cumulative particle size denotes the particle size limit at which 10%/50%/90% of the cumulative amount of particles are all above the particle size limit.

4. Polymer molecular weight test: measured according to ASTM D4020-18.

Example 1

(1) Preparation of the catalyst component

Adding 4.8 g of magnesium chloride, 90mL of toluene, 5.0mL of epoxy chloropropane and 15.0mL of tri-n-butyl phosphate into a reaction kettle, reacting for 2 hours under the conditions of stirring speed of 450rpm and temperature of 60 ℃, adding 1.1g of phthalic anhydride and 0.7mL of ethyl acetate, continuously keeping the temperature for 1 hour, cooling to-40 ℃, dropwise adding 70mL of titanium tetrachloride, gradually heating to 90 ℃, and keeping the temperature for 1 hour. 1mL of 2, 2-dimethyl-1, 3-diethoxy-propane and 0.2g of Compound A are added and the incubation is continued for 1 hour. Filtering to remove mother liquor, washing for many times by using an inert diluent toluene and an organic solvent hexane, and drying to obtain the solid catalyst component with good fluidity.

(2) Polymerisation reaction

A stainless steel reaction vessel having a capacity of 2L was sufficiently purged with high-purity nitrogen, 1L of hexane and 1.0mL of 1M triethylaluminum were added, and the solid catalyst component (containing 0.6 mg of titanium) prepared by the above method was added, and the temperature was raised to 80 ℃ and ethylene was introduced so that the total pressure in the vessel became 1.0MPa (gauge pressure), and polymerization was carried out at 80 ℃ for 2 hours, the polymerization results being shown in Table 1.

(3) Electron micrograph: the electron micrograph of the catalyst particles is shown in FIG. 4, and the electron micrograph of the powder particles is shown in FIGS. 5 and 6.

Example 2

(1) Preparation of the catalyst component

Adding 4.8 g of magnesium chloride, 90mL of toluene, 5.0mL of epoxy chloropropane and 15.0mL of tri-n-butyl phosphate into a reaction kettle, reacting for 2 hours under the conditions of stirring speed of 450rpm and temperature of 60 ℃, adding 1.1g of phthalic anhydride and 0.7mL of ethyl acetate, continuously keeping the temperature for 1 hour, cooling to-40 ℃, dropwise adding 70mL of titanium tetrachloride, gradually heating to 90 ℃, and keeping the temperature for 1 hour. 1mL of 1-ethoxy-3-methoxy-propane and 0.15g of Compound B were added and the incubation was continued for 1 hour. Filtering to remove mother liquor, washing for many times by using an inert diluent toluene and an organic solvent hexane, and drying to obtain the solid catalyst component with good fluidity.

(2) Polymerization reaction: the polymerization results are shown in Table 1, as in example 1.

(3) Electron micrograph: the electron micrograph of the catalyst particles is shown in FIG. 7, and the electron micrograph of the powder particles is shown in FIGS. 8 and 9.

Example 3

(1) Preparation of the catalyst component

Adding 4.8 g of magnesium chloride, 90mL of toluene, 5.0mL of epoxy chloropropane and 15.0mL of tri-n-butyl phosphate into a reaction kettle, reacting for 2 hours under the conditions of stirring speed of 450rpm and temperature of 60 ℃, adding 1.1g of phthalic anhydride and 0.7mL of ethyl acetate, continuously keeping the temperature for 1 hour, cooling to-40 ℃, dropwise adding 70mL of titanium tetrachloride, gradually heating to 90 ℃, and keeping the temperature for 1 hour. 1mL of o-phenyl diethyl ether and 0.2g of Compound P were added, and the temperature was kept constant for 1 hour. Filtering to remove mother liquor, washing for many times by using an inert diluent toluene and an organic solvent hexane, and drying to obtain the solid catalyst component with good fluidity.

(2) Polymerization reaction: the polymerization results are shown in Table 1, as in example 1.

Example 4

(1) Preparation of the catalyst component

Adding 4.8 g of magnesium chloride, 90mL of toluene, 5.0mL of epoxy chloropropane and 15.0mL of tri-n-butyl phosphate into a reaction kettle, reacting for 2 hours under the conditions of stirring speed of 450rpm and temperature of 60 ℃, adding 1.1g of phthalic anhydride and 0.7mL of ethyl acetate, continuously keeping the temperature for 1 hour, cooling to-40 ℃, dropwise adding 70mL of titanium tetrachloride, gradually heating to 90 ℃, and keeping the temperature for 1 hour. 1mL of o-dimethyl ether and 0.2g of Compound N were added, and the temperature was kept constant for 1 hour. Filtering to remove mother liquor, washing for many times by using an inert diluent toluene and an organic solvent hexane, and drying to obtain the solid catalyst component with good fluidity.

(2) Polymerization reaction: the polymerization results are shown in Table 1, as in example 1.

Example 5

(1) Preparation of the catalyst component

Adding 4.8 g of magnesium chloride, 90mL of toluene, 5.0mL of epoxy chloropropane and 15.0mL of tri-n-butyl phosphate into a reaction kettle, reacting for 2 hours under the conditions of stirring speed of 450rpm and temperature of 60 ℃, adding 1.1g of phthalic anhydride and 0.7mL of ethyl acetate, continuously keeping the temperature for 1 hour, cooling to-40 ℃, dropwise adding 70mL of titanium tetrachloride, gradually heating to 90 ℃, and keeping the temperature for 1 hour. 1mL2, 2-dimethyl-1, 3-diethoxy-propane, 0.1g Compound A and 0.1g Compound O were added and the incubation was continued for 1 hour. Filtering to remove mother liquor, washing for many times by using an inert diluent toluene and an organic solvent hexane, and drying to obtain the solid catalyst component with good fluidity.

(2) Polymerization reaction: the polymerization results are shown in Table 1, as in example 1.

Example 6

(1) Preparation of the catalyst component

Adding 4.8 g of magnesium chloride, 90mL of toluene, 5.0mL of epichlorohydrin and 15.0mL of tributyl phosphate into a reaction kettle, reacting for 2 hours under the conditions that the stirring speed is 450rpm and the temperature is 60 ℃, adding 1.1g of phthalic anhydride and 0.7mL of ethyl acetate, keeping the temperature for 1 hour, reducing the temperature to-40 ℃, dropwise adding 70mL of titanium tetrachloride, gradually increasing the temperature to 90 ℃, and keeping the temperature for 1 hour. 1mL of 2, 2-dimethyl-1, 3-diethoxy-propane, 0.1g of Compound B and 0.1g of Compound Z are added and the incubation is continued for 1 hour. Filtering to remove mother liquor, washing for many times by using an inert diluent toluene and an organic solvent hexane, and drying to obtain the solid catalyst component with good fluidity.

(2) Polymerization reaction: the polymerization results are shown in Table 1, as in example 1.

Comparative example 1

(1) Preparation of the catalyst component

Adding 4.8 g of magnesium chloride, 90mL of toluene, 5.0mL of epoxy chloropropane and 15.0mL of tri-n-butyl phosphate into a reaction kettle, reacting for 2 hours under the conditions of stirring speed of 450rpm and temperature of 60 ℃, adding 1.1g of phthalic anhydride, continuously keeping the temperature for 1 hour, cooling to-40 ℃, dropwise adding 70mL of titanium tetrachloride, gradually heating to 90 ℃, and keeping the temperature for 1 hour. Filtering to remove mother liquor, washing for many times by using an inert diluent toluene and an organic solvent hexane, and drying to obtain the solid catalyst component with good fluidity.

(2) Polymerization reaction: the polymerization results are shown in Table 1, as in example 1.

(3) Electron micrograph: the electron micrograph of the catalyst particles is shown in FIG. 10, and the electron micrograph of the powder particles is shown in FIGS. 11 and 12.

Comparative example 2

(1) Preparation of the catalyst component

Adding 4.8 g of magnesium chloride, 90mL of toluene, 5.0mL of epoxy chloropropane and 15.0mL of tri-n-butyl phosphate into a reaction kettle, reacting for 2 hours under the conditions of stirring speed of 450rpm and temperature of 60 ℃, adding 1.1g of phthalic anhydride and 0.7mL of ethyl acetate, continuously keeping the temperature for 1 hour, cooling to-40 ℃, dropwise adding 70mL of titanium tetrachloride, gradually heating to 90 ℃, and keeping the temperature for 1 hour. 1mL of ethyl benzoate was added and the incubation was continued for 1 hour. Filtering to remove mother liquor, washing for many times by using an inert diluent toluene and an organic solvent hexane, and drying to obtain the solid catalyst component with good fluidity.

(2) Polymerization reaction: the polymerization results are shown in Table 1, as in example 1.

Comparative example 3

(1) Preparation of the catalyst component

Adding 4.8 g of magnesium chloride, 90mL of toluene, 5.0mL of epoxy chloropropane and 15.0mL of tri-n-butyl phosphate into a reaction kettle, reacting for 2 hours under the conditions of stirring speed of 450rpm and temperature of 60 ℃, adding 1.1g of phthalic anhydride and 0.7mL of ethyl acetate, continuously keeping the temperature for 1 hour, cooling to-40 ℃, dropwise adding 70mL of titanium tetrachloride, gradually heating to 90 ℃, and keeping the temperature for 1 hour. 1mL of 2, 2-dimethyl-1, 3-diethoxy-propane was added and the temperature was kept constant for 1 hour. Filtering to remove mother liquor, washing for many times by using an inert diluent toluene and an organic solvent hexane, and drying to obtain the solid catalyst component with good fluidity.

(2) Polymerization reaction: the polymerization results are shown in Table 1, as in example 1.

Comparative example 4

(1) Preparation of the catalyst component

Adding 4.8 g of magnesium chloride, 90mL of toluene, 5.0mL of epoxy chloropropane and 15.0mL of tri-n-butyl phosphate into a reaction kettle, reacting for 2 hours under the conditions of stirring speed of 450rpm and temperature of 60 ℃, adding 1.1g of phthalic anhydride and 0.7mL of ethyl acetate, continuously keeping the temperature for 1 hour, cooling to-40 ℃, dropwise adding 70mL of titanium tetrachloride, gradually heating to 90 ℃, and keeping the temperature for 1 hour. 1mL of o-dimethyl ether was added and the temperature was maintained for 1 hour. Filtering to remove mother liquor, washing for many times by using an inert diluent toluene and an organic solvent hexane, and drying to obtain the solid catalyst component with good fluidity.

(2) Polymerization reaction: the polymerization results are shown in Table 1, as in example 1.

Comparative example 5

(1) Preparation of the catalyst component

Adding 4.8 g of magnesium chloride, 90mL of toluene, 5.0mL of epoxy chloropropane and 15.0mL of tri-n-butyl phosphate into a reaction kettle, reacting for 2 hours under the conditions of stirring speed of 450rpm and temperature of 60 ℃, adding 1.1g of phthalic anhydride and 0.7mL of ethyl acetate, continuously keeping the temperature for 1 hour, cooling to-40 ℃, dropwise adding 70mL of titanium tetrachloride, gradually heating to 90 ℃, and keeping the temperature for 1 hour. 1mL of 2, 2-dimethyl-1, 3-di-n-propoxy-propane and 0.2g of Compound B are added and the incubation is continued for 1 hour. Filtering to remove mother liquor, washing for many times by using an inert diluent toluene and an organic solvent hexane, and drying to obtain the solid catalyst component with good fluidity.

(2) Polymerization reaction: the polymerization results are shown in Table 1, as in example 1.

TABLE 1

As can be seen from the data in Table 1, compared with the comparative example, when the organic acid anhydride compound, the acetate compound, the electron donor a and the electron donor b are introduced into the catalyst component of the example, the viscosity average molecular weight of the powder obtained by polymerization is increased and can be more than 700 ten thousand, the bulk density can be more than or equal to 0.44g/mL, and the span value of the powder particle is less than 0.8.

While embodiments of the present invention have been described above, the above description is illustrative, not exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the described embodiments.

Claims (10)

1. A catalyst component for olefin polymerization, which is characterized by comprising a magnesium compound, an organic acid anhydride compound, an acetate compound, a titanium-containing compound, an electron donor a and a reaction product of an electron donor b, wherein the electron donor a is at least one selected from compounds shown in general formulas (I) and (II), and the electron donor b is at least one selected from compounds shown in general formulas (III) and (IV):

in the formula (I), R₁And R₂Independently is methyl or ethyl, R₃And R₄Independently hydrogen or methyl;

in the formula (II), R₉And R₁₀Independently is methyl or ethyl, R₁₁、R₁₂、R₁₃And R₁₄Same or different, independently hydrogen, halogen, C₁-C₁₀Straight chain alkyl group of (1), C₁-C₁₀Branched alkyl or C₁-C₁₀Alkoxy group of (a);

in the formula (III), M₁、M₂、M₃、M₄、M₅And M₆The same or different, each being selected from hydrogen, hydroxyl, amino, aldehyde, carboxyl, acyl, halogen atom, -R₁' OR-OR₂', wherein R₁' and R₂' each is substituted or unsubstituted C₁-C₁₀A hydrocarbon group, the substituent being selected from a hydroxyl group, an amino group, an aldehyde group, a carboxyl group, an acyl group, a halogen atom, an alkoxy group or a hetero atom;

in the formula (IV), N₁、N₂、N₃、N₄、N₅、N₆、N₇And N₈The same or different, each being selected from hydrogen, hydroxyl, amino, aldehyde, carboxyl, acyl, halogen atom, -R₃' OR-OR₄', wherein R₃' and R₄' each is substituted or unsubstituted C₁-C₁₀A hydrocarbyl group, the substituent being selected from a hydroxyl group, an amino group, an aldehyde group, a carboxyl group, an acyl group, a halogen atom, an alkoxy group or a heteroatom;

the amount of the organic acid anhydride-based compound is preferably 0.03 to 1.0 mole, more preferably 0.1 to 0.5 mole per mole of magnesium in the magnesium composite; the amount of the acetate compound is preferably 0.01 to 1 mol, more preferably 0.03 to 0.2 mol; the titanium-containing compound is preferably used in an amount of 0.5 to 120 moles, more preferably 5 to 20 moles; the dosage of the electron donor a is preferably 0.01 to 1.0 mol, and more preferably 0.1 to 0.3 mol; the amount of the electron donor b is preferably 0.001 to 1.0 mol, and more preferably 0.002 to 0.3 mol.

2. The catalyst component for olefin polymerization according to claim 1, wherein the compound represented by formula (i) is at least one selected from the group consisting of 2, 2-dimethyl-1, 3-diethoxy-propane, 2-dimethyl-1, 3-dimethoxy-propane, 2-dimethyl-1-ethoxy-3-methoxy-propane and 1-ethoxy-3-methoxy-propane;

in the formula (II), R₉And R₁₀Independently of one another, methyl or ethyl, R₁₁、R₁₂、R₁₃And R₁₄The same or different, independently are hydrogen, fluorine, chlorine, bromine, iodine, C₁-C₆Straight chain alkyl group of (1), C₁-C₆Branched alkyl or C₁-C₆Alkoxy group of (a); preferably, the compound represented by the formula (II) is at least one selected from the group consisting of o-dimethylether, o-diethylether and 1-ethoxy-2-methoxybenzene.

3. The catalyst component for the polymerization of olefins according to claim 1 in which the compound of formula (III) is chosen from at least one of the following compounds:

a compound A: m₁＝M₂＝M₃＝M₄＝M₅＝M₆＝OCH₃；

Compound B: m₁＝M₂＝M₃＝M₄＝M₅＝M₆＝OCH₂CH₃；

Compound C: m₁＝M₂＝M₃＝M₄＝M₅＝M₆＝OCH₂CH₂CH₃；

Compound D: m₁＝M₂＝M₃＝M₄＝M₅＝M₆＝OCH(CH₃)₂；

Compound E: m₁＝M₂＝M₃＝M₄＝M₅＝M₆＝OCH₂CH₂CH₂CH₃；

Compound F: m₁＝M₃＝M₅＝OCH₃；M₂＝M₄＝M₆＝OCH₂CH₃；

Compound G: m₁＝M₃＝M₅＝OCH₃；M₂＝M₄＝M₆＝OCH₂CH₂CH₃；

Compound H: m₁＝M₃＝M₅＝OCH₃；M₂＝M₄＝M₆＝OCH₂CH₂CH₂CH₃；

A compound L: m₁＝M₃＝M₅＝OCH₃；M₂＝M₄＝M₆＝Cl；

Compound M: m₁＝M₃＝M₅＝OCH₃；M₂＝M₄＝M₆＝OH；

Compound N: m₁＝M₃＝M₅＝OCH₃；M₂＝M₄＝M₆＝OCH₂CH₂Br；

The compound shown in the formula (IV) is selected from at least one of the following compounds:

compound O: n is a radical of₁＝N₂＝N₃＝N₄＝N₅＝N₆＝N₇＝N₈＝OCH₃；

Compound P: n is a radical of₁＝N₂＝N₃＝N₄＝N₅＝N₆＝N₇＝N₈＝OCH₂CH₃；

Compound Q: n is a radical of₁＝N₃＝N₅＝N₇＝OCH₃；N₂＝N₄＝N₆＝N₈＝OCH₂CH₃；

A compound R: n is a radical of₁＝N₃＝N₅＝N₇＝OCH₃；N₂＝N₄＝N₆＝N₈＝OCH₂CH₂CH₃；

A compound S: n is a radical of hydrogen₁＝N₂＝N₃＝N₄＝N₅＝N₆＝N₇＝N₈＝OH；

A compound T: n is a radical of₁＝N₃＝N₅＝N₇＝OCH₃；N₂＝N₄＝N₆＝N₈＝OH；

A compound U: n is a radical of₁＝N₃＝N₅＝N₇＝OCH₃；N₂＝N₄＝N₆＝N₈＝NH₂；

Compound V: n is a radical of₁＝N₃＝N₅＝N₇＝OCH₃；N₂＝N₄＝N₆＝N₈＝Cl；

A compound W: n is a radical of₁＝N₃＝N₅＝N₇＝OCH₃；N₂＝N₄＝N₆＝N₈＝Br；

Compound X: n is a radical of₁＝N₃＝N₅＝N₇＝OCH₃；N₂＝N₄＝N₆＝N₈＝I；

Compound Y: n is a radical of₁＝N₃＝N₅＝N₇＝OCH₃；N₂＝N₄＝N₆＝N₈＝CHO；

Compound Z: n is a radical of₁＝N₃＝N₅＝N₇＝OCH₃；N₂＝N₄＝N₆＝N₈＝OCH₂CH₂Br。

4. The catalyst component for olefin polymerization according to claim 1, wherein the magnesium complex is a complex formed by dissolving a magnesium halide in a solvent system containing an organic epoxy compound and an organic phosphorus compound;

the magnesium halide is selected from magnesium dihalide or a complex of magnesium dihalide and water, alcohol or an electron donor; the magnesium dihalide is magnesium dichloride, magnesium dibromide, magnesium difluoride or magnesium diiodide, preferably magnesium dichloride; the complex of magnesium dihalide and water, alcohol or electron donor is selected from the complex of magnesium dihalide and water, methanol, ethanol, propanol, butanol, pentanol, hexanol, isooctanol, ammonia, hydroxyamine, ether and ester;

the organic epoxy compound is C₂-C₁₈At least one of an oxide, glycidyl ether and internal ether of an aliphatic olefin, diolefin or halogenated aliphatic olefin or diolefin of (a); preferably, the organic epoxy compound is selected from at least one of ethylene oxide, propylene oxide, butylene oxide, butadiene oxide, epichlorohydrin, glycidyl methacrylate, ethyl glycidyl ether and butyl glycidyl ether;

the organophosphorus compound is a hydrocarbyl or halohydrocarbyl ester of orthophosphoric acid or phosphorous acid; preferably at least one selected from the group consisting of trimethyl phosphate, triethyl phosphate, tri-n-propyl phosphate, triisopropyl phosphate, tri-n-butyl phosphate, triisobutyl phosphate, tri-t-butyl phosphate, tri-n-pentyl phosphate, triisopentyl phosphate, tri-n-hexyl phosphate, triisohexyl phosphate, tri-n-heptyl phosphate, triisoheptyl phosphate, tri-n-octyl phosphate, triisooctyl phosphate, triphenyl phosphate, trimethyl phosphite, triethyl phosphite, tri-n-propyl phosphite, triisopropyl phosphite, tri-n-butyl phosphite, triisobutyl phosphite, tri-t-butyl phosphite, tri-n-pentyl phosphite, triisopentyl phosphite, tri-n-hexyl phosphite, triisohexyl phosphite, tri-n-heptyl phosphite, triisoheptyl phosphite, tri-n-octyl phosphite, triisooctyl phosphite, triphenyl phosphite and di-n-butyl phosphite;

optionally, the solvent system contains an inert diluent, wherein the inert diluent is an aromatic compound or an alkane compound, and the aromatic compound is selected from at least one of benzene, toluene, xylene, monochlorobenzene, dichlorobenzene, trichlorobenzene, monochlorobenzene and derivatives thereof; the alkane compound is at least one of linear alkane, branched alkane or cycloalkane with 3-20 carbon atoms, preferably at least one of butane, pentane, hexane, cyclohexane and heptane;

the organic epoxy compound is preferably used in an amount of 0.2 to 10 moles, more preferably 0.5 to 1.5 moles, per mole of magnesium in the magnesium composite; the organic phosphorus compound is preferably used in an amount of 0.1 to 10 moles, more preferably 0.5 to 1.5 moles.

5. The catalyst component for olefin polymerization according to claim 1, wherein the organic acid anhydride compound has a structure represented by formula (V):

in the formula (V), R₅And R₆Independently is hydrogen or C₁-C₁₀Alkyl radical, C₂-C₁₀Alkenyl radical, C₂-C₁₀Alkynyl, C₃-C₈Cycloalkyl or C₆-C₁₀Aromatic hydrocarbon radical, R₅And R₆Can form a ring at will;

preferably, the organic acid anhydride compound is selected from at least one of acetic anhydride, propionic anhydride, butyric anhydride, acrylic anhydride, phthalic anhydride, crotonic anhydride and maleic anhydride;

the general formula of the acetate compound is CH₃COOR₇In the formula, R₇Is C₁-C₁₀Alkyl radical, C₂-C₁₀Alkenyl radical, C₃-C₈Cycloalkyl radical, C₂-C₁₀Alkynyl or C₆-C₁₀An aromatic hydrocarbon group;

preferably, the acetate-based compound is at least one selected from the group consisting of methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, n-pentyl acetate, n-hexyl acetate, and n-octyl acetate.

6. The catalyst component for the polymerization of olefins according to claim 1 in which the titanium-containing compound has the general formula Ti (OR)₈)_aX_bIn the formula, R₈Is C₁-C₁₀Aliphatic hydrocarbon radical of (C)₆-C₁₄X is halogen, preferably fluorine, chlorine or bromine, a is 0, 1 or 2, b is an integer from 1 to 4, and a + b is 3 or 4;

preferably, the titanium-containing compound is at least one selected from the group consisting of titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, chlorotriethoxytitanium, titanium trichloride, dichlorodiethoxytitanium, and trichloromonoethoxytitanium.

7. Process for the preparation of a catalyst component for the polymerization of olefins according to any one of claims 1 to 6, characterized in that it comprises the following steps:

s1, dissolving magnesium halide in a solvent system containing an organic epoxy compound and an organic phosphorus compound to form a uniform solution;

s2, reacting the solution obtained in the step S1 with an organic acid anhydride compound and an acetate compound, then contacting with a titanium compound, and then heating to separate out magnesium/titanium-containing solid particles;

s3, adding the electron donor a and the electron donor b into the system obtained in the step S2, and carrying out constant temperature treatment to obtain a mixture;

s4, removing unreacted substances and the solvent from the mixture obtained in the step S3, and washing to obtain a solid catalyst component;

preferably, in step S1, the dissolving temperature is 50-70 deg.C and the time is 1-3 hours;

preferably, in step S2, the temperature of the system after the reaction is reduced to-60 ℃ to-20 ℃ and then contacted with the titanium compound; the temperature rise is gradual temperature rise, the rate of the temperature rise is 0.2-2 ℃/min, and the temperature rise is to 75-100 ℃;

preferably, in step S3, the processing time is 0.5 to 3 hours.

8. A catalyst for the polymerization of olefins, characterized in that it comprises the following components:

A) the method comprises the following steps The catalyst component according to claims 1 to 6 or the catalyst component produced by the production method according to claim 7;

B) the method comprises the following steps The general formula is AlR'_dX’_3-dWherein R' is hydrogen or C_l-C₂₀A hydrocarbon group, X' is a halogen atom, preferably fluorine, chlorine or bromine, and d is more than 0 and less than or equal to 3;

the organoaluminum compound is preferably Al (CH)₃)₃、Al(CH₂CH₃)₃、AlH(CH₂CH₃)₂、Al(i-Bu)₃、AlH(i-Bu)₂、AlCl(CH₂CH₃)₂、Al₂Cl₃(CH₂CH₃)₃、AlCl(CH₂CH₃)₂Or AlCl₂(CH₂CH₃) More preferably Al (CH)₂CH₃)₃Or Al (i-Bu)₃；

The molar ratio of aluminium in component B) to titanium in component A) is preferably from 5: 1 to 500: 1, more preferably from 20: 1 to 200: 1, most preferably from 50: 1 to 100: 1.

9. A process for preparing an ultrahigh molecular weight polyolefin, the process comprising: reacting one or more olefins having the formula CH in the presence of the catalyst of claim 8₂Wherein R is hydrogen or C₁-C₆Alkyl groups of (a); the olefin is preferably ethylene, propylene and/or butene;

the pressure of the reaction is preferably 0.5-1.5Mpa, the temperature of the reaction is preferably 70-100 ℃, and the time of the reaction is preferably 1.5-2.5 h.

10. Use of the catalyst component according to any one of claims 1 to 6 or the catalyst component obtained by the process according to claim 7 or the catalyst according to claim 8 or the process according to claim 9 for the preparation of ultra-high molecular weight polyolefins;

preferably, the ultrahigh molecular weight polyolefin is ultrahigh molecular weight polyethylene, powder particles of the ultrahigh molecular weight polyethylene are spherical or ellipsoidal, the viscosity-average molecular weight is more than 700 ten thousand, the bulk density is more than or equal to 0.44g/mL, and the span value is less than 0.8.

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