CN111138574B

CN111138574B - Supported Ziegler-Natta catalyst, preparation method thereof and application thereof in olefin polymerization

Info

Publication number: CN111138574B
Application number: CN201811308263.3A
Authority: CN
Inventors: 韩晓昱; 徐人威; 姜飞; 王雄; 陈雪蓉; 张翠玲; 郭义; 刘永军; 李磊; 王慧; 王海; 魏瑶; 穆蕊娟
Original assignee: Petrochina Co Ltd
Current assignee: Petrochina Co Ltd
Priority date: 2018-11-05
Filing date: 2018-11-05
Publication date: 2022-03-29
Anticipated expiration: 2038-11-05
Also published as: CN111138574A

Abstract

The invention discloses a supported Ziegler-Natta catalyst, which comprises the following components: a) magnesium metal; b) a mixed alcohol containing at least one halogenated alcohol; c) halogen and/or halogen-containing compounds; d) a titanium-containing compound; e) an internal electron donor compound. The innovation is that the supported Ziegler-Natta catalyst is directly obtained by introducing the halohydrin and adopting a one-step method, the catalyst has the characteristics of good form, excellent comprehensive performance and the like, is used for olefin, particularly propylene polymerization, has the polymerization activity of more than 40KgPP/gcat, has the melt index of 30-60 g/10min, has excellent hydrogen regulation sensitivity, has the isotacticity of more than 97 percent, is suitable for the development of polymers of different brands, and has very good application prospect.

Description

Supported Ziegler-Natta catalyst, preparation method thereof and application thereof in olefin polymerization

Technical Field

The invention relates to a supported Ziegler-Natta catalyst, a preparation method and application of the catalyst, in particular to a Ziegler-Natta catalyst supported by alkoxy magnesium, a preparation method of the catalyst and application of the catalyst in propylene polymerization.

Background

Currently, magnesium chloride supported ziegler-natta catalysts are the most widely used catalysts for olefin polymerization. The magnesium chloride supported ziegler-natta catalysts are generally composed of a solid catalyst component comprising magnesium, titanium, halogen and an organic compound of the electron donor type, mixed in suitable proportions with a cocatalyst of an organoaluminum and a stereoregularity controlling agent-organosilane for use in the polymerization of olefins such as propylene. Since the solid catalyst for olefin polymerization is used in various industrial operations including slurry polymerization, bulk polymerization and gaseous polymerization, it should satisfy requirements for various particle shapes such as suitable particle size and shape, uniform distribution of particle size, minimization and high bulk density of large and fine particles, and essential characteristics of high activity and stereoregularity. However, none of these catalysts can meet all the requirements, and supported Ziegler-Natta catalysts supported on magnesium alkoxides can have more excellent properties.

Currently, with the continuous development of the polyolefin industry, the preparation method of the polymerization catalyst is also rapidly developed. The commercial polyolefin catalyst is mainly prepared by synthesizing a polyolefin catalyst carrier and then synthesizing the polyolefin catalyst through a loading process, wherein the carrier of the catalyst is mainly solid particles such as an alcohol compound of magnesium chloride or alkoxy magnesium and the like.

The conventional method for preparing high activity supported catalysts is the co-precipitation method, which consists in dissolving magnesium halide in a solvent system to form a homogeneous solution, then precipitating the active magnesium halide with titanium halide and simultaneously loading the titanium active component. However, a problem that always exists is that the hydrogen response of the catalyst of the system is relatively low, so that the melt index of the polyolefin product is relatively low, and the development of the high-melt-index polyolefin product is limited. Therefore, it is urgently needed to develop a catalyst which can not only keep other properties of polyolefin unchanged, but also improve the hydrogen regulation sensitivity property, so as to meet the requirements for developing and applying high-melting-index numbers. The supported catalyst component with alkoxy magnesium as carrier is used in olefin polymerization, especially propylene polymerization, and has the features of excellent polymer grain form, low fine powder content, high stereo regularity, etc. Therefore, a method for producing a catalyst by using magnesium alkoxide obtained by reacting magnesium with an alcohol as a carrier has attracted attention in recent years.

In the prior art, the disclosed preparation methods of magnesium alkoxide particles are mainly divided into the following methods:

the first method is a method of preparing dialkoxy magnesium by reacting alcohol with metal magnesium, and then adjusting the particle size by mechanical pulverization;

the second method is a production method in which the final addition ratio of magnesium/ethanol is controlled to be in the range of 1/9-1/15 in the reaction of metallic magnesium and ethanol, and ethanol and magnesium are reacted intermittently or continuously at the time of ethanol reflux, as reported in Japanese patent laid-open No. 3-74341;

the third method is a method for producing round fine particles by spray-drying an alcoholic solution of carboxylated magnesium and then successively decarboxylating the solution, as reported in Japanese patent application laid-open No. 6-87773;

the fourth is a production method in which metallic magnesium is reacted with ethanol in the coexistence of saturated hydrocarbon, as reported in Japanese examined patent publication No. 63-4815;

the fifth is Mg (OR)₂Dispersing in R 'OH, spray drying to obtain solid particles, suspending in ROH, distilling to remove R' OH to obtain solid particles of formula Mg (OR)₂-&(OR′)&The method for producing a round article is described in Japanese patent application laid-open No. 62-51633.

In the preparation processes disclosed in the prior art, there are still many unsatisfactory aspects. In the first method, the shape of the particles is crushed and damaged, the yield is low, and the method is difficult to be suitable for industrial production; in the second method, although the final magnesium/ethanol addition ratio was described as 1/9-1/15, it was found that, in the latter half of the reaction, if sufficient stirring was not performed, the particles agglomerated and spherical particles with uniform morphology could not be obtained; if the stirring is forced, the particle shape is destroyed; the methods three to five require other raw materials in addition to magnesium and alcohol, and the preparation process is also complicated.

The alkoxy magnesium is conventionally prepared by reacting an alcohol with magnesium powder in the presence of an initiator. The alcohol is generally ethanol, the initiator is generally halogen-containing substances, and the most commonly used substances are elementary iodine and carbon tetrachloride compounds. In order to obtain dialkoxy magnesium with excellent performance, the magnesium alkoxide ratio and the halogen-magnesium ratio need to be strictly controlled in the reaction process, and the shape and the performance of the alkoxy magnesium are all influenced by different raw material properties, different charging sequences, different reaction conditions and different types of alcohol.

In order to obtain the alkoxy magnesium carrier meeting the above performance, researchers have studied the direct synthesis method of the magnesium alkoxide compound, and the patent work results reported in US5556820, US005965478A, US2001012908, WO2005044873, WO2009084799, US2009181845, US2009186755 mainly focus on three aspects: (1) the influence of the physical properties of the individual substances involved in the reaction on the properties of the product, such as the form of metallic magnesium, flakes, spheres or ribbons; the kind and water content of alcohol; the kind of initiator; elemental iodine, carbon tetrachloride, mercury chloride and other novel initiators. (2) The influence of the amount of the reactants on the performance of the product, such as halogen-magnesium ratio, alcohol-magnesium ratio and the like. (3) The influence of the process parameters on the product properties, such as reaction temperature, reaction time, mode of addition, order of addition, and time of addition.

CN201510043331.8 discloses a carrier of olefin polymerization catalyst, which is prepared by reacting alcohol and magnesium metal in the presence of halogen or halogen-containing compound to form magnesium compound carrier, wherein the alcohol (a) is lower alcohol with 1-6 carbon atoms, and is used singly or in combination of two or more. Characterized in that the olefin polymerization catalyst carrier has a general formula of Mg (OR)₁)_n(OR₂)_2-nWherein n is more than or equal to 0 and less than or equal to 2, R₁、R₂May be the same or different and is C₁-C₂₀The carrier has an X-ray diffraction spectrum in which a group of peaks having 1 to 4 diffraction peaks exists in a range of a 2 theta diffraction angle of 5 DEG to 15 deg. However, the patent reports that the magnesium compound suspension requires treatment at high temperature and high pressure to obtain the carrier, and thus the experimental preparation conditions are severe.

CN201410728055.4 relates to a preparation method and application of an alkoxy magnesium carrier, which is applied to the preparation of an alkoxy magnesium carrier of an olefin polymerization catalyst. The molar ratio of the components of the alkoxy magnesium carrier is as follows: magnesium powder: initiator: a crosslinking agent: monohydric organic alcohols: dispersing agent: dispersion medium 1: (0.00001-0.1): (0.0001-0.5): (2-100): (0.05-50): (1-100), wherein the monohydric organic alcohol is selected from C₂-C₁₅A monohydric organic fatty alcohol. The experimental process of this patent is relatively tedious.

CN201180010617.6 provides a mixed dialkoxy magnesium granular material comprising magnesium ethoxide, in which granular magnesium metal having an average particle size of 50 to 500 μm and two or more alcohols composed of at least one of ethanol and an alcohol having 3 to 6 carbon atoms are subjected to a direct solid-liquid reaction, the content of the alkoxide other than the ethoxide is 2.5 to 15 mol% of the total, and D is₅₀The average particle diameter is 20 to 100 μm, and the bulk density is 0.4g/mL or more. But the particle size distribution in the examples is greater than 3.5.

CN201210575900.X, CN201210574842.9 provide a method for preparing a solid catalyst for olefin polymerization and a carrier thereof, which comprises preparing a carrier for the solid catalyst for olefin polymerization from metal magnesium, alcohols, halogen or halogen compounds and halides of titanium, monohydric alcohols, polyhydric alcohols or a mixture of the alcohols; the carrier is further contacted with inert solvent, titanium halide, electron donor compound and the like to synthesize the solid catalyst for olefin polymerization. However, the bulk density of the obtained alkoxy magnesium carrier is less than 0.3 g/mL.

CN200910176719.X provides a method for preparing amorphous spherical particulate alkoxy magnesium, which takes magnesium powder and mixed alcohol as raw materials, takes halogen simple substance and/or inorganic halide as halogenating agent, takes an organic halogen-containing compound as modifier, and takes one or more inert organic solvents as dispersing agent to prepare amorphous spherical particulate alkoxy magnesium, wherein the mixed alcohol is a mixture of monohydric alcohol or polyhydric alcohol. Toluene is used as a dispersing agent, and the bulk density of the prepared alkoxy magnesium carrier reaches more than 0.35g/mL, but the prepared alkoxy magnesium carrier is not beneficial to environmental protection.

The preparation method of the supported catalyst component with alkoxy magnesium as the carrier generally comprises the steps of firstly synthesizing the alkoxy magnesium carrier, and then carrying out a supporting reaction on the carrier, a titanium-containing compound, an internal electron donor and the like. There have also been many studies on the preparation of olefin polymerization catalyst components using dialkoxy magnesium as a carrier.

CN 201410575008.0 discloses a method for preparing a catalyst component, which comprises the step of contacting an alkoxy magnesium carrier, an internal electron donor compound, a titanium compound and an alcohol compound. The internal electron donor compound is at least one of aliphatic dicarboxylic acid esters, and the alcohol compound is at least one of linear chain or branched chain monohydric alcohol or polyhydric alcohol. The catalyst has higher polymerization activity, and the prepared polymer has higher isotacticity, but the hydrogen regulation sensitivity needs to be improved.

CN 201010283034.8 discloses a solid catalyst component and a catalyst for olefin polymerization. The method comprises the steps of taking spherical alkoxy magnesium as a carrier, taking an inert solvent as a dispersing agent, contacting with a titanium compound at a certain temperature, reacting with a polyol ester compound with a special structure as an electron donor, and treating with the titanium compound to obtain the solid catalyst component. The catalyst has higher activity during polymerization, and the obtained polymer has better stereoregularity, but the hydrogen regulation sensitivity needs to be further improved.

CN201010522125.2 discloses an alkoxy magnesium carrier for preparing an olefin catalyst and a preparation method thereof. The catalyst solid component prepared by the reaction of the alkoxy magnesium carrier, the titanium compound and the phthalic acid ester internal electron donor and the corresponding olefin polymerization catalyst have high activity when used for olefin polymerization, and can obtain olefin polymers with excellent particle morphology, low content of ultrafine powder and high stereoregularity. However, the catalyst still needs to be improved in terms of compatibility between isotacticity and hydrogen response.

CN201310190424.4 discloses a solid catalyst component for olefin polymerization, which is prepared by dissolving a magnesium compound in a solvent system composed of an organic epoxy compound, an organic phosphorus compound and an inert diluent to form a uniform solution, mixing the uniform solution with a titanium compound, separating out a solid in the presence of a precipitation assistant, and finally treating the solid by an internal electron donor compound, wherein the magnesium compound is selected from magnesium dihalide, alkoxy magnesium, alkyl magnesium, hydrate or alcohol compound of magnesium dihalide, and a derivative of magnesium dihalide in which a halogen atom is substituted by alkoxy or halogenated alkoxy, and the internal electron donor is a 1, 3-diol benzoate compound with a specific structure.

CN 201310190990.5 discloses a method for preparing a solid catalyst component for olefin polymerization, which comprises dissolving a magnesium compound in a solvent system containing a hydrocarbon compound and an alcohol compound, then mixing a titanium compound with the solution at-40 ℃, adding an electron donor compound at (40-50) DEG-150 ℃, and washing with an inert diluent to obtain the solid catalyst component, wherein the magnesium compound is selected from magnesium dihalides, alkoxy magnesium, alkyl magnesium, hydrates or alcohol compounds of magnesium dihalides, and derivatives of magnesium dihalides in which one halogen atom is replaced by alkoxy or halogenated alkoxy, the alcohol compound comprises aliphatic alcohol, alicyclic alcohol and aromatic alcohol, and the electron donor is at least one glycol ester compound with a specific structure. The catalyst components prepared in the above 2 patents all have good hydrogen regulation sensitivity and high isotacticity. However, the catalyst loading process is complicated, and the use of an internal electron donor with a specific structure has certain limitation.

CN 201310508859.9 discloses a catalyst component for olefin polymerization. The catalyst is prepared by reacting alkoxy magnesium or an alcohol compound thereof, a composite internal electron donor of 2 electron donors and a titanium compound. The catalyst has higher activity, but cannot simultaneously achieve high isotacticity and good hydrogen regulation sensitivity.

CN 201610943416.6 discloses a solid catalyst component for olefin polymerization, which is prepared by mixing a magnesium compound, a titanium compound and a catalystThe internal electron donor compound is contacted and reacted under certain conditions, and preferably, the magnesium compound can be MgR⁴R⁵A magnesium compound represented by the formula MgR⁴R⁵Hydrates and MgRs of the magnesium Compounds shown⁴R⁵At least one of the alcohol adducts of the magnesium compounds shown, MgR⁴R⁵In, R⁴And R⁵Each of which is one of a halogen, a linear alkoxy group having 1 to 8 carbon atoms, and a branched alkyl group having 1 to 8 carbon atoms. The internal electron donor compound comprises an amino ester compound with a specific structure. The catalyst has higher activity, but can not simultaneously achieve high isotacticity and good hydrogen regulation sensitivity.

CN 201611062232.5 provides a solid catalyst component and a catalyst for olefin polymerization, which contains Mg, Ti, halogen and optionally an electron donor, wherein the C value of the solid catalyst component particle is more than or equal to 0.7, and the C value is the average sphericity. The patent firstly reacts alcohol and magnesium powder in the presence of halogen or a compound containing halogen to obtain a dialkoxy magnesium compound, and then the dialkoxy magnesium compound is subjected to a load reaction with a titanium-containing compound, an internal electron donor and the like. The polymerization activity of the catalyst is less than 44KgPP/gcat, and the isotacticity is more than 98%.

There are reports (high efficiency carrier catalyst using magnesium powder as raw material, synthetic resin and plastics, 23 (2): 16-20, 2006), new carrier catalyst prepared by using spherical magnesium powder as raw material and reacting with titanium propoxide and titanium tetrachloride under the action of initiator iodine, isobutanol, titanium propoxide and n-butyl chloride, article investigating magnesium powder particle size distribution, initiator iodine dosage and adding SiO₂Influence on the properties of the catalyst and the polymer. The test results show that when the particle size of the spherical magnesium powder is 30-70 μm, the catalytic activity is 313 mg/(mol. h. pa), the particle size distribution of the polyethylene is 80-264 μm, and the flowability of the obtained polyethylene is good. The amount of the initiator iodine is reduced, and the catalytic activity of the catalyst is not obviously changed, but the bulk density of the polyethylene is slightly reduced. Introduction of SiO in the preparation of catalysts₂The fluidity of the polyethylene is obviously improved,the fines content of the polymer is effectively reduced from 17% to 9%, but the disadvantage is that the fines content of the polymer is still high (typically not higher than 5% fines in slurry polymerization) and the bulk density of the polymer particles is low.

Disclosure of Invention

The invention aims to provide a supported Ziegler-Natta catalyst with better performance, a preparation method of the catalyst and further application of the catalyst in propylene polymerization. The supported Ziegler-Natta catalyst comprises the following components:

a) magnesium metal;

b) a mixed alcohol containing at least one halogenated alcohol;

c) halogen and/or halogen-containing compounds;

d) a titanium-containing compound;

e) an internal electron donor compound, which is a compound having a structure,

the catalyst comprises the following components in percentage by weight per mole of metal magnesium powder: the molar ratio of the mixed alcohol b to the metal magnesium a is 2-40, and the preferred molar ratio is 4-30; the molar ratio of the halogen and/or the halogen-containing compound c to the magnesium is 0.0001 to 0.2, preferably 0.001 to 0.1; the dosage of the titanium-containing compound is 0.5-150 mol; the dosage of the internal electron donor compound is 0.02-0.5 mol.

In the component (b), the halogenated alcohol in the mixed alcohol is selected from the general formula R¹An OH compound. In the formula, R¹Is C₁～C₂₀The hydrocarbon group is a saturated or unsaturated, linear, branched or cyclic chain hydrocarbon group, and the halogen atom and the hydroxyl group are located on different saturated carbon atoms, for example, adjacent carbon atoms.

Preferably, R in said halohydrin¹Is C₁～C₆The halogen atom is selected from chlorine or bromine.

Specifically, the halogenated alcohols include, but are not limited to, 2-chloroethanol, 3-chloropropanol, 4-chlorobutanol, 5-chloropentanol, 6-chlorohexanol, 2, 2-dichloroethanol, 2, 3-dichloropropanol, 3, 4-dichlorobutanol, 4, 5-dichloropentanol, 5, 6-dichlorohexanol, 2,2, 2-trichloroethanol, 2,2, 2-trichloropropanol, 2,2, 2-chlorobutanol, 2,2, 2-trichloropentanol, 2,2, 2-trichlorohexanol, 3,3, 3-chlorobutanol, 3,3, 3-trichloropentanol, 3,3, 3-trichlorohexanol, chlorotert-butanol, 2-chlorocyclohexanol, 2-bromoethanol, 3-bromopropanol, 4-bromobutanol, 5-bromopentanol, 6-bromohexanol, 2, 2-dibromoethanol, 2, 3-dibromopropanol, 3, 4-dibromobutanol, 4, 5-dibromopentanol, 5, 6-dibromohexanol, 2,2, 2-tribromoethanol, 2,2, 2-tribromopropanol, 2,2, 2-tribromobutanol, 2,2, 2-tribromopentanol, 2,2, 2-tribromohexanol, 3,3, 3-tribromobutanol, 3,3, 3-tribromopentanol, 3, 3-tribromohexanol, tribromotert-butanol or 2-bromocyclohexanol.

The halogenated alcohol is more preferably 2,2, 2-trichloroethanol or chlorobutanol.

In the mixed alcohol, the other alcohol is selected from the general formula R²OH compound of the formula wherein R²Is C₁～C₂₀A saturated or unsaturated linear, branched or cyclic chain hydrocarbon group.

The general formula R²OH compounds include, but are not limited to, methanol, ethanol, n-propanol, n-butanol, n-pentanol, n-hexanol, n-heptanol, n-octanol, n-nonanol, n-decanol, iso-propanol, 2-butanol, 2-pentanol, 2-hexanol, 2-heptanol, 2-octanol, 2-nonanol, 2-decanol, 2-ethylbutanol, 2-ethylhexanol, 4-methyl-2-pentanol, 3, 5-trimethylpentanol, or 4-methyl-3-heptanol, preferably ethanol.

Preferably, the amount of halohydrin in the mixed alcohol is not more than 30% by weight. In order to ensure the excellent performance of the prepared catalyst component, the lower the water content in the mixed alcohol, the better, generally below 1000mg/L, preferably below 200 mg/L.

The particle shape of the magnesium metal of the component (a) is not particularly restricted, but powder having an average particle size of 10 to 300. mu.m, more preferably 30 to 200 μm is preferred, so that the average particle size of the resulting magnesium alkoxide catalyst can be controlled to 10 to 80 μm, and at the same time, the reactivity of the catalyst can be ensured to be relatively uniform, and the particle morphology of the catalyst can be relatively perfect and uniform.

Said component (c) halogen and/or halogen-containing compound, wherein halogen is selected from chlorine, bromine or iodine, preferably iodine; the halogen-containing compound is preferably halogen-containingThe metal compound is selected from MgCl₂、MgBr₂、MgI₂、Mg(OEt)Cl、Mg(OEt)I、CaCl₂NaCl, KBr, particularly MgCl₂. The form, particle size, and the like of these compounds are not particularly limited, and may be any. These halogens or halogen-containing compounds may be used alone or in combination of two or more.

The titanium-containing compound of the component (d) is selected from compounds with a general formula of T_iX_m(OR₁)_4-mThe compound of (1). In the formula R₁Is C₁～C₂₀X is halogen, m is an integer of 1-4. The method specifically comprises the following steps: titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, methoxytitanium trichloride, ethoxytitanium trichloride, propoxytitanium trichloride, n-butoxytitanium trichloride, dimethoxytitanium dichloride, diethoxytitanium dichloride, dipropoxytitanium dichloride, di-n-butoxytitanium dichloride, trimethoxytitanium chloride, triethoxytitanium chloride, tripropoxytitanium chloride or tri-n-butoxytitanium chloride. These titanium halides may be used alone or in combination of two or more. Titanium tetrachloride is most preferred.

The internal electron donor compound of the component (e) is various esters, ethers or polyoxy functional group compounds disclosed in the prior art, preferably aromatic monoester compounds, aromatic diester compounds, succinate compounds, 1, 3-diether compounds, glycol ester compounds, diacid ester compounds, glycidyl ester compounds, citrate compounds, and ring-substituted compounds containing one ether group and one ester group, wherein the ring-substituted group is preferably cyclopentadiene or fluorene. These electron-donor compounds are used singly or in combination of two or more.

In the present invention, the molar ratio of the component (b) alcohol to the component (a) magnesium metal needs to be effectively controlled. When the addition amount of the alcohol is too small, the viscosity of a reaction system is rapidly increased, and the reaction system cannot be effectively and uniformly dispersed, so that the generated particles are deteriorated; when the amount of the alcohol is too large, the resulting catalyst generally has a low bulk density and a poor particle strength. Meanwhile, the molar ratio of the halogen and/or halogen-containing compound of component (c) to the metallic magnesium of component (a) also needs to be controlled to obtain a suitable initial reaction rate.

Further, the invention discloses a method for preparing the catalyst by adopting a one-step method, which is characterized by comprising the following steps:

1) magnesium metal, general formula R²Reacting OH compounds under the action of halogen and/or halogen-containing compounds at 0-reflux temperature until no hydrogen is released;

2) maintaining the reflux temperature, adding a compound of formula R¹Continuously reacting the OH compound for 1-6 h;

3) contacting the reaction solution with a titanium-containing compound at a temperature of between 25 ℃ below zero and 20 ℃, heating to a temperature above 20 ℃, and further adding an internal electron donor compound to react for 1 to 3 hours;

4) treating the reaction product with a titanium-containing compound or a mixed solution of the titanium-containing compound and an inert organic solvent at 60-130 ℃ for 1-4 times, and then washing and drying to obtain the catalyst.

The inert organic solvent is selected from liquid aromatic hydrocarbon or alkane, the aromatic hydrocarbon includes but is not limited to benzene, toluene, xylene, ethylbenzene, propylbenzene or trimethylbenzene, and toluene or xylene is preferred; alkanes include, but are not limited to, hexane, heptane, or cyclohexane. The organic solvents may be used alone or in combination.

In the preparation process, the magnesium metal is shown in the general formula R²OH compound of the formula R¹The OH compound can be added in one portion or in batches, and the reaction rate can be better controlled by adding in batches.

The catalyst of the invention is applied to olefin CH₂The CHR polymerization reaction can obtain ideal polymer products and is suitable for homopolymerization, prepolymerization and copolymerization processes. The olefin CH₂Wherein, R is hydrogen or alkyl group containing 1-12 carbon atoms, and the alkene can be straight-chain alkene, branched-chain alkene or dialkene. Wherein said linear olefin is preferably ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-heptene, 1-nonene, 1-decene or 1-octene; the branched olefin is preferably 3-methyl-1-butene or 4-methyl-1-pentene; the diene is preferably butadiene, vinylcyclopentene or vinylcyclohexene.

The catalyst of the invention can be applied to a polymerization catalytic system formed by the catalyst and the following components according to different polymerization processes and polymerization targets:

i. the catalyst of the present invention; and

ii. general formula AlR_nX_(3-n)Wherein R is hydrogen or alkyl with 1-20 carbon atoms, X is halogen, and n is an integer not less than 0 and not more than 3; and the combination of (a) and (b),

an external electron donor compound.

The AlR_nX_(3-n)The organic aluminum compound is at least one of trialkyl aluminum compound, trialkyl aluminum, alkyl aluminum halide and alkyl aluminum hydride.

Preferably, the organoaluminium compound is selected from trimethylaluminium, triethylaluminium, triisobutylaluminium, tri-n-butylaluminium, tri-n-hexylaluminium or trioctylaluminium.

The external electron donor compound can be selected from the general formula of R'_pSi(OR₁’)_4-pSiloxane compounds of the formula (I), wherein R' and R₁' is C₁～C₁₈P is an integer of 0 to 3.

The alkoxy magnesium supported Ziegler-Natta catalyst is directly obtained by introducing the halohydrin and adopting a one-step method, has the characteristics of good form, excellent comprehensive performance and the like, is used for olefin, particularly propylene polymerization, has the polymerization activity of more than 40KgPP/gcat, has the melt index of 30g/10 min-60 g/10min, has excellent hydrogen regulation sensitivity, has the isotacticity of more than 97 percent, is suitable for the development of polymers with different brands, and has very good application prospect.

Detailed Description

The test method comprises the following steps:

1. particle size and distribution testing of the catalyst: laser particle size distribution instrument, n-hexane as dispersant, span ═ D₉₀-D₁₀)/D₅₀；

2. Ti content test of the catalyst: measuring with ultraviolet-visible spectrophotometer;

3. conditions for determining melt index of polymer: the load is 2.16Kg and the temperature is 230 ℃;

4. isotacticity measurement conditions for polymers: measured by heptane extraction (6 h boiling extraction with heptane). Two grams of dried polymer samples were extracted in an extractor with boiling heptane for 6 hours and the residue was dried to constant weight and the ratio of the weight of the polymer (g) to 2 was found to be the isotacticity.

The following examples are given to further illustrate the present invention and are not to be construed as limiting.

Example 1:

fully replacing a reactor with high-purity nitrogen, sequentially adding 0.20g of iodine and 10mL of absolute ethyl alcohol under the protection of nitrogen, stirring and dissolving, heating, adding 1.0g of 100-200-mesh magnesium powder and 10mL of absolute ethyl alcohol, maintaining reflux reaction, adding 1.0g of 100-200-mesh magnesium powder and 10mL of absolute ethyl alcohol again at an interval of 20min, adding 4.0g of magnesium powder and 50mL of absolute ethyl alcohol in 4 times in total, and maintaining reflux reaction for 3 hours after materials are added. Adding 5mL of trichloroethanol at the reflux temperature, continuously reacting for 4h, reacting the reaction solution with titanium tetrachloride at the temperature of-20 ℃, slowly heating to 40 ℃, reacting with diisobutyl phthalate for 2h, treating a solid product obtained after the reaction with titanium tetrachloride at the temperature of 130 ℃ for 2 times, washing with hexane for 4 times, wherein the amount of hexane used in each time is 80mL, and drying to obtain the supported Ziegler-Natta catalyst after the washing is finished.

Polymerization of propylene: after the reactor was purged with high-purity nitrogen gas by full displacement, 1.5mmol of triethylaluminum and 0.1mmol of diphenyldimethoxysilane were added, 10mg of the above catalyst was further added, 2.5L of liquid propylene and 1L of hydrogen (under a standard condition) were added under stirring, and the reaction was maintained at 70 ℃ for 1 hour, and the specific results are shown in Table 1.

Example 2

"5 mL of trichloroethanol" in example 1 was changed to "10 mL of trichloroethanol", and the other conditions were the same as in example 1.

Example 3

The conditions were the same as in example 1 except that "0.20 g of iodine" in example 1 was changed to "0.40 g of iodine".

Example 4

The "10 mL of absolute ethanol" initially added in example 1 was adjusted to "30 mL of absolute ethanol", and the other conditions were the same as in example 1.

Example 5

"5 mL of trichloroethanol" initially charged in example 1 was changed to "5 mL of chlorobutanol", and the other conditions were the same as in example 1.

Example 6

"5 mL of trichloroethanol" initially added in example 1 was adjusted to "5 mL of 2-chloroethanol", and the other conditions were the same as in example 1.

Example 7

"5 mL of trichloroethanol" initially added in example 1 was adjusted to "5 mL of 2, 2-dichloroethanol", and the other conditions were the same as in example 1.

Example 8

"5 mL of trichloroethanol" initially added in example 1 was adjusted to "5 mL of 2, 3-dichloropropanol", and the other conditions were the same as in example 1.

Comparative example 1

Fully replacing a reactor with high-purity nitrogen, sequentially adding 0.20g of iodine and 10mL of absolute ethyl alcohol under the protection of nitrogen, stirring to dissolve, heating, adding 1.0g of 100-200-mesh magnesium powder and 10mL of absolute ethyl alcohol, maintaining reflux reaction, adding 1.0g of 100-200-mesh magnesium powder and 10mL of absolute ethyl alcohol again at an interval of 20min, adding 4.0g of magnesium powder and 50mL of absolute ethyl alcohol in 4 times in total, maintaining reflux reaction for 3h after adding materials, washing twice with hexane, wherein the amount of hexane is 80mL each time, and drying to obtain the alkoxy magnesium carrier after washing.

Adding 50mL of titanium tetrachloride into a reactor repeatedly replaced by high-purity nitrogen, cooling to 0 ℃, adding 5g of the obtained alkoxy magnesium carrier, slowly heating to 30 ℃, adding 1.5mL of LDIBP (diisobutyl phthalate), continuously heating to 110 ℃, maintaining the reaction for 2h, then performing pressure filtration on the liquid to be clean, adding 50mL of titanium tetrachloride again, heating to 110 ℃, maintaining the reaction for 2h, performing pressure filtration on the liquid to be clean, repeating the process again, washing the obtained solid for 3 times at 50 ℃ by using 100mL of hexane, and finally drying to obtain the supported Ziegler-Natta catalyst powder. Specific results are shown in table 1.

Comparative example 2

Fully replacing a reactor with high-purity nitrogen, sequentially adding 0.20g of iodine, 10mL of absolute ethyl alcohol and 5mL of trichloroethanol under the protection of nitrogen, stirring for dissolving, heating, adding 1.0g of 100-200-mesh magnesium powder and 10mL of absolute ethyl alcohol, maintaining reflux reaction, adding 1.0g of 100-200-mesh magnesium powder and 10mL of absolute ethyl alcohol again at intervals of 20min, adding 4.0g of magnesium powder and 50mL of absolute ethyl alcohol in 4 times in total, maintaining reflux reaction for 3h after the materials are added, washing twice with hexane, wherein the using amount of hexane is 80mL each time, and drying to obtain the alkoxy magnesium carrier after the washing is finished.

TABLE 1 comparison of test data for catalysts of examples 1-8 and comparative examples 1-2

As can be seen from the data in table 1: compared with comparative examples 1-2, the catalysts for olefin polymerization prepared in examples 1-8 have higher polymerization activity and better melt index, and the isotacticity of the obtained polymer is higher, which shows that the catalyst component has excellent comprehensive performance and shows a certain synergistic effect when applied to propylene polymerization, and not only has high catalyst activity, but also has stereotactic ability and hydrogen regulation sensitivity which are better than those of the prior art.

Claims

1. A supported ziegler-natta catalyst comprising:

a) magnesium metal;

b) a mixed alcohol containing at least one halogenated alcohol;

c) halogen and/or halogen-containing compounds;

d) a titanium-containing compound;

e) an internal electron donor compound;

the halogenated alcohol in the mixed alcohol of the component b is selected from a general formula R¹OH compound of the formula¹Is C₁～C₂₀The hydrocarbon group is a saturated or unsaturated, linear, branched or cyclic chain hydrocarbon group, and the halogen atom and the hydroxyl group are located on different saturated carbon atoms; r in the halohydrin¹Is C₁～C₆The halogen atom is selected from chlorine or bromine;

in the mixed alcohol, other alcohols are selected from the general formula R²OH compound of the formula wherein R²Is C₁～C₂₀A saturated or unsaturated linear, branched or cyclic chain hydrocarbon group of (a);

the amount of the halogenated alcohol in the mixed alcohol is not more than 30 percent in percentage by weight;

the halogen and/or the halogen-containing compound in the halogen-containing compound is a halogen-containing metal compound;

the catalyst comprises the following components in percentage by weight per mole of metal magnesium powder: the molar ratio of the mixed alcohol b to the metal magnesium a is 2-40; the molar ratio of the halogen and/or the halogen-containing compound c to the magnesium is 0.0001-0.2; the dosage of the titanium-containing compound is 0.5-150 mol; the dosage of the internal electron donor compound is 0.02-0.5 mol;

the preparation process of the catalyst comprises the following specific steps:

2. The catalyst of claim 1 wherein the halohydrin is 2-chloroethanol, 3-chloropropanol, 4-chlorobutanol, 5-chloropentanol, 6-chlorohexanol, 2, 2-dichloroethanol, 2, 3-dichloropropanol, 3, 4-dichlorobutanol, 4, 5-dichloropentanol, 5, 6-dichlorohexanol, 2,2, 2-trichloroethanol, 2,2, 2-trichloropropanol, 2,2, 2-chlorobutanol, 2,2, 2-trichloropentanol, 2,2, 2-trichlorohexanol, 3,3, 3-chlorobutanol, 3,3, 3-trichloropentanol, 3,3, 3-trichlorohexanol, chlorotert-butanol, 2-chlorocyclohexanol, 2-bromoethanol, 3-bromopropanol, 4-bromobutanol, 5-bromopentanol, 6-bromohexanol, 2, 2-dibromoethanol, 2, 3-dibromopropanol, 3, 4-dibromobutanol, 4, 5-dibromopentanol, 5, 6-dibromohexanol, 2,2, 2-tribromoethanol, 2,2, 2-tribromopropanol, 2,2, 2-tribromobutanol, 2,2, 2-tribromopentanol, 2,2, 2-tribromohexanol, 3,3, 3-tribromobutanol, 3, 3-tribromopentanol, 3,3, 3-tribromohexanol, tribromotert-butanol or 2-bromocyclohexanol.

3. The catalyst of claim 2, wherein the halohydrin is 2,2, 2-trichloroethanol or chlorobutanol.

4. The catalyst of claim 1, wherein the general formula R²The OH compound is methanol, ethanol, n-propanol, n-butanol, n-pentanol, n-hexanol, n-heptanol, n-octanol, n-nonanol, n-decanol, iso-propanol, 2-butanol, 2-pentanol, 2-hexanol, 2-heptanol, 2-octanol, 2-nonanol, 2-decanol, 2-ethylbutanol, 2-ethylhexanol, 4-methyl-2-pentanol, 3, 5-trimethylpentanol or 4-methyl-3-heptanol.

5. The catalyst of claim 4, wherein the general formulaR²The OH compound is ethanol.

6. The catalyst according to claim 1, wherein the water content in the mixed alcohol is controlled to 1000mg/L or less.

7. The catalyst according to claim 6, wherein the water content in the mixed alcohol is controlled to be 200mg/L or less.

8. The catalyst of claim 1, wherein the metallic magnesium has an average particle size of 10 to 300 μm.

9. The catalyst of claim 8, wherein the metallic magnesium has an average particle size of 30-200 μm.

10. The catalyst according to claim 1, wherein the halogen and/or the halogen in the halogen-containing compound is selected from one or more of chlorine, bromine and iodine.

11. The catalyst according to claim 10, wherein the halogen and/or the halogen in the halogen-containing compound is selected from iodine.

12. Catalyst according to claim 1, characterized in that the halogen and/or the halogen-containing compound of the halogen-containing compounds is selected from MgCl₂、MgBr₂、MgI₂、Mg(OEt)Cl、Mg(OEt)I、CaCl₂One or more of NaCl and KBr.

13. Catalyst according to claim 12, characterized in that the halogen and/or the halogen-containing compound of the halogen-containing compounds is MgCl₂。

14. The catalyst of claim 1 wherein the titanium-containing compound is selected from compounds of the formula TiX_m(OR₁)_4-mA compound of (1), wherein R₁Is C₁～C₂₀X is halogen, m is an integer of 1-4.

15. The catalyst according to claim 14, characterized in that the general formula TiX_m(OR₁)_4-mThe compound of (A) is titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, methoxytitanium trichloride, ethoxytitanium trichloride, propoxytitanium trichloride, n-butoxytitanium trichloride, dimethoxytitanium dichloride, diethoxytitanium dichloride, dipropoxytitanium dichloride, di-n-butoxytitanium dichloride, trimethoxytitanium chloride, triethoxytitanium chloride, tripropoxytitanium chloride or tri-n-butoxytitanium chloride.

16. The catalyst according to claim 14, characterized in that the general formula TiX_m(OR₁)_4-mThe compound of (a) is titanium tetrachloride.

17. The catalyst of claim 1, wherein the internal electron donor compound is selected from the group consisting of esters, ethers, and polyoxy functional compounds.

18. The catalyst of claim 17, wherein the internal electron donor compound is an aromatic monoester compound, an aromatic diester compound, a succinate compound, a 1, 3-diether compound, a glycol ester compound, a diacid ester compound, a glycidyl ester compound, a citrate ester compound, or a ring-substituted compound having one ether group and one ester group.

19. The catalyst of claim 18 wherein the ring-substituted compound comprises an ether group and an ester group, and wherein the ring-substituent is a cyclopentadiene or fluorene.

20. The catalyst according to claim 1, wherein the catalyst comprises the following components in the amount ratio per mole of the magnesium powder: the molar ratio of the mixed alcohol b to the metal magnesium a is 4-30; the molar ratio of the halogen and/or the halogen-containing compound c to magnesium is 0.001 to 0.1.

21. The catalyst of claim 1 wherein the inert organic solvent is selected from the group consisting of liquid aromatic hydrocarbons and liquid alkanes.

22. The catalyst of claim 21 wherein the aromatic hydrocarbon is benzene, toluene, xylene, ethylbenzene, propylbenzene or trimethylbenzene; the alkane is hexane, heptane or cyclohexane.

23. The catalyst of claim 1, wherein during the preparation process, the magnesium metal is of the general formula R²OH compound of the formula R¹The OH compound is added in one portion or in portions.

24. The catalyst of claim 23 wherein during the preparation, the magnesium metal is of the formula R²The OH compound is added in portions.

25. The use of the catalyst of claim 1 in olefin polymerization, wherein the catalyst, the organoaluminum compound, and the external electron donor together form a catalytic system for CH₂(ii) CHR polymerization, wherein R is hydrogen or a hydrocarbyl group containing 1 to 12 carbon atoms;

the organic aluminum compound is selected from the general formula AlR_nX_(3-n)The compound is shown in the formula, wherein R is hydrogen or alkyl with 1-20 carbon atoms, X is halogen, and n is an integer which is more than or equal to 0 and less than or equal to 3;

the external electron donor is selected from a general formula R^’ _pSi(OR₁ ^’)_4-pA siloxane compound of the formula^’And R₁ ^’Is C₁～C₁₈P is an integer of 0 to 3.

26. Use of a catalyst according to claim 25 for the polymerization of olefins, characterized in that the organoaluminum compound is selected from trimethylaluminum, triethylaluminum, triisobutylaluminum, tri-n-butylaluminum, tri-n-hexylaluminum or trioctylaluminum.