CN106832069A

CN106832069A - A kind of catalyst for olefinic polymerization and preparation method thereof

Info

Publication number: CN106832069A
Application number: CN201710094734.4A
Authority: CN
Inventors: 王磊; 王振国; 陈雪
Original assignee: YingKou Viewchem Co Ltd
Current assignee: YingKou Viewchem Co Ltd
Priority date: 2017-02-22
Filing date: 2017-02-22
Publication date: 2017-06-13
Anticipated expiration: 2037-02-22
Also published as: CN106832069B

Abstract

The present invention relates to a kind of catalyst for olefinic polymerization and preparation method thereof.In reactor, under nitrogen protection, organic solvent and titanium compound are added, be cooled to 30~10 DEG C, add carrier, maintain 30~10 DEG C, stir 30~40min；It is to slowly warm up to 100~120 DEG C, electron donor compound is added in temperature-rise period, after reacting 30~40min at 100~120 DEG C, liquid is filtered off, add titanium compound, it is warming up to 110~130 DEG C, after maintaining 30~40min at 110~130 DEG C, liquid is filtered off, the solid washing for obtaining, vacuum drying, obtains target product.The present invention, by in magnesium halide alcohol adduct forming process, add forming agent and grain type controlling agent, the carrier fractions distribution of gained is set more to concentrate, the catalyst prepared using the carrier be used for alkene particularly propylene polymerization when, the activity and hydrogen response energy of catalyst, the heap medium density of gained polymerizate, and the appearance expected without abnormity substantially can be improved.

Description

Catalyst for olefin polymerization and preparation method thereof

Technical Field

The invention belongs to the field of catalysts, and particularly relates to a catalyst for olefin polymerization and a preparation method thereof.

Background

Currently, Ziegler-Natta catalysts for olefin polymerization are essentially prepared by supporting a titanium halide on a support. The carrier commonly used for preparing the Ziegler-Natta catalyst is magnesium chloride alcoholate, and the comprehensive performance of the carrier is superior to that of catalysts prepared by other carriers. The carrier magnesium chloride alcoholate can be prepared by spray drying, spray cooling, high-pressure extrusion, high-speed stirring, emulsion molding, super-gravity rotating bed and other methods. However, the catalyst prepared from the carrier obtained by the method is easy to break polymer particles in the process of catalyzing olefin polymerization, and causes the phenomenon of excessive fine powder. Although attempts have been made to add an electron donor compound during the preparation process to obtain a composite spherical carrier, and then reacting the carrier with titanium tetrachloride to form the catalyst. However, the complex spherical carrier is easily sticky during the preparation process, and is difficult to form spherical particles with proper particle size.

In the prior art, the methods for preparing catalysts for the polymerization of olefins are mainly: firstly, preparing a carrier by reacting a magnesium halide alcoholate with an ethylene oxide compound, and directly adding the magnesium halide alcoholate into a reactor containing the ethylene oxide compound after melting and dispersing the magnesium halide alcoholate. ② dissolving magnesium chloride by epoxide and tributyl phosphate compound to form uniform solution, then separating out carrier and carrying out titanium load by titanium tetrachloride, the reaction product is complex, the produced by-product is difficult to process, and some auxiliary separating agent is used in the process of separating out titanium tetrachloride, which makes the reaction by-product more complex. In addition, because the alcohol is added into the dissolving system, although the dissolving action of tributyl phosphate and epoxy compound is accelerated by the addition of the alcohol, the alcohol can react with titanium tetrachloride, and the subsequent catalyst morphology and performance are affected. Since titanium tetrachloride is used to precipitate out the carrier to prepare the catalyst, the reaction in this process is complicated and the waste liquid cannot be recovered. CN102040680A reports a new magnesium adduct carrier (I) with complex structure, and the olefin polymerization catalyst prepared by the carrier has higher catalytic activity and orientation capability and better hydrogen regulation sensitivity. However, the preparation of the carrier needs to prepare a corresponding magnesium halide adduct first and then carry out contact reaction with the alkylene oxide compound to obtain the carrier, and the steps are complicated and the reaction controllability is poor. And fourthly, the preparation of the catalyst is also reported by adopting an alkoxy magnesium carrier to load a titanium metal compound, wherein the alkoxy magnesium carrier is prepared by reacting metal magnesium with ethanol, but the defects of low bulk density of the obtained polymer and the like exist.

Disclosure of Invention

In order to overcome the problems of the prior art, it is an object of the present invention to provide a catalyst for olefin polymerization.

It is another object of the present invention to provide a process for the preparation of a catalyst for the polymerization of olefins.

The technical scheme adopted by the invention is as follows: a catalyst for olefin polymerization is prepared by the following steps: adding an organic solvent and a titanium compound into a reaction kettle under the protection of nitrogen, cooling to-30 to-10 ℃, adding a carrier, maintaining the temperature at-30 to-10 ℃, and stirring for 30-40 min; slowly heating to 100-120 ℃, adding an electron donor compound in the heating process, reacting for 30-40 min at 100-120 ℃, filtering out liquid, adding a titanium compound, heating to 110-130 ℃, reacting for 30-40 min at 110-130 ℃, filtering out liquid, washing the obtained solid, and drying in vacuum to obtain the target product.

In the present invention, the titanium compound is represented by the general formula [ Ti (OR')_4-qA_q]The titanium compound shown in the formula (I), wherein,

r' is selected from C₁～C₃₀Aliphatic hydrocarbon groups or aromatic hydrocarbon groups of (1); preferably, R' is selected from C₁～C₂₀Alkyl, alkenyl, aralkyl or aryl. More preferably, R' is selected from one of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, n-hexyl, isohexyl, n-heptyl, n-octyl, n-decyl, allyl, butenyl, cyclopentyl, cyclohexyl, cyclohexenyl, benzyl, phenethyl, phenyl, tolyl, and ethylphenyl.

A is a halogen atom. Preferably, A is a chlorine atom or a bromine atom. More preferably, A is a chlorine atom.

q is an integer of 0 to 4; when q is 2,3 or 4, the multiple R's present may be the same or different.

Further, the general formula is [ Ti (OR')_4-qA_q]The titanium compound is a titanium tetraalkoxide, a titanium tetrahalide, a titanium trialkoxyhalide, a titanium dialkoxide dihalide or a titanium alkoxytrihalide.

Further, the general formula is[Ti(OR″)_4-qA_q]The titanium compound is one of tetramethoxytitanium, tetraethoxytitanium, tetra-n-propoxytitanium, tetra-isopropoxytitanium, tetra-n-butoxytitanium, tetra-isobutoxytitanium, tetra-tert-butoxytitanium, tetracyclohexyloxytitanium and tetraphenoxytitanium. The titanium tetrahalide is one of titanium tetrachloride, titanium tetrabromide or titanium tetraiodide. The trialkoxy titanium halide is one of trimethoxy titanium chloride, triethoxy titanium chloride, tri-n-propoxyl titanium chloride, triisopropoxyl titanium chloride, tri-n-butoxytitanium chloride, triisobutoxy titanium chloride, triphenoxytitanium chloride, trimethoxy titanium bromide, triethoxy titanium bromide, tri-n-propoxyl titanium bromide, triisopropoxyl titanium bromide, tri-n-butoxytitanium bromide, triisobutoxy titanium bromide or triphenoxytitanium bromide. The dialkoxy titanium dihalide is one of dimethoxy titanium dichloride, diethoxy titanium dichloride, di-n-propoxy titanium dichloride, diisopropoxy titanium dichloride, di-n-butoxy titanium dichloride, diisobutoxy titanium dichloride and diphenoxy titanium dichloride, dimethoxy titanium dibromide, diethoxy titanium dibromide, di-n-propoxy titanium dibromide, diisopropoxy titanium dibromide, di-n-butoxy titanium dibromide, diisobutoxy titanium dibromide or diphenoxy titanium dibromide.

By molar ratio, Mg in the carrier²⁺The titanium compound is 1:0.1 to 200.

In the invention, the carrier is a magnesium compound represented by a general formula { (MgXY) m { (Mg (OR') Z) ] p · (ROH) n }; wherein,

x and Y are each independently bromine or chlorine; preferably, both X and Y are chlorine.

R and R' may be the same or different, and are preferably C₁～C₁₀Linear or branched alkyl of (a); more preferably C₂～C₅Linear or branched alkyl of (a); further, ethyl, propyl, butyl or pentyl.

Z is preferably C₁～C₁₀Straight or branched alkyl or alkoxy of(ii) a More preferably C₂～C₅Linear or branched alkyl or alkoxy.

m is 0.001-2; preferably, m is 0.01 to 1.

p is 0.01 to 0.10; preferably, p is 0.05 to 0.2.

n is 1.5-3; preferably, n is 2.5 to 2.7.

The preparation method of the magnesium compound shown by the general formula { (MgXY) m { (Mg (OR') Z) ] p · (ROH) n } is as follows:

1) mixing magnesium halide with a general formula of MgXY, a compound with a general formula of ROH, a halogenating agent serving as a grain type control agent and a first inert medium, adding or not adding a surfactant, and heating at 90-150 ℃ for 0.5-5 hours to obtain a liquid mixture. Preferably, the temperature is 110-130 ℃ and the time is 2-3 hours.

2) Emulsifying the liquid mixture obtained in the step 1), introducing the emulsified product into a second inert medium cooled to-40 ℃ to 10 ℃ for rapid cooling and forming, carrying out solid-liquid separation to obtain a spherical carrier, washing and drying to obtain the target product. Preferably, the emulsified product is rapidly cooled and formed in a second inert medium which is cooled to-30 ℃ to-20 ℃. The solid-liquid separation can adopt various existing methods for realizing the solid-liquid separation, such as suction filtration, filter pressing or centrifugal separation, and the preferable solid-liquid separation is filter pressing. The solid product can be washed by methods known to those skilled in the art, for example, the obtained solid product can be washed by an inert hydrocarbon solvent (pentane, hexane, heptane, petroleum ether, gasoline, etc.), and the number of washing times is preferably 3-5. The drying conditions are not particularly limited, for example, the drying temperature may be 30 to 60 ℃, the drying time may be 0.5 to 10 hours, and the drying may be performed under normal pressure or reduced pressure.

Wherein the compound of formula Mg (OR') Z is added either to the first inert medium in step 1) OR to the second inert medium in step 2).

The MgXY is preferably magnesium dichloride or magnesium dibromide, and is more preferably magnesium dichloride.

The surfactant is selected from fatty glyceride, sorbitan fatty acid, polysorbate, polyoxyethylene ether or polyoxyethylene-polyoxypropylene copolymer. In molar ratio, Mg²⁺The surfactant is 1: 0.001-1.

The halogenating agent used as the particle type control agent is selected from iodine, bromine, chlorine, sodium chloride, sodium bromide, sodium iodide, zinc chloride, zinc iodide, zinc bromide, calcium chloride, calcium bromide, calcium iodide, manganese chloride, manganese iodide, manganese bromide, potassium chloride, potassium iodide, potassium bromide, mercury chloride, mercury iodide or mercury bromide. In molar ratio, Mg²⁺The particle-type control agent is a halogenating agent of 1:0.005 to 1, more preferably 1:0.01 to 0.5.

The compound with the general formula of ROH is selected from one or a mixture of more than two of ethanol, n-propanol, isopropanol, n-butanol, isobutanol, n-pentanol, isoamyl alcohol, n-hexanol, n-octanol and 2-ethyl-1-hexanol. Preferably one or a mixture of two or more of ethanol, n-propanol, isopropanol, n-butanol, isobutanol, n-pentanol and isoamyl alcohol. In the present invention, the amount of the magnesium halide represented by the formula MgXY and the compound represented by the formula ROH to be used may be selected depending on the composition of the compound represented by the formula. Preferably, each mole of Mg²⁺The amount of the compound represented by the general formula ROH is 1 to 6 mol, and more preferably 2 to 3 mol.

The compound shown as the general formula Mg (OR') Z is selected from ethyl ethoxy magnesium, propyl ethoxy magnesium, butyl ethoxy magnesium, ethyl propoxy magnesium, propyl propoxy magnesium, diethoxy magnesium, dipropoxy magnesium, dibutoxy magnesium, ethoxy magnesium chloride, ethoxy magnesium iodide, propoxy magnesium chloride OR propoxy magnesium iodide. Per mole of Mg²⁺The amount of the compound represented by the general formula Mg (OR') Z is 0.005 to 5 mol, more preferably (0.01 to 1): 1.

the first inert medium is not in a chemical phase with the magnesium chloride adductThe liquid medium of interaction. The first inert medium may be silicone oil, white oil or high boiling point hydrocarbons. Specifically, the oil may be one or a mixture of two or more of kerosene, paraffin oil, vaseline oil, white oil, methyl silicone oil, ethyl silicone oil, methyl ethyl silicone oil, phenyl silicone oil, methylphenyl silicone oil, decane, toluene, xylene and mesitylene, and white oil and xylene are preferable. In the present invention, the amount of the first inert medium is chosen according to the amount of MgXY used, per mole of Mg²⁺Adding 0.1-15L of first inert medium, preferably 0.5-10L.

The second inert medium is a liquid which does not have chemical action with reactants or reaction products, and can be a hydrocarbon solvent with a lower boiling point, such as one or a mixture of more than two of hexane, heptane, decane or toluene; hexane or heptane is preferred. Per mole of Mg²⁺And adding 0.1-20L of a second inert medium, preferably 1-15L.

In the present invention, the electron donor compound includes esters, ethers, ketones, amines and the like, and preferably, the electron donor compound is selected from one or more of aliphatic and/or aromatic monocarboxylic acid esters, aliphatic and/or aromatic polycarboxylic acid esters, aliphatic ethers and/or aromatic phenol ethers, cycloaliphatic ethers, aliphatic ketones, and aliphatic and/or aromatic amines. More preferably, said electron donor compound is selected from C₁～C₅Alkyl esters of saturated fatty carboxylic acids, C₆～C₁₀Alkyl esters of aromatic carboxylic acids, C₂～C₈Fatty ethers of (2), C₃～C₆Cyclic ether, C₃～C₇Aliphatic ketones and amines.

Further, the electron donor compound is selected from the group consisting of ethyl formate, ethyl acetate, ethyl propionate, butyl acetate, di-n-butyl phthalate, diisobutyl phthalate, di-n-pentyl phthalate, diisopentyl phthalate, di-tert-pentyl phthalate, dioctyl phthalate, diisooctyl phthalate, 1, 3-dipentyl phthalate, diethyl malonate, di-n-butyl malonate, diisobutyl malonate, di-n-pentyl malonate, diisopentyl malonate, diethyl 2-n-propylmalonate, diethyl 2-isopropylmalonate, diethyl 2-n-butylmalonate, diethyl 2-isobutylmalonate, diethyl 2-n-pentylmalonate, diethyl 2-isoamylmalonate, diethyl 2-cyclopentylmalonate, diethyl 2-isobutylmalonate, diethyl 2-pentylmalonate, diethyl 2-isopropylmalonate, diethyl 2-cyclopentylmalonate, diethyl 2-octylmalonate, diethyl phthalate, and mixtures thereof, 2, 2-diisopropyl diethyl malonate, 2-methyl-2-isopropyl diethyl malonate, 2-ethyl-2-isopropyl diethyl malonate, diethyl succinate, 2-n-propyl diethyl succinate, 2-isopropyl diethyl succinate, 2-n-butyl diethyl succinate, 2-isobutyl diethyl succinate, 2-n-pentyl diethyl succinate, 2-isopentyl diethyl succinate, 2-cyclopentyl diethyl succinate, 2-cyclohexyl diethyl succinate, 2, 3-di-isopropyl dibutyl succinate, 2, 3-di-isobutyl dibutyl succinate, diethyl ether, hexyl ether, cyclohexyl ether, tetrahydrofuran, tetrahydropyran, acetone and methyl isobutyl ketone.

By molar ratio, Mg in the carrier²⁺The electron donor compound is 1: 0.005-10, preferably 1: 0.01-5.

The invention has the beneficial effects that:

1. the present inventors have surprisingly found that during the process of carrying out the support (MgXY) m (ROH) n for an olefin polymerization catalyst, Mg (OR') Z is added as a co-former, a halogenating agent is added as a particle-type control agent and an inert solvent is added as a diluent. The novel catalyst carrier has good particle shape, smooth surface and no abnormal particles, and when the catalyst prepared by the carrier is used for olefin polymerization (especially propylene polymerization), the bulk density of a polymerization product is lower than that of a polymer prepared by a conventional magnesium chloride alcoholate carrier catalyst, but higher than that of a polymer prepared by a conventional alkoxy magnesium carrier catalyst. In addition, the particle form of the carrier is good, the hydrogen response of the obtained catalyst is high, and the fine powder content of the polymer is low.

2. In the invention, the forming agent and the grain type control agent are added in the process of forming the magnesium halide alcohol compound, so that the grain size distribution of the obtained carrier is more concentrated, when the catalyst prepared by using the carrier is used for olefin, particularly propylene polymerization, the activity and the hydrogen regulation sensitivity of the catalyst can be improved, the bulk density of the obtained polymerization product is moderate, and no special-shaped material is basically generated.

3. The carrier prepared by the method has the average particle size (average particle diameter) of 10-100 microns and the particle size distribution of less than 1.3.

4. The carrier of the olefin polymerization catalyst prepared by the method has good particle shape and spherical shape, and has no particle stickiness phenomenon in the preparation process. The surface is smooth, no special-shaped particles exist basically, and the catalyst prepared by using the adduct obtained by the invention as a carrier shows better hydrogen regulation sensitivity and higher stereospecific capacity when used for propylene polymerization reaction, so that the good balance between the hydrogen regulation capacity and the stereospecific capacity of the catalyst is obtained, and the comprehensive performance is better.

Drawings

Fig. 1 is an optical microscopic view of the support prepared in example 1.

Fig. 2 is an optical microscopic view of the support prepared in example 2.

Detailed Description

The following specific examples are intended to illustrate the invention in further detail and are not to be construed as limiting the invention.

Example 1

Preparation of the support

150ml of white oil, 30g of magnesium chloride, 50ml of absolute ethyl alcohol, 2.0g of diethoxymagnesium and 0.012g of sodium chloride are added into a 500ml reaction kettle, and the mixture is heated to 125 ℃ under stirring and reacts for 2 hours at constant temperature to obtain a liquid mixture.

The liquid mixture is pressed into 300ml of methyl silicone oil preheated to 125 ℃, and dispersed and emulsified for 30min by high-speed stirring (1600 rpm).

Introducing the emulsified product into 2L hexane solution cooled to-35 deg.C, rapidly cooling, and dispersing into small droplets of MgCl₂The alcohol polymer melt is cooled, solidified and molded into spherical particles. The liquid was removed by filtration, and the solid was washed 5 times with 300ml of hexane and dried under vacuum at 30 ℃ for 1 hour to obtain a magnesium chloride alcoholate solid carrier.

By infrared spectroscopy and¹after HNMR nuclear magnetic measurement and analysis, the structure of the product is determined to be { MgCl₂·[Mg(OEt)₂]_0.04·(EtOH)_2.6}。

The morphology of the carrier was observed by an optical microscope using Eclipse E200 from Nikon, and as shown in FIG. 1, the particle morphology of the carrier was better as seen in FIG. 1.

The average particle diameter of the carrier and the particle size distribution thereof were measured by a Master Sizer 2000 laser particle Sizer (manufactured by Malvern instruments Ltd.), and the average particle diameter (average particle diameter) was 10 to 100 μm and the particle size distribution was less than 1.3.

(II) preparation of a catalyst for olefin polymerization:

in a 300ml glass reaction kettle, under the protection of nitrogen, 18ml of hexane and 90ml of titanium tetrachloride are sequentially added, the mixture is cooled to-20 ℃, 8.0g of the prepared carrier is added, and the mixture is stirred for 30min under the condition of maintaining the temperature of-20 ℃. The temperature was slowly raised to 110 ℃ and 1.5g of diisobutylphthalate was added during the temperature rise. After 30min of isothermal reaction at 110 ℃, the liquid was filtered off.

Adding 80ml titanium tetrachloride into the obtained solid, heating to 120 deg.C, maintaining at 120 deg.C for 30min, filtering to remove liquid, repeating the operation once, filtering, and removing filtrate.

The solid obtained was washed 5 times with hexane (80 ml/time). Vacuum drying to obtain the catalyst for olefin polymerization.

Example 2

Preparation of the support

150ml of white oil, 30g of magnesium chloride, 50ml of absolute ethyl alcohol, 4.0g of diethoxymagnesium and 0.012g of sodium chloride are added into a 500ml reaction kettle, and the mixture is heated to 125 ℃ under stirring and reacts for 2 hours at constant temperature to obtain a liquid mixture.

The composition of the resulting magnesium halide adduct is { MgCl₂·[Mg(OEt)₂]_0.08·(EtOH)_2.6}。

The morphology of the support was observed by an optical microscope of Eclipse E200 from Nikon, as shown in FIG. 2, and as can be seen from FIG. 2, the magnesium halide adduct was spherical, no profile was present, and no blocking was observed between the particles.

(II) preparation of a catalyst for olefin polymerization: the procedure was as in (two) of example 1.

Example 3

Preparation of the support

150ml of white oil, 30g of magnesium chloride, 50ml of absolute ethyl alcohol, 2.0g of diethoxymagnesium and 0.015g of manganese chloride are added into a 500ml reaction kettle, the temperature is raised to 125 ℃ under stirring, and after 2 hours of constant temperature reaction, a liquid mixture is obtained.

Example 4

Preparation of the support

150ml of white oil, 30g of magnesium chloride, 50ml of absolute ethyl alcohol, 2.0g of diethoxymagnesium and 0.018g of zinc chloride are added into a 500ml reaction kettle, and the mixture is heated to 125 ℃ under stirring and reacts for 2 hours at constant temperature to obtain a liquid mixture.

The emulsified product was introduced into 2L of hexane solution (containing 0.018g of zinc chloride) previously cooled to-35 ℃ and, after rapid cooling, dispersed as MgCl in small droplets₂The alcohol polymer melt is cooled, solidified and molded into spherical particles. The liquid was removed by filtration, and the solid was washed 5 times with 300ml of hexane and dried under vacuum at 30 ℃ for 1 hour to obtain a magnesium chloride alcoholate solid carrier.

Example 5

Preparation of the support

150ml of white oil, 30g of magnesium chloride, 50ml of absolute ethyl alcohol and 0.012g of sodium chloride are added into a 500ml reaction kettle, the temperature is raised to 125 ℃ under stirring, and after 2 hours of constant temperature reaction, a liquid mixture is obtained.

The emulsified product was introduced into 2L of hexane solution (containing 2.0g of diethoxymagnesium) previously cooled to-35 ℃ and, after rapid cooling, MgCl dispersed as small droplets₂The alcohol polymer melt is cooled, solidified and molded into spherical particles. The liquid was removed by filtration, and the solid was washed 5 times with 300ml of hexane and dried under vacuum at 30 ℃ for 1 hour to obtain a magnesium chloride alcoholate solid carrier.

Example 6

Preparation of the support

150ml of white oil, 30g of magnesium chloride, 50ml of absolute ethyl alcohol, 2.0g of diethoxymagnesium, 0.012g of sodium chloride and 2.0g of polyoxyethylene ether are added into a 500ml reaction kettle, the temperature is raised to 125 ℃ under stirring, and after 2 hours of constant temperature reaction, a liquid mixture is obtained.

Example 7 application

1. Comparative catalyst

Preparation of comparative support: the same procedure as in example 1 was followed, except that diethoxymagnesium was not used. The comparative support is MgCl₂·(EtOH)_2.6。

Comparative catalyst preparation: in a 300ml glass reaction kettle, under the protection of nitrogen, 18ml of hexane and 90ml of titanium tetrachloride are sequentially added, the temperature is cooled to-20 ℃, 8.0g of contrast carrier is added, and the mixture is stirred for 30min under the condition of maintaining the temperature at-20 ℃. The temperature was slowly raised to 110 ℃ and 1.5g of diisobutylphthalate was added during the temperature rise. After 30min of isothermal reaction at 110 ℃, the liquid was filtered off. 80ml titanium tetrachloride was added, the temperature was raised to 120 ℃ and maintained at 120 ℃ for 30min, and the liquid was filtered off, and the above operation was repeated once. The solid obtained was finally washed 5 times with hexane (80 ml/time). Vacuum drying gave the comparative catalyst.

2. Catalytic olefin polymerization

In a 5L stainless steel autoclave, 5ml of a hexane solution of triethylaluminum (concentration: 0.5mmol/ml), 1ml of a hexane solution of methylcyclohexyldimethoxysilane (concentration: 0.1mmol/ml) and 9mg of the catalyst for olefin polymerization prepared in examples 1 to 5 were sequentially charged into the autoclave under a nitrogen atmosphere. The autoclave was closed and 1.5L of hydrogen (or 5.0L of hydrogen, or 8.0L of hydrogen, standard volume) and 2.3L of liquid propylene were added. The temperature was raised to 70 ℃ and the reaction was carried out for 1 hour. The temperature is reduced, the pressure is relieved, the material is discharged and dried to obtain polymer powder, and the results are shown in Table 1.

TABLE 1

Table 1 shows the polymerization results of the catalysts prepared in examples 1 to 6 and comparative example when they were used for catalyzing the polymerization of propylene. As can be seen from table 1, compared with the catalyst prepared by using the adduct as the carrier in the prior art, the catalyst prepared by using the carrier obtained by the method of the present invention shows more excellent hydrogen response and higher stereospecific capacity when being used for catalyzing propylene polymerization, and the hydrogen response and the stereospecific capacity of the catalyst reach better balance, that is, the polymer with higher melt index obtained under high hydrogen concentration still has higher isotactic index; in addition, the catalyst obtained by the invention has good particle shape of the polymer obtained by catalyzing propylene polymerization, can reduce the bulk density of the polymer and basically has no appearance of abnormal materials.

In a word, the olefin polymerization catalyst prepared by the method shows better hydrogen regulation sensitivity and higher stereospecific capacity when used for propylene polymerization reaction, obtains good balance between the hydrogen regulation capacity and the stereospecific capacity of the catalyst, and has better comprehensive performance.

The preferred embodiments of the present invention have been described in detail, but the present invention is not limited to the specific details of the above embodiments, and various simple modifications can be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications also belong to the protection scope of the present invention.

It should be noted that the various features described in the above embodiments may be combined in any suitable manner without departing from the scope of the invention. The invention is not described in detail in order to avoid unnecessary repetition.

In addition, various embodiments of the present invention can be combined arbitrarily, and the same should be regarded as the disclosure of the present invention as long as it does not depart from the idea of the present invention.

Claims

1. A catalyst for olefin polymerization, which is prepared by the following steps: adding an organic solvent and a titanium compound into a reaction kettle under the protection of nitrogen, cooling to-30 to-10 ℃, adding a carrier, maintaining the temperature at-30 to-10 ℃, and stirring for 30-40 min; slowly heating to 100-120 ℃, adding an electron donor compound in the heating process, reacting at 100-120 ℃ for 30-40 min, filtering out liquid, adding a titanium compound, heating to 110-130 ℃, reacting at 110-130 ℃ for 30-40 min, filtering out liquid, washing the obtained solid, and drying in vacuum to obtain a target product;

the titanium compound is represented by the general formula [ Ti (OR')_4-qA_q]A titanium compound as shown; wherein R' is selected from C₁～C₃₀A is a halogen atom, and q is an integer of 0 to 4; when q is 2,3 or 4, the multiple R's present may be the same or different;

the carrier is represented by the general formula { (MgXY) m · [ (Mg (OR') Z)]A magnesium compound represented by p (ROH) n }; wherein X and Y are each independently bromine or chlorine; r and R' may be the same or different and are C₁～C₁₀Linear or branched alkyl of (a); z is C₁～C₁₀Linear or branched alkyl or alkoxy of (a); m is 0.001-2; p is 0.01 to 0.10; n is 1.5-3;

the electron donor compound is aliphatic and/or aromatic monocarboxylic acid ester, aliphatic and/or aromatic polycarboxylic acid ester, aliphatic ether and/or aromatic phenol ether, cycloaliphatic ether, aliphatic ketone, aliphatic and/or aromatic amine compound.

2. The catalyst for the polymerization of olefins according to claim 1, characterized in that said formula is [ Ti (OR ")_4-qA_q]The titanium compound shown in the specification, R' is selected from C₁～C₂₀Alkyl, alkenyl, aralkyl or aryl of (a); a is a chlorine atom or a bromine atom; by molar ratio, Mg in the carrier²⁺The titanium compound is 1:0.1 to 200.

3. The catalyst for the polymerization of olefins according to claim 2 characterized in that said formula is [ Ti (OR ")_4-qA_q]In the titanium compound shown, R' is selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, n-hexyl, isohexyl, n-heptyl, n-octyl, n-decyl, allyl, butenyl, cyclopentyl, cyclohexyl, cyclohexenyl, benzyl, phenethyl, phenyl, tolyl or ethylbenzene group.

4. The catalyst for the polymerization of olefins according to claim 3 characterized in that said formula is [ Ti (OR ")_4-qA_q]The titanium compound is tetraalkoxytitanium, titanium tetrahalide, trialkoxytitanium halide, dialkoxytitanium dihalide, alkoxytitanium trihalide.

5. The catalyst for olefin polymerization as claimed in claim 4, wherein the titanium tetraalkoxide is titanium tetramethoxide, titanium tetraethoxide, titanium tetra-n-propoxide, titanium tetraisopropoxide, titanium tetra-n-butoxide, titanium tetra-isobutoxide, titanium tetra-t-butoxide, titanium tetracyclohexyloxide or titanium tetraphenoxide; the titanium tetrahalide is titanium tetrachloride, titanium tetrabromide or titanium tetraiodide; the trialkoxytitanium halide is trimethoxytitanium chloride, triethoxytitanium chloride, tri-n-propoxytitanium chloride, triisopropoxytitanium chloride, tri-n-butoxytitanium chloride, triisobutoxytitanium chloride, triphenoxytitanium chloride, trimethoxytitanium bromide, triethoxytitanium bromide, tri-n-propoxytitanium bromide, triisopropoxytitanium bromide, tri-n-butoxytitanium bromide, triisobutoxytitanium bromide or triphenoxytitanium bromide; the dialkoxy titanium dihalide is dimethoxy titanium dichloride, diethoxy titanium dichloride, di-n-propoxy titanium dichloride, diisopropoxy titanium dichloride, di-n-butoxy titanium dichloride, diisobutoxy titanium dichloride and diphenoxy titanium dichloride, and the dialkoxy titanium dibromide, diethoxy titanium dibromide, di-n-propoxy titanium dibromide, diisopropoxy titanium dibromide, di-n-butoxy titanium dibromide, diisobutoxy titanium dibromide or diphenoxy titanium dibromide.

6. The catalyst of claim 1, wherein the magnesium compound represented by the formula { (MgXY) m { (Mg (OR') Z) ] p · (ROH) n } is prepared by the following method:

1) mixing magnesium halide with a general formula of MgXY, a compound with a general formula of ROH, a halogenating agent serving as a grain type control agent and a first inert medium, adding or not adding a surfactant, and heating at 90-150 ℃ for 0.5-5 hours to obtain a liquid mixture;

2) emulsifying the liquid mixture obtained in the step 1), introducing the emulsified product into a second inert medium cooled to-40 ℃ to 10 ℃, cooling, filtering, washing and drying to obtain a target product;

7. The catalyst for olefin polymerization as claimed in claim 6, wherein the MgXY is MgCl₂(ii) a The surfactant is selected from fatty glyceride, sorbitan fatty acid, polysorbate, polyoxyethylene ether or polyoxyethylene-polyoxypropylene copolymer; the halogenating agent used as the particle type control agent is selected from iodine, bromine, chlorine, sodium chloride, sodium bromide, sodium iodide, zinc chloride, zinc iodide, zinc bromide, calcium chloride, calcium bromide, calcium iodide, manganese chloride, manganese iodide, manganese bromide, potassium chloride, potassium iodide, potassium bromide, mercury chloride, mercury iodide or mercury bromide; the compound with the general formula of ROH is selected from one or a mixture of more than two of ethanol, n-propanol, isopropanol, n-butanol, isobutanol, n-pentanol, isoamyl alcohol, n-hexanol, n-octanol and 2-ethyl-1-hexanol; the compound shown as the general formula Mg (OR') Z is selected from ethyl ethoxy magnesium, propyl ethoxy magnesium, butyl ethoxy magnesium, ethyl propoxy magnesium, propyl propoxy magnesium, diethoxy magnesium, dipropoxy magnesium, dibutoxy magnesium, ethoxy magnesium chloride, ethoxy magnesium iodide, propoxy magnesium chloride OR propoxy magnesium iodide; the first inert medium is selected from kerosene, paraffin oil, vaseline oil, white oil, methyl silicone oil, ethyl silicone oil, methyl ethyl silicone oil, phenyl silicone oil, methyl phenyl silicone oil, decane, toluene, xylene or triphenyl; the second inert medium is selected from hexane, heptane, decane or toluene.

8. Catalyst for the polymerization of olefins according to claim 6 or 7Agent characterized by, in molar ratio, Mg²⁺The surfactant is 1: 0.001-1; in molar ratio, Mg²⁺A particle-type control agent which is a halogenating agent in a ratio of 1: 0.005-1; per mole of Mg²⁺The dosage of the compound shown as the general formula ROH is 1-6 mol; per mole of Mg²⁺The compound represented by the general formula Mg (OR') Z is used in an amount of 0.005 to 5 mol; per mole of Mg²⁺Adding 0.1-15L of a first inert medium; per mole of Mg²⁺And adding 0.1-20L of a second inert medium.

9. The catalyst as claimed in claim 1, wherein the electron donor compound is selected from C₁～C₅Alkyl esters of saturated fatty carboxylic acids, C₆～C₁₀Alkyl esters of aromatic carboxylic acids, C₂～C₈Fatty ethers of (2), C₃～C₆Cyclic ether, C₃～C₇Aliphatic ketones and amines of (a); by molar ratio, Mg in the carrier²⁺The electron donor compound is 1: 0.005-10.

10. The catalyst of claim 9, wherein the electron donor compound is selected from the group consisting of ethyl formate, ethyl acetate, ethyl propionate, butyl acetate, di-n-butyl phthalate, diisobutyl phthalate, di-n-pentyl phthalate, diisopentyl phthalate, di-t-pentyl phthalate, dioctyl phthalate, diisooctyl phthalate, 1, 3-dipentyl phthalate, diethyl malonate, di-n-butyl malonate, diisobutyl malonate, di-n-pentyl malonate, diisopentyl malonate, diethyl 2-n-propylmalonate, diethyl 2-isopropylmalonate, diethyl 2-n-butylmalonate, diethyl 2-isobutylmalonate, diethyl 2-n-pentylmalonate, diethyl 2-isopentylmalonate, Diethyl 2-cyclopentylmalonate, diethyl 2, 2-diisopropylmalonate, diethyl 2-methyl-2-isopropylmalonate, diethyl 2-ethyl-2-isopropylmalonate, diethyl succinate, diethyl 2-n-propylsuccinate, diethyl 2-isopropylsuccinate, diethyl 2-n-butylsuccinate, diethyl 2-isobutylsuccinate, diethyl 2-n-pentylsuccinate, diethyl 2-isopentylsuccinate, one of 2-cyclopentyl diethyl succinate, 2-cyclohexyl diethyl succinate, 2, 3-di-isopropyl dibutyl succinate, 2, 3-di-isobutyl dibutyl succinate, diethyl ether, hexyl ether, cyclohexyl ether, tetrahydrofuran, tetrahydropyran, acetone and methyl isobutyl ketone.