Catalyst for olefin polymerization and preparation method and application thereof

Abstract

The invention provides a catalyst for olefin polymerization as well as a preparation method and application of the catalyst. The catalyst comprises titanium, magnesium, halogen and a (2-oxopropyl) phosphonate internal electron donor, wherein the (2-oxopropyl) phosphonate internal electron donor has a structure as shown in a formula I: # imgabs0 #, in the formula I, R1 and R2 are the same or different, and are respectively and independently selected from linear alkyl of C1-C20, branched alkyl of C1-C20, naphthenic base of C3-C20, aryl of C6-C20, alkaryl of C7-C20, alkoxyaryl of C7-C20 and aryl alkyl of C7-C20. The catalyst has high catalytic activity, and the obtained product has good isotacticity.

Description

Technical Field

[0001] The invention provides a catalyst for olefin polymerization and a preparation method and application thereof, belonging to the field of catalysts. Background Art

[0002] With the continuous development of the plastics industry, medical technology and biotechnology, as well as people's increasing concern for health, polyolefin materials have been increasingly used in the medical field due to their safety and non-toxicity. However, the quality of polypropylene resins currently produced is poor, and one of the main reasons is that the ash content is too high. To reduce the ash content in PP, the catalyst must have the following characteristics: (1) high polymerization activity, high PP yield per unit catalyst, low PP ash content, and as the amount of catalyst is reduced, the chlorine content in the powder is greatly reduced, and the amount of calcium stearate used in the production process can also be reduced accordingly; (2) it can maintain a high polymerization activity at a low alkyl aluminum concentration, which can reduce the amount of alkyl aluminum used and reduce the ash introduced by aluminum.

[0003] As one of the important components of Ziegler-Natta catalyst, internal electron donor compound plays a vital role in improving the performance of catalyst. It can not only improve the directional ability of catalyst, but also improve the activity of catalyst.

[0004] The invention of 1,3-diether electron donor compounds has significantly improved the catalytic activity of catalysts and the isotacticity of polymers. People have conducted detailed research on the structures of different 1,3-diether electron donor compounds and the performance of the catalysts obtained therefrom, such as: CN1473809A, CN1376722A, CN1298887A, CN1268957A, CN1143651A, CN1141303A, CN1141285A; EP0728770A1, EP0728724A1, EP0361493A1, US5095153A, US5068213A, US4978648A, etc.

[0005] CN1313869A discloses a catalyst prepared by using succinate or substituted succinate compounds as internal electron donor components, but the catalytic activity of propylene polymerization and the isotacticity of the polymer are relatively low.

[0006] CN1974612A discloses that a phosphate compound electron donor is used in a polypropylene catalyst. When the catalyst is used for propylene polymerization, the catalytic activity is average, but a polypropylene homopolymer or copolymer product with a Mw / Mn of 7-9 can be obtained. The structural formula of the phosphate compound is:

[0007]

[0008] CN105985469B discloses a polypropylene catalyst containing a biphenyl structure bisphosphine compound as an internal electron donor, which has good polymerization reaction catalytic activity when used for propylene polymerization. The structure of the internal electron donor is:

[0009] Wherein R1-R6 are respectively the same or different straight chain or branched chain alkyl, aryl or alkoxyaryl groups. However, the isotacticity of the obtained polymer is relatively low.

[0010] CN101787088A discloses a polymerization catalyst using a phosphorus-substituted sulfonyl compound as an internal electron donor, the catalyst has good polymerization catalytic activity, and the polymerization product has high isotacticity. The structure of the internal electron donor is:

[0011] Where R 1 , R 2 They are respectively the same or different chain alkyl or aryl groups, and the hydrogen atoms on the substituents may be substituted by any halogen atoms. Summary of the invention

[0012] In order to solve the above problems, the purpose of the present invention is to provide a catalyst for olefin polymerization and a preparation method and application thereof, wherein the catalyst has high catalytic activity and the obtained product has good isotacticity.

[0013] In order to achieve the above object, the present invention provides a catalyst for olefin polymerization, which comprises titanium, magnesium, halogen, and (2-oxopropyl)phosphonate internal electron donor; wherein the (2-oxopropyl)phosphonate internal electron donor has a structure shown in Formula I:

[0014]

[0015] In Formula I, R1 and R2 are the same or different and are independently selected from C1-C 20 Straight chain alkyl, C1-C 20 Branched alkyl, C3-C 20 Cycloalkyl, C6-C 20 Aryl, C7-C 20 Alkyl, C7-C 20 Alkoxyaryl, C7-C 20 of arylalkyl.

[0016] According to a specific embodiment of the present invention, preferably, the catalyst comprises an alcoholate of a magnesium halide, a titanium compound, and the (2-oxopropyl)phosphonate internal electron donor.

[0017] According to a specific embodiment of the present invention, preferably, in Formula I, R1 and R2 are each independently selected from C3-C10 Alkyl, C3-C 10 Cycloalkyl, C6-C 10 Aryl, C7-C 10 Alkyl, C7-C 10 of an alkoxyaryl group.

[0018] According to a specific embodiment of the present invention, preferably, the (2-oxopropyl)phosphonate internal electron donor is selected from the group consisting of dimethyl (2-oxopropyl)phosphonate, diethyl (2-oxopropyl)phosphonate, di-n-propyl (2-oxopropyl)phosphonate, diisopropyl (2-oxopropyl)phosphonate, diisobutyl (2-oxopropyl)phosphonate, di-n-pentyl (2-oxopropyl)phosphonate, dicyclopentyl (2-oxopropyl)phosphonate, di-n-hexyl (2-oxopropyl)phosphonate, and diisopropyl (2-oxopropyl)phosphonate. ) phosphonic acid dicyclohexyl ester, (2-oxopropyl) phosphonic acid diisooctyl ester, (2-oxopropyl) phosphonic acid di-n-decyl ester, (2-oxopropyl) phosphonic acid diphenyl ester, (2-oxopropyl) phosphonic acid di(2-methylphenyl) ester, (2-oxopropyl) phosphonic acid di(3-methylphenyl) ester, (2-oxopropyl) phosphonic acid di(4-methylphenyl) ester, (2-oxopropyl) phosphonic acid di(2-ethylphenyl) ester, (2-oxopropyl) phosphonic acid di(4-ethylphenyl) ester, (2-oxopropyl) phosphonic acid di(2-ethylphenyl) ester, (2-oxopropyl) phosphonic acid di(4-ethylphenyl) ester, (2-oxopropyl) )phosphonic acid di(2-n-propylphenyl) ester, (2-oxopropyl)phosphonic acid di(3-n-propylphenyl) ester, (2-oxopropyl)phosphonic acid di(4-isopropylphenyl) ester, (2-oxopropyl)phosphonic acid di(3-isobutylphenyl) ester, (2-oxopropyl)phosphonic acid di(4-isobutylphenyl) ester, (2-oxopropyl)phosphonic acid di(4-n-pentylphenyl) ester, (2-oxopropyl)phosphonic acid di(4-n-hexylphenyl) ester, (2-oxopropyl)phosphonic acid di(4-cyclohexylphenyl) ester phenyl) ester, (2-oxopropyl)phosphonic acid bis(4-isooctylphenyl) ester, (2-oxopropyl)phosphonic acid bis(2,4-dimethylphenyl) ester, (2-oxopropyl)phosphonic acid bis(2,4-diethylphenyl) ester, (2-oxopropyl)phosphonic acid bis(2,4-di-n-propylphenyl) ester, (2-oxopropyl)phosphonic acid bis(2,4-diisopropylphenyl) ester, (2-oxopropyl)phosphonic acid bis(2,4-di-n-butylphenyl) ester, (2-oxopropyl)phosphonic acid bis(2,4-di-n-butylphenyl) ester, (2-oxopropyl)phosphonic acid bis(2,4-diisobutylphenyl) ester, (2-oxopropyl)phosphonic acid di(2-methoxyphenyl) ester, (2-oxopropyl)phosphonic acid di(2-ethoxyphenyl) ester, (2-oxopropyl)phosphonic acid di(2-n-propoxyphenyl) ester, (2-oxopropyl)phosphonic acid di(2-isopropoxyphenyl) ester, (2-oxopropyl)phosphonic acid di(2-n-butoxyphenyl) ester, (2-oxopropyl)phosphonic acid di(3-methoxyphenyl) ester, (2-oxopropyl)phosphonic acid di(3-ethoxyphenyl) ester, (2-oxopropyl)phosphonic acid di(2-n-propoxyphenyl) ester, (2-oxopropyl)phosphonic acid di(2-isopropoxyphenyl) ester, (2-oxopropyl)phosphonic acid di(2-n-butoxyphenyl) ester, (2-oxopropyl)phosphonic acid di(3-methoxyphenyl) ester, (2-oxopropyl)phosphonic acid di(3-ethoxyphenyl) ester, (2-oxopropyl)phosphonic acid di(2- bis(3-n-propoxyphenyl)phosphonate, bis(3-isopropoxyphenyl)phosphonate, bis(3-n-butoxyphenyl)phosphonate, bis(3-isobutoxyphenyl)phosphonate, bis(4-methoxyphenyl)phosphonate, bis(4-ethoxyphenyl)phosphonate, bis(4-n-propoxyphenyl)phosphonate, bis(4-isopropoxyphenyl)phosphonate, bis(2-oxopropyl)phosphonate ) phosphonic acid di(4-n-butoxyphenyl) ester, (2-oxopropyl) phosphonic acid di(4-isobutoxyphenyl) ester, (2-oxopropyl) phosphonic acid di(2,4-dimethoxyphenyl) ester, (2-oxopropyl) phosphonic acid di(2,4-diethoxyphenyl) ester, (2-oxopropyl) phosphonic acid di(2,4-di-n-propoxyphenyl) ester, (2-oxopropyl) phosphonic acid di(2,4-diisopropoxyphenyl) ester, (2-oxopropyl) phosphonic acid di(2,4-di-n-butoxyphenyl) ester, (2-oxopropyl) phosphonic acid di( 2,4-diisobutyloxyphenyl) ester, (2-oxopropyl)phosphonic acid dibenzyl ester, (2-oxopropyl)phosphonic acid diphenylethyl ester, (2-oxopropyl)phosphonic acid diphenylpropyl ester, (2-oxopropyl)phosphonic acid di(2-phenylpropyl) ester, (2-oxopropyl)phosphonic acid diphenylbutyl ester, (2-oxopropyl)phosphonic acid di(2-phenyl n-butyl) ester, (2-oxopropyl)phosphonic acid di(3-phenyl n-butyl) ester, (2-oxopropyl)phosphonic acid di(2-methyl-3-phenylpropyl) ester, or a combination of two or more thereof.

[0019] According to a specific embodiment of the present invention, preferably, in the alcoholate of the magnesium halide, the magnesium halide is selected from one or more of magnesium chloride, magnesium bromide, chloromethoxymagnesium, and chloroethoxymagnesium, and the alcohol is selected from one or more of methanol, ethanol, n-propanol, isopropanol, n-butanol, and isobutanol. The present invention does not particularly limit the alcoholate of the magnesium halide, and can be selected from the magnesium halide alcoholates conventionally used in the art.

[0020] According to a specific embodiment of the present invention, preferably, in the alcoholate of magnesium halide, the magnesium halide is magnesium chloride, and the alcohol is ethanol.

[0021] According to a specific embodiment of the present invention, preferably, the general formula of the titanium compound is Ti(OR') n X (4－n) , R' is selected from C1-C 20 Alkyl, C6-C 20 Aryl, C7-C 20 Aralkyl, X is halogen, and n is an integer of 0≤n≤4.

[0022] According to a specific embodiment of the present invention, preferably, the titanium compound is selected from one or a combination of two or more of tetraethoxytitanium, tetrabutoxytitanium, chlorotrialkoxytitanium, dichlorodialkoxytitanium, trichloroalkoxytitanium, titanium tetrachloride and titanium tetrabromide.

[0023] According to a specific embodiment of the present invention, preferably, the titanium compound is titanium tetrachloride.

[0024] According to a specific embodiment of the present invention, preferably, based on the mass of the catalyst as 100%, the composition of the catalyst comprises 6-20% of (2-oxopropyl)phosphonate internal electron donors, more preferably 7-14% of (2-oxopropyl)phosphonate internal electron donors, and the contents of titanium, magnesium and halogen are comparable to those of the prior art. The present invention does not particularly limit the contents of titanium, magnesium and halogen. More preferably, based on the mass of the catalyst as 100%, the composition of the catalyst comprises 10-25% of magnesium, 1.5-10% of titanium, 50-60% of halogen and 6-20% of (2-oxopropyl)phosphonate internal electron donors.

[0025] The polypropylene catalyst of the present invention can be prepared by existing technology, such as the catalyst preparation method disclosed in patent CN1453298A. The commonly used method is: mixing magnesium halide alcoholate and part of titanium halide, adding internal electron donor, heating treatment and filtering, adding remaining titanium halide, heating treatment, filtering, washing and drying to obtain the catalyst product.

[0026] The present invention also provides a method for preparing the above catalyst, which comprises the following steps:

[0027] (1) adding a magnesium halide alcoholate to a titanium compound at -50°C to 50°C, and reacting for 10 min to 6 h. In step (1), the molar ratio of magnesium to titanium is 1:5 to 1:100;

[0028] (2) raising the temperature to 0° C. to 100° C., adding a (2-oxopropyl)phosphonate internal electron donor represented by formula I, wherein the molar ratio of magnesium to the (2-oxopropyl)phosphonate internal electron donor is 2:1-20:1;

[0029] (3) heating to 100°C to 150°C and reacting for 0.5-6h;

[0030] (4) After filtering, add the same amount of titanium compound as in step (1), and react at 100° C. to 150° C. for 0.5-6 h to obtain the catalyst.

[0031] According to a specific embodiment of the present invention, preferably, the above preparation method comprises the following steps:

[0032] (1) adding a magnesium halide alcoholate to a titanium compound liquid at -30°C to 0°C, and reacting for 1-4 hours. In step (1), the molar ratio of magnesium to titanium is 1:20-1:60;

[0033] (2) raising the temperature to 30° C. to 60° C., adding a (2-oxopropyl)phosphonate internal electron donor represented by formula I, wherein the molar ratio of magnesium to the (2-oxopropyl)phosphonate internal electron donor is 2:1 to 12:1;

[0034] (3) heating to 110°C to 130°C and reacting for 1-4 hours;

[0035] (4) After filtering, add the same amount of titanium compound liquid as in step (1), react at 110° C. to 130° C. for 1-2 hours, and obtain the catalyst after filtering, washing and drying.

[0036] The catalyst of the present invention is used for propylene polymerization, and a certain amount of co-catalyst needs to be added. In order to obtain a better polymerization effect, the present invention also provides a catalyst system for olefin polymerization, which comprises the above catalyst, alkyl aluminum compound, and alkoxysilane compound.

[0037] According to a specific embodiment of the present invention, preferably, the general formula of the alkyl aluminum compound is AlR" m Y (3-m) , R" is selected from C1-C 20 Alkyl, C6-C 20 Aryl, C7-C 20 wherein Y is a halogen, and m is an integer of 0≤m≤3.

[0038] According to a specific embodiment of the present invention, preferably, the alkyl aluminum compound is selected from one or a combination of two or more of trimethyl aluminum, triethyl aluminum, triisobutyl aluminum, diethyl aluminum monochloride, and diisobutyl aluminum monochloride.

[0039] According to a specific embodiment of the present invention, preferably, the alkyl aluminum compound is triethyl aluminum and / or triisobutyl aluminum.

[0040] According to a specific embodiment of the present invention, preferably, the alkoxysilane compound is selected from one or a combination of two or more of dimethoxydimethylsilane, diethoxydimethylsilane, dimethoxydiphenylsilane and methylcyclohexyldimethoxysilane.

[0041] According to a specific embodiment of the present invention, preferably, the alkoxysilane compound is methylcyclohexyldimethoxysilane.

[0042] According to a specific embodiment of the present invention, preferably, the molar ratio of titanium to aluminum in the catalyst system is 1:1-1:2000; the molar ratio of titanium to silicon is 1:1-1:50.

[0043] According to a specific embodiment of the present invention, preferably, the molar ratio of titanium to aluminum in the catalyst system is 1:1-1:500; the molar ratio of titanium to silicon is 1:1-1:20.

[0044] The present invention also provides application of the catalyst or the catalyst system in olefin polymerization.

[0045] According to a specific embodiment of the present invention, preferably, the olefin polymerization is propylene polymerization, such as bulk polymerization or slurry polymerization of propylene.

[0046] According to a specific embodiment of the present invention, preferably, the polymerization temperature is 0°C to 80°C, more preferably 20°C to 70°C.

[0047] The present invention has the following beneficial effects:

[0048] (1) The (2-oxopropyl)phosphonate compound used in the catalyst of the present invention makes the catalyst have higher activity during propylene polymerization;

[0049] (2) The (2-oxopropyl)phosphonate compound used in the catalyst of the present invention enables the product prepared by the catalyst during propylene polymerization to have an isotacticity comparable to that of the prior art. DETAILED DESCRIPTION

[0050] In order to have a clearer understanding of the technical features, purposes and beneficial effects of the present invention, the technical solution of the present invention is now described in detail below, but it should not be construed as limiting the applicable scope of the present invention.

[0051] Test Method

[0052] (1) The Ti content in the catalyst was determined by spectrophotometry (722S model) in the following steps:

[0053] Under the protection of inert gas, weigh 0.2000g sample and dissolve it with 20mL (1:4) sulfuric acid; extract with 9mL heptane three times, shake for 5min each time to separate organic matter; place the organic phase in a 10mL volumetric flask and dilute with heptane (for determination of organic content); dilute the inorganic phase to a 50mL volumetric flask with water, shake well for use; take 2mL of the test solution in 25mL volumetric flasks, add 1mL 3% (m / v) hydrogen peroxide, dilute to scale with sulfuric acid (1:9), shake well, and place for 10min. Use blank as reference solution and 3cm colorimetric dish to determine the absorbance value at a wavelength of 410nm. Find the corresponding value from the titanium standard fitting line to calculate the content.

[0054] (2) The content of electron donor compounds was determined by gas chromatography (Techcomp GC7900): the organic phase was directly subjected to gas chromatography analysis using a heptane solution of the pure substance as a reference, and the content was calculated by the ratio of the peak area of ​​the analyte to that of the pure substance solution.

[0055] (3) The magnesium content in the catalyst is determined by the EDTA volumetric method. Triethanolamine and potassium sodium tartrate are used to mask impurities such as Ti, Al, and Fe. At pH = 10, acid chrome blue K-naphthol green B is used as a joint indicator and EDTA standard solution is used for complexometric titration. The experimental steps are as follows: 5 mL of the prepared test solution (for the determination of Ti, Mg, and Cl) is taken in duplicate, and 10 mL of 1:2 (v / v) triethanolamine aqueous solution, 10 mL of 10% (m / v) potassium sodium tartrate aqueous solution, 20 mL of pH = 10 buffer solution, 5-6 drops of indicator are added to a 250 mL conical flask, and shake well. Titrate with EDTA standard solution (C = 0.02 mol / L) until pure blue is the end point, and a blank test is performed at the same time. Calculate the magnesium content based on the volume of the EDTA standard solution used.

[0056] (4) The chlorine content in the catalyst is determined by potentiometric titration. In a weakly acidic ethanol aqueous solution, a standard silver nitrate solution is used as the titrant, and the titration endpoint is determined by means of the titration potential jump. The test steps are as follows: 10 mL of the prepared test solution for titanium measurement is placed in a 100 mL beaker, 20 mL of anhydrous ethanol and 20 mL of distilled water are added, the electromagnetic stirring bar is placed in the beaker, and placed on the tray of the potentiometer magnetic stirrer, the measuring electrode (silver electrode) and the reference electrode (calomel electrode) are inserted into the cup, and the stirrer is turned on. First, zero point calibration is performed, then positioning is performed, and titration is performed with a standard silver nitrate solution (C = 0.025 mol / L), and a blank test is performed at the same time. The chlorine content is calculated based on the volume of the standard silver nitrate solution used.

[0057] (5) The gage index is tested in accordance with GB / T 2412-1980.

[0058] Synthesis of Internal Electron Donor Compounds

[0059] Preparation Example 1

[0060] This preparation example provides diisopropyl (2-oxopropyl)phosphonate, and its synthesis steps are as follows:

[0061] (1) Add 42 g of anhydrous potassium carbonate, 60 mL of petroleum ether, and 30.7 mL of isopropanol to a reaction flask, stir and heat to reflux, then slowly drop 20 mL of petroleum ether and 8.7 mL of phosphorus trichloride into the reaction solution. After the addition is completed, continue to reflux for 1 hour, cool to room temperature and filter, wash the filter cake with petroleum ether, combine the filtrate, remove the solvent, and distill under reduced pressure to obtain a colorless liquid, which is diisopropyl phosphite;

[0062] (2) Bromoacetone reacts with diisopropyl phosphite to obtain the product (2-oxopropyl)phosphonic acid diisopropyl ester. 1 HNMR (CDCl3, 300MHz) analysis results: δ3.57 (2H, CH); δ2.93 (2H, CH2); δ2.09 (3H, CH3); δ1.16 (12H, CH3).

[0063] The reaction of bromoacetone and diisopropyl phosphite was prepared according to the literature “M.-L.Ma, Z.-H.Peng, L.Chen, et al. Erratum: Synthesis of new MeO-BIPHEP-type chiral diphosphines by an improved way (Chinese Journal of Chemistry (2006) 24, 10, (1391)) [J]. 2006.”

[0064] The internal electron donor compounds used in the following examples were synthesized according to the above method.

[0065] Example 1

[0066] This embodiment provides a catalyst, and the preparation method thereof is as follows:

[0067] Under anhydrous and oxygen-free conditions, 5.0 g of microspherical magnesium chloride alcoholate particles (self-made, preparation steps refer to CN1110281A) were added to 140 ml of titanium tetrachloride liquid at -20°C, reacted for 1 hour, gradually heated to 60°C, added 0.825 g of (2-oxopropyl) diisopropyl phosphonate, gradually heated to 120°C, reacted for 2 hours, and filtered; then 140 ml of titanium tetrachloride was added, reacted at 120°C for 1 hour and filtered, washed 5 times with 100 ml of hexane at 60°C, washed once with 30 ml of hexane at room temperature, and vacuum dried to obtain the catalyst.

[0068] Preparation of spherical magnesium chloride alcoholate particles (self-made, preparation steps refer to CN1110281A, the same below): under anhydrous and oxygen-free conditions, add 24g of anhydrous magnesium chloride, 50mL of anhydrous ethanol, 390mL of white vaseline oil, 10mL of silicone oil and 2mL of Siban in a 1L high-pressure reactor, stir and heat to 130°C, and react at this temperature for 4 hours to completely dissolve the solid. Use nitrogen to pressurize the reactor to 1.0MPa, open the valve to discharge the material, and let the material in the reactor pass through a capillary with a diameter of 1.2mm and a length of 3.5m into 2.5L of anhydrous hexane cooled to -30°C in advance. The solid particles are washed 5 times with hexane and dried in vacuum at room temperature to obtain spherical magnesium chloride alcoholate particles with an average particle size of 50μm and a specific surface area of ​​150-230m 2 / g, the molar ratio of alcohol to magnesium chloride is 2.85:1, and the molecular formula is: MgCl2·2.85CH3CH2OH.

[0069] The obtained catalyst was used for bulk polymerization: 2 kg of propylene, triethylaluminum and methylcyclohexyldimethoxysilane were added to a 10-liter stainless steel reactor that had been vacuum dried and fully replaced with nitrogen and propylene gas, with the molar ratio of titanium to aluminum being 1:200 and the molar ratio of titanium to silicon being 1:20; 30 mg of the above catalyst and 0.3 g of hydrogen were added, the temperature was raised to 70°C, the reaction was carried out for 1 hour, the temperature was lowered to room temperature, the pressure was released, and a polymer was obtained.

[0070] The polymerization results are shown in Table 1.

[0071] Example 2

[0072] This embodiment provides a catalyst, and the preparation method thereof is as follows:

[0073] Under anhydrous and oxygen-free conditions, 5.0 g of microspherical magnesium chloride alcoholate particles were added to 74 ml of titanium tetrachloride liquid at -20°C, reacted for 1 hour, and then gradually heated to 60°C; 0.775 g of (2-oxopropyl) di-n-pentyl phosphonate was added, the temperature was gradually raised to 120°C, reacted for 2 hours, and filtered; 74 ml of titanium tetrachloride was added, reacted at 120°C for 1 hour and filtered, washed 5 times with 100 ml of hexane at 60°C, washed once with 30 ml of hexane at room temperature, and vacuum dried to obtain a catalyst.

[0074] The obtained catalyst was used for bulk polymerization: 2 kg of propylene, triethylaluminum and methylcyclohexyldimethoxysilane were added to a 10-liter stainless steel reactor that had been vacuum dried and fully replaced with nitrogen and propylene gas, with the molar ratio of titanium to aluminum being 1:250 and the molar ratio of titanium to silicon being 1:20; 30 mg of the above catalyst and 0.2 g of hydrogen were added, the temperature was raised to 70°C, the reaction was carried out for 1 hour, the temperature was lowered to room temperature, the pressure was released, and a polymer was obtained.

[0075] The polymerization results are shown in Table 1.

[0076] Example 3

[0077] This embodiment provides a catalyst, and the preparation method thereof is as follows:

[0078] Under anhydrous and oxygen-free conditions, 5.0 g of microspherical magnesium chloride alcoholate particles were added to 74 ml of titanium tetrachloride liquid at -20°C, reacted for 1 hour, and then gradually heated to 80°C; 0.748 g of (2-oxopropyl) dicyclohexylphosphonate was added, the temperature was gradually raised to 120°C, reacted for 2 hours, and filtered; 74 ml of titanium tetrachloride was added, reacted at 120°C for 1 hour and filtered, washed 5 times with 100 ml of hexane at 60°C, washed once with 30 ml of hexane at room temperature, and vacuum dried to obtain a catalyst.

[0079] The obtained catalyst was used for bulk polymerization: 2 kg of propylene, triethylaluminum and methylcyclohexyldimethoxysilane were added to a 10-liter stainless steel reactor that had been vacuum dried and fully replaced with nitrogen and propylene gas, with a titanium to aluminum molar ratio of 1:250 and a titanium to silicon molar ratio of 1:22; 30 mg of the above catalyst and 0.3 g of hydrogen were added, the temperature was raised to 70°C, the reaction was carried out for 1 hour, the temperature was lowered to room temperature, the pressure was released, and a polymer was obtained.

[0080] The polymerization results are shown in Table 1.

[0081] Example 4

[0082] This embodiment provides a catalyst, and the preparation method thereof is as follows:

[0083] Under anhydrous and oxygen-free conditions, 5.0 g of microspherical magnesium chloride alcoholate particles were added to 123 ml of titanium tetrachloride liquid at -20°C, reacted for 1 hour, and then gradually heated to 60°C; 0.886 g of (2-oxopropyl) di-n-decylphosphonate was added, the temperature was gradually raised to 120°C, reacted for 2 hours, and filtered; 123 ml of titanium tetrachloride was added, reacted at 120°C for 1 hour and filtered, washed 5 times with 100 ml of hexane at 60°C, washed once with 30 ml of hexane at room temperature, and vacuum dried to obtain a catalyst.

[0084] The obtained catalyst was used for bulk polymerization: 2 kg of propylene, triethylaluminum and methylcyclohexyldimethoxysilane were added to a 10-liter stainless steel reactor that had been vacuum dried and fully replaced with nitrogen and propylene gas, with the molar ratio of titanium to aluminum being 1:200 and the molar ratio of titanium to silicon being 1:20; 30 mg of the above catalyst and 0.3 g of hydrogen were added, the temperature was raised to 70°C, the reaction was carried out for 1 hour, the temperature was lowered to room temperature, the pressure was released, and a polymer was obtained.

[0085] The polymerization results are shown in Table 1.

[0086] Example 5

[0087] This embodiment provides a catalyst, and the preparation method thereof is as follows:

[0088] Under anhydrous and oxygen-free conditions, 5.0 g of microspherical magnesium chloride alcoholate particles were added to 123 ml of titanium tetrachloride liquid at -20°C, reacted for 1 hour, and then gradually heated to 80°C; 0.923 g of (2-oxopropyl) diphenyl phosphonate was added, the temperature was gradually raised to 120°C, reacted for 2 hours, and filtered; 123 ml of titanium tetrachloride was added, reacted at 120°C for 1 hour and filtered, washed 5 times with 100 ml of hexane at 60°C, washed once with 30 ml of hexane at room temperature, and vacuum dried to obtain a catalyst.

[0089] The obtained catalyst was used for bulk polymerization: 2 kg of propylene, triethylaluminum and methylcyclohexyldimethoxysilane were added to a 10-liter stainless steel reactor that had been vacuum dried and fully replaced with nitrogen and propylene gas, with the molar ratio of titanium to aluminum being 1:200 and the molar ratio of titanium to silicon being 1:25; 30 mg of the above catalyst and 0.2 g of hydrogen were added, the temperature was raised to 70°C, the reaction was carried out for 1 hour, the temperature was lowered to room temperature, the pressure was released, and a polymer was obtained.

[0090] The polymerization results are shown in Table 1.

[0091] Example 6

[0092] This embodiment provides a catalyst, and the preparation method thereof is as follows:

[0093] Under anhydrous and oxygen-free conditions, 5.0 g of microspherical magnesium chloride alcoholate particles were added to 98 ml of titanium tetrachloride liquid at -20°C, reacted for 1 hour, and then gradually heated to 60°C; 1.281 g of (2-oxopropyl) phosphonic acid di(4-isobutylphenyl) ester was added, and the temperature was gradually raised to 120°C, reacted for 2 hours, and filtered; 98 ml of titanium tetrachloride was added, reacted at 120°C for 1 hour and filtered, washed 5 times with 100 ml of hexane at 60°C, washed once with 30 ml of hexane at room temperature, and vacuum dried to obtain a catalyst.

[0094] The obtained catalyst was used for bulk polymerization: 2 kg of propylene, triethylaluminum and methylcyclohexyldimethoxysilane were added to a 10-liter stainless steel reactor that had been vacuum dried and fully replaced with nitrogen and propylene gas, with the molar ratio of titanium to aluminum being 1:220 and the molar ratio of titanium to silicon being 1:20; 30 mg of the above catalyst and 0.3 g of hydrogen were added, the temperature was raised to 70°C, the reaction was carried out for 1 hour, the temperature was lowered to room temperature, the pressure was released, and a polymer was obtained.

[0095] The polymerization results are shown in Table 1.

[0096] Example 7

[0097] This embodiment provides a catalyst, and the preparation method thereof is as follows:

[0098] Under anhydrous and oxygen-free conditions, 5.0 g of microspherical magnesium chloride alcoholate particles were added to 147 ml of titanium tetrachloride liquid at -20°C, reacted for 1 hour, and then gradually heated to 60°C; 1.509 g of (2-oxopropyl) phosphonic acid di(3-n-propoxyphenyl) ester was added, and the temperature was gradually raised to 120°C, reacted for 2 hours, and filtered; 147 ml of titanium tetrachloride was added, reacted at 120°C for 1 hour and filtered, washed 5 times with 100 ml of hexane at 60°C, washed once with 30 ml of hexane at room temperature, and vacuum dried to obtain a catalyst.

[0099] The obtained catalyst was used for bulk polymerization: 2 kg of propylene, triethylaluminum and methylcyclohexyldimethoxysilane were added to a 10-liter stainless steel reactor that had been vacuum dried and fully replaced with nitrogen and propylene gas, with the molar ratio of titanium to aluminum being 1:200 and the molar ratio of titanium to silicon being 1:20; 30 mg of the above catalyst and 0.2 g of hydrogen were added, the temperature was raised to 70°C, the reaction was carried out for 1 hour, the temperature was lowered to room temperature, the pressure was released, and a polymer was obtained.

[0100] The polymerization results are shown in Table 1.

[0101] Example 8

[0102] This embodiment provides a catalyst, and the preparation method thereof is as follows:

[0103] Under anhydrous and oxygen-free conditions, 5.0 g of microspherical magnesium chloride alcoholate particles were added to 110 ml of titanium tetrachloride liquid at -20°C, reacted for 1 hour, and then gradually heated to 40°C; 0.914 g of (2-oxopropyl)phosphonic acid di(2,4-dimethoxyphenyl) ester was added, and the temperature was gradually raised to 120°C, reacted for 2 hours, and filtered; 110 ml of titanium tetrachloride was added, reacted at 120°C for 2 hours and filtered, washed 5 times with 100 ml of hexane at 60°C, washed once with 30 ml of hexane at room temperature, and vacuum dried to obtain a catalyst.

[0104] The obtained catalyst was used for bulk polymerization: 2 kg of propylene, triethylaluminum and methylcyclohexyldimethoxysilane were added to a 10-liter stainless steel reactor that had been vacuum dried and fully replaced with nitrogen and propylene gas, with the molar ratio of titanium to aluminum being 1:180 and the molar ratio of titanium to silicon being 1:25; 30 mg of the above catalyst and 0.2 g of hydrogen were added, the temperature was raised to 70°C, the reaction was carried out for 1 hour, the temperature was lowered to room temperature, the pressure was released, and a polymer was obtained.

[0105] The polymerization results are shown in Table 1.

[0106] Example 9

[0107] This embodiment provides a catalyst, and the preparation method thereof is as follows:

[0108] Under anhydrous and oxygen-free conditions, 5.0 g of microspherical magnesium chloride alcoholate particles were added to 61 ml of titanium tetrachloride liquid at -20°C, reacted for 1 hour, and then gradually heated to 50°C; 1.182 g of (2-oxopropyl) dibenzyl phosphonate was added, the temperature was gradually raised to 120°C, reacted for 2 hours, and filtered; 61 ml of titanium tetrachloride was added, reacted at 120°C for 2 hours and filtered, washed 5 times with 100 ml of hexane at 60°C, washed once with 30 ml of hexane at room temperature, and vacuum dried to obtain a catalyst.

[0109] The obtained catalyst was used for bulk polymerization: 2 kg of propylene, triethylaluminum and methylcyclohexyldimethoxysilane were added to a 10-liter stainless steel reactor that had been vacuum dried and fully replaced with nitrogen and propylene gas, with the molar ratio of titanium to aluminum being 1:300 and the molar ratio of titanium to silicon being 1:20; 30 mg of the above catalyst and 0.5 g of hydrogen were added, the temperature was raised to 70°C, the reaction was carried out for 1 hour, the temperature was lowered to room temperature, the pressure was released, and a polymer was obtained.

[0110] The polymerization results are shown in Table 1.

[0111] Comparative Example 1

[0112] This comparative example provides a catalyst, and its preparation method and propylene polymerization method are the same as those in Example 4, except that 1.038g of triphenyl phosphate (synthesis method reference CN1974612A) is used instead of (2-oxopropyl) di-n-decyl phosphonate during the catalyst preparation process.

[0113] The polymerization results are shown in Table 1.

[0114] Comparative Example 2

[0115] This comparative example provides a catalyst, and its preparation method and propylene polymerization method are the same as those in Example 4, except that 2.236 g of 6,6'-dimethoxy-2,2'-di(di-4-methoxyphenylphosphine)-1,1'-biphenyl (synthesis method reference CN105985469B) is used instead of (2-oxopropyl) di-n-decylphosphonate during the catalyst preparation process.

[0116] The polymerization results are shown in Table 1.

[0117] Comparative Example 3

[0118] This comparative example provides a catalyst, and its preparation method and propylene polymerization method are the same as Example 4, except that 1.293g of phenylphosphine-substituted sulfonyl compound (synthesis method reference CN101787088A) is used instead of (2-oxopropyl) di-n-decyl phosphonate during the catalyst preparation process.

[0119] The structure of the above-mentioned phenylphosphine-substituted sulfonyl compound is as follows:

[0120]

[0121] The polymerization results are shown in Table 1.

[0122] Comparative Example 4

[0123] This comparative example provides a catalyst, and its preparation method and propylene polymerization method are the same as those in Example 4, except that 0.886 g of phthalate is used instead of (2-oxopropyl) di-n-decylphosphonate during the catalyst preparation process.

[0124] The polymerization results are shown in Table 1.

[0125] Comparative Example 5

[0126] This comparative example provides a catalyst, and its preparation method and propylene polymerization method are the same as those in Example 4, except that 0.8094 g of 9,9-di(methoxymethyl)fluorene (synthesis method reference CN1473809A) is used instead of (2-oxopropyl) di-n-decylphosphonate during the catalyst preparation process.

[0127] Comparative Example 6

[0128] This comparative example provides a catalyst, and its preparation method and propylene polymerization method are the same as those in Example 4, except that 0.822 g of diethyl 2,3-diisopropylsuccinate is used instead of di-n-decyl (2-oxopropyl)phosphonate during the catalyst preparation process.

[0129] The polymerization results are shown in Table 1.

[0130] Table 1 Catalyst propylene polymerization test results

[0131]

[0132]

[0133] The content percentages in Table 1 are calculated based on the mass of the obtained catalyst as 100%.

[0134] Example 10

[0135] The catalyst used in Example 4 was used to carry out propylene slurry polymerization: 3L hexane, 200g propylene, triethylaluminum and methylcyclohexyldimethoxysilane were added to a 5L stainless steel reactor that had been vacuum dried and fully replaced with nitrogen and propylene gas, with the molar ratio of titanium to aluminum being 1:200 and the molar ratio of titanium to silicon being 1:20; 30mg of the above catalyst and 0.2g of hydrogen were added, the temperature was raised to 70°C, the reaction was carried out for 1 hour, the temperature was lowered to room temperature, the pressure was released, the polymer was dried and weighed to calculate the catalyst activity.

[0136] The polymerization results are shown in Table 2.

[0137] Comparative Example 7

[0138] The catalyst used in this comparative example is the same as that in comparative example 4, and the polymerization method is the same as that in example 10.

[0139] The polymerization results are shown in Table 2.

[0140] Table 2 Catalyst propylene slurry polymerization test results

[0141]

[0142] As can be seen from Table 1, the (2-oxopropyl)phosphonate compound used in the catalyst of the present invention makes the catalyst have higher activity during propylene polymerization, and the obtained product has an isotacticity equivalent to that of the conventional internal electron donor.

Claims

1. A catalyst for olefin polymerization, comprising titanium, magnesium, halogen, and (2-oxopropyl)phosphonate internal electron donor; in, The (2-oxopropyl)phosphonate internal electron donor has a structure shown in Formula I: In Formula I, R1 and R2 are the same or different and are independently selected from C1-C 20 Straight chain alkyl, C1-C 20 Branched alkyl, C3-C 20 Cycloalkyl, C6-C 20 Aryl, C7-C 20 Alkyl, C7-C 20 Alkoxyaryl, C7-C 20 of arylalkyl.

2. The catalyst according to claim 1, wherein The catalyst comprises an alcoholate of magnesium halide, a titanium compound and the (2-oxopropyl)phosphonate internal electron donor.

3. The catalyst according to claim 1 or 2, wherein In Formula I, R1 and R2 are each independently selected from C3-C 10 Alkyl, C3-C 10 Cycloalkyl, C6-C 10 Aryl, C7-C 10 Alkyl, C7-C 10 of an alkoxyaryl group.

4. The catalyst according to claim 1 or 2, wherein The (2-oxopropyl)phosphonate internal electron donor is selected from the group consisting of dimethyl (2-oxopropyl)phosphonate, diethyl (2-oxopropyl)phosphonate, di-n-propyl (2-oxopropyl)phosphonate, diisopropyl (2-oxopropyl)phosphonate, diisobutyl (2-oxopropyl)phosphonate, di-n-pentyl (2-oxopropyl)phosphonate, dicyclopentyl (2-oxopropyl)phosphonate, di-n-hexyl (2-oxopropyl)phosphonate, dicyclohexyl (2-oxopropyl)phosphonate, and diisopropyl (2-oxopropyl)phosphonate. 2-Oxopropyl)phosphonic acid diisooctyl ester, (2-oxopropyl)phosphonic acid di-n-decyl ester, (2-oxopropyl)phosphonic acid diphenyl ester, (2-oxopropyl)phosphonic acid di(2-methylphenyl) ester, (2-oxopropyl)phosphonic acid di(3-methylphenyl) ester, (2-oxopropyl)phosphonic acid di(4-methylphenyl) ester, (2-oxopropyl)phosphonic acid di(2-ethylphenyl) ester, (2-oxopropyl)phosphonic acid di(4-ethylphenyl) ester, (2-oxopropyl)phosphonic acid di(2-n-propyl)phosphonic acid bis(4-isopropylphenyl)phosphonate, bis(3-isobutylphenyl)phosphonate, bis(4-isobutylphenyl)phosphonate, bis(4-n-pentylphenyl)phosphonate, bis(4-n-hexylphenyl)phosphonate, bis(4-cyclohexylphenyl)phosphonate , (2-oxopropyl)phosphonic acid bis(4-isooctylphenyl) ester, (2-oxopropyl)phosphonic acid bis(2,4-dimethylphenyl) ester, (2-oxopropyl)phosphonic acid bis(2,4-diethylphenyl) ester, (2-oxopropyl)phosphonic acid bis(2,4-di-n-propylphenyl) ester, (2-oxopropyl)phosphonic acid bis(2,4-diisopropylphenyl) ester, (2-oxopropyl)phosphonic acid bis(2,4-di-n-butylphenyl) ester, (2-oxopropyl)phosphonic acid bis(2,4-di-n-butylphenyl) ester, (2-oxopropyl)phosphonic acid bis(2,4-diisobutylphenyl) ester, (2-oxopropyl)phosphonic acid di(2-methoxyphenyl) ester, (2-oxopropyl)phosphonic acid di(2-ethoxyphenyl) ester, (2-oxopropyl)phosphonic acid di(2-n-propoxyphenyl) ester, (2-oxopropyl)phosphonic acid di(2-isopropoxyphenyl) ester, (2-oxopropyl)phosphonic acid di(2-n-butoxyphenyl) ester, (2-oxopropyl)phosphonic acid di(3-methoxyphenyl) ester, (2-oxopropyl)phosphonic acid di(3-ethoxyphenyl) ester, (2-oxopropyl)phosphonic acid di(2-n-propoxyphenyl) ester, (2-oxopropyl)phosphonic acid di(2-isopropoxyphenyl) ester, (2-oxopropyl)phosphonic acid di(2-n-butoxyphenyl) ester, (2-oxopropyl)phosphonic acid di(3-methoxyphenyl) ester, (2-oxopropyl)phosphonic acid di(3-ethoxyphenyl) ester, (2-oxopropyl)phosphonic acid di(2- bis(3-n-propoxyphenyl)phosphonate, bis(3-isopropoxyphenyl)phosphonate, bis(3-n-butoxyphenyl)phosphonate, bis(3-isobutoxyphenyl)phosphonate, bis(4-methoxyphenyl)phosphonate, bis(4-ethoxyphenyl)phosphonate, bis(4-n-propoxyphenyl)phosphonate, bis(4-isopropoxyphenyl)phosphonate, bis(2-oxopropyl)phosphonate ) phosphonic acid di(4-n-butoxyphenyl) ester, (2-oxopropyl) phosphonic acid di(4-isobutoxyphenyl) ester, (2-oxopropyl) phosphonic acid di(2,4-dimethoxyphenyl) ester, (2-oxopropyl) phosphonic acid di(2,4-diethoxyphenyl) ester, (2-oxopropyl) phosphonic acid di(2,4-di-n-propoxyphenyl) ester, (2-oxopropyl) phosphonic acid di(2,4-diisopropoxyphenyl) ester, (2-oxopropyl) phosphonic acid di(2,4-di-n-butoxyphenyl) ester, (2-oxopropyl) phosphonic acid di( 2,4-diisobutyloxyphenyl) ester, (2-oxopropyl)phosphonic acid dibenzyl ester, (2-oxopropyl)phosphonic acid diphenylethyl ester, (2-oxopropyl)phosphonic acid diphenylpropyl ester, (2-oxopropyl)phosphonic acid di(2-phenylpropyl) ester, (2-oxopropyl)phosphonic acid diphenylbutyl ester, (2-oxopropyl)phosphonic acid di(2-phenyl n-butyl) ester, (2-oxopropyl)phosphonic acid di(3-phenyl n-butyl) ester, (2-oxopropyl)phosphonic acid di(2-methyl-3-phenylpropyl) ester, or a combination of two or more thereof.

5. The catalyst according to claim 2, wherein In the alcoholate of magnesium halide, the magnesium halide is selected from one or a combination of two or more of magnesium chloride, magnesium bromide, chloromethoxymagnesium, and chloroethoxymagnesium, and the alcohol is selected from one or a combination of two or more of methanol, ethanol, n-propanol, isopropanol, n-butanol, and isobutanol; Preferably, in the alcoholate of magnesium halide, the magnesium halide is magnesium chloride and the alcohol is ethanol.

6. The catalyst according to claim 2, wherein The general formula of the titanium compound is Ti(OR') n X (4－n) , R' is selected from C1-C 20 Alkyl, C6-C 20 Aryl, C7-C 20 Aralkyl, X is halogen, and n is an integer of 0≤n≤4.

7. The catalyst according to claim 6, wherein The titanium compound is selected from one or a combination of two or more of tetraethoxytitanium, tetrabutoxytitanium, chlorotrialkoxytitanium, dichlorodialkoxytitanium, trichloroalkoxytitanium, titanium tetrachloride, and titanium tetrabromide; Preferably, the titanium compound is titanium tetrachloride.

8. The catalyst according to claim 1 or 2, wherein Taking the mass of the catalyst as 100%, the composition of the catalyst comprises 6-20% of (2-oxopropyl)phosphonate internal electron donor, preferably 7-14% of (2-oxopropyl)phosphonate internal electron donor.

9. A method for preparing a catalyst according to any one of claims 1 to 8, comprising the following steps: (1) adding a magnesium halide alcoholate to a titanium compound at -50°C to 50°C, and reacting for 10 min to 6 h. In step (1), the molar ratio of magnesium to titanium is 1:5 to 1:100; (2) raising the temperature to 0° C. to 100° C., adding a (2-oxopropyl)phosphonate internal electron donor represented by formula I, wherein the molar ratio of magnesium to the (2-oxopropyl)phosphonate internal electron donor is 2:1-20:1; (3) heating to 100°C to 150°C and reacting for 0.5-6h; (4) After filtering, add the same amount of titanium compound as in step (1), and react at 100° C. to 150° C. for 0.5-6 h to obtain the catalyst.

10. The preparation method according to claim 9, wherein: The preparation method comprises the following steps: (1) adding a magnesium halide alcoholate to a titanium compound liquid at -30°C to 0°C, and reacting for 1-4 hours. In step (1), the molar ratio of magnesium to titanium is 1:20-1:60; (2) raising the temperature to 30° C. to 60° C., adding a (2-oxopropyl)phosphonate internal electron donor represented by formula I, wherein the molar ratio of magnesium to the (2-oxopropyl)phosphonate internal electron donor is 2:1 to 12:1; (3) heating to 110°C to 130°C and reacting for 1-4 hours; (4) After filtering, add the same amount of titanium compound liquid as in step (1), react at 110° C. to 130° C. for 1-2 hours, and obtain the catalyst after filtering, washing and drying.

11. A catalyst system for olefin polymerization, comprising the catalyst according to any one of claims 1 to 8, an alkyl aluminum compound, and an alkoxysilane compound.

12. The catalyst system according to claim 11, wherein The general formula of the alkyl aluminum compound is AlR" m Y (3-m) , R" is selected from C1-C 20 Alkyl, C6-C 20 Aryl, C7-C 20 wherein Y is a halogen, and m is an integer of 0≤m≤3.

13. The catalyst system according to claim 12, wherein The alkyl aluminum compound is selected from one or a combination of two or more of trimethyl aluminum, triethyl aluminum, triisobutyl aluminum, diethyl aluminum monochloride, and diisobutyl aluminum monochloride; Preferably, the alkylaluminum compound is triethylaluminum and / or triisobutylaluminum.

14. The catalyst system according to claim 11, wherein The alkoxysilane compound is selected from one or a combination of two or more of dimethoxydimethylsilane, diethoxydimethylsilane, dimethoxydiphenylsilane, and methylcyclohexyldimethoxysilane; Preferably, the alkoxysilane compound is methylcyclohexyldimethoxysilane.

15. The catalyst system according to claim 11, wherein The molar ratio of titanium to aluminum in the catalyst system is 1:1-1:2000; the molar ratio of titanium to silicon is 1:1-1:

50.

16. The catalyst system according to claim 15, wherein The molar ratio of titanium to aluminum in the catalyst system is 1:1-1:500; the molar ratio of titanium to silicon is 1:1-1:

20.

17. Use of the catalyst according to any one of claims 1 to 8 or the catalyst system according to any one of claims 11 to 16 in olefin polymerization.

18. The use according to claim 17, wherein: The olefin polymerization is propylene polymerization, preferably bulk polymerization or slurry polymerization of propylene.

19. The use according to claim 18, wherein: The polymerization temperature is 0°C to 80°C.

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