Olefin polymerization catalyst composition

Abstract

The invention discloses an olefin polymerization catalyst composition. The olefin polymerization catalyst composition comprises the following components: A) a Ziegler-Natta type catalyst; b) an aluminum alkyl compound; c) a chlorinated alkyl compound; the Ziegler-Natta type catalyst is prepared by reacting at least one solid magnesium compound, at least one silicon compound and at least one titanium compound; the molar ratio of the alkyl aluminum compound to the chlorinated alkyl compound is (1: 2)-(1: 30). The Ziegler-Natta type main catalytic body is combined with a cocatalyst composed of a chlorinated alkyl compound and an alkyl aluminum compound, so that the activity of the catalyst can be improved by more than two times, the electrostatic quantity generated in the use process of the catalyst can be remarkably reduced, the caking problem and the wall sticking problem of the catalyst in the polymerization process are effectively solved, and the polymerization stability of the catalyst is improved. The long-period operation of a slurry method polyethylene device is facilitated.

Description

Technical Field

[0001] This invention relates to a catalytic system for ethylene polymerization or copolymerization, belonging to the fields of catalysis and olefin polymerization. Background Technology

[0002] As is well known, Ti / Mg composite catalyst systems dominate the industrial production of polyethylene. The core research focuses on catalyst polymerization activity, particle morphology and size distribution, hydrogen sensitivity, and copolymerization performance. However, in the slurry polymerization process of ethylene, not only is high catalytic activity required, but the catalyst must also be resistant to static electricity during storage, feeding, and polymerization. Static electricity can cause catalyst powder to agglomerate and adhere to the reactor, resulting in lumps during ethylene polymerization and clogging of equipment and pipelines.

[0003] Catalysts are typically prepared using the following two methods.

[0004] The first method involves dissolving magnesium compounds, such as magnesium chloride, in a solvent to obtain a homogeneous solution. This solution is then mixed with a titanium compound and optionally an electron donor, and a solid containing magnesium, titanium, and optionally an electron donor is obtained through precipitation. This solid is then treated with an excess of liquid titanium compound to obtain catalyst particles. This is a recrystallization process of the magnesium support component, and its stability is difficult to control. For example, in patent CN1229092, using magnesium chloride as the support and titanium tetrachloride as the active component, the catalyst is prepared as follows: MgCl2 is first dissolved in a solvent system to form a homogeneous and transparent solution. Then, it is reacted with TiCl4 in the presence of phthalic anhydride as a co-precipitant at low temperature, and a solid catalyst is precipitated by slowly increasing the temperature. When the obtained catalyst component is used for ethylene polymerization, the catalytic activity is not satisfactory. Furthermore, the synthesis of this catalyst requires the use of organic compounds such as phthalic anhydride as co-precipitants to promote precipitation, and a large amount of titanium tetrachloride needs to be added. Therefore, not only does the presence of anhydride have an adverse effect on the catalyst, but the use of large amounts of titanium tetrachloride also causes significant waste and pollution.

[0005] The second method involves first preparing a magnesium compound support with good particle morphology, then loading it with titanium, and reacting to obtain a polyolefin catalyst. Examples include Chinese patents CN85105150 and CN101300278. Chinese patent CN85105150 first reacts magnesium halide with alkoxytitanium, then with alkylaluminum to generate a solid magnesium-containing support with good particle morphology. Finally, this support reacts with titanium tetrachloride to obtain a solid catalyst. The polyethylene polymer prepared using this catalyst has a high bulk density. However, the particle morphology of this catalyst is not ideal and it is prone to static electricity.

[0006] Chinese Patent CN201710725365.4 discloses a main catalyst component for solution ethylene polymerization, which is prepared by reacting at least one alkyl magnesium compound, at least one chloroalkane compound, at least one titanium compound and at least one chlorosilicon compound; wherein, the general formula of the alkyl magnesium compound is MgR 1 n Cl 2-n (Ⅰ), where R 1 is the same or different saturated or unsaturated straight-chain, branched-chain or cyclic hydrocarbon groups of C2-C 20 , 0 < n ≤ 2; the general formula of the chloroalkane compound is R 2 Cl (Ⅱ), where R 2 is the saturated or unsaturated straight-chain, branched-chain or cyclic hydrocarbon group of C2-C 20 ; the general formula of the chlorosilicon compound is Si(OR 3 ) n Cl 4-n (Ⅲ), where R 3 is the saturated or unsaturated straight-chain, branched-chain or cyclic hydrocarbon group of C2-C 20 , 0 ≤ n < 4; the general formula of the titanium compound is Ti(OR 4 ) n Cl 4-n (Ⅳ), where R 4 is the saturated or unsaturated straight-chain, branched-chain or cyclic hydrocarbon group of C2-C20, 0 ≤ n < 4. However, the particle morphology of this catalyst is not ideal enough and it is easy to generate static electricity.

[0007] Therefore, it is highly desirable to provide a catalyst suitable for the slurry polymerization process of ethylene, which has the characteristics of high catalytic activity, good powder fluidity and not easy to generate static electricity, etc. Summary of the Invention

[0008] The purpose of the present invention is to provide an olefin polymerization catalyst composition, which has the characteristics of high catalyst activity and not easy to generate static electricity when catalyzing ethylene polymerization.

[0009] To achieve the above object, the present invention provides an olefin polymerization catalyst composition, which comprises:

[0010] A) Ziegler-Natta type catalyst;

[0011] B) alkyl aluminum compound;

[0012] C) chloroalkyl compound;

[0013] The Ziegler-Natta type catalyst is prepared by reacting at least one solid magnesium compound, at least one silicon compound, and at least one titanium compound; the molar ratio of the alkylaluminum compound and the chloroalkyl compound is 1:2 to 1:30.

[0014] The olefin polymerization catalyst composition of the present invention, wherein the solid magnesium compound is such as general formula (I)Mg(OR) 1 As shown in Figure 2, R 1 It is C2~C 20 The hydrocarbon group can be a saturated or unsaturated straight chain, branched chain, or cyclic chain.

[0015] Preferably, the solid magnesium compound comprises a mixture of magnesium diethoxy, magnesium dibutoxy, magnesium dipropoxy, magnesium chloride, and fatty alcohol, and the solid magnesium compound is spherical or near-spherical particles with an average particle size ranging from 2 to 20 micrometers, preferably 5 to 15 micrometers.

[0016] The olefin polymerization catalyst composition of the present invention, wherein the silicon compound is such as general formula (II)Si(OR) 2 ) n Cl 2-n As shown in the formula, R 2 It is C2~C 20 The hydrocarbon group can be a saturated or unsaturated straight chain, branched chain, or cyclic chain, and 0 < n ≤ 2.

[0017] Preferably, the silicon compound comprises the reaction product of silicon tetrachloride and a fatty alcohol. When silicon tetrachloride and a fatty alcohol are used in the reaction, the molar ratio of the fatty alcohol to silicon tetrachloride should be less than 4.0, the reaction temperature is generally controlled between room temperature and 50°C, and the reaction time is controlled between 0.5 and 5 hours.

[0018] The olefin polymerization catalyst composition of the present invention, wherein the titanium compound is of general formula (III)Ti(OR) 4 ) n Cl 4-n As shown in the formula, R 4 It is C2~C 20 The hydrocarbon group can be a saturated or unsaturated straight chain, branched chain, or cyclic chain, and 0 ≤ n < 4.

[0019] Preferably, the titanium compound comprises titanium tetrachloride or the reaction product of titanium tetrachloride and a fatty alcohol. When titanium tetrachloride and a fatty alcohol are used in the reaction, the molar ratio of the fatty alcohol to titanium tetrachloride should be less than 4.0, the reaction temperature is generally controlled between room temperature and 100°C, and the reaction time is controlled between 0.5 and 5 hours.

[0020] The olefin polymerization catalyst composition of the present invention, wherein the preparation method of the Ziegler-Natta type catalyst includes the following steps:

[0021] (1) The solid magnesium compound and the silicon compound are mixed to form a reaction product;

[0022] (2) The reaction product obtained in step (1) is reacted with the titanium compound to obtain the Ziegler-Natta catalyst.

[0023] The olefin polymerization catalyst composition of the present invention comprises, in proportions such that, per mole of solid magnesium compound, the silicon compound is 0.1 to 10 moles, preferably 0.5 to 5 moles, and the titanium compound is 0.05 to 3 moles, preferably 0.1 to 2 moles.

[0024] The olefin polymerization catalyst composition of the present invention comprises a solid magnesium compound in spherical or hemispherical particle morphology, with an average particle size ranging from 2 to 20 micrometers, preferably 5 to 15 micrometers. If the solid magnesium compound is an alkoxymagnesium compound, it can be prepared by reacting magnesium powder with a fatty alcohol under certain conditions; if the solid magnesium compound is a magnesium chloride alcohol, it is obtained by dissolving magnesium chloride in a fatty alcohol, then transferring it to hexane at low temperature, stirring, dispersing, melting, and solidifying.

[0025] To facilitate the reaction of solid magnesium compounds, an inert dispersant can be added. The inert dispersant does not participate in the reaction process; its purpose is simply to enhance the dispersion of the solid components. Suitable solvents for use as inert dispersants include at least one of hexane, heptane, octane, toluene, xylene, 1,2-dichloroethane, chlorocyclohexane, chlorobenzene, and other hydrocarbons or halogenated hydrocarbons. Generally, inert solvents such as pentane, hexane, heptane, or toluene are required.

[0026] In the above-described catalyst preparation method, the solid magnesium compound is reacted with a silicon compound and a titanium compound, respectively. The order of addition of the silicon and titanium compounds is not particularly important; the silicon compound can be added first, followed by the titanium compound, or vice versa. This step primarily involves the chlorination of the solid magnesium compound, simultaneously removing other substituent groups. Experiments have shown that the addition temperature and rate of the silicon and titanium compounds are crucial for controlling the morphology of the solid particles. Higher addition temperatures and faster addition rates will damage the particle morphology of the solid magnesium compound. Therefore, in this step, the reaction temperature of the silicon compound is selected to be between -10°C and 100°C, and the addition time is between 30 minutes and 5 hours. Similarly, the reaction process of the titanium compound also requires precise control. Typically, the addition temperature of the titanium compound is controlled between -10°C and 20°C, and the addition time is between 30 minutes and 5 hours. After addition, it is preferable to slowly raise the system temperature to 80-100°C and stir the reaction for a period of time; this reaction is called the catalyst ripening reaction. The aging reaction is beneficial to the particle shape of the catalyst, narrowing its particle size distribution and increasing its strength, thereby reducing particle breakage during the catalytic polymerization of ethylene. The aging reaction temperature is generally equal to or higher than the feeding temperature of the titanium compound, and the aging reaction time can be controlled between 0.5 and 15 hours, preferably between 2 and 5 hours.

[0027] After the aging reaction, the aged catalyst suspension is typically washed to remove excess reactants and byproducts formed during the preparation process. Any inert solvent can be used for this washing step, such as one or a combination of isobutane, pentane, hexane, heptane, or cyclohexane, with hexane usually chosen as the inert solvent. After washing, the main catalyst suspension needs to undergo a drying step to obtain a solid main catalyst. This drying step can be completed by purging the catalyst suspension with hot nitrogen gas under heating conditions.

[0028] The olefin polymerization catalyst composition of the present invention comprises an alkyl aluminum compound having the general formula AlR3, wherein R is an alkyl group having 1 to 20 carbon atoms; preferably, the alkyl aluminum compound includes AlEt3, Al(iso-Bu)3, Al(n-C6H13)3, Al(n-C8H13)3, Al(n-C8H13)3, etc. 17 At least one of the following: alkylaluminum compound and titanium in the Ziegler-Natta catalyst; the molar ratio of the alkylaluminum compound to titanium in the catalyst is 1 to 500; preferably, the molar ratio of the alkylaluminum compound to the chloroalkyl compound is 1:2 to 1:8.

[0029] The olefin polymerization catalyst composition of the present invention, wherein the chloroalkyl compound has the general formula R'Cl, where R' is an alkyl group having 1 to 20 carbon atoms; preferably, the chloroalkyl compound includes at least one selected from chloromethane, chloroethane, 1-chloropropane, 2-chloropropane, 1-chloron-butane, 2-chloron-butane, tert-butane, chlorocyclohexane, and chlorobenzene, and more preferably tert-butane and 2-chloropropane.

[0030] Preferably, the alkylaluminum compound and the chloroalkyl compound can be mixed sequentially with the Ziegler-Natta type catalyst, or they can be pre-mixed before being mixed with the Ziegler-Natta type catalyst. More preferably, the alkylaluminum compound and the chloroalkyl compound are pre-mixed before being mixed with the Ziegler-Natta type catalyst. The mixing temperature is 25-80°C, and the mixing time is 0.5-3 hours.

[0031] During their research, the inventors unexpectedly discovered a Ziegler-Natta type main catalytic system. This main catalytic system, combined with a co-catalyst composed of chloroalkyl compounds and alkylaluminum compounds, can increase the activity of the catalyst by more than 2 times and significantly reduce the amount of static electricity generated by the catalyst during use. This effectively solves the problems of catalyst agglomeration and wall adhesion during the polymerization process, which is beneficial to the long-term operation of slurry polyethylene plants. Detailed Implementation

[0032] The present invention will be further described below through specific embodiments, but the present invention is not limited to the following embodiments. Unless otherwise defined, the technical terms used in the following embodiments have the same meaning as commonly understood by those skilled in the art. Unless otherwise specified, the experimental reagents used in the following embodiments are all conventional reagents, which can be purchased commercially or synthesized according to conventional methods in the art; the experimental methods, unless otherwise specified, are all conventional methods.

[0033] Test method for electrostatic properties of catalyst powder

[0034] a) Electrostatic test of catalyst powder

[0035] 10g of catalyst powder was placed into a 100mL thoroughly dried glass bottle and continuously shaken on a sieve for 2 hours. Then, the bottle cap was opened, the bottle inverted, and the catalyst powder was allowed to flow out freely without any external force. The weight of the freely flowing catalyst was measured, and the amount of catalyst remaining in the bottle was calculated. If the catalyst generated static electricity during shaking, the charged powder would adhere to the glass bottle wall. The amount of catalyst remaining in the glass bottle can be used to represent the magnitude of the powder's charge.

[0036] b) Electrostatic test of the mixture of alkylaluminum compound and catalyst powder

[0037] 10g of catalyst powder was placed into a 100mL thoroughly dried glass bottle, and then a specified amount of alkyl aluminum compound solution was added. The bottle was continuously shaken on a sieve for 2 hours. After thorough vacuum drying, the bottle cap was opened, the bottle was inverted, and the catalyst powder was allowed to flow out freely without any external force. The weight of the freely flowing catalyst was recorded, and the amount of catalyst remaining in the bottle was calculated. If the catalyst generates static electricity during shaking, the charged powder will be adsorbed onto the glass bottle wall. The amount of catalyst remaining in the glass bottle can be used to represent the amount of charge on the powder.

[0038] c) Electrostatic testing of the mixture of alkylaluminum compound / chloroalkyl compound and catalyst powder

[0039] 10g of catalyst powder was placed into a 100mL thoroughly dried glass bottle. Then, a specified amount of alkylaluminum compound solution and a specified amount of chloroalkyl compound were added. The mixture was continuously shaken on a sieve for 2 hours. Finally, after thorough vacuum drying, the bottle cap was opened, the bottle was inverted, and the catalyst powder was allowed to flow out freely without any external force. The weight of the freely flowing catalyst was measured, and the amount of catalyst remaining in the bottle was calculated. If the catalyst generated static electricity during shaking, the charged powder would adhere to the glass bottle wall. The amount of catalyst remaining in the glass bottle can be used to represent the amount of charge on the powder.

[0040] Example 1

[0041] (1) Preparation of catalyst

[0042] A 500 mL reactor was dried and fully purged with nitrogen. Then, 200 mL of anhydrous hexane and 10 g of magnesium diethoxy were added, and the temperature was raised to 80 °C. A mixture of silicon tetrachloride and ethanol (molar ratio of silicon tetrachloride to ethanol 1:2) was added, and the mixture was stirred for 0.5 hours. Then, 20 mL of titanium tetrachloride was added, and the reaction was continued for another 0.5 hours. Finally, the temperature was raised to 110 °C, and the mixture was stirred for 60 minutes. Stirring was then stopped, and the supernatant was collected after the solid particles settled. Another 200 mL of anhydrous hexane was added, and the mixture was stirred for 0.5 hours. Stirring was then stopped, and the supernatant was collected after the solid particles settled. This process was repeated three times. Finally, the mixture was heated to 80 °C and dried under vacuum to obtain catalyst powder.

[0043] (2) Catalytic ethylene polymerization reaction

[0044] a) In a 2L polymerization reactor, add 1L of hexane, 2.0mL of a mixed solution of triethylaluminum and tert-butane chloride (the mixed solution is prepared by mixing triethylaluminum and tert-butane chloride in hexane at a molar ratio of 1:2, with a total concentration of 1M), then add about 10mg of the main catalyst powder, heat to 80℃, and continuously introduce ethylene to carry out the polymerization reaction of ethylene. Maintain the total polymerization pressure at 1.0MPa. After the polymerization reaction is completed for 2 hours, cool down, depressurize, discharge, and dry to obtain polyethylene powder. Weigh the powder and calculate the activity of the catalyst. Test the bulk density and melt flow index of the polymer powder. The results are shown in Table 1.

[0045] b) Without the addition of tert-butane chloride, the activity of the catalyst was tested using a 1M triethylaluminum hexane solution alone. At the same time, the bulk density and melt index of the polymer powder were tested. The results are shown in Table 1.

[0046] (3) Test of the charge of catalyst powder

[0047] a) Test the charge on the catalyst powder according to the method described above;

[0048] b) According to the method described above, test the charge of 10 g of catalyst powder mixed with 2.0 mL of triethylaluminum hexane solution (1.0 M);

[0049] c) According to the method described above, test the charge carried by mixing 10 g of catalyst powder with 2.0 mL of a mixed solution of triethylaluminum hexane and tert-butane chloride (triethylaluminum and tert-butane chloride are prepared in hexane at a molar ratio of 1:2, with a total concentration of 1.0 M).

[0050] Example 2

[0051] (1) Preparation of catalyst

[0052] The 10g of magnesium diethoxy in the catalyst preparation was adjusted to 10g of magnesium diethoxy, the silicon tetrachloride was adjusted to a mixture of silicon tetrachloride and ethanol in a 1:3 molar ratio, and the amount added was adjusted to 12mL. Other conditions were the same as in Example 1.

[0053] (2) Catalytic ethylene polymerization reaction

[0054] The catalytic polymerization reaction of ethylene uses triisobutylaluminum and chloromethane, and the molar ratio of triisobutylaluminum to chloromethane is 1:3, with other conditions the same as in Example 1.

[0055] (3) Test of the charge of catalyst powder

[0056] a) Test the charge on the catalyst powder according to the method described above;

[0057] b) According to the method described above, test the charge of 10 g of catalyst powder mixed with 2.0 mL of triisobutylaluminum hexane solution (1.0 M);

[0058] c) According to the method described above, test the charge carried by mixing 10 g of catalyst powder with 2.0 mL of a mixed solution of triisobutylaluminum hexane and chloromethane (triethylaluminum and chloromethane were prepared in hexane at a molar ratio of 1:3, with a total concentration of 1.0 M).

[0059] Example 3

[0060] (1) Preparation of catalyst

[0061] The 10g magnesium diethoxy in the catalyst preparation was adjusted to 12g magnesium diepropoxy, the silicon tetrachloride was adjusted to a mixture of silicon tetrachloride and ethanol in a 1:3 molar ratio, and the amount added was adjusted to 12mL. Other conditions were the same as in Example 1.

[0062] (2) Catalytic ethylene polymerization reaction

[0063] Trihexylaluminum and chlorocyclohexane were used in the catalytic ethylene polymerization reaction, and the molar ratio of trihexylaluminum to chlorocyclohexane was adjusted to 1:10. Other conditions were the same as in Example 1.

[0064] (3) Test of the charge of catalyst powder

[0065] a) Test the charge on the catalyst powder according to the method described above;

[0066] b) According to the method described above, test the charge of 10 g of catalyst powder mixed with 2.0 mL of triisobutylaluminum hexane solution (1.0 M);

[0067] c) According to the method described above, test the charge of 10 g of catalyst powder mixed with 2.0 mL of a mixed solution of triisobutylaluminum hexane and chlorocyclohexane (triisobutylaluminum and chlorocyclohexane were prepared in hexane at a molar ratio of 1:10, with a total concentration of 1.0 M).

[0068] Example 4

[0069] (1) Preparation of catalyst

[0070] The silicon tetrachloride in the catalyst preparation was adjusted to be a mixture of silicon tetrachloride and ethanol in a 1:3 molar ratio, and the amount added was adjusted to 12 mL. Other conditions were the same as in Example 1.

[0071] (2) Catalytic ethylene polymerization reaction

[0072] Trioctylaluminum and 2-chloropropane were used in the catalytic ethylene polymerization reaction, and the molar ratio of trioctylaluminum to 2-chloropropane was adjusted to 1:20. Other conditions were the same as in Example 1.

[0073] (3) Test of the charge of catalyst powder

[0074] a) Test the charge on the catalyst powder according to the method described above;

[0075] b) According to the method described above, test the charge of 10 g of catalyst powder mixed with 2.0 mL of triethylaluminum hexane solution (1.0 M);

[0076] c) According to the method described above, test the charge carried by mixing 10 g of catalyst powder with 2.0 mL of a mixed solution of triethylaluminum hexane and 2-chloropropane (triethylaluminum and 2-chloropropane are prepared in hexane at a molar ratio of 1:20, with a total concentration of 1.0 M).

[0077] Example 5

[0078] (1) Preparation of catalyst

[0079] The silicon tetrachloride in the catalyst preparation was adjusted to be a mixture of silicon tetrachloride and ethanol in a 1:3 molar ratio, and the amount added was adjusted to 12 mL. Other conditions were the same as in Example 1.

[0080] (2) Catalytic ethylene polymerization reaction

[0081] Triisobutylaluminum and chlorobenzene were used in the catalytic ethylene polymerization reaction, and the molar ratio of triisobutylaluminum to chlorobenzene was adjusted to 1:30. Other conditions were the same as in Example 1.

[0082] (3) Test of the charge of catalyst powder

[0083] a) Test the charge on the catalyst powder according to the method described above;

[0084] b) According to the method described above, test the charge of 10 g of catalyst powder mixed with 2.0 mL of triisobutylaluminum hexane solution (1.0 M);

[0085] c) According to the method described above, test the charge carried by mixing 10 g of catalyst powder with 2.0 mL of a mixed solution of triisobutylaluminum and chlorobenzene (triethylaluminum and chlorobenzene are prepared in hexane at a molar ratio of 1:30, with a total concentration of 1.0 M).

[0086] Example 6

[0087] (1) Preparation of catalyst

[0088] The 20 mL of titanium tetrachloride used in the preparation of the catalyst main component was adjusted to 25 mL of a mixture of titanium tetrachloride and isooctyl alcohol in a 1:2 ratio, with other conditions the same as in Example 1.

[0089] (2) Catalytic ethylene polymerization reaction

[0090] Triethylaluminum and ethane chloride were used in the catalytic ethylene polymerization reaction, and the molar ratio of triethylaluminum to ethane chloride was adjusted to 1:5. Other conditions were the same as in Example 1.

[0091] (3) Test of the charge of catalyst powder

[0092] a) Test the charge on the catalyst powder according to the method described above;

[0093] b) According to the method described above, test the charge of 10 g of catalyst powder mixed with 2.0 mL of triethylaluminum hexane solution (1.0 M);

[0094] c) According to the method described above, test the charge carried by mixing 10 g of catalyst powder with 2.0 mL of a mixed solution of triethylaluminum and chloroethane (triethylaluminum and chloroethane were prepared in hexane at a molar ratio of 1:5, with a total concentration of 1.0 M).

[0095] Example 7

[0096] (1) Preparation of catalyst

[0097] The 10g diethoxymagnesium in the preparation of the catalyst main component was adjusted to 10g magnesium chloride ethanolate (MgCl2·2.5CH3CH2OH), and other conditions were the same as in Example 1.

[0098] (2) Catalytic ethylene polymerization reaction

[0099] Triethylaluminum and 1-chloro-n-butane were used in the catalytic ethylene polymerization reaction, and the molar ratio of triethylaluminum to 1-chloro-n-butane was adjusted to 1:10. Other conditions were the same as in Example 1.

[0100] (3) Test of the charge of catalyst powder

[0101] a) Test the charge on the catalyst powder according to the method described above;

[0102] b) According to the method described above, test the charge of 10 g of catalyst powder mixed with 2.0 mL of triethylaluminum hexane solution (1.0 M);

[0103] c) According to the method described above, test the charge of 10 g of catalyst powder mixed with 2.0 mL of a mixed solution of triethylaluminum and 1-chloro-n-butane (triethylaluminum and 1-chloro-n-butane were prepared in hexane at a molar ratio of 1:10, with a total concentration of 1.0 M).

[0104] Example 8

[0105] The 10g magnesium diethoxy in the preparation of the catalyst main component was adjusted to 10g magnesium chloride ethanolate (MgCl2·2.5CH3CH2OH), and the 20mL titanium tetrachloride was adjusted to 20mL of a mixture of titanium tetrachloride and isopropanol (the molar ratio of titanium tetrachloride to isopropanol was 1:2). Other conditions were the same as in Example 1.

[0106] (2) Catalytic ethylene polymerization reaction

[0107] Triethylaluminum and 2-chlorobutane were used in the catalytic ethylene polymerization reaction, and the molar ratio of triethylaluminum to 2-chlorobutane was adjusted to 1:20. Other conditions were the same as in Example 1.

[0108] (3) Test of the charge of catalyst powder

[0109] a) Test the charge on the catalyst powder according to the method described above;

[0110] b) According to the method described above, test the charge of 10 g of catalyst powder mixed with 2.0 mL of triethylaluminum hexane solution (1.0 M);

[0111] c) According to the method described above, test the charge carried by mixing 10 g of catalyst powder with 2.0 mL of a mixed solution of triethylaluminum hexane and 2-chloro-n-butane (triethylaluminum and 2-chloro-n-butane are prepared in hexane at a molar ratio of 1:20, with a total concentration of 1.0 M).

[0112] Example 9

[0113] The 10g diethoxymagnesium in the preparation of the catalyst main component was adjusted to 12g magnesium chloride ethanolate (MgCl2·2.5CH3CH2OH), and the 20mL titanium tetrachloride was adjusted to 20mL of a mixture of titanium tetrachloride and isooctanol (the molar ratio of titanium tetrachloride to isopropanol was 1:2). Other conditions were the same as in Example 1.

[0114] (2) Catalytic ethylene polymerization reaction

[0115] The molar ratio of triethylaluminum and tert-butane chloride in the catalytic ethylene polymerization reaction was adjusted to 1:20, and other conditions were the same as in Example 1.

[0116] (3) Test of the charge of catalyst powder

[0117] a) Test the charge on the catalyst powder according to the method described above;

[0118] b) According to the method described above, test the charge of 10 g of catalyst powder mixed with 2.0 mL of triethylaluminum hexane solution (1.0 M);

[0119] c) According to the method described above, test the charge carried by mixing 10 g of catalyst powder with 2.0 mL of a mixed solution of triethylaluminum hexane and tert-butane chloride (triethylaluminum and tert-butane chloride were prepared in hexane at a molar ratio of 1:20, with a total concentration of 1.0 M).

[0120] Example 10

[0121] The 10g diethoxymagnesium in the preparation of the catalyst main component was adjusted to 10g magnesium chloride alcohol (MgCl2·2.5CH3CH2OH), and the 10mL silicon tetrachloride was adjusted to a mixture of silicon tetrachloride and ethanol in a 1:3 molar ratio. The amount added was adjusted to 12mL. Other conditions were the same as in Example 1.

[0122] (2) Catalytic ethylene polymerization reaction

[0123] The molar ratio of triethylaluminum and tert-butane chloride in the catalytic ethylene polymerization reaction was adjusted to 1:5, and other conditions were the same as in Example 1.

[0124] (3) Test of the charge of catalyst powder

[0125] a) Test the charge on the catalyst powder according to the method described above;

[0126] b) According to the method described above, test the charge of 10 g of catalyst powder mixed with 2.0 mL of triethylaluminum hexane solution (1.0 M);

[0127] c) According to the method described above, test the charge carried by mixing 10 g of catalyst powder with 2.0 mL of a mixed solution of triethylaluminum hexane and tert-butane chloride (triethylaluminum and tert-butane chloride are prepared in hexane at a molar ratio of 1:5, with a total concentration of 1.0 M).

[0128] Example 11

[0129] The 10g diethoxymagnesium in the preparation of the catalyst main component was adjusted to 10g magnesium chloride alcohol (MgCl2·2.5CH3CH2OH), and the 10mL silicon tetrachloride was adjusted to a mixture of silicon tetrachloride and isooctyl alcohol in a 1:3 molar ratio. The amount added was adjusted to 12mL. Other conditions were the same as in Example 1.

[0130] (2) Catalytic ethylene polymerization reaction

[0131] The molar ratio of triethylaluminum and tert-butane chloride in the catalytic ethylene polymerization reaction was adjusted to 1:5, and other conditions were the same as in Example 1.

[0132] (3) Test of the charge of catalyst powder

[0133] a) Test the charge on the catalyst powder according to the method described above;

[0134] b) According to the method described above, test the charge of 10 g of catalyst powder mixed with 2.0 mL of triethylaluminum hexane solution (1.0 M);

[0135] c) According to the method described above, test the charge carried by mixing 10 g of catalyst powder with 2.0 mL of a mixed solution of triethylaluminum hexane and tert-butane chloride (triethylaluminum and tert-butane chloride are prepared in hexane at a molar ratio of 1:5, with a total concentration of 1.0 M).

[0136] Comparative Example 1

[0137] The catalyst was prepared according to the method disclosed in patent CN201210402234. The specific preparation method is shown below.

[0138] (1) Preparation of catalyst

[0139] A 500 mL reactor was dried and fully purged with nitrogen. Then, 4.0 g magnesium chloride, 50 mL toluene, 2.0 mL epichlorohydrin, and 3.0 mL tributyl phosphate were added sequentially. The mixture was heated to 50 °C with stirring and maintained for 15 minutes. 6.0 mL ethanol was added, and the reaction was continued with stirring for another 15 minutes. The solution was cooled to -5 to 0 °C, and 30 mL titanium tetrachloride was added dropwise. Then, 10 mL of 1,2-dichlorohexane was added, and the solution was heated to 80 °C. The mother liquor was removed. Another 40 mL of 1,2-dichlorohexane was added, and the reaction was carried out at 60 °C for 30 minutes. After filtration, the mixture was washed four times with hexane and dried under vacuum to obtain the solid catalyst main component.

[0140] (2) Catalytic ethylene polymerization reaction

[0141] The molar ratio of triethylaluminum and tert-butane chloride in the catalytic ethylene polymerization reaction was adjusted to 1:5, and other conditions were the same as in Example 1.

[0142] (3) Test of the charge of catalyst powder

[0143] a) Test the charge on the catalyst powder according to the method described above;

[0144] b) According to the method described above, test the charge of 10 g of catalyst powder mixed with 2.0 mL of triethylaluminum hexane solution (1.0 M);

[0145] c) According to the method described above, test the charge carried by mixing 10 g of catalyst powder with 2.0 mL of a mixed solution of triethylaluminum hexane and tert-butane chloride (triethylaluminum and tert-butane chloride are prepared in hexane at a molar ratio of 1:5, with a total concentration of 1.0 M).

[0146] Comparative Example 2

[0147] The main component of the catalyst was prepared by referring to the method disclosed in patent CN201710725365.4 and making appropriate adjustments. The specific preparation method is shown below.

[0148] (1) Preparation of the main component of the catalyst

[0149] After drying the 500 mL reaction vessel and fully purging it with nitrogen, add 200 mL of anhydrous cyclohexane and 5 mL of dibutylmagnesium.

[0150] The solution (Aldrich product, 1M hexane solution containing 12 mol% triethylaluminum) and 1.1 mL of anhydrous tert-butane chloride were added. The temperature was raised to 50 °C, and then 0.05 mL of silicon tetrachloride was added. After reacting for 5 minutes, 0.1 mL of titanium tetrachloride was added. Finally, the temperature was raised to 100 °C, and the reaction was stirred for 5 minutes. After filtration, the solution was washed four times with hexane and dried under vacuum to obtain the solid catalyst main component.

[0151] (2) Catalytic ethylene polymerization reaction

[0152] a) In a 2L polymerization reactor, add 1L of hexane, 2.0mL of a mixed solution of triethylaluminum and tert-butane chloride (the mixed solution is prepared by mixing triethylaluminum and tert-butane chloride in hexane at a molar ratio of 1:2, with a total concentration of 1M), then add about 10mg of the main catalyst powder, heat to 80℃, and continuously introduce ethylene to carry out the polymerization reaction of ethylene. Maintain the total polymerization pressure at 1.0MPa. After the polymerization reaction is completed for 2 hours, cool down, depressurize, discharge, and dry to obtain polyethylene powder. Weigh the powder and calculate the activity of the catalyst. Test the bulk density and melt flow index of the polymer powder. The results are shown in Table 1.

[0153] b) Without the addition of tert-butane chloride, the activity of the catalyst was tested using a 1M triethylaluminum hexane solution alone. At the same time, the bulk density and melt index of the polymer powder were tested. The results are shown in Table 1.

[0154] (3) Test of the charge of catalyst powder

[0155] a) Test the charge on the catalyst powder according to the method described above;

[0156] b) According to the method described above, test the charge of 10 g of catalyst powder mixed with 2.0 mL of triethylaluminum hexane solution (1.0 M);

[0157] c) According to the method described above, test the charge carried by mixing 10 g of catalyst powder with 2.0 mL of a mixed solution of triethylaluminum hexane and tert-butane chloride (triethylaluminum and tert-butane chloride are prepared in hexane at a molar ratio of 1:2, with a total concentration of 1.0 M).

[0158] Table 1

[0159]

[0160]

[0161] As can be seen from the data in the table, when the Ziegler-Natta type catalyst of the present invention is combined with alkylaluminum compounds and chloroalkane-based compounds to form a catalyst composition, the activity of the catalytic system is greatly improved, and the amount of static electricity generated by the catalyst powder is also significantly reduced.

[0162] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the claims of the present invention.

Claims

1. An olefin polymerization catalyst composition, characterized in that, Include: A) Ziegler-Natta type catalyst; B) Alkyl aluminum compounds; C) Chloroalkyl compounds; The Ziegler-Natta type catalyst is prepared by reacting at least one solid magnesium compound, at least one silicon compound, and at least one titanium compound; the molar ratio of the alkylaluminum compound and the chloroalkyl compound is 1:2 to 1:

30.

2. The olefin polymerization catalyst composition according to claim 1, characterized in that, The solid magnesium compound is such as general formula (Ⅰ)Mg(OR) 1 As shown in Figure 2, R 1 It is C2~C 20 The hydrocarbon group is a saturated or unsaturated straight chain, branched chain, or cyclic chain; Preferably, the solid magnesium compound comprises a mixture of magnesium diethoxy, magnesium dibutoxy, magnesium dipropoxy, magnesium chloride, and fatty alcohols.

3. The olefin polymerization catalyst composition according to claim 1, characterized in that, The silicon compound is such as general formula (II)Si(OR) 2 ) n Cl 2-n As shown in the formula, R 2 It is C2~C 20 The hydrocarbon group is a saturated or unsaturated straight chain, branched chain, or cyclic chain, where 0 < n ≤ 2; Preferably, the silicon compound comprises the reaction product of silicon tetrachloride and a fatty alcohol; the molar ratio of the fatty alcohol to silicon tetrachloride is less than 4.0, the reaction temperature is between room temperature and 50°C, and the reaction time is 0.5-5 hours.

4. The olefin polymerization catalyst composition according to claim 1, characterized in that, The titanium compound, such as general formula (Ⅲ)Ti(OR) 4 ) n Cl 4-n As shown in the formula, R 4 It is C2~C 20 The hydrocarbon group is a saturated or unsaturated straight chain, branched chain, or cyclic chain, and 0 ≤ n < 4; Preferably, the titanium compound comprises titanium tetrachloride or the reaction product of titanium tetrachloride and a fatty alcohol; the molar ratio of the fatty alcohol to titanium tetrachloride is less than 4.0, the reaction temperature is between room temperature and 100°C, and the reaction time is 0.5-5 hours.

5. The olefin polymerization catalyst composition according to claim 1, characterized in that, The preparation method of the Ziegler-Natta type catalyst includes the following steps: (1) The solid magnesium compound and the silicon compound are mixed to form a reaction product; (2) The reaction product obtained in step (1) is reacted with the titanium compound to obtain the Ziegler-Natta catalyst.

6. The olefin polymerization catalyst composition according to claim 1 or 5, characterized in that, The proportions of the components are such that, per mole of solid magnesium compound, the silicon compound is 0.1 to 10 moles, preferably 0.5 to 5 moles, and the titanium compound is 0.05 to 3 moles, preferably 0.1 to 2 moles.

7. The olefin polymerization catalyst composition according to claim 1 or 5, characterized in that, The solid magnesium compound includes at least one of alkoxy magnesium compounds and magnesium chloride alcohols; The alkoxy magnesium compound is prepared by reacting magnesium powder with fatty alcohol; The preparation process of the magnesium chloride alcohol complex includes: dissolving magnesium chloride in a fatty alcohol, then transferring it to low-temperature hexane, stirring, dispersing, melting and solidifying to obtain the product; Preferably, an inert dispersant is added during the preparation of the solid magnesium compound; the inert dispersant is selected from at least one of hexaane, heptane, octane, toluene, xylene, 1,2-dichloroethane, chlorocyclohexane, chlorobenzene and other hydrocarbons or halogenated hydrocarbons.

8. The olefin polymerization catalyst composition according to claim 1, characterized in that, The general formula of the alkylaluminum compound is AlR3, where R is an alkyl group having 1 to 20 carbon atoms; Preferably, the alkylaluminum compound includes AlEt3, Al(iso-Bu)3, Al(n-C6H13)3, Al(n-C8H13)3, and Al(n-C8H13)3. 17 At least one of the alkylaluminum compounds; the molar ratio of the alkylaluminum compound to titanium in the Ziegler-Natta catalyst is 1 to 500.

9. The olefin polymerization catalyst composition according to claim 1, characterized in that, The general formula of the chloroalkyl compound is R'Cl, where R' is an alkyl group having 1 to 20 carbon atoms; Preferably, the chloroalkyl compound includes at least one selected from chloromethane, chloroethane, 1-chloropropane, 2-chloropropane, 1-chloron-butane, 2-chloron-butane, tert-chlorobutane, chlorocyclohexane, and chlorobenzene. Preferably, the molar ratio of the alkylaluminum compound to the chloroalkyl compound is 1:2 to 1:

8.

10. The olefin polymerization catalyst composition according to claim 1, characterized in that, The alkylaluminum compound and the chloroalkyl compound are mixed sequentially with the Ziegler-Natta type catalyst, or the alkylaluminum compound and the chloroalkyl compound are premixed and then mixed with the Ziegler-Natta type catalyst.

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