Slurry catalysts and paste catalysts, and methods of making and using the same

Abstract

This invention discloses a slurry catalyst and a paste catalyst, their preparation methods, and applications. The preparation method of the slurry catalyst includes: Step 1, sieving the catalyst using a support; Step 2, using the sieved support, reacting it with a titanium compound and an electron donor compound in the presence of an inert diluent, filtering, washing the resulting solid with low-boiling-point alkane B to obtain a first mixture in which solid catalyst component A is dispersed in alkane B, and mixing the first mixture with white oil C to obtain a second mixture; Step 3, removing the low-boiling-point alkane B from the second mixture under vacuum to obtain a slurry catalyst in white oil C containing solid catalyst component A. The slurry catalyst or paste catalyst of this invention can be directly prepolymerized and then used for olefin polymerization, exhibiting good activity, orientation ability, and hydrogen sensitivity. Simultaneously, the polymer obtained from the olefin polymerization reaction produces very little fine powder or lumps.

Description

Technical Field

[0001] This invention relates to a slurry catalyst and its preparation method, a paste catalyst comprising the slurry catalyst, and a method for olefin polymerization. Background Technology

[0002] Ziegler-Natta catalysts are widely used in the preparation of polyolefins. Industrially applied Ziegler-Natta catalysts mainly consist of three parts: (1) the Ziegler-Natta main catalyst; (2) an alkylaluminum compound as a co-catalyst; and (3) an external electron donor. In industrial applications, the Ziegler-Natta main catalyst can be directly introduced into the reactor or prepolymerized before being introduced. The prepolymerization ratio is generally 1-300 times.

[0003] In propylene polymerization industrial plants such as Spheripol and ST, the prepolymerization step of the catalyst is as follows: (1) a mixture of dry powder Ziegler-Natta main catalyst, oil and grease is prepared into a paste; (2) the above paste is added to a continuously fed loop prepolymerization reactor, and propylene, alkyl aluminum and silane are added simultaneously for prepolymerization; (3) the prepolymerized catalyst enters the reactor for propylene polymerization. This method has the following shortcomings: (1) When the dry powder Ziegler-Natta main catalyst enters the reactor through pipelines or short circuits, there will inevitably be residues or adhesions, which can easily cause corrosion. The rust residue generated by corrosion will enter the prepolymerization reactor with the dry powder, thereby clogging the filter screen, pipelines and even catalyst nozzles, which may cause the plant to shut down in severe cases. (2) The feeding of dry powder Ziegler-Natta main catalyst must be hoisted, which poses a high operational risk. (3) The stirring and friction process during the drying and sieving of the dry powder Ziegler-Natta main catalyst will increase the amount of fine powder in the catalyst, and these fine powders will form fine powder in the polymer powder after polymerization. (4) The packaging barrels of dry powder catalysts are not easy to recycle, which increases the generation of hazardous waste and is not conducive to green production.

[0004] In the preparation of polyolefins using Ziegler-Natta catalysts, the polymer powder particles replicate the particle morphology of the catalyst. The amount of fine powder in the polymer is a crucial control parameter. Fine powder can enter components such as pipes and heat exchangers with the gas, gradually agglomerating and even further reacting and plasticizing, leading to clumping and blockages, thus affecting the long-term stable operation of the equipment. Summary of the Invention

[0005] To address the aforementioned problems in existing technologies, this invention provides a novel slurry catalyst and a paste catalyst, along with their preparation methods. The slurry or paste catalyst of this invention can be directly prepolymerized and then used in olefin polymerization, exhibiting excellent activity, orientation capability, and hydrogen sensitivity. Simultaneously, the polymer obtained from the olefin polymerization reaction produces very little fine powder and lumps. Compared to introducing dry powder into the prepolymerization reactor, directly introducing the slurry catalyst and / or paste catalyst into the prepolymerization reactor is more convenient and carries less injection risk. More importantly, since the added component is a solid catalyst slurry that has not undergone the traditional long-term drying process, there is less catalyst breakage and fine powder, which is more conducive to the long-term stable operation of the equipment.

[0006] The first aspect of this invention provides a method for preparing a slurry catalyst, comprising:

[0007] Step 1: The catalyst support is sieved to obtain a sieved support.

[0008] Step 2: Using a sieved carrier, react with titanium compounds and electron donor compounds in the presence of an inert diluent, filter, and wash the resulting solid with low-boiling-point alkane B to obtain a first mixture in which solid catalyst component A is dispersed in alkane B. The first mixture is then mixed with white oil C to obtain a second mixture.

[0009] Step 3: Vacuum removal of low-boiling-point alkane B from the second mixture to obtain a slurry catalyst of solid catalyst component A in white oil C.

[0010] According to some embodiments of the preparation method described in this invention, the catalyst support refers to a magnesium-containing precursor that can ultimately react to form an active magnesium chloride support for the preparation of a Ziegler-Natta polyolefin catalyst. The particle size and morphology of this magnesium-containing precursor (support) are defined, and the particle size and morphology of the catalyst substantially replicate the particle size and morphology of the support. The support includes, but is not limited to, the alkoxymagnesium support prepared in CN102453150B and the magnesium chloride alcohol support prepared in CN1289542C. The support is a magnesium-containing support for the preparation of the Ziegler-Natta polyolefin catalyst; preferably, the support is one or more of a spherical alkoxymagnesium support and a spherical magnesium chloride alcohol support.

[0011] Solid catalyst components prepared by solvent extraction methods known in the art are not suitable for the preparation method of the prepolymer catalyst described in this invention. Specifically, as described in CN85100997A, a solid catalyst component is prepared by dissolving magnesium chloride in a solvent, precipitating it into active magnesium chloride particles under certain conditions, and then loading titanium and esters. Since the precipitated active magnesium chloride particles (as a support) cannot be sieved to remove some irregular or agglomerated unqualified particles, the solid catalyst component prepared by this method cannot be used for the preparation of the prepolymer catalyst described in this invention.

[0012] In some embodiments of the preparation method according to the present invention, the support needs to be sieved before use. If sieved, large particles or agglomerated support will enter the catalyst preparation process, resulting in large-particle or agglomerated catalysts. However, the catalyst preparation method of the present invention does not include the separation and sieving process of the dry catalyst powder. The aforementioned large-particle or agglomerated catalyst entering the polymerization reactor will form hot spots, leading to unstable reactor temperature and the risk of polymer agglomeration, thus affecting the operation of the equipment. Therefore, sieving the support is one of the keys to ensuring the smooth implementation of this method. Preferably, the average particle size of the support obtained by the sieving process is not greater than 100 μm, preferably 10-80 μm. Preferably, for example, but not limited to, using an 80-250 mesh sieve for sieving.

[0013] According to some embodiments of the preparation method described in this invention, no drying process is performed in step 2 to obtain solid catalyst component A. That is, the reaction is carried out using a sieved support in the presence of an inert diluent with the titanium compound and the electron carrier compound, and no drying process is performed during filtration.

[0014] In this invention, solid catalyst component A can be prepared using conventional methods for preparing olefin catalyst components in the art. For example, the solid catalyst component of this invention can be prepared by the following methods.

[0015] Method 1 involves suspending alkoxymagnesium or alkoxyhalide magnesium in an inert diluent to form a suspension. This suspension is then mixed and contacted with the aforementioned titanium compound and internal electron donor to obtain a solid dispersion system, commonly referred to as the mother liquor. The mother liquor is filtered, and the resulting solid material is suspended in a solution containing titanium tetrachloride for contact treatment, commonly referred to as titanium treatment. After filtration and washing, the solid catalyst component of this invention is obtained.

[0016] As specific examples of the aforementioned alkoxymagnesium compounds in Method 1, examples include dimethoxymagnesium, diethoxymagnesium, dipropoxymagnesium, diisopropoxymagnesium, dibutoxymagnesium, diisobutoxymagnesium, dipentoxymagnesium, dihexyloxymagnesium, di(2-ethyl)hexyloxymagnesium, and mixtures thereof, preferably diethoxymagnesium or a mixture of diethoxymagnesium and other alkoxymagnesium compounds. The preparation method of this alkoxymagnesium compound can be based on methods known in the art, such as the preparation of metallic magnesium with a fatty alcohol in the presence of a small amount of iodine disclosed in patent CN101906017A.

[0017] As specific examples of the aforementioned alkoxymagnesium halides in Method 1, methoxymagnesium chloride, ethoxymagnesium chloride, propoxymagnesium chloride, butoxymagnesium chloride, etc., are given, with ethoxymagnesium chloride being preferred. The preparation method of this alkoxymagnesium halide compound can be carried out by methods known in the art, such as preparing ethoxymagnesium chloride by mixing the Grignard reagent butylmagnesium chloride with tetraethoxytitanium and tetraethoxysilane.

[0018] In Method 1, the inert diluent used to form the mother liquor can be at least one of hexane, heptane, octane, decane, benzene, toluene, and xylene.

[0019] In Method 1, the amounts of each component used in the formation of the mother liquor are as follows: per mole of magnesium, the amount of titanium compound used is 0.5-100 moles, preferably 1-50 moles; the amount of inert diluent used is usually 0.5-100 moles, preferably 1-50 moles; and the total amount of internal electron donor compound is usually 0.005-10 moles, preferably 0.01-1 moles.

[0020] In Method 1, the contact temperature of the components during the formation of the mother liquor is typically -40 to 200°C, preferably -20 to 150°C; the contact time is typically 1 minute to 20 hours, preferably 5 minutes to 8 hours.

[0021] In the titanium treatment process described in Method 1, an inert diluent, such as at least one of hexane, heptane, octane, decane, benzene, toluene, and xylene, may be selectively added to the solution containing titanium tetrachloride.

[0022] In the titanium treatment process of Method 1, the amount of each component in the titanium tetrachloride solution used is 0.5-100 moles of titanium compound per mole of magnesium, preferably 1-50 moles; the amount of inert diluent used is usually 0-100 moles, preferably 0-50 moles.

[0023] In Method 1, the number of titanium treatments is 0-10 times, preferably 1-5 times.

[0024] In the titanium treatment process of Method 1, the above-mentioned electron donor compound may be selectively added, wherein the amount of internal electron donor is usually 0.005-10 mol, preferably 0.01-1 mol.

[0025] In Method 1, the titanium treatment temperature is typically 0-200℃, preferably 30-150℃; the contact time is typically 1 minute-20 hours, preferably 5 minutes-6 hours.

[0026] Method 2 involves suspending the magnesium dihalide alkoxide in an inert diluent to form a suspension, then mixing and contacting this suspension with the aforementioned titanium compound and internal electron donor to obtain a solid dispersion system, hereinafter referred to as the mother liquor. The mother liquor is filtered, and the resulting solid material is suspended in a solution containing titanium tetrachloride for contact treatment, hereinafter referred to as titanium treatment; then filtered and washed to obtain the solid catalyst component of this invention.

[0027] The magnesium dihalide ethanolate described in Method 2 can be prepared by the following method: In the presence of an inert solvent (such as hexane, heptane, octane, decane, benzene, toluene, and xylene, etc.) that is immiscible with the adduct, an alcohol (such as methanol, ethanol, propanol, or isopropanol, etc.) and magnesium halide are mixed to form an emulsion, and the emulsion is rapidly cooled and dispersed. The resulting spherical particles are the magnesium dihalide ethanolate.

[0028] In Method 2, the inert diluent used to form the mother liquor can be at least one of hexane, heptane, octane, decane, benzene, toluene, and xylene.

[0029] In Method 2, the amounts of each component used in the formation of the mother liquor are as follows: per mole of magnesium, the amount of titanium compound used is 0.5-100 moles, preferably 1-50 moles; the amount of inert diluent used is usually 0.5-100 moles, preferably 1-50 moles; and the total amount of electron donor compound is usually 0.005-10 moles, preferably 0.01-1 moles.

[0030] In Method 2, the contact temperature of the components during the formation of the mother liquor is typically -40 to 200°C, preferably -20 to 150°C; the contact time is typically 1 minute to 20 hours, preferably 5 minutes to 8 hours.

[0031] In the titanium treatment process described in Method 2, an inert diluent, such as at least one of hexane, heptane, octane, decane, benzene, toluene, and xylene, may be selectively added to the solution containing titanium tetrachloride.

[0032] In the titanium treatment process of Method 2, the amount of each component in the titanium tetrachloride solution used is 0.5-100 moles of titanium compound per mole of magnesium, preferably 1-50 moles; the amount of inert diluent used is usually 0-100 moles, preferably 0-50 moles.

[0033] In Method 2, the number of titanium treatments is 0-10 times, preferably 1-5 times.

[0034] In the titanium treatment process of Method 2, the above-mentioned electron donor compound may be selectively added, wherein the amount of internal electron donor is usually 0.005-10 mol, preferably 0.01-1 mol.

[0035] In Method 2, the titanium treatment temperature is typically 0-200℃, preferably 30-150℃; the contact time is typically 1 minute-20 hours, preferably 5 minutes-6 hours.

[0036] In Method 1 and Method 2 above, the internal electron donor compound may be selected from at least one of phthalate compounds, glycol ester compounds, cyanosuccinate compounds, diether compounds, and succinate compounds; preferably selected from at least one of glycol ester compounds, cyanosuccinate compounds, diether compounds, and succinate compounds.

[0037] Examples of the phthalate compounds include, but are not limited to, those selected from the phthalate compounds of formula (I).

[0038]

[0039] In equation (I), R 15 and R 16 Whether they are the same or different, they are each independently selected from C1-C. 20 Straight-chain alkanes, C3-C 20 Branched alkyl groups, C3-C 20 cycloalkyl, C6-C 20 aryl, C7-C 20 alkylaryl or C7-C 20 The aralkyl group, wherein the hydrogen atom on the carbon atom of the alkyl, cycloalkyl, aryl, alkylaryl, or aralkyl group may optionally be substituted with a heteroatom, alkyl group, or alkoxy group, and the carbon atom on the main chain of the alkyl, cycloalkyl, aryl, alkylaryl, or aralkyl group may optionally be substituted with a heteroatom. Preferably, R 15 and R 16 Each is independently selected from C1-C 10 Straight-chain alkyl, C3-C 10 Branched alkyl groups, C3-C 10 cycloalkyl or C6-C 10 aryl; more preferably, R 15 and R 16 Each is independently selected from C1-C6 straight-chain alkyl or C1-C6 branched alkyl; more preferably, R 15 and R 16 Each is independently selected from methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, or phenyl.

[0040] According to some embodiments of the preparation method described in this invention, examples of the phthalate compounds represented by formula (I) include, but are not limited to: dimethyl phthalate, diethyl phthalate, di-n-propyl phthalate, diisopropyl phthalate, di-n-butyl phthalate, diisobutyl phthalate, di(1-methyl)propyl phthalate, di-tert-butyl phthalate, di-n-pentyl phthalate, di(1-methyl)butyl phthalate, di(2-methyl)butyl phthalate, diisopentyl phthalate, di(1,1'-dimethyl)propyl phthalate, di-tert-pentyl phthalate, di(1,2-dimethyl)propyl phthalate, n-hexyl phthalate, and di(1-methyl)phthalate. Di(2-methyl)pentyl phthalate, di(3-methyl)pentyl phthalate, diisohexyl phthalate, di(1,1'-dimethyl)butyl phthalate, di(2,2'-dimethyl)butyl phthalate, ditert-hexyl phthalate, di(1,2-dimethyl)butyl phthalate, di(2,3-dimethyl)butyl phthalate, di(1,3-dimethyl)butyl phthalate, di(1,1',2-trimethyl)propyl phthalate, di(1,2,2'-trimethyl)propyl phthalate, n-heptyl phthalate, di(1-methyl)hexyl phthalate, di(2-methyl)hexyl phthalate, di(3-methyl)hexyl phthalate, di(4- Di(1,1'-dimethyl)pentyl phthalate, di(2,2'-dimethyl)pentyl phthalate, di(3,3'-dimethyl)pentyl phthalate, ditert-heptyl phthalate, di(1,2-dimethyl)pentyl phthalate, di(1,3-dimethyl)pentyl phthalate, di(1,4-dimethyl)pentyl phthalate, di(2,3-dimethyl)pentyl phthalate, di(2,4-dimethyl)pentyl phthalate, di(3,4-dimethyl)pentyl phthalate, di(1,1',2-trimethyl)butyl phthalate, di(1,1',3-trimethyl)butyl phthalate, di(1,2,2'-trimethyl)butyl phthalate ) butyl phthalate, di(2,2',3-trimethyl) butyl phthalate, di(1,3,3'-trimethyl) butyl phthalate, di(2,3,3'-trimethyl) butyl phthalate, di(1,1',2,2'-tetramethyl) propyl phthalate, n-octyl phthalate, di(1-methyl)heptyl phthalate, di(2-methyl)heptyl phthalate, di(3-methyl)heptyl phthalate, di(4-methyl)heptyl phthalate, di(5-methyl)heptyl phthalate, di(1,1'-dimethyl)hexyl phthalate, di(2,2'-dimethyl)hexyl phthalate, di(3,3'-dimethyl)hexyl phthalate, di(4,4'-Dimethyl)hexyl phthalate, di(5,5'-dimethyl)hexyl phthalate, di(1,2-dimethyl)hexyl phthalate, di(1,3-dimethyl)hexyl phthalate, di(1,4-dimethyl)hexyl phthalate, di(1,5-dimethyl)hexyl phthalate, di(2,3-dimethyl)hexyl phthalate, di(2,4-dimethyl)hexyl phthalate Di(2,5-dimethyl)hexyl phthalate, di(3,4-dimethyl)hexyl phthalate, di(3,5-dimethyl)hexyl phthalate, di(4,5-dimethyl)hexyl phthalate, di(1,1',2-trimethyl)pentyl phthalate, di(1,1',3-trimethyl)pentyl phthalate, di(1,1',3-trimethyl)pentyl phthalate Di(1,2,2'-trimethyl)pentyl phthalate, di(2,2',3-trimethyl)pentyl phthalate, di(2,2',4-trimethyl)pentyl phthalate, di(1,3,3'-trimethyl)pentyl phthalate, di(2,3,3'-trimethyl)pentyl phthalate, di(3,3',4-trimethyl)pentyl phthalate Di(1,4,4'-trimethyl)pentyl phthalate, di(2,4,4'-trimethyl)pentyl phthalate, di(3,4,4'-trimethyl)pentyl phthalate, di(1,1',2,2'-tetramethyl)butyl phthalate, di(1,1',3,3'-tetramethyl)butyl phthalate, di(2,2',3,3'-Tetramethyl)butyl phthalate, diphenyl phthalate, di(o-methyl)phenyl phthalate, di(p-methyl)phenyl phthalate, di(m-methyl)phenyl phthalate, di(o-methoxy)phenyl phthalate, di(p-methoxy)phenyl phthalate, di(m-methoxy)phenyl phthalate; preferably selected from dimethyl phthalate, diethyl phthalate, di(o-methoxy)phenyl phthalate, di(o-methoxy)phenyl phthalate, di(o-methoxy)phenyl phthalate; Dipropyl formate, diisopropyl phthalate, dibutyl phthalate, diisobutyl phthalate, ditert-butyl phthalate, dipentyl phthalate, diisopentyl phthalate, n-hexyl phthalate, diisohexyl phthalate, n-heptyl phthalate, isoheptyl phthalate, n-octyl phthalate, isooctyl phthalate, diphenyl phthalate, n- Di(o-methyl)phenyl phthalate, di(p-methyl)phenyl phthalate, di(m-methyl)phenyl phthalate, di(o-methoxy)phenyl phthalate, di(p-methoxy)phenyl phthalate, di(m-methoxy)phenyl phthalate; more preferably selected from dimethyl phthalate, diethyl phthalate, di-n-propyl phthalate, diisopropyl phthalate, di(o-methoxy)phenyl ... Dibutyl formate, diisobutyl phthalate, ditert-butyl phthalate, di-n-pentyl phthalate, diisopentyl phthalate, n-hexyl phthalate, isohexyl phthalate, diphenyl phthalate, di(o-methyl)phenyl phthalate, di(p-methyl)phenyl phthalate, di(o-methoxy)phenyl phthalate, di(p-methoxy)phenyl phthalate.

[0041] Examples of the diol ester compounds include, but are not limited to, those selected from the diol ester compounds shown in formula (II).

[0042]

[0043] In equation (II), R 17 and R 18 The same or different, respectively, are substituted or unsubstituted C1-C. 20 Straight-chain alkanes, substituted or unsubstituted C3-C 20 Branched alkyl groups, substituted or unsubstituted C3-C 20 cycloalkyl, substituted or unsubstituted C6-C 20 aryl, substituted or unsubstituted C7-C 20 alkylaryl, substituted or unsubstituted C7-C 20 Aryl, substituted or unsubstituted C2 to C3 10 olefinic or substituted or unsubstituted C 10 -C 20 Fused ring aryl group; R 19 -R 24They may be the same or different, each being a straight-chain C1-C with hydrogen, halogen, substituted or unsubstituted components. 20 Straight-chain alkyl, substituted or unsubstituted C3-C 20 Branched alkyl groups, substituted or unsubstituted C3-C 20 cycloalkyl, substituted or unsubstituted C6-C 20 aryl, substituted or unsubstituted C7-C 20 alkylaryl, substituted or unsubstituted C7-C 20 Aryl, substituted or unsubstituted C2-C 10 olefinic group or substituted or unsubstituted C 10 -C 20 Fused ring aryl; or R 19 -R 22 At least one of them is related to R 23 -R 24 At least one of them forms a ring.

[0044] Examples of the diol ester compounds represented by formula (II) include, but are not limited to: 2-ethyl-1,3-propanediol dibenzoate, 2-propyl-1,3-propanediol dibenzoate, 2-isopropyl-2-isopentyl-1,3-propanediol dibenzoate, 1,3-butanediol dimethylbenzoate, 2-methyl-1,3-butanediol dichlorobenzoate, 2,3-dimethyl-1,3-butanediol dibenzoate, 1,3-pentanediol neopentanoate, 2,4-pentanediol dibenzoate, 2-methyl- At least one of 1,3-pentanediol benzoate, 2,2-dimethyl-1,3-pentanediol dibenzoate, 2,4-heptanediol dibenzoate, 3,5-heptanediol dibenzoate, 4-ethyl-3,5-heptanediol dibenzoate and 2-methyl-3,5-heptanediol dibenzoate; preferably at least one of 3,5-heptanediol dibenzoate, 4-ethyl-3,5-heptanediol dibenzoate and 2,4-pentanediol dibenzoate; more preferably 3,5-heptanediol dibenzoate.

[0045] Examples of the cyanosuccinate compounds include, but are not limited to, those selected from the cyanosuccinate compounds shown in formula (III).

[0046]

[0047] In equation (III), R 25 and R 26 Whether they are the same or different, they are each independently selected from hydrogen, C1-C 14 Straight-chain alkyl, C3-C 14 Branched alkyl groups, C3-C 10 cycloalkyl, C6-C 10 aryl, C7-C10 alkylaryl or C7-C 10 Aryl groups; R 27 and R 28 Whether they are the same or different, they are each independently selected from C1-C. 10 Straight-chain alkyl, C1-C 10 Branched alkyl groups, C3-C 10 cycloalkyl, C6-C 10 aryl, C7-C 20 alkylaryl or C7-C 20 Aryl groups.

[0048] Examples of the cyanosuccinate compounds represented by formula (III) include, but are not limited to: dimethyl 2,3-diisopropyl-2-cyanosuccinate, diethyl 2,3-diisopropyl-2-cyanosuccinate, di-n-propyl 2,3-diisopropyl-2-cyanosuccinate, diisopropyl 2,3-diisopropyl-2-cyanosuccinate, di-n-butyl 2,3-diisopropyl-2-cyanosuccinate, diisobutyl 2,3-diisopropyl-2-cyanosuccinate, and 1-methyl-4-ethyl 2,3-diisopropyl-2-cyanosuccinate (R 25 =Methyl, R 26 =Ethyl), 2,3-diisopropyl-2-cyanosuccinic acid-1-ethyl ester-4-methyl ester (R 25 =Ethyl, R 26 =Methyl), 2,3-diisopropyl-2-cyanosuccinic acid-1-n-butyl ester-4-ethyl ester (R 25 = n-Butyl, R 26 =Ethyl), 2,3-diisopropyl-2-cyanosuccinic acid-1-ethyl ester-4-n-butyl ester (R 25 =Ethyl, R 26 = n-Butyl), dimethyl 2,3-diisobutyl-2-cyanosuccinate, diethyl 2,3-diisobutyl-2-cyanosuccinate, di-n-propyl 2,3-diisobutyl-2-cyanosuccinate, di-n-butyl 2,3-diisobutyl-2-cyanosuccinate, di-n-butyl 2,3-diisobutyl-2-cyanosuccinate, di-isobutyl 2,3-diisobutyl-2-cyanosuccinate, 1-methyl-4-ethyl 2,3-diisobutyl-2-cyanosuccinate (R 25 =Methyl, R 26 =Ethyl), 2,3-diisobutyl-2-cyanosuccinic acid-1-ethyl ester-4-methyl ester (R 25 =Ethyl, R 26 =Methyl), 2,3-diisobutyl-2-cyanosuccinic acid-1-n-butyl ester-4-ethyl ester (R 25 = n-Butyl, R 26 =Ethyl), 2,3-diisobutyl-2-cyanosuccinic acid-1-ethyl ester-4-n-butyl ester (R25 =Ethyl, R 26 = n-Butyl), dimethyl 2,3-disec-butyl-2-cyanosuccinate, diethyl 2,3-disec-butyl-2-cyanosuccinate, di-n-propyl 2,3-disec-butyl-2-cyanosuccinate, diisopropyl 2,3-disec-butyl-2-cyanosuccinate, di-n-butyl 2,3-disec-butyl-2-cyanosuccinate, diisobutyl 2,3-disec-butyl-2-cyanosuccinate, 1-methyl-4-ethyl 2,3-disec-butyl-2-cyanosuccinate (R 25 =Methyl, R 26 =Ethyl), 2,3-disec-butyl-2-cyanosuccinic acid-1-ethyl ester-4-methyl ester (R 25 =Ethyl, R 26 =Methyl), 2,3-di-sec-butyl-2-cyanosuccinic acid-1-n-butyl ester-4-ethyl ester (R 25 = n-Butyl, R 26 =Ethyl), 2,3-di-sec-butyl-2-cyanosuccinic acid-1-ethyl ester-4-n-butyl ester (R 25 =Ethyl, R 26 = n-Butyl), dimethyl 2,3-dicyclopentyl-2-cyanosuccinate, diethyl 2,3-dicyclopentyl-2-cyanosuccinate, di-n-propyl 2,3-dicyclopentyl-2-cyanosuccinate, diisopropyl 2,3-dicyclopentyl-2-cyanosuccinate, di-n-butyl 2,3-dicyclopentyl-2-cyanosuccinate, diisobutyl 2,3-dicyclopentyl-2-cyanosuccinate, 1-methyl-4-ethyl 2,3-dicyclopentyl-2-cyanosuccinate (R 25 =Methyl, R 26 =Ethyl), 2,3-dicyclopentyl-2-cyanosuccinic acid-1-ethyl ester-4-methyl ester (R 25 =Ethyl, R 26 =Methyl), 2,3-dicyclopentyl-2-cyanosuccinic acid-1-n-butyl ester-4-ethyl ester (R 25 = n-Butyl, R 26 =Ethyl), 2,3-dicyclopentyl-2-cyanosuccinic acid-1-ethyl ester-4-n-butyl ester (R 25 =Ethyl, R 26 = n-Butyl), dimethyl 2,3-dicyclohexyl-2-cyanosuccinate, diethyl 2,3-dicyclohexyl-2-cyanosuccinate, di-n-propyl 2,3-dicyclohexyl-2-cyanosuccinate, diisopropyl 2,3-dicyclohexyl-2-cyanosuccinate, di-n-butyl 2,3-dicyclohexyl-2-cyanosuccinate, diisobutyl 2,3-dicyclohexyl-2-cyanosuccinate, 1-methyl-4-ethyl 2,3-dicyclohexyl-2-cyanosuccinate (R 25 =Methyl, R 26=Ethyl), 2,3-dicyclohexyl-2-cyanosuccinic acid-1-ethyl ester-4-methyl ester (R 25 =Ethyl, R 26 =Methyl), 2,3-dicyclohexyl-2-cyanosuccinic acid-1-n-butyl ester-4-ethyl ester (R 25 = n-Butyl, R 26 =Ethyl), 2,3-dicyclohexyl-2-cyanosuccinic acid-1-ethyl ester-4-n-butyl ester (R 25 =Ethyl, R 26 = n-Butyl); preferably diethyl 2,3-diisopropyl-2-cyanosuccinate, di-n-propyl 2,3-diisopropyl-2-cyanosuccinate, diisopropyl 2,3-diisopropyl-2-cyanosuccinate, di-n-butyl 2,3-diisopropyl-2-cyanosuccinate, diisobutyl 2,3-diisopropyl-2-cyanosuccinate; more preferably diethyl 2,3-diisopropyl-2-cyanosuccinate.

[0049] Examples of the diether compounds include, but are not limited to, those selected from the diether compounds shown in formula (IV).

[0050]

[0051] In equation (IV), R 29 and R 30 Whether the two are the same or different, they are each independently selected from C1-C. 10 Straight chain or C3-C 10 Branched alkyl groups; R 32 and R 33 Whether the two are the same or different, they are each independently selected from C1-C. 20 Straight chain, C3-C 20 Branched alkyl groups, C3-C 20 cycloalkyl, C6-C 20 Substituted or unsubstituted aryl groups or C7-C 20 alkylaryl; R 31 and R 34 Whether the two are the same or different, they are each independently selected from hydrogen, C1-C 10 Straight-chain alkyl or C3-C 10 Branched alkyl groups.

[0052] Examples of the diether compounds represented by formula (IV) include, but are not limited to: 2-isopropyl-2-isopentyl-1,3-dimethoxypropane, 9,9-di(methoxymethyl)fluorene, 2-isobutyl-2-isopropyl-1,3-dimethoxypropane, 2,2-dicyclopentyldimethoxypropane, 2,2-diphenyl-1,3-dimethoxypropane, 2-isobutyl-2-isopropyl-1,3-dimethoxypropane, 2,2-dicyclopentyl-1,3-dimethoxypropane, 2,2-diisobutyl-1,3-dimethoxypropane, preferably 2-isopropyl-2-isopentyl-1,3-dimethoxypropane and 9,9-di(methoxymethyl)fluorene.

[0053] Examples of the succinate compounds include, but are not limited to, those selected from the succinate compounds shown in formula (V).

[0054]

[0055] In equation (V), R 35 and R 36 Whether the two are the same or different, they are each independently selected from C1-C. 20 Straight-chain alkyl, C3-C 20 Branched alkyl groups, C2-C 20 alkenyl, C3-C 20 cycloalkyl, C6-C 20 aryl, C 7-20 Aryl or C7-C 20 alkylaryl; R 37 -R 40 They may be the same or different from each other, and each is independently selected from hydrogen, C1-C 20 Straight-chain alkyl, C3-C 20 Branched alkyl groups, C2-C 20 alkenyl, C3-C 20 cycloalkyl, C6-C 20 aryl, C7-C 20 Aryl or C7-C 20 alkylaryl; the R 35 and R 36 It may optionally contain heteroatoms.

[0056] Examples of succinate compounds represented by formula (V) include, but are not limited to: 2,3-bis(2-ethylbutyl)succinate diethyl ester, 2,3-diethyl-2-isopropylsuccinate diethyl ester, 2,3-diisopropylsuccinate diethyl ester, 2,3-di-tert-butylsuccinate diethyl ester, 2,3-diisobutylsuccinate diethyl ester, 2,3-(bis(trimethylsilyl)succinate diethyl ester), 2-(,3,3,3-trifluoropropyl)-3-methylsuccinate diethyl ester, 2,3-dineopentylsuccinate diethyl ester, 2,3-diisopentylsuccinate diethyl ester, 2,3-(1- Diethyl trifluoromethyl-ethyl)succinate, 2-isopropyl-3-isobutylsuccinate, 2-tert-butyl-3-isopropylsuccinate, 2-isopropyl-3-cyclohexylsuccinate, 2-isopentyl-3-cyclohexylsuccinate, 2,2,3,3-methylsuccinate, 2,2,3,3-tetraethylsuccinate, 2,2,3,3-tetrapropylsuccinate, 2,3-diethyl-2,3-diisopropyldisuccinate, 2,3-bis(2-ethylbutyl)succinate, 2,3-diethyl-2-isopropylsuccinate Diisobutyl succinate, 2,3-diisopropyl diisobutyl succinate, 2,3-di-tert-butyl diisobutyl succinate, 2,3-diisobutyl diisobutyl succinate, 2,3-(bis(trimethylsilyl)succinate)diisobutyl succinate, 2-(,3,3,3-trifluoropropyl)-3-methylsuccinate, 2,3-dineopentyl diisobutyl succinate, 2,3-diisopentyl diisobutyl succinate, 2,3-(1-trifluoromethyl-ethyl)succinate, 2-isopropyl-3-isobutyl diisobutyl succinate, 2-tert-butyl-3-isopropyl diisobutyl succinate Diisopropyl-3-cyclohexylsuccinate diisobutyl ester, 2-isopentyl-3-cyclohexylsuccinate diisobutyl ester, 2,2,3,3-methylsuccinate diisobutyl ester, 2,2,3,3-tetraethylsuccinate diisobutyl ester, 2,2,3,3-tetrapropylsuccinate diisobutyl ester, 2,3-diethyl-2,3-diisopropyldisuccinate diisobutyl ester; preferably 2,3-diisopropylsuccinate diethyl ester, 2,3-di-tert-butylsuccinate diethyl ester, 2,3-diisobutylsuccinate diethyl ester, 2,3-diisopropylsuccinate diisobutyl ester; 2,3-diisopropylsuccinate.

[0057] According to some embodiments of the preparation method described in this invention, the aforementioned internal electron donor can be used alone or in combination with two or more internal electron donor compounds.

[0058] According to some embodiments of the preparation method of the present invention, the solid catalyst component A obtained after washing is not subjected to drying and corresponding sieving treatment, so as to reduce the damage to the catalyst particle morphology caused by the drying process and the corresponding sieving process.

[0059] According to some embodiments of the preparation method of the present invention, the low-boiling-point alkane B is an alkane or a mixture of alkanes with a boiling point below 100°C, preferably selected from at least one of pentane, isopentane, hexane, cyclohexane and heptane.

[0060] According to some embodiments of the preparation method described in this invention, the weight ratio of solid catalyst component A to low-boiling-point alkane is such that the suspension can be well stirred and homogenized.

[0061] According to some embodiments of the preparation method of the present invention, the white oil C may be selected from various types of white oil or mixtures thereof that conform to the People's Republic of China Petroleum and Chemical Industry Standard NB / SH / T 0006-2017 or the People's Republic of China National Standard GB1886.215-2016, which are industrial white oils or food additive white oils. Preferably, the white oil C is 68# industrial white oil and / or 100# industrial white oil.

[0062] According to some embodiments of the preparation method of the present invention, the weight ratio of the added white oil C to the weight of the solid catalyst component A is 1-10:1, preferably 4-7:1.

[0063] According to some embodiments of the preparation method of the present invention, when adding white oil C, the mixture of solid catalyst component A and part of alkane B is kept in a stirred and dispersed state to prevent catalyst agglomeration. The weight ratio of A to B is not strictly limited, but it is preferable to ensure that the system can be sufficiently stirred and dispersed. Preferably, the weight ratio of A to B is 1:1 to 1:10, more preferably 1:2 to 1:4.

[0064] According to some embodiments of the preparation method described in this invention, the removal of low-boiling-point alkane B by vacuum can be carried out at a certain temperature. Increasing the temperature can improve the removal efficiency, but excessively high temperatures may damage the performance of solid catalyst component A. Preferably, the conditions for vacuum removal of low-boiling-point alkane B include a temperature of 20-100°C, preferably 40-80°C. Lower vacuum levels are beneficial for the efficient removal of alkane B, while lowering the removal temperature helps maintain the performance of solid catalyst component A. Therefore, lower vacuum levels are more conducive to the removal of alkane B.

[0065] According to some embodiments of the preparation method of the present invention, when removing low-boiling-point alkane B by vacuum, the material can be mixed in any form to ensure uniform removal of alkane B, such as rotation, stirring, etc.; preferably, a low-speed stirring form with less shear on the material is used to reduce damage to the solid catalyst components, such as ribbon stirring.

[0066] According to some embodiments of the preparation method described in this invention, the lower the residual amount of alkane B in white oil C, the better. However, achieving a lower alkane B content requires a longer time, thereby reducing production efficiency and increasing production costs. The residual amount of alkane B in white oil C is 0.3-5.0% by weight, more preferably 0.8-3.0% by weight, and most preferably 1.0-2.0% by weight.

[0067] In some embodiments of the preparation method described in this invention, filtration of the slurry catalyst in step 3 is necessary, provided that the slurry flow is relatively smooth. However, due to the presence of white oil, the fluid volume of the particles increases; and the online liquid filtration area is limited. To ensure the timeliness of filtration, the mesh size needs to be reduced. However, this reduces the filtration effect. For example, the dried powder of solid catalyst component A with a particle size of 30-40 μm can be sieved using an 80-200 mesh screen, while the slurry catalyst obtained from solid catalyst component A with the same particle size requires filtration using a 40-60 mesh screen. In other words, the slurry filtration effect is lower than the sieving effect of the dried solid catalyst component, which leads to more agglomerated catalyst residue. This is also the reason why a sieved support must be used in the preparation of the prepolymerized catalyst described in this invention. The sieving process of the support removes agglomerated particles and reduces the risk of subsequent catalyst agglomeration.

[0068] A second aspect of the present invention provides a slurry catalyst prepared according to the preparation method described above.

[0069] According to some embodiments of the slurry catalyst of the present invention, the slurry catalyst comprises a solid catalyst component A, white oil C, and residual alkane B.

[0070] According to some embodiments of the slurry catalyst of the present invention, the weight ratio of white oil C to solid catalyst component A is 1-10:1, preferably 4-7:1.

[0071] According to some embodiments of the slurry catalyst of the present invention, the residual amount of alkane B in white oil C is 0.3-5.0 wt%, more preferably 0.8-3.0 wt%, and most preferably 1.0-2.0 wt%.

[0072] A third aspect of the present invention provides a paste-like catalyst, characterized in that it comprises the above-described slurry catalyst and petrolatum.

[0073] According to some embodiments of the paste catalyst of the present invention, the petroleum jelly may be medical petroleum jelly conforming to national standard GB1790-2003 or industrial petroleum jelly conforming to national standard SH / T 0039-90, preferably medical petroleum jelly conforming to national standard GB1790-2003, and more preferably medical white petroleum jelly conforming to national standard GB1790-2003.

[0074] According to some embodiments of the paste catalyst of the present invention, when adding petroleum jelly to prepare catalyst paste F, the ratio of white oil to petroleum jelly is the key to controlling the fluidity of the paste. Preferably, based on the white oil in the slurry catalyst, the weight ratio of white oil to petroleum jelly is 1:5-5:1, more preferably 1:3-3:1.

[0075] Both slurry and paste catalysts can be directly used for prepolymerization reactions, depending primarily on the catalyst feeding equipment of the industrial plant. Specifically, for existing Spheripol and ST industrial plants, formulating the catalyst into a paste form for feeding is more suitable.

[0076] According to some specific embodiments of the present invention, preferred methods for preparing slurry catalysts and / or paste catalysts are as follows:

[0077] The catalyst solid obtained according to the method in Example 1 of CN102453150B was washed with hexane four times, and without drying, it was directly added to 68# white oil that had undergone dehydration and oxygen treatment. The concentration of the solid catalyst component was 26%. The catalyst was stirred and vacuum dried for 8 hours to remove residual hexane, thus obtaining a slurry catalyst in white oil.

[0078] Melted medical-grade white petrolatum was added to the above-mentioned white oil slurry catalyst, controlling the weight ratio of white oil to petrolatum to be 2:1. The mixture was stirred evenly and cooled to room temperature to prepare a paste-like catalyst.

[0079] The above-mentioned slurry or paste catalyst (solid catalyst weight concentration of 19%) was stirred evenly, and then alkylaluminum and silane were added, wherein the Al / Si molar ratio was 10 / 1 and the Al / Ti molar ratio was 100 / 1. The mixture was then added to 2 L of propylene and stirred at 25°C for 10 minutes to obtain a dispersion mixture of the prepolymer catalyst in propylene. Further reaction of the prepolymer catalyst yielded polypropylene powder particles.

[0080] The above-mentioned paste can be directly injected into the prepolymerization loop reactor of the Spheripol or ST process unit for prepolymerization, and then enter the main loop reactor to undergo polymerization.

[0081] A fourth aspect of the present invention provides a catalyst system for olefin polymerization, comprising:

[0082] (1) The above-mentioned slurry catalyst and / or the above-mentioned paste catalyst;

[0083] (2) Alkyl aluminum compounds as co-catalysts; and

[0084] (1) An optional external electron donor.

[0085] According to some embodiments of the catalyst system described in this invention, the alkylaluminum compound used as a co-catalyst can be any alkylaluminum compound commonly used in the field of olefin polymerization that can be used as a co-catalyst for Ziegler-Natta type catalysts. Preferably, the alkylaluminum compound can be a compound represented by formula (VI).

[0086] AlR' n' X' 3-n' (VI)

[0087] Among them, R' is one of the following substances: hydrogen, C1-C 20 Alkyl or C6-C 20 The aryl group; X' is a halogen, and n' is an integer from 1 to 3.

[0088] The alkylaluminum compound is preferably selected from at least one of trimethylaluminum, triethylaluminum, triisobutylaluminum, trioctylaluminum, diethylaluminum hydrogen, diisobutylaluminum hydrogen, diethylaluminum chloride, diisobutylaluminum chloride, sesquiethylaluminum chloride, and diethylaluminum chloride. More preferably, it is triethylaluminum and / or triisobutylaluminum.

[0089] According to some embodiments of the catalyst system of the present invention, the external electron donor compound can be any external electron donor compound commonly used in the field of olefin polymerization that can be used as a co-catalyst for Ziegler-Natta type catalysts. Preferably, the external electron donor compound can be an organosilicon compound represented by formula (VII).

[0090] R1” m” R2” n” Si(OR3”)4 -m”-n” (VII),

[0091] In equation (VII), R1” and R2” can be the same or different, and respectively represent halogen, hydrogen atom, and C1-C. 20 Alkyl, C3-C 20 cycloalkyl, C6-C 20 aryl and C1-C 20 One of the haloalkyl groups; R3” is C1-C 20 Alkyl, C3-C 20 cycloalkyl, C6-C 20 aryl and C1-C 20One of the haloalkyl groups; m” and n” are integers from 0 to 3, and m”+n”<4. Specific examples of the said external electron donor compounds include trimethylmethoxysilane, trimethylethoxysilane, trimethylphenoxytriethylmethoxysilane, triethylethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, ethylisopropyldimethoxysilane, propylisopropyldimethoxysilane, diisopropyldimethoxysilane, diisobutyldimethoxysilane, isopropylisobutyldimethoxysilane, di-tert-butyldimethoxysilane, tert-butylmethyldimethoxysilane, tert-butylethyldimethoxysilane, tert-butylpropyldimethoxysilane, tert-butylisopropyldimethoxysilane, tert-butyl Butyl dimethoxysilane, tert-butyl isobutyl dimethoxysilane, tert-butyl (sec-butyl) dimethoxysilane, tert-butyl pentyl dimethoxysilane, tert-butyl nonyl dimethoxysilane, tert-butyl hexyl dimethoxysilane, tert-butyl heptyl dimethoxysilane, tert-butyl octyl dimethoxysilane, tert-butyl decyl dimethoxysilane, methyl tert-butyl dimethoxysilane, cyclohexyl methyl dimethoxysilane, cyclohexyl ethyl dimethoxysilane, cyclohexyl propyl dimethoxysilane, cyclohexyl isobutyl dimethoxysilane, dicyclohexyl dimethoxysilane, cyclohexyl tert-butyl dimethoxysilane, cyclopentyl methyl dimethoxysilane Cyclopentylethyl dimethoxysilane, cyclopentylpropyl dimethoxysilane, cyclopentyl tert-butyl dimethoxysilane, dicyclopentyl dimethoxysilane, cyclopentylcyclohexyl dimethoxysilane, bis(2-methylcyclopentyl)dimethoxysilane, diphenyl dimethoxysilane, diphenyl diethoxysilane, phenyl triethoxysilane, methyl trimethoxysilane, methyl triethoxysilane, ethyl trimethoxysilane, ethyl triethoxysilane, propyl trimethoxysilane, isopropyl trimethoxysilane, butyl trimethoxysilane, butyl triethoxysilane, isobutyl trimethoxysilane, tert-butyl trimethoxysilane, sec-butyl trimethoxysilane The compound may be at least one of the following: methoxysilane, pentyltrimethoxysilane, isopentyltrimethoxysilane, cyclopentyltrimethoxysilane, cyclohexyltrimethoxysilane, diphenyldimethoxysilane, diphenyldiethoxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, n-propyltrimethoxysilane, vinyltrimethoxysilane, tetramethoxysilane, tetraethoxysilane, tetrabutoxysilane, 2-ethylpiperidinyl-2-tert-butyldimethoxysilane, (1,1,1-trifluoro-2-propyl)-2-ethylpiperidinyldimethoxysilane, and (1,1,1-trifluoro-2-propyl)-methyldimethoxysilane. More preferably, the external electron donor compound may be at least one of dicyclopentyldimethoxysilane, diisopropyldimethoxysilane, diisobutyldimethoxysilane, cyclohexylmethyldimethoxysilane, methyltert-butyldimethoxysilane, and tetramethoxysilane.

[0092] According to some embodiments of the catalyst system of the present invention, the amount of the alkylaluminum compound can be a conventional amount in the art. Generally, the molar ratio of aluminum in the alkylaluminum compound to titanium in the solid catalyst composition is 0.05-50:1; preferably 1-20:1; more preferably 1-10:1.

[0093] According to some embodiments of the catalyst system of the present invention, the molar ratio of aluminum to the external electron donor in the alkylaluminum compound is 0.5-50:1, preferably 1-30:1, and more preferably 1-20:1.

[0094] According to some embodiments of the catalyst system of the present invention, a silane compound as an external electron donor may be selectively added, and the type and content of the external electron donor compound are not particularly limited. Preferably, the molar ratio of the alkylaluminum compound (calculated as aluminum) to the external electron donor compound is 0.1-500:1, more preferably 1-100:1, and more preferably 2-20:1.

[0095] The fifth aspect of the present invention provides a method for olefin polymerization, comprising contacting one or more olefins with the above-described catalyst system to obtain a polymer.

[0096] In some embodiments of the olefin polymerization method according to the present invention, at least one of the olefin monomers is an olefin represented by the general formula CH2=CHR, wherein R is a C1-C6 alkyl group. Specific examples include: ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, and 4-methyl-1-pentene. Preferably, the α-olefin CH2=CHR is one or more selected from ethylene, propylene, 1-butene, 4-methyl-1-pentene, and 1-hexene. More preferably, the olefin represented by the general formula CH2=CHR is one or more selected from propylene and ethylene.

[0097] In some embodiments of the olefin polymerization method according to the present invention, the weight ratio of the olefin monomer to solid catalyst component A in the catalyst system is 0.5-1000:1, preferably 1-100:1, and more preferably 1-10:1.

[0098] In some embodiments of the olefin polymerization method according to the present invention, the polymerization temperature is 5-80°C, preferably 10-60°C, and more preferably 15-35°C.

[0099] According to some embodiments of the slurry catalyst of the present invention, the polymerization pressure (gauge pressure) is 0-3.5 MPa, preferably 0.01-1.0 MPa, and more preferably 0.02-0.6 MPa.

[0100] The beneficial effects of this invention are:

[0101] (1) The slurry or paste catalyst prepared by this method can be directly prepolymerized and then used for olefin polymerization, exhibiting good activity, orientation ability, and hydrogen sensitivity. Simultaneously, very little fine powder and lumps of polymer are obtained. Compared to direct prepolymerization followed by polymerization of dry powder catalysts, direct slurry prepolymerization followed by polymerization produces even less fine powder; compared to catalysts without sieving, the polymer lumps prepared by this method are significantly reduced; and compared to dry powder catalysts, the direct slurry preparation method provided by this invention significantly improves production efficiency.

[0102] (2) The slurry catalyst or paste catalyst of the present invention can be directly injected into the prepolymerization loop reactor of the Spheripol or ST process unit for prepolymerization, and then enter the main loop reactor to undergo polymerization reaction. Detailed Implementation

[0103] To make the present invention easier to understand, the present invention will be described in detail below with reference to embodiments. These embodiments are for illustrative purposes only and are not limited to the scope of application of the present invention.

[0104] The testing method and equipment used in this invention are as follows:

[0105] 1. The hexane content in white oil was determined using an Agilent 7890 gas chromatograph.

[0106] 2. Analysis of polymer fine powder: The polymer powder obtained by catalyst polymerization was sieved using a 150-mesh sieve, and the weight percentage of powder smaller than 150 mesh was characterized as the fine powder content.

[0107] 3. Analysis of polymer lumps: The polymer powder obtained by catalyst polymerization was sieved using a 5-mesh sieve, and the weight percentage of powder larger than 5 mesh was characterized as the lumps content.

[0108] 4. Determination of polymer melt index (MI): Determined according to GB / T3682-2000.

[0109] 5. Polymer isotacticity (II) is determined by heptane extraction method: 2 g of dry polymer sample is placed in an extractor and extracted with boiling heptane for 6 hours. After drying the residue to constant weight, the ratio of the polymer weight (g) to 2 (g) is the isotacticity.

[0110] 6. Titanium content in the catalyst: tested using a 721 spectrophotometer.

[0111] 7. Prepolymerization ratio of the catalyst: The obtained prepolymerization catalyst is filtered, washed with hexane, and dried to obtain a solid prepolymerization catalyst. A certain amount of the solid prepolymerization catalyst is dissolved in ethanol, the polymer is separated, and the weight ratio of the polymer to the catalyst is calculated as the prepolymerization ratio.

[0112] 8. Polymerization activity = polymer weight (kg) / solid catalyst component weight (g Cat).

[0113]

Example 1

[0114] 1. Preparation of slurry catalyst A1:

[0115] (1) Preparation of diekoxy magnesium support:

[0116] After thoroughly purging the 16L pressure reactor equipped with a stirrer with nitrogen, add 10000mL of ethanol, 300mL of 2-ethylhexanol, and 200mL of isopropanol, along with 12g of iodine and 8g of magnesium chloride to dissolve them. Start stirring and heat until the reflux temperature of the reaction system is reached. Then, add 640g of magnesium powder sequentially. Continue the reaction until completion, i.e., no more hydrogen gas is emitted. Then, wash, separate, and dry. The obtained diekoxymagnesium support is sieved through a 150-mesh sieve to remove lumps, yielding the sieved alkoxymagnesium support.

[0117] (2) Preparation of catalyst components:

[0118] A suspension was prepared by mixing 650 g of the aforementioned dialkoxymagnesium support, 3250 mL of toluene, and 65 mL of di-n-butyl phthalate (DNBP). In a 16L pressure-resistant reactor that had undergone repeated purging with high-purity nitrogen, 2600 mL of toluene and 3900 mL of titanium tetrachloride were added. The mixture was cooled to -5°C, and then the prepared suspension was added to the reactor. After maintaining this temperature for 1 hour, the temperature was slowly raised to 110°C. When the temperature reached 80°C, 65 mL of DNBP was added, and the mixture was maintained for 2 hours. The liquid was then filtered clean. A mixture of 5070 mL of toluene and 3380 mL of titanium tetrachloride was then added, and the mixture was heated to 110°C and stirred for 1 hour. This process was repeated three times. The liquid was then filtered off, and the resulting solid was washed four times with 150 mL of hexane. The liquid was then filtered off again to obtain the solid catalyst component. Without drying, 2000 mL of hexane was added again to obtain a mixture of the solid catalyst component dispersed in hexane.

[0119] (3) Preparation of slurry catalyst:

[0120] The mixture obtained in step (2) was stirred (the titanium content of the solid catalyst after separation was 2.55%), and 2035 g of dehydrated and oxygen-treated 68# industrial white oil was directly added. While stirring, the mixture was dried under vacuum at 60°C for 12 hours to remove residual hexane, resulting in a slurry catalyst A1 in the white oil. The catalyst concentration was 25.8% by weight, and the hexane content in the white oil was 0.3% by weight.

[0121] 2. Evaluation of slurry catalyst A1:

[0122] In a 5-liter high-pressure reactor, after complete purging with gaseous propylene, 2 mL of a triethylaluminum hexane solution (0.5 mmol / mL), 1 mL of a cyclohexylmethyldimethoxysilane (CHMMS) hexane solution (0.1 mmol / mL), 2 L of liquid propylene, 4.5 L of hydrogen gas, and 0.4 mL of catalyst slurry A1 were added at room temperature. The reactor was closed, and the reaction was stirred at 25 °C for 10 min for catalyst prepolymerization. The temperature was then raised to 70 °C. Polymerization was carried out at 70 °C for 1 hour. After the reaction was completed, stirring was stopped, unpolymerized propylene monomers were removed, the polymer was collected, vacuum dried, and weighed. Catalyst activity = (polymer weight) / (catalyst weight). The results are shown in Table 1.

[0123]

Example 2

[0124] 1. Preparation of slurry catalyst A2:

[0125] (1) Preparation of alkoxymagnesium support:

[0126] After fully purging the 16L pressure reactor equipped with a stirrer with nitrogen, add 10L ethanol, 300mL 2-ethylhexanol, 11.2g iodine, 8g magnesium chloride, and 640g magnesium powder to the reactor. While stirring, heat the system to 75°C and reflux until no more hydrogen is emitted. Stop the reaction, wash with 3L ethanol, filter, and dry. Obtain the alkoxymagnesium support. The obtained alkoxymagnesium support has a D50 of 30.2μm, a Span value of 0.81, and a m value of 0.015. The alkoxymagnesium support is then sieved through a 150-mesh sieve to remove lumps, yielding the sieved alkoxymagnesium support.

[0127] (2) Preparation of catalyst components:

[0128] A suspension was prepared by mixing 650g of sieved alkoxymagnesium support with 3250mL of toluene and 65mL of 2-isopropyl-2-isopentyl-1,3-dimethoxypropane. In a 16L pressure-resistant reactor that had undergone repeated purging with high-purity nitrogen, 2600mL of toluene and 3900mL of titanium tetrachloride were added, and the temperature was raised to 80℃. The prepared suspension was then added to the reactor and kept at this temperature for 1 hour. 65mL of 2-isopropyl-2-isopentyl-1,3-dimethoxypropane (ether #1) was then added, and the temperature was slowly raised to 110℃ and kept at this temperature for 2 hours. The mixture was then filtered to obtain a solid. The obtained solid was added to a mixture of 5070mL of toluene and 3380mL of titanium tetrachloride and stirred at 110℃ for 1 hour. This treatment was repeated three times. After filtration, the solid was washed four times with 6000mL of hexane each time, and the liquid was filtered off to obtain the solid catalyst component product. Without drying, the above solid catalyst components were added again to 2000 mL of hexane to obtain a mixture in which the solid catalyst components were dispersed in hexane.

[0129] (3) Preparation of slurry catalyst:

[0130] The mixture obtained in step (2) was stirred (the titanium content of the solid catalyst after separation was 4.1%), and 2035 g of dehydrated and oxygenated 68# industrial white oil was directly added. While stirring, the mixture was dried under vacuum at 60°C for 8 hours to remove residual hexane, resulting in catalyst slurry A2 in the white oil. The catalyst concentration was 26.2% by weight, and the hexane content in the white oil was 1.0% by weight.

[0131] 2. The polymerization evaluation of the slurry catalyst A2 was the same as in Example 1. The results are shown in Table 1.

[0132]

Example 3

[0133] 1. Preparation of slurry catalyst A3:

[0134] (1) Preparation of magnesium chloride / alcohol adduct melt: In a 150L reactor with stirring, 10kg of anhydrous magnesium chloride and 12.6kg of ethanol were added to 60L of white oil with a viscosity of 30 centipoise (20℃), and reacted at 125℃ for 2 hours. Then the resulting molten adduct and white oil mixture was transferred to a methyl silicone oil medium preheated to 125℃; the viscosity of the methyl silicone oil was 300 centipoise (20℃), and the amount of methyl silicone oil used was 120L; the mixture was stirred at 200 rpm for 20 minutes.

[0135] (2) Dispersion: The above-mentioned mixture enters the high-gravity rotating bed through the feed inlet 1 and is evenly sprayed onto the inner edge of the high-speed rotating packing 3 by the static liquid distributor 2 located at the center of the rotor. After being sheared and dispersed by the high-speed rotating packing, the magnesium chloride / alcohol adduct melt is dispersed in the inert medium in the form of fine droplets and led out through the discharge port 4. The rotor speed is 1500 rpm, and the packing is corrugated metal wire mesh packing with a wire diameter of 0.2 mm, a porosity of 97.8%, and a specific surface area of ​​852 m². 2 / m 3 .

[0136] (3) Rapid cooling and solidification: The mixed liquid from outlet 4 enters a stirred hexane medium that has been pre-cooled to -35°C, with a hexane dosage of 1200L. The magnesium chloride / alcohol adduct melt, dispersed as small droplets, is cooled and solidified into spherical solid particles.

[0137] (4) Filtration, washing and drying: Solid particles were filtered out from the suspension obtained after rapid cooling; the particles were washed with hexane at room temperature, with 100 L of hexane per wash, for a total of five washes; the particles were then dried under vacuum at 40 °C to obtain spherical magnesium chloride / alcohol adduct carriers. The spherical magnesium chloride / alcohol adduct carriers were obtained by sieving through a 150-mesh sieve to remove lumps.

[0138] (5) In a 350 mL glass reactor equipped with a stirrer, add 50 mL of hexane and 50 mL of titanium tetrachloride, and cool to -20 °C; add 7 g of magnesium chloride alcohol spherical particles, heat to 40 °C after 5 hours, maintain at 40 °C for 0.5 hours, and then filter off the filtrate; then add 100 mL of titanium tetrachloride and 1.2 mL of diisobutyl phthalate, heat to 100 °C, maintain at 100 °C for 2 hours, and then filter off the liquid; add 50 mL of hexane and 50 mL of titanium tetrachloride, heat to 80 °C, maintain at 80 °C for 0.5 hours, and then filter off the liquid; add 100 mL of titanium tetrachloride, heat to 120 °C, maintain at 120 °C for 0.5 hours, and then filter off the liquid; then wash the obtained solid with 60 mL of hexane at 60 °C 5 times. Filter off the liquid to obtain the solid catalyst component product. Without drying, the above solid catalyst components were added again with 60 mL of hexane to obtain a mixture in which the solid catalyst components were dispersed in hexane.

[0139] (6) The obtained mixture was stirred, and 16 grams of dehydrated and oxygenated 68# industrial white oil was directly added. While stirring, the mixture was dried under vacuum at 60°C for 8 hours to remove residual hexane, resulting in a slurry catalyst A3 in the white oil. The catalyst concentration was 26.2% by weight, and the hexane content in the white oil was 1.0% by weight.

[0140] 2. The polymerization evaluation of slurry catalyst A3 was the same as in Example 1. The results are shown in Table 1.

[0141]

Example 4

[0142] 1. Preparation of slurry catalyst A4:

[0143] The slurry catalyst A3 was prepared according to the preparation method of Example 3.

[0144] 2. Preparation of paste catalyst A4:

[0145] Petrolatum (OINTMENT BASE 6 from Calumet, USA) was added to catalyst slurry A3, with the petrolatum amounting to half the weight of the white oil in the catalyst slurry. A paste-like catalyst was obtained.

[0146] 3. The polymerization evaluation of the paste catalyst A4 was the same as in Example 1. The results are shown in Table 1.

[0147]

Example 5

[0148] 1. Preparation of slurry catalyst A5:

[0149] The preparation method of slurry catalyst A5 is the same as that of slurry catalyst A1 in Example 1, except that it is scaled up accordingly. Slurry catalyst A1 is scaled up by 169 times. The obtained solid is washed with hexane 4 times to obtain a mixture of solid catalyst components dispersed in hexane. (3) While stirring the mixture obtained in step (2), 280 kg of dehydrated and oxygenated 68# industrial white oil is directly added. While stirring, the mixture is vacuum dried at 60°C for 12 hours to remove residual hexane and obtain a slurry of catalyst in white oil. The catalyst concentration is 30.5% by weight and the hexane content in the white oil is 0.5% by weight.

[0150] 2. The polymerization evaluation of the slurry catalyst A5 was the same as in Example 1. The results are shown in Table 1.

[0151]

Example 6

[0152] 1. The preparation method of slurry catalyst A6 is the same as in Example 1, except that the catalyst carrier is replaced by a 120-mesh sieve instead of a 150-mesh sieve for sieving to remove lumps.

[0153] 2. The polymerization evaluation of the slurry catalyst A6 was the same as in Example 1. The results are shown in Table 1.

[0154]

Example 7

[0155] 1. The preparation method of slurry catalyst A7 is the same as in Example 1, except that the catalyst support is replaced by a 200-mesh sieve instead of a 150-mesh sieve for sieving to remove lumps.

[0156] 2. The polymerization evaluation of slurry catalyst A7 was the same as in Example 1. The results are shown in Table 1.

[0157] Comparative Example 1

[0158] 1. Preparation of dry powder catalyst D1:

[0159] The support and catalyst components were prepared according to Example 1, except that the solid catalyst component after washing with hexane four times was dried to obtain dry powder catalyst D1, as detailed below:

[0160] (1) Preparation of diekoxymagnesium support

[0161] After thoroughly purging the 16L pressure reactor equipped with a stirrer with nitrogen, add 10000mL of ethanol, 300mL of 2-ethylhexanol, and 200mL of isopropanol, along with 12g of iodine and 8g of magnesium chloride to dissolve them. Start stirring and heat until the reflux temperature of the reaction system is reached. Then, add 640g of magnesium powder sequentially. Continue the reaction until completion, i.e., no more hydrogen gas is emitted. Then, wash, separate, and dry. The obtained diekoxymagnesium support is sieved through a 150-mesh sieve to remove lumps, yielding the sieved alkoxymagnesium support.

[0162] (2) Preparation of catalyst components

[0163] A suspension was prepared by mixing 650 g of the aforementioned magnesium dialkoxy support, 3250 mL of toluene, and 65 mL of di-n-butyl phthalate (DNBP). In a 16 L pressure-resistant reactor that had undergone repeated purging with high-purity nitrogen, 2600 mL of toluene and 3900 mL of titanium tetrachloride were added. The mixture was cooled to -5 °C, and then the prepared suspension was added to the reactor. After maintaining this temperature for 1 hour, the temperature was slowly raised to 110 °C. When the temperature reached 80 °C, 65 mL of DNBP was added, and the mixture was maintained at this temperature for 2 hours. The liquid was then filtered clean. A mixture of 5070 mL of toluene and 3380 mL of titanium tetrachloride was then added, and the mixture was heated to 110 °C and stirred for 1 hour. This process was repeated three times. The liquid was then filtered off, and the resulting solid was washed four times with 150 mL of hexane. The liquid was filtered off again, and the solid was dried at 60 °C for 12 hours. The dried solid catalyst component D1 was obtained by sieving through a 150-mesh sieve.

[0164] 2. The evaluation of the polymerization of dry powder catalyst D1 was the same as in Example 1. The results are shown in Table 1.

[0165] Comparative Example 2

[0166] 1. The preparation method of slurry catalyst D2 is the same as in Example 1, except that the catalyst support is not screened to remove lumps (i.e., the diekoxy magnesium support obtained in step (1) is not screened to remove lumps), and finally slurry catalyst D2 is obtained.

[0167] 2. The evaluation of the D2 polymerization of the slurry catalyst was the same as in Example 1. The results are shown in Table 1.

[0168] Comparative Example 3

[0169] 1. Preparation of slurry catalyst D3:

[0170] The catalyst component was prepared according to Example 1 of CN85100997A, but without drying, as follows:

[0171] In a reactor fully purged with high-purity nitrogen, 0.05 mol of anhydrous magnesium chloride, 75 mL of toluene, 0.1 mol of epichlorohydrin, and 0.03 mol of tributyl phosphate were added sequentially. The mixture was heated to 50°C with stirring and maintained for 2 hours until the solid completely dissolved. Then, 0.008 mol of phthalic anhydride was added, and the mixture was maintained for another hour. The melt was cooled to -25°C, and 55 mL of titanium tetrachloride was added dropwise over 1 hour. The temperature was slowly raised to 80°C, during which a solid gradually precipitated. 0.0125 mol of diisobutyl phthalate was added, and the mixture was maintained at 80°C for 1 hour. After filtration, the mixture was washed twice with 100 mL of toluene to obtain a brownish-yellow solid precipitate. Then, 60 mL of toluene and 40 mL of titanium tetrachloride were added, and the mixture was treated at 90°C for 2 hours. After discarding the filtrate, the treatment was repeated once. The mixture was washed once with 100 mL of dichloroethane and four times with 100 mL of hexane, and then filtered to obtain the solid catalyst component. Without drying, the above solid catalyst components were added to 60 mL of hexane to obtain a mixture in which the solid catalyst components were dispersed in hexane. This mixture was stirred, and 18.5 g of dehydrated and oxygen-treated 68# industrial white oil was directly added. While stirring, the mixture was vacuum dried at 60°C for 12 hours to remove residual hexane, yielding a slurry catalyst D3 in the white oil. The catalyst concentration was 25.8% by weight, and the hexane content in the white oil was 0.2% by weight.

[0172] 2. The evaluation of slurry catalyst D3 was the same as in Example 1. The results are shown in Table 1.

[0173] Comparative Example 4

[0174] 1. Preparation of slurry catalyst D4:

[0175] The catalyst component was prepared and dried according to Example 1 of CN85100997A, as follows:

[0176] In a reactor fully purged with high-purity nitrogen, 0.05 mol of anhydrous magnesium chloride, 75 mL of toluene, 0.1 mol of epichlorohydrin, and 0.03 mol of tributyl phosphate were added sequentially. The mixture was heated to 50°C with stirring and maintained for 2 hours until the solid was completely dissolved. Then, 0.008 mol of phthalic anhydride was added, and the mixture was maintained for another hour. The melt was cooled to -25°C, and 55 mL of titanium tetrachloride was added dropwise over 1 hour. The temperature was slowly raised to 80°C, during which a solid gradually precipitated. 0.0125 mol of diisobutyl phthalate was added, and the mixture was maintained at 80°C for 1 hour. After filtration, the mixture was washed twice with 100 mL of toluene to obtain a brownish-yellow solid precipitate. Then, 60 mL of toluene and 40 mL of titanium tetrachloride were added, and the mixture was treated at 90°C for 2 hours. After discarding the filtrate, the treatment was repeated once more. After washing once with 100 mL of dichloroethane and four times with 100 mL of hexane, the mixture was dried at 60 °C for 8 h and sieved through a 200-mesh sieve to obtain a solid catalyst component powder. 18.5 g of dehydrated and oxygen-treated 68# industrial white oil was directly added to obtain a slurry catalyst D4 in the white oil containing the solid catalyst component. The catalyst concentration was 25.9 wt%, and the hexane content in the white oil was 0.2 wt%.

[0177] 2. The evaluation of slurry catalyst D4 was the same as in Example 1. The results are shown in Table 1.

[0178] Comparative Example 5

[0179] 1. Preparation of slurry catalyst D5:

[0180] The preparation of the support and catalyst components was the same as in Example 5. The obtained solid hexane was washed, filtered, dried at 60°C for 35 hours, and then sieved through a 200-mesh sieve to obtain a free-flowing solid catalyst powder. 120 kg of the above solid powder was gradually added to 341 kg of 68# industrial white oil and stirred for 8 hours to obtain a catalyst slurry in the white oil. The catalyst concentration was 26.0% by weight.

[0181] 2. The evaluation of slurry catalyst D5 was the same as in Example 1. The results are shown in Table 1.

[0182] Table 1

[0183]

[0184]

[0185] The data above show that the slurry or paste catalyst prepared by this method can be directly prepolymerized and then used for olefin polymerization, exhibiting good activity, orientation ability, and hydrogen sensitivity. Simultaneously, the yield of polymer powder and lumps is minimal. Compared to direct prepolymerization followed by polymerization of dry powder catalysts, slurry prepolymerization followed by polymerization produces even less fine powder; compared to catalysts without sieving, the polymer lumps prepared by this method are significantly reduced; and compared to dry powder catalysts, the direct slurry preparation method provided by this invention significantly improves production efficiency.

[0186] Examples 1, 6, 7, and Comparative Example 2 demonstrate that the method of this invention requires sieving of the support before use. Without sieving, large particles or agglomerated support will enter the catalyst preparation process, resulting in large-particle or agglomerated catalysts. These large-particle or agglomerated catalysts entering the polymerization reactor can form hot spots, leading to unstable reactor temperatures and the risk of polymer agglomeration, thus affecting plant operation. The method of this invention effectively overcomes these problems.

[0187] The above description is merely a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, based on the technical teachings provided by the present invention and as common knowledge in the field, other equivalent modifications and improvements can be made, and these should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing a slurry catalyst, comprising: Step 1: The catalyst support is sieved to obtain a sieved support. Step 2: Using a sieved carrier, react with a titanium compound and an electron donor compound in the presence of an inert diluent. After filtration, the resulting solid is washed with low-boiling-point alkane B to obtain a first mixture in which solid catalyst component A is dispersed in alkane B. The first mixture is then mixed with white oil C to obtain a second mixture. No drying process is performed during the process of obtaining solid catalyst component A in Step 2. Step 3: Vacuum removal of low-boiling-point alkane B from the second mixture to obtain a slurry catalyst of solid catalyst component A in white oil C; The weight ratio of solid catalyst component A to low-boiling-point alkane B is 1:1 to 1:10; The low-boiling-point alkane B is an alkane or a mixture of alkanes with a boiling point below 100°C.

2. The preparation method according to claim 1, characterized in that, The support is a magnesium-containing support used to prepare Ziegler-Natta polyolefin catalysts.

3. The preparation method according to claim 2, characterized in that, The carrier is one or more of spherical alkoxy magnesium carriers and spherical magnesium chloride alcohol carriers.

4. The preparation method according to any one of claims 1-3, characterized in that, The average particle size of the carrier obtained by the sieving process is no greater than 100 μm.

5. The preparation method according to claim 4, characterized in that, The average particle size of the carrier obtained by the sieving process is 10-80 μm.

6. The preparation method according to any one of claims 1-3, characterized in that, The low-boiling-point alkane B is selected from at least one of pentane, isopentane, hexane, cyclohexane, and heptane.

7. The preparation method according to any one of claims 1-3, characterized in that, The white oil C is 68# industrial white oil and / or 100# industrial white oil; and / or, the weight ratio of the added white oil C to the weight of the solid catalyst component A is 1-10:1; and / or, the conditions for vacuum removal of low-boiling-point alkanes B include a temperature of 20-100℃.

8. The preparation method according to claim 7, characterized in that, The weight ratio of the added white oil C to the solid catalyst component A is 4-7:1; and / or, the conditions for vacuum removal of low-boiling-point alkanes B include a temperature of 40-80°C.

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