阅读说明：本技术 一种聚合用钛系主催化剂、其制备方法以及包含其的催化剂组合物与应用 (Titanium-based main catalyst for polymerization, preparation method thereof, catalyst composition containing titanium-based main catalyst and application of catalyst composition ) 是由 王毅 马冬 郭子芳 苟清强 黄廷杰 徐世媛 于 2019-10-14 设计创作，主要内容包括：本发明涉及一种聚合用钛系主催化剂、其制备方法以及包含其的催化剂组合物与应用,所述聚合用钛系主催化剂的制备原料包括含镁化合物、含铝无机物、四氯化锡、醇类化合物和过渡金属钛的卤化物或其衍生物。先将含镁化合物、含铝无机物、四氯化锡和醇类化合物混合,再与过渡金属钛的卤化物或其衍生物进行反应,后处理得到所述钛系主催化剂。将所述钛系主催化剂与含铝有机物按一定比例混合,得到聚合用催化剂组合物,尤其可以用于乙烯均聚合反应或共聚合中。本发明所述聚合用钛系主催化剂及其制备方法避免使用含磷化合物以及毒害较大的苯酐,更加有利于环保；同时所述制备方法省略了助析出剂的溶解反应步骤,缩短了聚合用钛系主催化剂的制备周期。(The invention relates to a titanium-based main catalyst for polymerization, a preparation method thereof, a catalyst composition containing the same and an application of the catalyst composition. Firstly, mixing a magnesium-containing compound, an aluminum-containing inorganic substance, tin tetrachloride and an alcohol compound, then reacting with a halide of transition metal titanium or a derivative thereof, and carrying out post-treatment to obtain the titanium-based main catalyst. The titanium main catalyst and an aluminum-containing organic matter are mixed according to a certain proportion to obtain the catalyst composition for polymerization, and the catalyst composition can be particularly used for ethylene homopolymerization or copolymerization. The titanium-based main catalyst for polymerization and the preparation method thereof avoid using phosphorus-containing compounds and phthalic anhydride with larger toxicity, and are more beneficial to environmental protection; meanwhile, the preparation method omits the step of dissolution reaction of the precipitation aid and shortens the preparation period of the titanium-based main catalyst for polymerization.)

1. A titanium-based main catalyst for olefin polymerization, characterized in that raw materials for preparing the titanium-based main catalyst for olefin polymerization comprise a magnesium-containing compound, an aluminum-containing inorganic substance, tin tetrachloride, an alcohol compound and a halide of transition metal titanium or a derivative thereof.

2. The titanium-based main catalyst for polymerization according to claim 1, wherein the titanium-based main catalyst for polymerization is a titanium-based main catalyst for polymerization, which comprises a magnesium-containing compound in an amount of 1mol,

the dosage of the aluminum-containing inorganic substance is 0.002-1 mol, preferably 0.005-0.5 mol; and/or

The using amount of the stannic chloride is 0.005-4 mol, and preferably 0.02-1 mol;

wherein the molar amount of the magnesium-containing compound is calculated as the molar amount of magnesium element therein, and the molar amount of the aluminum-containing inorganic substance is calculated as the molar amount of aluminum element therein.

3. The titanium-based procatalyst for polymerization according to claim 1,

the magnesium-containing compound is selected from one or more of magnesium dihalide, a water or alcohol complex of magnesium dihalide and a magnesium dihalide derivative, wherein the magnesium dihalide derivative is a derivative of magnesium dihalide in which one halogen atom in a molecule is substituted by a hydrocarbon group or a hydrocarbon alkoxy group, preferably, the magnesium dihalide is selected from one or more of magnesium dichloride, magnesium dibromide and magnesium diiodide, and more preferably, the magnesium dichloride; and/or

The aluminium-containing inorganic substance is selected from metallic aluminium and/or inorganic aluminium compounds, preferably: the metal aluminum is nano aluminum powder; the inorganic aluminum compound is anhydrous aluminum chloride, and fine powder anhydrous aluminum chloride is preferred.

4. The titanium-based procatalyst for polymerization according to claim 1,

the alcohol compound is selected from C₁～C₁₂Fatty alcohol of (2), C₇～C₁₂Wherein the substituted alcohol is selected from one or more of aromatic alcohol and substituted alcohol of (1), wherein the substituted alcohol is selected from C₁～C₁₂Fatty alcohol or C₇～C₁₂Substituted alcohols derived from aromatic alcohols of (a); preferably, the alcohol compound is selected from one or more of methanol, ethanol, propanol, isopropanol, butanol, isobutanol, 2-ethylhexanol, n-octanol, dodecanol, benzyl alcohol, and phenethyl alcohol, more preferably from one or more of ethanol, isooctanol, butanol, 2-ethylhexanol, benzyl alcohol, and phenethyl alcohol; and/or

The halide of the transition metal titanium or the derivative thereof has the general formula of TiX_n(OR)_4-nWherein: x represents halogen, R represents C₁～C₁₄Aliphatic hydrocarbon radical of (C)₆～C₁₄An aromatic hydrocarbon group, n is an integer of 0 to 4; preferably, the halide of the transition metal titanium or the derivative thereof is selected from one or more of titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, tetrabutoxytitanium, tetraethoxytitanium, chlorotriethoxytitanium, dichlorodiethoxytitanium, and trichloromonoethoxytitanium; and/or

The preparation raw materials optionally further comprise an electron donor; preferably, the electron donor is selected from one or more of organic ethers, silicon-containing compounds and boron-containing compounds.

5. The titanium-based main catalyst for polymerization according to any one of claims 1 to 4, wherein the titanium-based main catalyst for polymerization contains, based on 1mol of the magnesium-containing compound,

the dosage of the alcohol compound is 0.1-10 mol, preferably 0.2-6 mol; and/or

The dosage of the halide of the transition metal titanium or the derivative thereof is 0.2 to 100mol, preferably 1.0 to 20 mol; and/or

The dosage of the electron donor is 0-5 mol, preferably 0-1 mol;

wherein the molar amount of the magnesium-containing compound is based on the molar amount of the magnesium element therein, and the molar amount of the halide of titanium transition metal or the derivative thereof is based on the molar amount of the titanium element therein.

6. A process for producing a titanium-based main catalyst for polymerization according to any one of claims 1 to 5, which comprises the steps of:

step 1, mixing a magnesium-containing compound, an aluminum-containing inorganic substance, an alcohol compound and tin tetrachloride in the presence of an inert diluent to obtain a mixed solution containing magnesium and aluminum;

step 2, cooling, and then dropping the halide of the transition metal titanium or the derivative thereof into the mixed solution containing magnesium and aluminum, or dropping the mixed solution containing magnesium and aluminum into the halide of the transition metal titanium or the derivative thereof for reaction;

and 3, heating after reaction, stirring, and then carrying out aftertreatment to obtain the titanium-based main catalyst for polymerization.

7. The production method according to claim 6,

in the step 1, the mixing is carried out at a temperature of 0-170 ℃, preferably 40-140 ℃, and more preferably, the mixing is carried out under stirring; and/or

In step 1, the inert diluent may be selected from one or more of benzene, toluene, xylene, 1, 2-dichloroethane, chlorobenzene, and other hydrocarbons or halogenated hydrocarbons; and/or

In the step 2, the temperature is reduced to-35-60 ℃, preferably-30-20 ℃; and/or

In the step 3, heating to 10-150 ℃, preferably to 20-130 ℃; and/or

In step 3, the post-treatment comprises settling, filtering, washing solids and drying treatment; and/or

The electron donor is optionally added in step 1 or step 2.

8. A catalyst composition for polymerization comprising a main catalyst and a cocatalyst, wherein,

the main catalyst is the titanium-based main catalyst for polymerization according to any one of claims 1 to 5 or the titanium-based main catalyst for polymerization obtained by the preparation method according to any one of claims 6 to 7,

the cocatalyst is an organic aluminum compound.

9. The catalyst composition for polymerization according to claim 8,

the organic aluminum compound has a general formula of AlR_nX_3-nIn the formula: r is C₁～C₂₀Preferably, R is selected from alkyl, aralkyl or aryl; x is halogen, preferably chlorine and/or bromine; n is an integer of more than 0 and less than or equal to 3; and/or

In the catalyst composition, the molar ratio of the organoaluminum compound to the titanium-based main catalyst for polymerization is (5 to 1000):1, preferably (20 to 800): 1; wherein the molar amount of the titanium-based main catalyst for polymerization is based on the molar amount of the titanium element therein, and the molar amount of the organoaluminum compound is based on the molar amount of the aluminum element therein.

10. Use of a catalyst composition for polymerization according to claim 9 for the polymerization of olefins, in particular for the homopolymerization or copolymerization of ethylene.

Technical Field

The invention belongs to the field of catalysts, particularly relates to a main catalyst for olefin polymerization, and particularly relates to a titanium system main catalyst, a preparation method thereof, a catalyst composition containing the titanium system main catalyst and application of the titanium system main catalyst.

Background

The development of the polyolefin industry is one of the important criteria for measuring the chemical production and development level of the state, and the catalyst is the core technology of the key factors in the polyolefin industry. Among them, the titanium catalyst has been widely used and developed because of its high catalytic efficiency and low price.

Many studies and reports on the improvement of the catalyst performance are made, and the following aspects are mainly focused on: catalytic efficiency, particle morphology control, copolymerization ability, molecular weight distribution, and the like. However, in the preparation of the catalysts disclosed in the prior art, the use of environmentally polluting substances, such as organic phosphorus-containing compounds, phthalic anhydride, is mostly involved. Meanwhile, the catalyst disclosed by the prior art also relates to the use of a precipitation aid in preparation, so that the production period is prolonged, and the production efficiency is reduced.

For the production of general polyolefin resin, on the basis of further improving the catalyst performance, the catalyst preparation process is simplified, the catalyst cost is reduced, and an environment-friendly technology is developed to improve the benefit and enhance the competitiveness.

Disclosure of Invention

In order to develop an environment-friendly catalyst, the invention obtains an improved titanium polyethylene catalyst under the condition of avoiding the use of an organic phosphorus-containing compound and a precipitation assistant, the catalyst prepared by the method has better performance than the existing catalyst, the step of dissolution reaction of the precipitation assistant is omitted, and the raw materials are more environment-friendly than the system containing the organic phosphorus-containing compound and phthalic anhydride while the preparation period of the catalyst is shortened.

An object of the present invention is to provide a titanium-based main catalyst for polymerization, which is prepared from a raw material comprising a magnesium-containing compound, an aluminum-containing inorganic substance, tin tetrachloride, an alcohol compound and a halide of titanium as a transition metal or a derivative thereof.

According to a preferred embodiment of the present invention, the magnesium-containing compound is selected from one or more of magnesium dihalides, water or alcohol complexes of magnesium dihalides, magnesium dihalide derivatives.

In a further preferred embodiment, the magnesium dihalide derivative is a derivative in which one halogen atom in a magnesium dihalide molecule is substituted with a hydrocarbon group or a hydrocarbon oxy group.

In a still further preferred embodiment, the magnesium dihalide is selected from one or more of magnesium dichloride, magnesium dibromide, magnesium diiodide, preferably magnesium dichloride.

Wherein, when the magnesium-containing compound is dissolved, inert diluents such as: benzene, toluene, xylene, 1, 2-dichloroethane, chlorobenzene and other hydrocarbons or halogenated hydrocarbons, inert in this context means that the diluent should not participate in the reaction and should not adversely affect the dissolution of the magnesium dihalide.

According to a preferred embodiment of the invention, the aluminium-containing inorganic substance is selected from metallic aluminium and/or inorganic aluminium compounds.

In a further preferred embodiment, nano-sized aluminum powder is preferred when the aluminum is metal aluminum, wherein the smaller the size of the metal aluminum, the more advantageous the dispersion and the shorter the reaction time.

In a further preferred embodiment, the inorganic aluminium compound is selected from anhydrous aluminium chloride, preferably finely powdered anhydrous aluminium chloride.

According to a preferred embodiment of the present invention, the aluminum-containing inorganic substance is used in an amount of 0.002 to 1mol based on 1mol of the magnesium-containing compound.

In a further preferred embodiment, the aluminum-containing inorganic substance is used in an amount of 0.005 to 0.5mol based on 1mol of the magnesium-containing compound.

Wherein the molar amount of the magnesium-containing compound is calculated as the molar amount of magnesium element therein, and the molar amount of the aluminum-containing inorganic substance is calculated as the molar amount of aluminum element therein.

After a lot of experiments, the inventor finds that a catalyst system formed by adding an aluminum-containing inorganic substance into a titanium-based main catalyst for polymerization has higher catalytic activity, and the analysis reason is probably that the components have synergistic effect after adding the aluminum-containing inorganic substance, so that the invention emphasizes that the components in the titanium-based main catalyst for polymerization have synergistic effect and act as a whole, and cannot be separated and analyzed from each other.

According to a preferred embodiment of the present invention, the tin tetrachloride is used in an amount of 0.005 to 4mol based on 1mol of the magnesium-containing compound.

In a further preferred embodiment, the tin tetrachloride is used in an amount of 0.02 to 1mol based on 1mol of the magnesium-containing compound.

Wherein the molar amount of the magnesium-containing compound is based on the molar amount of the magnesium element therein.

The inventors have added tin tetrachloride to the titanium-based main catalyst for polymerization in an amount equivalent to imparting a multi-metal component to the main catalyst, and have found that the addition of tin tetrachloride promotes the precipitation of the main catalyst and increases the bulk density.

According to a preferred embodiment of the invention, the alcohol compound is selected from C₁～C₁₂Fatty alcohol of (2), C₇～C₁₂Wherein the derived substituted alcohol is one or more of C₁～C₁₂Fatty alcohol or C₇～C₁₂Substituted alcohols derived from aromatic alcohols.

In a further preferred embodiment, the alcohol compound is selected from at least one of methanol, ethanol, propanol, isopropanol, butanol, isobutanol, 2-ethylhexanol, n-octanol, dodecanol, benzyl alcohol and phenethyl alcohol.

In a still further preferred embodiment, the alcohol compound is selected from at least one of ethanol, isooctanol, butanol, 2-ethylhexanol, benzyl alcohol, and phenethyl alcohol.

When two mixed alcohols are adopted, the molar ratio of the two mixed alcohols is 1-50: 1, 1-20: preferably 1.

Wherein, the alcohol compound mainly has the function of dissolving the magnesium-containing compound to form the alcohol compound with the magnesium-containing compound.

According to a preferred embodiment of the present invention, the alcohol compound is used in an amount of 0.1 to 10mol based on 1mol of the magnesium-containing compound.

In a further preferred embodiment, the alcohol compound is used in an amount of 0.2 to 6mol based on 1mol of the magnesium-containing compound.

Wherein the molar amount of the magnesium-containing compound is based on the molar amount of the magnesium element therein.

In the prior art, for example, chinese patent CN1229092A proposes a catalyst for ethylene polymerization or copolymerization and a preparation method thereof, wherein the catalyst is obtained by dissolving magnesium halide in an organic epoxy compound, an organic phosphorus compound, adding an electron donor to form a homogeneous solution, and reacting with at least one precipitation assistant and a halide of transition metal titanium or a derivative thereof. For another example, chinese patent CN111516A discloses a method for ethylene polymerization or copolymerization, the titanium-containing component of the catalyst is prepared by the following steps: (1) dissolving magnesium halide in an organic epoxy compound and an organic phosphorus compound to form a uniform solution; (2) during or after the dissolution, simultaneously or respectively carrying out contact reaction with at least one organic alcohol and at least one compound selected from C3-C5 cyclic ethers; (3) and (3) carrying out contact reaction on the mixture obtained in the step (2) and at least one Ti-containing compound in the presence of at least one organic acid anhydride to obtain the titanium-containing titanium-based main catalyst for solid polymerization.

In the preparation process of the catalyst disclosed in the above patents, in order to obtain a solid catalyst, the dissolving system adopts an organic phosphorus compound, and a method of adding a precipitation aid is also adopted, in particular, phthalic anhydride is adopted as the precipitation aid in the examples, and for this purpose, phthalic anhydride is completely dissolved in a mixed solvent system, and then the temperature is reduced to mix with a titanium compound, so that the use of the precipitation aid correspondingly prolongs the preparation period of the catalyst. In addition, the auxiliary precipitating agent system has relatively high toxicity and high requirement on operation conditions.

In the present application, the inventors avoided the use of organophosphorus compounds; the inventors have also found that the dissolving effect of the magnesium-containing compound is better when two or more alcohol compounds are used. Meanwhile, different alcohols generate different titanium products when reacting with the titanium-containing compound at the later stage, so that more than two titanium products are obtained when more than two alcohol compounds are adopted, and a polymer with wider molecular weight distribution can be obtained when the alcohol compounds are applied to the preparation of polyolefin, thereby being beneficial to the processability of the polymer.

According to a preferred embodiment of the present invention, the halide of the transition metal titanium or the derivative thereof has the general formula TiX_n(OR)_4-nWherein: x represents halogen, R represents C₁～C₁₄Aliphatic hydrocarbon radical of (C)₆～C₁₄An aromatic hydrocarbon group, n is an integer of 0 to 4.

In a further preferred embodiment, the halide of the transition metal titanium or its derivative is selected from one or more of titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, tetrabutoxytitanium, tetraethoxytitanium, chlorotriethoxytitanium, dichlorodiethoxytitanium, trichloromonoethoxytitanium, for example titanium tetrachloride.

According to a preferred embodiment of the present invention, the halide of the transition metal titanium or the derivative thereof is used in an amount of 0.2 to 100mol based on 1mol of the magnesium-containing compound.

In a further preferred embodiment, the halide of the transition metal titanium or the derivative thereof is used in an amount of 1.0 to 20mol based on 1mol of the magnesium-containing compound.

Wherein the molar amount of the magnesium-containing compound is based on the molar amount of the magnesium element therein, and the molar amount of the halide of titanium transition metal or the derivative thereof is based on the molar amount of the titanium element therein.

According to a preferred embodiment of the present invention, the raw material for preparing the titanium-based main catalyst for polymerization optionally further comprises an electron donor.

In a further preferred embodiment, the electron donor is selected from one or more of organic ethers, silicon-containing compounds and boron-containing compounds.

Preferably: (I) the organic ether is selected from one or more of methyl ether, ethyl ether, propyl ether, butyl ether, amyl ether and isoamyl ether; (II) the silicon-containing compound has the general formula R¹ _xR² _ySi(OR³)_zSilicon compounds having no active hydrogen atom shown, wherein R¹And R²Each is a C1-10 alkyl group or halogen, R³The carbon atom number of the alkyl is 1-10, wherein x, y and z are positive integers, x is more than or equal to 0 and less than or equal to 2, y is more than or equal to 0 and less than or equal to 2, z is more than or equal to 0 and less than or equal to 4, and x + y + z is 4. (III) boron compound of the formula R¹ _xR² _yB(OR³)_zBoron compounds having no active hydrogen atom shown, wherein R¹And R²Each is a C1-10 alkyl group or halogen, R³The carbon atom number is 1-10 alkyl, wherein x, y and z are positive integers, x is more than or equal to 0 and less than or equal to 2, y is more than or equal to 0 and less than or equal to 1, z is more than or equal to 0 and less than or equal to 3, and x + y + z is 3.

In a still further preferred embodiment, the silicon-containing compound is selected from one or more of silicon tetrachloride, tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, and tetrakis (2-ethylhexyloxy) silane, preferably silicon tetrachloride, tetraethoxysilane; the boron-containing compound is selected from one or more of boron trichloride, trimethoxyborane, triethoxyborane, tripropoxyborane and tributoxyborane, and preferably boron trichloride and triethoxyborane.

Wherein the electron donor acts as a lewis base in the titanium-based procatalyst for polymerization, providing electron pairs to the metal in the catalyst.

According to a preferred embodiment of the present invention, the electron donor is used in an amount of 0 to 5mol based on 1mol of the magnesium-containing compound.

In a further preferred embodiment, the electron donor is used in an amount of 0 to 1mol based on 1mol of the magnesium-containing compound.

Wherein the molar amount of the magnesium-containing compound is based on the molar amount of the magnesium element therein.

In the invention, preferably, the titanium-based main catalyst contains 0.0075-0.4 mol of aluminum-containing inorganic substances, 0.1-0.65 mol of tin tetrachloride, 3.5-5.5 mol of alcohol compounds, 0-0.5 mol of electron donor compounds and 6.0-20 mol of titanium-containing compounds per mol of magnesium-containing compounds.

Another object of the present invention is to provide a method for preparing the titanium-based main catalyst for polymerization, which comprises the following steps:

step 1, mixing a magnesium-containing compound, an aluminum-containing inorganic substance, an alcohol compound and tin tetrachloride in the presence of an inert diluent to obtain a mixed solution containing magnesium and aluminum;

step 2, cooling, and then dropping the halide of the transition metal titanium or the derivative thereof into the mixed solution containing magnesium and aluminum, or dropping the mixed solution containing magnesium and aluminum into the halide of the transition metal titanium or the derivative thereof for reaction;

and 3, heating after reaction, stirring, and then carrying out aftertreatment to obtain the titanium-based main catalyst for polymerization.

According to a preferred embodiment of the present invention, in step 1, the mixing is performed at a temperature of 0 to 170 ℃, preferably 40 to 140 ℃, and more preferably, the mixing is performed under stirring.

In a further preferred embodiment, in step 1, the inert diluent may be selected from one or more of benzene, toluene, xylene, 1, 2-dichloroethane, chlorobenzene and other hydrocarbons or halogenated hydrocarbons.

The term "inert" as used herein means that the diluent should not participate in the reaction and should not adversely affect the dissolution of the magnesium-containing compound.

According to a preferred embodiment of the present invention, in step 2, the temperature is reduced to-35 to 60 ℃, preferably to-30 to 20 ℃.

According to a preferred embodiment of the present invention, in step 3, the temperature is raised to 10 to 150 ℃, preferably 20 to 130 ℃.

In a further preferred embodiment, in step 3, the post-treatment comprises settling, filtration, washing of solids and drying.

Among them, the mother liquor is removed by filtration, and the solid is preferably washed with a hydrocarbon solvent.

In a preferred embodiment according to the present invention, an electron donor is optionally added in step 1 or step 2.

In the invention, the obtained titanium-based main catalyst for polymerization is powdery solid particles, the average particle size is about 2-50 microns, and the particle size can be controlled by changing the preparation conditions.

The third object of the present invention is to provide a catalyst composition for polymerization, which comprises a main catalyst and a co-catalyst, wherein the main catalyst is the titanium-based main catalyst for polymerization of one object of the present invention or the titanium-based main catalyst for polymerization obtained by the production method of the second object of the present invention, and the co-catalyst is an organoaluminum compound.

According to a preferred embodiment of the present invention, the organoaluminum compound has the formula AlR_nX_3-nIn the formula: r is C₁～C₂₀Preferably, R is selected from alkyl, aralkyl or aryl; x is halogen, preferably chlorine or bromine; n is an integer of more than 0 and less than or equal to 3.

In a further preferred embodiment, the organoaluminum compound is selected from one or more of trialkylaluminums, alkylaluminum hydrides, and alkylaluminum chlorides.

Wherein the trialkylaluminum includes trimethylaluminum, triethylaluminum, triisobutylaluminum, trioctylaluminum, and the like; the alkyl aluminum hydride includes diethyl aluminum hydride, diisobutyl aluminum hydride and the like; the alkyl aluminum chloride includes diethyl aluminum monochloride, diisobutyl aluminum monochloride, ethyl aluminum sesquichloride, ethyl aluminum dichloride and the like.

In a still further preferred embodiment, the organoaluminum compound is selected from triethylaluminum and/or triisobutylaluminum.

According to a preferred embodiment of the present invention, the molar ratio of the organoaluminum compound to the titanium-based main catalyst for polymerization used in the catalyst is (5 to 1000):1, preferably (20 to 800): 1.

Wherein the molar amount of the titanium-based main catalyst for polymerization is based on the molar amount of the titanium element therein, and the molar amount of the organoaluminum compound is based on the molar amount of the aluminum element therein.

In the present invention, the titanium-based main catalyst for polymerization may be used in the form of a solid or a suspension, and the titanium-based main catalyst for polymerization and the organoaluminum compound may be directly used in the polymerization system or may be used in the polymerization system after being pre-complexed.

It is a fourth object of the present invention to provide the use of the catalyst composition of the third object of the present invention in olefin polymerization, for olefin homopolymerization and copolymerization, preferably for ethylene homopolymerization or for copolymerization of ethylene with an alpha-olefin selected from one or more of propylene, butene, pentene, hexene, octene and 4-methyl-1-pentene.

Among them, liquid phase polymerization or gas phase polymerization may be employed for the polymerization. In the liquid phase polymerization, an inert solvent such as a saturated aliphatic hydrocarbon or an aromatic hydrocarbon such as propane, hexane, heptane, cyclohexane, isobutane, isopentane, naphtha, raffinate oil, hydrogenated gasoline, kerosene, benzene, toluene, xylene, etc. may be used as a reaction medium, and a prepolymerization may be carried out before the polymerization. The polymerization may be carried out in a batch, semi-continuous or continuous manner.

In the polymerization, the polymerization temperature is preferably from room temperature to 150 ℃ and more preferably from 50 ℃ to 100 ℃. In order to regulate the molecular weight of the polymer, hydrogen is used as a molecular weight regulator.

Compared with the prior art, the invention has the following beneficial effects:

(1) the titanium-based main catalyst for polymerization and the preparation method thereof avoid using phosphorus-containing compounds and phthalic anhydride with larger toxicity, and are more beneficial to environmental protection;

(2) the titanium-based main catalyst for polymerization contains tin tetrachloride, so that the main catalyst is more beneficial to precipitation during preparation, and the main catalyst is endowed with more excellent bulk density;

(3) the preparation method of the invention omits the step of dissolution reaction of the precipitation aid and shortens the preparation period of the titanium-based main catalyst for polymerization;

(4) the catalyst of the invention has better activity and bulk density.

Detailed Description

While the present invention will be described in detail with reference to the following examples, it should be understood that the following examples are illustrative of the present invention and are not to be construed as limiting the scope of the present invention.

Example 1

In the presence of high purity N₂To the fully displaced reactor, 0.04mol of anhydrous MgCl was added in sequence₂0.0015mol of metallic aluminum and 0.4mol of n-decane, 0.0043mol of anhydrous tin tetrachloride, 0.13mol of isooctanol and 0.05mol of n-butanol are added, the temperature is raised to 130 ℃, the temperature is maintained for 1 hour, the temperature is reduced to-5 ℃, 0.6mol of titanium tetrachloride is dripped into the anhydrous tin tetrachloride, the temperature is maintained for half an hour, 0.015mol of silane is added, the temperature is maintained for 1 hour, the temperature is raised to 110 ℃, the temperature is maintained for 1 hour, the mixture is filtered, washed for 4 times by hexane and dried in vacuum, and the titanium-based main catalyst for polymerization is obtained.

Example 2

In the presence of high purity N₂To the fully displaced reactor, 0.04mol of anhydrous MgCl was added in sequence₂0.006mol of metallic aluminum and 0.4mol of n-decane, 0.009mol of silicon tetrachloride and 0.0086mol of anhydrous tin tetrachloride are added, the mixture is maintained for 5 minutes, 0.13mol of isooctanol is added, the temperature is raised to 130 ℃, the mixture is maintained for half an hour, 0.06mol of n-butanol is added, the mixture is maintained for half an hour, the temperature is reduced to-10 ℃, 0.5mol of titanium tetrachloride is dripped into the mixture, the mixture is maintained for half an hour, 0.015mol of titanium tetrachloride is addedAnd keeping the silane mol for 1 hour, then raising the temperature to 110 ℃, keeping for 1 hour, filtering, washing with hexane for 4 times, and drying in vacuum to obtain the titanium-based main catalyst for solid polymerization.

Example 3

In the presence of high purity N₂In the fully displaced reactor, 0.03mol of anhydrous MgCl was added in succession₂0.012mol of anhydrous aluminum chloride and 0.4mol of n-decane, 0.01mol of silicon tetrachloride is added, 0.017mol of anhydrous stannic chloride is added, the reaction is maintained for 5 minutes, 0.13mol of isooctanol is added, the temperature is raised to 130 ℃, the reaction is maintained for half an hour, 0.05mol of n-butanol is added, the reaction is maintained for half an hour, the temperature is lowered to-15 ℃, 0.45mol of titanium tetrachloride is dripped into the reaction, the reaction is maintained for half an hour, 0.015mol of silane is added, the reaction is maintained for 1 hour, the reaction is raised to 110 ℃, the reaction is maintained for 1 hour, the reaction is washed for 4 times by hexane after filtration, and vacuum drying is.

Example 4

In the presence of high purity N₂To the fully displaced reactor, 0.04mol of anhydrous MgCl was added in sequence₂0.0003mol of anhydrous aluminum chloride and 0.6mol of toluene are added, 0.026mol of anhydrous stannic chloride, 0.09mol of n-butyl alcohol and 0.08mol of ethanol are heated to 80 ℃ and maintained for 1 hour, the temperature is reduced to 20 ℃, 0.4mol of titanium tetrachloride is dripped into the anhydrous stannic chloride, the temperature is maintained for half an hour, then the temperature is heated to 85 ℃ and maintained for 1 hour, the mixture is filtered and washed for 4 times by hexane, and the mixture is dried in vacuum, so that the titanium-based main catalyst for solid polymerization is obtained.

Example 5

In the presence of high purity N₂To the fully displaced reactor, 0.04mol of anhydrous MgCl was added in sequence₂0.0003mol of anhydrous aluminum chloride and 0.6mol of toluene are added, 0.026mol of anhydrous stannic chloride, 0.09mol of n-butyl alcohol and 0.08mol of phenethyl alcohol are heated to 80 ℃ and maintained for 1 hour, the temperature is reduced to minus 20 ℃, 0.4mol of titanium tetrachloride is dripped into the anhydrous stannic chloride, the temperature is maintained for half an hour, then the temperature is raised to 85 ℃ and maintained for 1 hour, the mixture is filtered and washed with hexane for 4 times, and the mixture is dried in vacuum, so that the titanium-based main catalyst for solid polymerization is obtained.

Example 6

In the presence of high purity N₂To the fully displaced reactor, 0.04mol of anhydrous MgCl was added in sequence₂、0.0004mol of anhydrous aluminum chloride and 0.6mol of toluene, 0.012mol of anhydrous stannic chloride and 0.16mol of n-butyl alcohol are added, the temperature is raised to 110 ℃, the temperature is maintained for 1 hour, the temperature is lowered to-20 ℃, 0.8mol of titanium tetrachloride is dripped into the anhydrous stannic chloride, the temperature is raised to 85 ℃, the temperature is maintained for 1 hour, the mixture is filtered, washed for 4 times by hexane and dried in vacuum, and the titanium-based main catalyst for solid polymerization is obtained.

Comparative example 1

In the presence of high purity N₂To the fully displaced reactor, 0.04mol of anhydrous MgCl was added in sequence₂0.6mol of toluene, 0.03mol of epichlorohydrin, 0.02mol of tributyl phosphate and 0.06mol of ethanol are added under stirring, the temperature is raised to 60 ℃ and maintained for 1 hour, 0.0074mol of phthalic anhydride is added and maintained for half an hour, the solution is cooled to-15 ℃, 0.60mol of titanium tetrachloride is dripped into the solution and maintained for 1 hour, the temperature is raised to 60 ℃ and maintained for 1 hour, the solution is filtered, washed for 4 times by hexane and dried in vacuum, and the titanium-based main catalyst for solid polymerization is obtained.

Comparative example 2

In the presence of high purity N₂To the fully displaced reactor, 0.04mol of anhydrous MgCl was added in sequence₂0.30mol of n-decane, 0.15mol of 2-ethylhexanol is added under stirring, the temperature is raised to 115 ℃, the temperature is maintained for 1 hour, the temperature is lowered to 50 ℃, 0.026mol of silicon tetrachloride is added, the solution is cooled to-10 ℃, 0.45mol of titanium tetrachloride is dripped into the solution, the solution is maintained for 1 hour, then the temperature is raised to 120 ℃, the solution is maintained for 1 hour, the solution is filtered, washed by hexane for 4 times, and dried in vacuum, thus obtaining the titanium-based main catalyst for solid polymerization.

Experimental example ethylene polymerization

Stainless steel kettle vessel H with volume of 2 liters₂After the sufficient substitution, 1000ml of hexane, 1.0ml of a triethylaluminum hexane solution having a concentration of 1mol/L, and a metered amount (9 to 12mg) of the titanium-based main catalyst for polymerization prepared in examples 1 to 4 and comparative examples 1 to 2 were added thereto, the temperature was raised to 70 ℃ and the pressure was increased to 0.26MPa (gauge pressure), and ethylene was introduced into the autoclave to make the pressure in the autoclave 0.72MPa (gauge pressure) and the polymerization was carried out at 80 ℃ for 2 hours. The results are shown in Table 1.

Table 1:

as can be seen from the data in table 1, the catalyst of the present invention has better activity and bulk density under the same polymerization conditions than the comparative example.