Patent Description:
The present disclosure relates to a magnesium halide solution, a preparing method and a use thereof.

With the development of olefin polymerization technology, the research on catalyst that is used in polymerization reaction has made a great progress, among which the high efficiency catalyst holds an important position in polyolefin catalyst field by virtue of its good polymerization performance and mature application techniques. In particular, the production and development of polyolefin resin with new structure is drawing increasingly more attention, and thus the requirement for the overall performance of the catalyst used in olefin polymerization reaction is becoming increasingly high. On the one hand, the catalyst should adapt to the production equipment, and on the other hand, the structure of the resin produced therein can be regulated and controlled. After years of research, it is demonstrated that Mg-Ti series high efficiency catalysts can meet the requirement.

At present, the Mg-Ti series high efficiency catalysts are mainly prepared through a dissolution-precipitation method. That is, a magnesium compound is dissolved in a solvent, and a corresponding catalyst can be obtained after precipitation. For example, <CIT> discloses that a magnesium compound is dissolved in a titanate compound, <CIT> and <CIT> disclose that a magnesium compound is dissolved in alcohol, aldehyde, amine, or carboxylic acid compounds, <CIT> discloses that a magnesium compound is dissolved in an organic phosphorus compound, and <CIT> discloses that a magnesium compound is dissolved in a mixed solvent of an organic epoxy compound and an organic phosphorus compound (a phosphate ester compound).

The disadvantages of grinding method can be overcome to a certain extent by the aforesaid magnesium compound dissolution method, but there are still a lot of disadvantages in this method. The activity of the catalyst that is precipitated from the magnesium compound solution disclosed by <CIT>, <CIT>, and <CIT> is relatively low. Besides, the activity of the catalyst drops apparently when the polymerization time is prolonged. Moreover, the bulk density of the polymer obtained therein is relatively low.

As a result, there is still a need for the Mg-Ti series high efficiency catalyst with a good overall performance and a magnesium halide solution used for preparing the catalyst so as to further improve the technical effect of the olefin polymerization reaction.

<CIT> is directed to an olefin polymerization process and a catalyst used therefor. The catalyst is prepared by using a magnesium chloride alcohol adduct.

<CIT> is related to a catalyst component which is used for vinyl polymerization or copolymerization. Magnesium halide is dissolved in a solvent system which contains organic epoxy compounds and an organophosphorus compound and forms a homogeneous solution.

<CIT> describes a solution comprising heptane, magnesium chloride, tetrabutyltitanate, epichlorohydrin and ethylbenzoate.

A magnesium halide solution and a method for preparing the magnesium halide solution according to the present invention are defined in the claims. The following disclosure provides further information useful for understanding the invention.

It is discovered after repeated experiments that, a proper magnesium halide solution can be used for preparing an Mg-Ti series high efficiency catalyst with a good catalytic performance which can be used in olefin polymerization reaction.

The present disclosure aims to provide a magnesium halide solution. The preparing condition of the magnesium halide solution is mild, and the raw material is cheap and easy to be obtained. The magnesium halide solution can be used for preparing a Mg-Ti series catalyst with a good catalytic performance in olefin polymerization reaction, such as ethylene polymerization reaction.

The present disclosure provides a method for preparing the magnesium halide solution. The preparing condition is mild, and the equipment utilization rate thereof is high. The method is easy to be performed and is environment-friendly.

The present disclosure further provides a use of the aforesaid magnesium halide solution.

The present disclosure provides a magnesium halide solution. The magnesium halide solution comprises a magnesium halide, an oxygen-containing organic titanium compound, a hydroxyl-containing compound, and an organic solvent. The magnesium halide solution further comprises an organic heterocyclic compound. The organic solvent is a hydrocarbon and/or a halogenated hydrocarbon. The magnesium halide solution can be used for preparing a catalyst for olefin polymerization reaction.

According to the present disclosure, a raw material anhydrous magnesium halide is preferably a crystalline magnesium halide, which can have α, β, or γ crystal shape. In the magnesium halide solution according to the present disclosure, the magnesium halide is in an amorphous state. That is, according to the present disclosure, the magnesium halide solution does not contain crystalline magnesium halide, which is a prominent advantage of the present disclosure. In general, magnesium halide is difficult to be absolutely dissolved in organic solvent, and at least part of crystalline magnesium halide would be contained in the organic solvent, which would not facilitate the effective utilization thereof. During preparing of catalyst, magnesium halide should be converted into an amorphous state from a crystalline state, whereby the catalyst can have a high activity. It is discovered after long periods of experiments that, the anhydrous magnesium halide in the crystalline state can be dissolved fully in some specific mixed organic solvents so as to form an amorphous magnesium halide solution, which can be used for preparing catalyst for olefin polymerization reaction.

According to some embodiments, the magnesium halide solution is composed of a magnesium halide, an oxygen-containing organic titanium compound, a hydroxyl-containing compound, an organic solvent, and an organic heterocyclic compound. The organic solvent is a hydrocarbon and/or a halogenated hydrocarbon. That is, the magnesium halide solution is composed of magnesium halide and a mixed solvent consisting of four solvents, i.e., the oxygen-containing organic titanium compound, the organic heterocyclic compound, the hydroxyl-containing compound, and the organic solvent.

According to the present disclosure, in addition to the aforesaid five essential ingredients, the magnesium halide solution can further contain other organic solvent. For example, the organic solvent can be selected from a group consisting of ester, ketone, and amine compounds. The use amount of these organic solvents should not affect the liquid phase of the final magnesium halide solution product.

According to the present disclosure, the organic heterocyclic compound is at least one selected from a group consisting of a sulphur-containing organic heterocyclic compound, and a nitrogen-containing organic heterocyclic compound.

The sulphur-containing organic heterocyclic compound is at least one selected from a group consisting of thiophene, thiazole, isothiazole and a sulphur-containing heterocyclic compound that is in parallel connection with a benzene ring to form a condensed ring, preferably the sulphur-containing heterocyclic compound that is in parallel connection with a benzene ring to form a condensed ring is benzothiophene, and <NUM>,<NUM>-dimethylbenzothiophene.

The nitrogen-containing organic heterocyclic compound is at least one selected from a group consisting of a <NUM> to <NUM>-membered ring nitrogen-containing heterocyclic compound and a nitrogen-containing heterocyclic compound that is in parallel connection with a benzene ring to form a condensed ring, preferably at least one selected from a group consisting of pyrrole, thiazole, imidazole, pyridine, pyrazine, pyrimidine, pyridazine, indole, quinoline, and pteridine.

According to the present disclosure, the magnesium halide solution does not contain an organic phosphorus compound, especially a phosphate ester compound. In this case, when downstream product is prepared with the magnesium halide solution disclosed herein, residual phosphorus would not be contained therein. Therefore, the quality of the downstream product can be improved, and environmental pollution can be avoided. The organic phosphorus compound is a commonly used raw material for preparing catalyst of olefin polymerization reaction. However, when the magnesium halide solution provided herein is used, magnesium halide can be dissolved fully in the organic solvent system without organic phosphorus compound being introduced. The magnesium halide solution can be used for preparing olefin polymerization catalyst with good catalytic performance, and the environmental pollution can be reduced. The phosphate ester compound is tributyl phosphate, tri-isobutyl phosphate, tripropyl phosphate, triethyl phosphate, or trimethyl phosphate.

According to the present disclosure, the magnesium halide solution is formed by dissolving the anhydrous magnesium halide into a mixed solvent that is composed of the oxygen-containing organic titanium compound, the organic heterocyclic compound, the hydroxyl-containing compound, and the organic solvent.

According to one preferred embodiment of the present disclosure, a molar concentration of magnesium halide in the magnesium halide solution ranges from <NUM> mol/L to <NUM> mol/L, preferably from <NUM> mol/L to <NUM> mol/L, more preferably from <NUM> mol/L to <NUM> mol/L.

According to one preferred embodiment of the present disclosure, measuring by per molar of magnesium halide, the magnesium halide solution contains the oxygen-containing organic titanium compound <NUM> mol to <NUM> mol, preferably <NUM> mol to <NUM> mol, more preferably <NUM> mol to <NUM> mol. Specifically, the magnesium halide solution can contain the oxygen-containing organic titanium compound <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, or <NUM> mol.

Measuring by per molar of magnesium halide, the magnesium halide solution contains the organic heterocyclic compound <NUM> mol to <NUM> mol, preferably <NUM> mol to <NUM> mol, more preferably <NUM> mol to <NUM> mol. Specifically, the magnesium halide solution can contain the organic heterocyclic compound <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol or <NUM> mol.

Measuring by per molar of magnesium halide, the magnesium halide solution contains the hydroxyl-containing compound <NUM> mol to <NUM> mol, preferably <NUM> mol to <NUM> mol, more preferably <NUM> mol to <NUM> mol. Specifically, the magnesium halide solution can contain the hydroxyl-containing compound <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol, <NUM> mol or <NUM> mol.

Through selecting proper solvents and a proper ratio thereamong, the crystalline anhydrous magnesium halide can be fully dissolved in the mixed organic solvent, whereby the utilization rate of magnesium halide can be improved, the using amount of solvent can be reduced, and thus the cost thereof can be saved.

According to the present disclosure, a formula of the magnesium halide is MgX<NUM>, X being halogen.

According to the present disclosure, a formula of the oxygen-containing organic titanium compound is Ti(OR<NUM>)nX<NUM>-n, R<NUM> representing C<NUM> to C<NUM> saturated or unsaturated linear, branched, or cyclic hydrocarbyl, <NUM><n≤<NUM>, and X being halogen. Here, it can be understood that, X in the formula MgX<NUM> of magnesium halide can be the same as or different from X in the formula Ti(OR<NUM>)nX<NUM>-n of the oxygen-containing organic titanium compound.

According to the present disclosure, a formula of the hydroxyl-containing compound is HOR<NUM>, R<NUM> representing C<NUM> to C<NUM> saturated or unsaturated linear, branched, or cyclic hydrocarbyl.

According to the present disclosure, the hydrocarbon is C<NUM> to C<NUM> saturated or unsaturated linear, branched, or cyclic aliphatic hydrocarbon or aromatic hydrocarbon, preferably C<NUM> to C<NUM> hydrocarbon. The halogenated hydrocarbon is C<NUM> to C<NUM> saturated or unsaturated linear, branched, or cyclic aliphatic halogenated hydrocarbon or aromatic halogenated hydrocarbon, preferably C<NUM> to C<NUM> halogenated hydrocarbon.

Preferably, the magnesium halide is at least one selected from a group consisting of magnesium chloride, magnesium bromide, and magnesium iodide. The oxygen-containing organic titanium compound is a titanate compound, preferably at least one selected from a group consisting of tetraethyl titanate, tetraisopropyl titanate, tetrabutyl titanate, and tetraisooctyl titanate. The hydroxyl-containing compound is at least one selected from a group consisting of aliphatic alcohols, aromatic alcohols, and phenols, preferably at least one selected from a group consisting of methanol, ethanol, isopropanol, n-butanol, n-hexanol, isooctanol, benzyl alcohol, and phenylethyl alcohol. The hydrocarbon is at least one selected from a group consisting of benzene, toluene, xylene, n-butane, isobutene, isopentane, n-pentane, n-hexane, cyclohexane, heptanes, octane, and decane. The halogenated hydrocarbon is selected from <NUM>, <NUM>-dichloroethane and/or chlorobenzene.

The present disclosure provides a method for preparing the aforesaid magnesium halide solution, and the method comprises dissolving an anhydrous magnesium halide into a mixed solvent that is composed of an oxygen-containing organic titanium compound, an organic heterocyclic compound, a hydroxyl-containing compound, and an organic solvent in a uniform manner. The adding order of each solvent is generally not defined.

According to one preferred embodiment of the present disclosure, the method comprises mixing the anhydrous magnesium halide with the oxygen-containing organic titanium compound, the organic heterocyclic compound, and the hydroxyl-containing compound in a uniform manner (a transparent solution can be obtained at this time), and mixing the solution with the organic solvent so as to obtain the magnesium halide solution.

During preparing procedure of amorphous magnesium halide solution, the temperature at which the magnesium compound, the organic heterocyclic compound, the oxygen-containing organic titanium compound, the hydroxyl-containing compound, the hydrocarbon and the halogenated hydrocarbon contact with one another depends on the property of the reactants. The reactants are generally mixed at a relatively high temperature, preferably below the decomposition temperature of the reactants. The temperature is no higher than <NUM>, preferably no higher than <NUM>. The dissolution time depends on the property of the reactants and the operational condition thereof. The dissolution should proceed for a period of time until a completely transparent solution can be obtained. The time generally ranges from <NUM> minutes to <NUM> hours, preferably from <NUM> hours to <NUM> hours.

According to one preferred embodiment of the present disclosure, in the aforesaid method, a mixing temperature ranges from <NUM> to <NUM>, preferably from <NUM> to <NUM>, and a mixing time ranges from <NUM> minutes to <NUM> hours, preferably from <NUM> hours to <NUM> hours.

After magnesium halide is dissolved, the hydrocarbon and/or the halogenated hydrocarbon as above defined can be added to the solution. The magnesium halide solution can be regulated to a certain concentration, so that it can be preserved for a relatively long period of time.

The present disclosure further provides a use of the aforesaid magnesium halide solution in olefin polymerization reaction. For example, the magnesium halide solution can be used for preparing a catalyst for olefin polymerization reaction.

According to the present disclosure, the raw material of the magnesium halide solution is cheap and can be obtained easily. The magnesium halide solution can be used for preparing Mg-Ti series catalyst with a good catalytic performance in olefin polymerization reaction, for example, ethylene polymerization reaction. The preparing method of the magnesium halide solution disclosed herein has the advantages of convenient operation, mild using condition, a high equipment utilization rate, and environment-friendly.

The present disclosure will be illustrated in detail hereinafter with reference to specific examples. It can be understood that, the examples disclosed herein are not used for restricting the present disclosure.

An amorphous magnesium halide solution was prepared: anhydrous magnesium chloride (<NUM>) was added into a mixed solvent composed of tetrabutyl titanate (<NUM>), thiophene (<NUM>), anhydrous ethanol (<NUM>), and toluene (<NUM>), and the mixed solution was maintained at <NUM> and stirred for <NUM> hours so as to form a transparent solution.

An amorphous magnesium halide solution was prepared: anhydrous magnesium chloride (<NUM>) was added into a mixed solvent composed of tetrabutyl titanate (<NUM>), thiophene (<NUM>), and anhydrous ethanol (<NUM>). Hexane (<NUM>) was further added therein, and the mixed solution was maintained at <NUM> and stirred for <NUM> hours so as to obtain a transparent magnesium halide solution.

According to the present Example, the "anhydrous ethanol (<NUM>)" in the preparing method of the amorphous magnesium halide solution in Example <NUM> was replaced by "n-butanol (<NUM>)," while other conditions were the same as those in Example <NUM>.

According to the present Example, the "tetrabutyl titanate (<NUM>)" in the preparing method of the amorphous magnesium halide solution in Example <NUM> was replaced by "tetraethyl titanate (<NUM>)," and "thiophene (<NUM>)" thereof was replaced by "benzothiophene (<NUM>). " Other conditions were the same as those in Example <NUM>.

According to the present Example, the "thiophene (<NUM>)" in the preparing method of the amorphous magnesium halide solution in Example <NUM> was replaced by "thiazole (<NUM>)," while other conditions were the same as those in Example <NUM>.

Anhydrous magnesium chloride (<NUM>) was added into a mixed solvent composed of tetrabutyl titanate (<NUM>), thiophene (<NUM>), anhydrous ethanol (<NUM>), and toluene (<NUM>), and the mixed solution was maintained at <NUM> and stirred so as to form a transparent solution. Toluene (<NUM>) was further added therein to obtain a magnesium halide solution.

An amorphous magnesium halide solution is prepared: anhydrous magnesium chloride (<NUM>) was added into a mixed solvent composed of tetrabutyl titanate (<NUM>), pyridine (<NUM>), anhydrous ethanol (<NUM>), and toluene (<NUM>), and the mixed solution was maintained at <NUM> and stirred for <NUM> hours so as to form a transparent solution.

An amorphous magnesium halide solution is prepared: anhydrous magnesium chloride (<NUM>) was added into a mixed solvent composed of tetraisooctyl titanate (<NUM>), pyridine (<NUM>), and anhydrous ethanol (<NUM>), and the mixed solution was maintained at <NUM> and stirred so as to obtain a uniform transparent solution. Hexane (<NUM>) was further added therein, and the mixed solution was maintained at <NUM> and stirred for <NUM> hours so as to obtain a transparent magnesium halide solution.

According to the present Example, the "anhydrous ethanol (<NUM>)" in the preparing method of the amorphous magnesium halide solution in Example <NUM> was replaced by "benzyl alcohol (<NUM>)," while other conditions were the same as those in Example <NUM>.

According to the present Example, the "pyridine (<NUM>)" in the preparing method of the amorphous magnesium halide solution in Example <NUM> was replaced by "pyrrole (<NUM>)," while other conditions were the same as those in Example <NUM>.

According to the present Example, the "pyridine (<NUM>)" in the preparing method of the amorphous magnesium halide solution in Example <NUM> was replaced by "quinoline (<NUM>)," while other conditions were the same as those in Example <NUM>.

According to the present Example, the "tetrabutyl titanate (<NUM>)" in the preparing method of the amorphous magnesium halide solution in Example <NUM> was replaced by "tetraethyl titanate (<NUM>)," and "pyridine (<NUM>)" thereof was replaced by "pyridine (<NUM>). " Other conditions were the same as those in Example <NUM>.

Anhydrous magnesium chloride (<NUM>) was added into a mixed solvent composed of tetrabutyl titanate (<NUM>), pyridine (<NUM>), anhydrous ethanol (<NUM>), and toluene (<NUM>), and the mixed solution was maintained at <NUM> and stirred so as to form a transparent solution. Toluene (<NUM>) was further added therein to obtain a magnesium halide solution.

An amorphous magnesium halide solution was prepared: anhydrous magnesium chloride (<NUM>) was added into a mixed solvent composed of tetrabutyl titanate (<NUM>), epichlorohydrin (<NUM>), anhydrous ethanol (<NUM>), and toluene (<NUM>), and the mixed solution was maintained at <NUM> and stirred for <NUM> hours so as to form a transparent solution.

According to the present Example, the "toluene (<NUM>)" in the preparing method of the amorphous magnesium halide solution in Example <NUM> was replaced by "chlorobenzene (<NUM>)," while other conditions were the same as those in Example <NUM>.

According to the present Example, the "anhydrous ethanol (<NUM>)" in the preparing method of the amorphous magnesium halide solution in Example <NUM> was replaced by "isooctanol (<NUM>)," while other conditions were the same as those in Example <NUM>.

According to the present Example, the "anhydrous ethanol (<NUM>)" in the preparing method of the amorphous magnesium halide solution in Example <NUM> was replaced by "anhydrous ethanol (<NUM>)," while other conditions were the same as those in Example <NUM>.

According to the present Example, the "epichlorohydrin (<NUM>)" in the preparing method of the amorphous magnesium halide solution in Example <NUM> was replaced by "trityl glycidyl ether (<NUM>)," while other conditions were the same as those in Example <NUM>.

According to the present Example, the "epichlorohydrin (<NUM>)" in the preparing method of the amorphous magnesium halide solution in Example <NUM> was replaced by "<NUM>,<NUM>-butadiene monoepoxide (<NUM>)," while other conditions were the same as those in Example <NUM>.

According to the present Example, the "tetrabutyl titanate (<NUM>)" in the preparing method of the amorphous magnesium halide solution in Example <NUM> was replaced by "tetraethyl titanate (<NUM>)," "epichlorohydrin (<NUM>)" thereof was replaced by "tetrahydrofuran (<NUM>)," and "<NUM>" was changed to be "<NUM>. " Other conditions were the same as those in Example <NUM>.

Anhydrous magnesium chloride (<NUM>) was added into a mixed solvent composed of tetrabutyl titanate (<NUM>), epichlorohydrin (<NUM>), anhydrous ethanol (<NUM>), and toluene (<NUM>), and the mixed solution was maintained at <NUM> and stirred so as to form a transparent solution. Toluene (<NUM>) was further added therein to obtain a magnesium halide solution.

The operational steps were the same as those in Example <NUM>, except that tetrabutyl titanate was not added therein. A solid-liquid mixture could be obtained. That is, magnesium chloride could not be dissolved completely.

The operational steps were the same as those in Example <NUM>, except that anhydrous ethanol was not added therein. A solid-liquid mixture could be obtained. That is, magnesium chloride could not be dissolved completely.

The operational steps were the same as those in Example <NUM>, except that epichlorohydrin was not added therein. A solid-liquid mixture could be obtained. That is, magnesium chloride could not be dissolved completely.

A catalyst was prepared. The temperature of the amorphous magnesium halide solution obtained in Example <NUM> was reduced to -<NUM>, and titanium tetrachloride (<NUM>) was dropwise added therein slowly with a buret. The temperature of the solution was maintained at -<NUM>, and reaction proceeds for half an hour. The temperature thereof was then raised to <NUM>, and reaction proceeded for <NUM> hours. At last, the temperature of the solution was raised to <NUM>, and reaction proceeded for another <NUM> hours so as to obtain a catalyst suspension. The catalyst suspension stayed for a period of time for precipitation. The catalyst suspension was washed for four times with toluene, and a use amount of toluene was <NUM> for each time. Then, the catalyst suspension was washed for two times with hexane, and a use amount of hexane was <NUM> for each time. The catalyst suspension was blew and dried with high-pure nitrogen at a bath temperature being <NUM> so as to obtain an off-white solid flowable powder, and an average particle size of the powder was <NUM>. The elemental analysis results were shown as follows: Ti, <NUM> wt%; and Mg, <NUM> wt%.

The performance of the catalyst was measured. Hexane (<NUM>), triethylaluminum (<NUM> mmol), and a certain amount of catalyst were added into a stainless steel stirring tank (<NUM>), and the temperature in the tank was raised to <NUM>. Hydrogen (<NUM> MPa) was added into the tank once, and the total pressure of the system was maintained at <NUM> MPa with ethylene so that polymerization reaction could proceed. After the reaction proceeded for <NUM> hours, the supply of ethylene stopped, and the temperature and the pressure thereof were both reduced. Polyethylene powder was weighed, and an activity of the catalyst was calculated. A bulk density (BD) of the polyethylene powder and a melt index (MI<NUM>) thereof under a load of <NUM> were measured. The results were shown in Table <NUM>.

A catalyst was prepared. The operational step was the same as that in Example <NUM>, except that the amorphous magnesium halide obtained in Example <NUM> was replaced by the amorphous magnesium halide obtained in Example <NUM>. An off-white solid flowable powder could be obtained, and an average particle size of the powder was <NUM>. The elemental analysis results were shown as follows: Ti, <NUM> wt%; and Mg, <NUM> wt%.

The performance of the catalyst could be measured according to the method disclosed in Example <NUM>, and the results were shown in Table <NUM>.

A catalyst was prepared. The operational steps were the same as those in Example <NUM>, except that the amorphous magnesium halide obtained in Example <NUM> was replaced by the amorphous magnesium halide obtained in Example <NUM>. An off-white solid flowable powder could be obtained, and an average particle size of the powder was <NUM>. The elemental analysis results were shown as follows: Ti, <NUM> wt%; and Mg, <NUM> wt%.

It can be seen from Table <NUM> that, the catalyst that is prepared with the magnesium halide solution disclosed herein shows a high catalytic activity in olefin polymerization reaction. Moreover, the bulk density and the melt index of the catalyst that is prepared with the magnesium halide solution disclosed herein can both be regulated according to actual needs so as to obtain a suitable value.

Other magnesium halide solutions prepared in the aforesaid Examples <NUM> to <NUM> and reference Examples <NUM> to <NUM> (i.e., the magnesium halide solutions except those prepared in Examples <NUM>, <NUM>, and <NUM>) were used for preparing the catalyst for olefin polymerization reaction, and the performances thereof were measured accordingly. The catalytic results were similar to those shown in Table <NUM>, and the specific data thereof were not shown herein for conciseness.

Claim 1:
A magnesium halide solution,
wherein the magnesium halide solution comprises a magnesium halide, an oxygen-containing organic titanium compound, a hydroxyl-containing compound, and an organic solvent;
wherein the magnesium halide solution further comprises an organic heterocyclic compound; and
wherein the organic solvent is a hydrocarbon and/or a halogenated hydrocarbon,
wherein the magnesium halide solution does not contain an organic phosphorus compound, especially a phosphate ester compound;
wherein the organic heterocyclic compound is at least one selected from a group consisting of a sulphur-containing organic heterocyclic compound and a nitrogen-containing organic heterocyclic compound;
wherein the sulphur-containing organic heterocyclic compound is at least one selected from a group consisting of thiophene, thiazole, isothiazole, and a sulphur-containing heterocyclic compound that is in parallel connection with a benzene ring to form a condensed ring, and
wherein the nitrogen-containing organic heterocyclic compound is at least one selected from a group consisting of a <NUM> to <NUM>-membered ring nitrogen-containing heterocyclic compound and a nitrogen-containing heterocyclic compound that is in parallel connection with a benzene ring to form a condensed ring.