KR20110078820A

KR20110078820A - Process for preparing ziegler-natta catalyst for olefin polymerization

Info

Publication number: KR20110078820A
Application number: KR1020090135724A
Authority: KR
Inventors: 이상훈
Original assignee: 주식회사 효성
Priority date: 2009-12-31
Filing date: 2009-12-31
Publication date: 2011-07-07

Abstract

The present invention relates to a method for preparing a Ziegler-Natta catalyst for olefin polymerization having high activity and high stereoregularity. In detail, first, anhydrous hydrocarbon solvent is added to anhydrous magnesium dichloride carrier, and then a transition metal compound is added. step; Second, reacting the internal electron donor with the mixed solution; Thirdly, after adding the transition metal compound, washing the compound with a hydrocarbon solvent to obtain a solid catalyst; Fourth, the internal electron donor is a fatty acid ester (Glyceryl Tri-alkylate) or a tri-ether (Ziegler-Natta catalyst for olefin polymerization including a step that is necessarily added in the first step and / or third step of the catalyst manufacturing process) It relates to a manufacturing method of.

Olefin, Ziegler-Natta, Catalyst

Description

Process for preparing Ziegler-Natta catalyst for olefin polymerization

The present invention relates to a process for preparing a Ziegler-Natta catalyst for olefin polymerization having high activity and high stereoregularity.

The catalyst for olefin polymerization, generally called a Ziegler-Natta catalyst, refers to a catalyst system composed of a combination of a main catalyst composed mainly of a transition metal compound, a cocatalyst composed of an organometallic compound, and an electron donor. It has been extensively researched in order to improve and many related technologies have been proposed.

The Ziegler-Natta catalyst directly affects the properties and properties of the polyolefin produced according to its constituents, structure, and preparation method. Therefore, in order to change the properties of the resulting polyolefin, a change in the constituents of the catalyst, the structure of the carrier and the preparation method of the catalyst should be accompanied during the preparation of the catalyst. The activity of and the molecular weight, stereoregularity of the polymerized polymer should also be studied.

Conventional Ziegler-Natta catalysts consist of a solid catalyst component centered on titanium, magnesium and halogen compounds and an organoaluminum compound system that is a promoter. Many improvements have been made to improve the catalytic activity and stereoregularity, which are the basic elements in this system, but due to the diversification of the use of polyolefins, further improvement of catalytic activity and stereoregularity is currently required.

In order to solve the stereoregularity problem, U.S. Patent No. 4,544,717 describes a method of adding an electron donor, and U.S. Patent No. 4,226,741 relates to a high stereoregularity catalyst having a stereoregularity of 94 to 95 or more. It is described. EP 045,977 also describes the technology of solid Ziegler-Natta catalysts which are characterized by high activity, high stereoregularity, and derivatives of certain carboxylic acid ester compounds, preferably phthalate derivatives, are solid catalysts as internal electron donors. Coordination to the compound produces a Ziegler-Natta catalyst with the titanium compound. In addition, these main catalysts have been proposed to improve the polymerization activity and stereoregularity by alpha-olefin polymerization using an aluminum alkyl compound and a silicon compound having at least one silicon-ether bond as an external electron donor. However, in these manufacturing methods, there is a difficulty in controlling the particle size of the carrier, and the molecular weight distribution of the polymer is often not good.

Therefore, there is a need for development of a new Ziegler-Natta catalyst for olefin polymerization having a relatively simple polymerization method and high polymerization activity and stereoregularity.

The inventors of the present invention studied Ziegler-Natta catalysts for olefin polymerization having high activity and high stereoregularity. After adding a hydrocarbon solvent to anhydrous magnesium dichloride carrier, a transition metal compound was added thereto, and an internal electron donor was added thereto. The reaction was carried out to obtain a compound, and then the compound was washed with a hydrocarbon solvent to prepare a solid catalyst, and the prepared solid catalyst exhibited high activity, and in the case of polyolefin prepared by using the solid catalyst in an olefin polymerization reaction, It confirmed that regularity was high and completed this invention.

The method for preparing a Ziegler-Natta catalyst for olefin polymerization according to the present invention comprises the steps of: (a) adding anhydrous hydrocarbon solvent to anhydrous magnesium halide carrier, adding a transition metal compound represented by the formula (1), and reacting (b) Adding an internal electron donor represented by the formula (2) or (3) to the mixed solution to obtain a precipitate, and then (c) adding a transition metal compound represented by the formula (1) thereto, followed by reaction to obtain a precipitate, It comprises the step of obtaining a solid catalyst by washing with a hydrocarbon solvent, in any one or more of the steps (a) or (c) is characterized in that the addition of the internal electron donor represented by the formula (2) or formula (3).

According to another preferred feature of the present invention, the anhydrous magnesium halide in step (a) is anhydrous magnesium dichloride.

According to another preferable feature of the present invention, the polymerization olefin is CH ₂ 〓CHR. Where R is H, C ₁₁ ~ C ₁₂ .

Ziegler-Natta catalyst for olefin polymerization according to the present invention is a solid catalyst prepared by the above-described method, 0.5 to 6.0% by weight of titanium, 10 to 20% by weight of magnesium, 40 to 70% by weight of halogen and internal to the total weight of the catalyst It is characterized in that it comprises 5 to 25% by weight electron donor.

The Ziegler-Natta catalyst for olefin polymerization according to the present invention exhibits high activity and high solidity regularity, and can significantly reduce the amount of expensive titanium in the raw material, thereby reducing the catalyst manufacturing cost. In addition, polyolefins prepared using the Ziegler-Natta catalyst of the present invention can be usefully used for plastic materials requiring high strength due to the increase in rigidity due to the high stereoregularity.

The present invention provides a transition metal compound represented by the formula (1) at -40 ^o C ~ 20 ^o C after adding anhydrous hydrocarbon solvent to the anhydrous magnesium dichloride carrier (prepared in US Pat. No. 4,399,054 Example 2 method) Putting, reacting for 1 to 5 hours; 2) heating the mixed solution at 60 to 130 ° C. for 1 to 6 hours, then adding an internal electron donor represented by Formula 2 or 3 to react for 1 to 4 hours to obtain a precipitate; 3) adding a transition metal compound represented by Chemical Formula 1 to it again, reacting for 1 to 3 hours to obtain a precipitate, and then washing with a hydrocarbon solvent to obtain a solid catalyst; 4) The internal electron donor provides a method for preparing a Ziegler-Natta catalyst for olefin polymerization comprising the step of necessarily being added in steps 1) and / or 3) of the catalyst preparation process.

MX n (OR 1 ) 4-n

In Formula 1, M is a metal, X is halogen, R ¹ is C ₁ ~ C ₁₀ It is hydrocarbyloxy, n is the oxidation number of metal of 0-4.

Preferably, in Formula 1, M is a group IVB, such as Ti, Zr, Hf, Rf; VB group, such as V, Nb, Ta, and Db; Or VB groups such as Cr, Mo, W, Sg, X is Cl, Br, I, and R ¹ is C ₁ -C ₄ alkoxy or phenoxy. More preferably, in Formula 1, M is a group IVB, such as Ti, Zr, Hf, Rf, X is Cl, R ¹ is ethoxy, butoxy, chlorotriethoxy, dichlorodiethoxy, trichloro Ethoxy. Most preferably, in Chemical Formula 1, M is Ti and R ¹ is Cl.

R ¹ and R ² and R ³ in Formula 2 may be the same or different, hydrogen or C ₁ ~ C ₂₀ linear or branched alkyl, alkenyl, cycloalkyl, aryl or aryl substituent, alkylaryl or alkylaryl Alkylaryl including a substituent, heteroatom.

R ¹ in Chemical Formula 3 And R ² and R ³ and R ⁴ may be the same or different, hydrogen or C ₁ to C ₂₀ linear or branched alkyl, alkenyl, cycloalkyl, aryl or aryl substituent, alkylaryl or alkylaryl substituent, hetero Alkylaryl comprising an atom.

Hereinafter, the present invention will be described in detail.

Step 1) in the preparation method of the present invention is 0.1 to anhydrous magnesium carrier (prepared by the method of Example 2 of U.S. Pat. No. 4,399,054) (7.5 g, 0.066 mol) in which a transition metal compound is added to anhydrous magnesium dichloride carrier. 20 mol of a hydrocarbon solvent is added, and 0.1-10 mol of a transition metal compound and a hydrocarbon solvent are slowly added dropwise for 1 to 5 hours between -40 to 20 ° C.

The hydrocarbon solvent may be aliphatic hydrocarbons such as butane, isobutane, pentane, hexane, heptane, octane, nonane, decane, dodecane, hexadecane and octadecane; Alicyclic hydrocarbons such as cyclopentane, methylcyclopentane, cyclohexane and cyclooctane; Aromatic hydrocarbons such as benzene, toluene, xylene and the like may be included, preferably aliphatic hydrocarbons, more preferably decane.

Step 2) is a step of obtaining a precipitate of a solid catalyst, the mixed solution is heated to 60 ~ 130 ℃ for 1-6 hours, and then reacted 0.01 to 2 mol of the internal electron donor for 1 to 4 hours and then the precipitate get. Temperature conditions then affect carrier uniformity.

Wherein the internal electron donor may be the same or different from R ¹ and R ² and R ³ in Formula 2, hydrogen or C ₁ ~ C ₂₀ linear or branched alkyl, alkenyl, cycloalkyl, aryl or aryl substituent, Alkylaryl or alkylaryl substituent, alkylaryl including heteroatoms, specifically glyceryl tributylate (Glyceryl tributyrate), Glyceryl trioctanoate, Glyceryl trienathate (Glyceryl trienathate), Glyceryl Glyceryl triheptanoate, Glyceryl trinonanoate, Glyceryl tristearate, Glyceryl tribenzoate, Glyceryl tripalmitate, etc. Fatty Acid Esters (Glyceryl trialkylate) Compounds, Glycerol diglycidyl ethers, Diethylene Glycol Monoethyl Eke Tri-ether compounds such as diethylene glycol monoethyl ether acetate and diethylene glycol dimethyl ether may be included.

Step 3) is a step of adding a transition metal compound to the solid catalyst precipitate secondly, after the addition of 0.1 to 10 mol of the transition metal compound at 60 ~ 130 ℃, and then reacted for 1 to 3 hours to obtain a precipitate, Washing with a hydrocarbon solvent gives a solid catalyst. The prepared compound is washed with a hydrocarbon solvent until no titanium component is detected to obtain a solid catalyst.

In step 4), the internal electron donor is necessarily added in steps 1) and / or 3) of the catalyst manufacturing process.

Components of the solid catalyst prepared by the above method include 0.5 to 6.0 wt% titanium, 10 to 20 wt% magnesium, 40 to 70 wt% halogen, and 5 to 30 wt% internal electron donor based on the total weight of the catalyst. In addition, the prepared solid catalyst exhibits high activity, high solid regularity, and is preferably prepared in a form in which a transition metal compound is supported on a carrier for improving catalytic activity.

When the prepared solid catalyst is applied to olefin polymerization, the prepared catalyst is used as the main catalyst, the organoaluminum compound represented by the following Chemical Formula 4 is used as a promoter, and the external electron donor represented by the following Chemical Formula 5 is a subcatalyst. Used as

R 4 n AlX 3- n

In Formula 4, R ⁴ is C ₁ ~ C ₂₀ Alkyl, X is halogen, n is 0-3.

R 5 n Si (OR 6 ) 4-n

In Formula 5, R ⁵ C ₁ to C ₂₀ Hydrocarbon, preferably C ₁ -C ₁₀ Alkyl, C ₅ -C ₁₂ Cycloalkyl, C ₆ -C ₂₀ Aryl _, C ₁ to C ₁₀ Alkenyl, A ₁ to C ₁₀ Haloalkyl or C ₁ to C ₁₀ Aminoalkyl, chlorine, R ⁶ C ₁ to C ₂₀ Hydrocarbon, preferably C ₁ -C ₁₀ Alkyl, C ₅ -C ₁₂ Cycloalkyl, C ₆ to C ₂₀ aryl _, C ₁ to C ₁₀ Alkenyl, C ₂ ~ C ₁₀ Alkoxy alkyl.

The compound represented by the formula (5) is preferably an organic silicon compound, specifically triethylmethoxysilane, trimethylethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, diisopropyldimethoxysilane, diphenyldimethoxy Silane, phenylmethyldimethoxysilane, diphenyldiethoxysilane, dicyclohexyldimethoxysilane, cyclohexylmethyldimethoxysilane, cyclohexylmethyldiethoxysilane, dicyclopentyldimethoxysilane, dicyclopentyl diethoxysilane, ethyl Trimethoxysilane, ethyltriethoxysilane, vinyltrimethoxysilane and vinyltriethoxysilane, preferably diphenyldimethoxysilane, cyclohexylmethyldimethoxysilane and dicyclopentyldiethoxysilane.

The external electron donor is used together with the promoter in the polymerization, and may be used if necessary. The concentration of the external electron donor includes 0.001 to 50 mol%, preferably 0.01 to 20 mol%, more preferably 0.02 to 10 mol% per mole of promoter. If the concentration of the external electron donor is less than 0.001 mol%, there is a problem that the improvement of stereoregularity does not occur.

When the solid catalyst according to the present invention is applied to olefin polymerization, a polyolefin having high stereoregularity and activity of the polymer can be prepared.

In the present invention, 'polymerization' includes not only homopolymerization but also copolymerization.

The polymerization can be in gas phase, liquid phase, or solution phase. When performing a polymerization reaction in a liquid phase, a hydrocarbon solvent may be used and olefin itself can also be used as a solvent. The polymerization temperature is usually in the range of -50 to 350 ° C, preferably 0 to 200 ° C. If the polymerization temperature is less than -50 ° C, the activity of the catalyst is not good, and if it exceeds 350 ° C, the stereoregularity is poor, which is not good. The polymerization pressure is usually at normal pressure to 250 kg / cm 2, preferably at atmospheric pressure to 200 kg / cm 2, and the polymerization reaction can be carried out by any of batch, semi-continuous and continuous methods. When the polymerization pressure is 250 kg / cm 2 or more, it is not preferable from an industrial and economical point of view.

To the polyolefin prepared using the solid catalyst according to the present invention, a heat stabilizer, a light stabilizer, a flame retardant, carbon black, a pigment, an antioxidant, and the like, which are commonly added, may be added. In addition, the prepared polyolefin may be used in combination with low density polyethylene (LDPE), high density polyethylene (HDPE), polypropylene, polybutene, EP (ethylene / propylene) rubber and the like.

The Ziegler-Natta catalyst for olefin polymerization according to the present invention exhibits high activity and high solidity regularity, and can significantly reduce the amount of expensive titanium in the raw material, thereby reducing the catalyst manufacturing cost.

Hereinafter, preferred embodiments of the present invention will be described in order to facilitate understanding of the present invention. However, the following examples are merely provided to more easily understand the present invention, and the contents of the present invention are not limited by the examples.

Examples 1-2 and Comparative Example 1 : Preparation of Ziegler-Natta Catalyst

Example One

In a high-purity nitrogen atmosphere, anhydrous magnesium dichloride carrier (prepared by US Pat. No. 4,399,054 Example 2) (8.0 g, 0.07 mol) and 60 mL of toluene were injected into a double jacketed vitreous reactor with a stirrer and the temperature was -10. ^{o After} lowering to C, slowly add dropwise addition of titanium tetrachloride (TiCl ₄ ) (30 mL, 0.2 mol) and 60 mL of tutuene, and then constantly raise the temperature to 110 ° C. at a rate of 1.0 ° C./min.

Then, glyceryl tributyrate (Glyceryl tributyrate) (3.0 g, 0.01 mol) is added and reacted for 1 hour to obtain a precipitate. After washing the solid component with toluene, titanium tetrachloride (TiCl ₄ ) (30 mL, 0.2 mol) and 100 mL of toluene were added again, and reacted for 1 hour. The solid component is washed with toluene and hexane to give a solid catalyst.

Example 2

A solid catalyst was prepared in the same manner as in Example 1, except that diglyme diglyme (1.3 g, 0.01 mol) was used instead of Glyceryl tributyrate in Example 1.

Comparative example One

A solid catalyst was prepared in the same manner as in Example 1, except that ethyl benzoate (1.5 g, 0.01 mol) was used instead of glyceryl tributyrate in Example 1.

Experimental Example 1 : Catalyst Performance Evaluation Experiment

In order to evaluate the performance of the Ziegler-Natta catalyst for olefin polymerization according to the present invention, the following experiment was performed.

The polymerization of propylene was carried out using a 2 L polymerization reactor. The reactor was depressurized to 3 torr or less vacuum and charged with nitrogen of high purity three times. After 500 g of propylene and 750 cc of hydrogen were charged to the reactor at room temperature, 3 mmol of triethylaluminum, 0.18 mmol of dicyclopentyldimethoxysilane, and 0.0044 mmol of the catalyst prepared in Examples 1 to 4 and Comparative Example 1 were added thereto. After raising the temperature to 70 ° C. for 1 hour, the final polymerization product was obtained.

The activity of the catalyst was determined in units of kg-polymer / g-catalyst from the weight of the final polymerization product. The stereoregularity (I.I .: isotacticity index) of polypropylene was performed with stereoregularity, an amount insoluble in boiling heptane. The polymer was pretreated with antioxidants to prevent degradation during analysis. A certain amount of the completely dried polymer was quantitatively placed in a timing filter and extracted with heptane in a Soxhlet type extraction apparatus. The extraction time was fixed at 6 hours, and the remaining polymer after extraction was collected, dried in vacuo at 80 ° C, quantitatively weighed, and the stereoregularity was determined based on the weight ratio of the polymer remaining without melting and the weight of the original polymer. It was.

The polymerization activity of the catalyst, the stereoregularity and the properties of the polymerization product are shown in Table 1.

Ti content
(weight%) activation
(kg / g cat) Stereoregularity Average particle
Diameter (μm) Volume density (BD) MI Example 1 2.05 28.0 98.1 611 0.32 2.11 Example 2 2.42 21.5 98.3 603 0.31 2.24 Comparative Example 3 2.17 22.0 97.1 573 0.33 1.80

As shown in Table 1, it was confirmed that the Ziegler-Natta catalyst for olefin polymerization according to the present invention exhibits high activity and high solid regularity.

Claims

(a) adding anhydrous hydrocarbon solvent to the anhydrous magnesium halide carrier, and then adding and reacting the transition metal compound represented by Formula 1,

(b) adding an internal electron donor represented by Formula 2 or Formula 3 to the reacted mixed solution to obtain a precipitate after the reaction;

(c) adding a transition metal compound represented by the formula (1) to it, followed by reaction to obtain a precipitate, and then washing with a hydrocarbon solvent to obtain a solid catalyst,

Method of producing a Ziegler-Natta catalyst for olefin polymerization, characterized in that the addition of the internal electron donor represented by the formula (2) or (3) in any one or more of the steps (a) or (c).

[Formula 1]

MX _n (OR ¹ ) _4-n

Where M is a metal, X is halogen, and R ¹ is C ₁ to C ₁₀ It is hydrocarbyloxy, n is the oxidation number of metal of 0-4.

[Formula 2]

Wherein R ¹ and R ² and R ³ may be the same or different, hydrogen or C ₁ to C ₂₀ linear or branched alkyl, alkenyl, cycloalkyl, aryl or aryl substituent, alkylaryl or alkylaryl substituent, Alkylaryl including heteroatoms.

(3)

Where R ¹ And R ² and R ³ and R ⁴ may be the same or different, hydrogen or C ₁ to C ₂₀ linear or branched alkyl, alkenyl, cycloalkyl, aryl or aryl substituent, alkylaryl or alkylaryl substituent, hetero Alkylaryl comprising an atom.

According to claim 1, wherein in Formula 1, M is Ti, Zr, Hf, Rf IVB; Or C, Group V, Cr, Mo, W, Sg, X is Cl, Br, I, R ¹ is ethoxy, butoxy, chlorotriethoxy, dichlorodiethoxy, trichloroethoxy Method for preparing a Ziegler-Natta catalyst.

The method of claim 1, wherein in Chemical Formula 1, M is Ti, and R ¹ is Cl.

The method of claim 1, wherein the anhydrous magnesium halide in step (a) is an anhydrous magnesium dichloride, the method for producing a Ziegler-Natta catalyst for olefin polymerization.

The method of claim 1, wherein the hydrocarbon solvent is butane, isobutane, pentane, hexane, heptane, octane, nonane, decane, dodecane, hexadecane, octadecane, cyclopentane, methylcyclopentane, cyclohexane, cyclooctane, benzene , Toluene and xylene is one or more selected from the group consisting of a method for producing a Ziegler-Natta catalyst for olefin polymerization.

The method for preparing a Ziegler-Natta catalyst according to claim 1, wherein the olefin for polymerization is H ₂ , C ₁₁ to C ₁₂ in CH ₂ 〓CHR.

A solid catalyst prepared by the method of any one of claims 1 to 6, wherein 0.5 to 6.0 wt% titanium, 10 to 20 wt% magnesium, 40 to 70 wt% halogen, and internal electron donor 5 Ziegler-Natta catalyst for olefin polymerization, characterized by comprising ~ 25% by weight.