KR20210066215A - Catalyst for polymerization of polyolefin - Google Patents

Abstract

The present invention relates to a catalyst for polyolefin polymerization and a method for manufacturing the same, and more particularly, to a catalyst for polyolefin polymerization comprising: an internal electron donor comprising a compound represented by chemical formula 1, and a compound represented by chemical formula 2; and a transition metal compound, and to a method for manufacturing the same. The catalyst for polyolefin polymerization of the present invention exhibits excellent catalytic activity, and by using the same, a polyolefin polymer having excellent stereoregularity, high melt index, and wide molecular weight distribution can be formed.

Description

Catalyst for polyolefin polymerization {CATALYST FOR POLYMERIZATION OF POLYOLEFIN}

The present invention relates to a catalyst for polyolefin polymerization, and more particularly, while using an eco-friendly internal electron donor, catalytic activity is improved, the stereoregularity of the polymerized polyolefin is excellent, has a high melt index, and furthermore, the molecular weight distribution is wide. It relates to a catalyst for polyolefin polymerization.

Catalysts used to prepare polyolefins can be divided into Ziegler-Natta catalysts, chromium-based catalysts and metallocene-based catalysts according to the type of central metal applied. Since these catalysts have different catalytic activity, hydrogen reactivity, molecular weight distribution, and reaction characteristics for comonomers, they have been selectively used according to the required characteristics of the manufacturing process and application products. Among them, the Ziegler-Natta catalyst containing magnesium has advantages in terms of high activity, operational stability, excellent physical properties, and economic efficiency compared to other catalysts, and thus is most often used in the manufacture of polyolefin polymers.

The Ziegler-Natta catalyst directly affects the properties and properties of the polyolefin produced according to its constituents, structure, and manufacturing method. Therefore, in order to change the properties of the produced polyolefin, changes in the composition of the catalyst, the structure of the carrier, and the method of preparing the catalyst must be accompanied during the preparation of the catalyst, and the method of preparing each catalyst or the difference in the composition Studies on catalyst activity, molecular weight, and stereoregularity of the polymerized polymer should be conducted in parallel.

In the polyolefin polymerization as described above, in order to lower the cost through increased catalytic activity and improve the physical properties of the polymer produced by improving the catalytic performance such as stereoregularity, a method of using a phthalate-based compound as an internal electron donor or coagulant This is widely known. For example, Japanese Patent Laid-Open No. 1993-001112 discloses a method for preparing a magnesium complex compound (MCC) using magnesium and a halogen organic compound and preparing a solid catalyst using the same, and a phthalate-based compound as an internal electron donor. is using

However, phthalate compounds are a kind of 'endocrine disrupter' that enters the body of animals or humans and interferes with or disrupts the action of hormones. It has been found to have adverse effects on humans and ecosystems, such as mordant, so its use is now banned.

Accordingly, many studies have been conducted to synthesize a compound that can replace the phthalate-based compound as an internal electron donor, but phthalate-based compounds such as phthalic anhydride or phthalic chloride are mainly used as coagulants until now.

Therefore, the development of a catalyst for polyolefin polymerization that contains an eco-friendly coagulant and an internal electron donor, exhibits high polymerization activity, and a polymer polymerized using it has excellent stereoregularity, and can further express a high melt index is still in progress. need.

One aspect of the present invention is to provide a catalyst capable of polymerizing polyolefins that includes an environmentally friendly internal electron donor compound, has excellent catalytic activity, has a high melt index and a wide molecular weight distribution, and has excellent stereoregularity.

According to one aspect of the present invention, an internal electron donor comprising a compound represented by the following formula (1) and a compound represented by the following formula (2); and a transition metal compound, a catalyst for polyolefin polymerization is provided. In the following formula (1), R ¹ to R ⁴ , and in the following formula (2), R ⁵ and R ⁶ are as defined in the specification.

[Formula 1]

[Formula 2]

The catalyst for polyolefin polymerization of the present invention exhibits excellent catalytic activity, and by using it, a polyolefin polymer having excellent stereoregularity, high melt index, and wide molecular weight distribution can be formed. Due to such a wide molecular weight distribution, various molded articles can be manufactured, and production costs can be reduced during the molding and processing of molded articles. In addition, the catalyst for polymerization of polyolefin of the present invention can exhibit catalytic activity equal to or greater than that in the case of using the phthalate-based internal electron donor, which is an environmentally hazardous material.

Hereinafter, preferred embodiments of the present invention will be described. However, the embodiment of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below.

The present invention uses an eco-friendly internal electron donor and has catalytic properties equal to or higher than that of a catalyst using a conventional phthalate-based compound, and the polyolefin polymerized using the same exhibits excellent stereoregularity, particularly a high melt index and a wide molecular weight distribution. It relates to a catalyst and a method for preparing the same to simultaneously represent.

The catalyst for polyolefin polymerization of the present invention comprises: an internal electron donor comprising a compound represented by the following formula (1) which is a diether-based compound, and a compound represented by the following formula (2), which is a malonate-based compound; and transition metal compounds.

In Formula 1, R ¹ and R ⁴ are each independently selected from the group consisting of hydrogen, and a straight-chain or branched (C ₁ -C ₂₀ ^{)alkyl group, R 2} and R ³ are each independently hydrogen, a straight-chain type or branched (C ₁ -C ₂₀ )alkyl group, (C ₂ -C ₂₀ )alkenyl group, (C ₃ -C ₂₀ )cycloalkyl group, (C ₆ -C ₂₀ )aryl group, (C ₁ -C ₂₀ )alkyl Silyl group, (C ₇ -C ₂₀ )arylalkyl group, (C ₇ -C ₂₀ )alkylaryl group, hetero atom-substituted (C ₂ -C ₂₀ )heteroalkyl group and hetero atom-substituted (C ₅ -C ₂₀ )hetero selected from the group consisting of aryl groups.

In Formula 2, R ⁵ and R ⁶ are each independently hydrogen, a straight-chain or branched (C ₁ -C ₂₀ )alkyl group, (C ₂ -C ₂₀ )alkenyl group, (C ₃ -C ₂₀ )cycloalkyl group, (C ₆ -C ₂₀ )aryl group, (C ₁ -C ₂₀ )alkylsilyl group, (C ₇ -C ₂₀ )arylalkyl group, (C ₇ -C ₂₀ )alkylaryl group, hetero atom substituted (C ₂ - It is selected from the group consisting of a _{C 20} )heteroalkyl group and a (C ₅ -C _{20 )heteroaryl group substituted with a hetero atom.}

^{When R 2} , R ³ , R ⁵ and R ⁶ in Formulas 1 and 2 are a heteroatom-substituted (C ₂ -C ₂₀ )heteroalkyl group or a heteroatom-substituted (C ₅ -C ₂₀ )heteroaryl group, the The hetero atom may be at least one selected from the group consisting of S, N, O, Si, P, and B.

As used herein, the cycloalkyl group refers to a monovalent functional group derived from cycloalkane, and the aryl group refers to a monovalent or divalent functional group derived from arene, an aromatic hydrocarbon. In addition, the alkylsilyl group means a silyl group substituted with an alkyl group, the arylalkyl group means an alkyl group substituted with an aryl group, and the alkylaryl group means an aryl group substituted with an alkyl group.

In the catalyst for polyolefin polymerization, the internal electron donor may be used together with a transition metal compound to increase the activity of the catalyst in the polyolefin polymerization reaction, and to improve the stereoregularity and hydrogen reactivity of the polyolefin to be prepared.

On the other hand, in the compound represented by Formula 1 of the present invention as an internal electron donor, preferably, R ¹ and R ⁴ are each independently selected from the group consisting of a straight-chain (C ₁ -C ₁₀ )alkyl group, and R ² and R ³ are each independently selected from the group consisting of a _{branched (C 1} -C ₁₀ ^{)alkyl group, and R 2} and R ³ are different substituents from each other.

Preferred examples of the compound represented by Formula 1 of the present invention, which are internal electron donors, include 2,2-dicyclopentyl-1,3-dimethoxypropane, 2,2-dicyclohexyl-1,3-dimethoxy Propane, 2,2-diisobutyl-1,3-dimethoxypropane, 2,2-isopropyl-1,3-dimethoxypropane, 2,2-diisopentyl-1,3-dimethoxypropane, 2 ,2-diphenyl-1,3-dimethoxypropane, 2,2-dibenzyl-1,3-dimethoxypropane, 2,2-bis(cyclohexylmethyl) 1,3-dimethoxypropane, 2,2 -Diisobutyl-1,3-dimethoxypropane, 2,2-diisobutyl-1,3-ethoxypropane, 2-ethyl-2-butyl-1,3-dimethoxypropane, 2-ethyl-2 -Isopropyl-1,3-dimethoxypropane, 2-ethyl-2-isopentyl-1,3-dimethoxypropane, 2-ethyl-2-isobutyl-1,3-dimethoxypropane, 2-ethyl- 2'-phenyl-1,3-dimethoxypropane, 2-ethyl-2-benzyl-1,3-dimethoxypropane, 2-ethyl-2-cyclopentyl-1,3-dimethoxypropane, 2-ethyl- 2-Cyclohexyl-1,3-dimethoxypropane, 2-methyl-2-isopropyl-1,3-dimethoxypropane, 2-methyl-2-butyl-1,3-dimethoxypropane, 2-methyl- 2-phenyl-1,3-dimethoxypropane, 2-methyl-2-benzyl-1,3-dimethoxypropane, 2-methyl-2-cyclopentyl-1,3-dimethoxypropane, 2-methyl-2 -Cyclohexyl-1,3-dimethoxypropane, 2-methyl-2-isopropyl-1,3-dimethoxypropane, 2-methyl-2-isopentyl-1,3-dimethoxypropane, 2-isopropyl -2-butyl-1,3-dimethoxypropane, 2-isopropyl-2-isopentyl-1,3-dimethoxypropane, 2-isopropyl-2-isobutyl-1,3-dimethoxypropane, 2 -Isopropyl-2-phenyl-1,3-dimethoxypropane, 2-isopropyl-2-benzyl-1,3-dimethoxypropane, 2-isopropyl-2-cyclopentyl-1,3-dimethoxypropane , 2-isopropyl-2-cyclohexyl-1,3-dimethoxypropane, 2-isobutyl-2-butyl-1,3-dimethoxypropane, 2-isobutyl-2-isopentyl-1,3- Dimethoxypropane, 2-isobutyl-2-phenyl-1,3-dimethoxypropane, 2-isobutyl-2-benzyl-1,3-dimethoxypropane , 2-isobutyl-2-cyclopentyl-1,3-dimethoxypropane, 2-isobutyl-2-cyclohexyl-1,3-dimethoxypropane, 2-isopentyl-2-butyl-1,3- Dimethoxypropane, 2-isopentyl-2-phenyl-1,3-dimethoxypropane, 2-isopentyl-2-benzyl-1,3-dimethoxypropane, 2-isopentyl-2-cyclopentyl-1, 3-dimethoxypropane and 2-isopentyl-2-cyclohexyl-1,3-dimethoxypropane may be mentioned, and one type or a mixture of two or more thereof may be used as the internal electron donor. Among them, 2-isopropyl-2-isopentyl-1,3-dimethoxypropane, 2-isopropyl-2-isobutyl-1,3-dimethoxy in terms of simultaneously implementing high activity and excellent stereoregularity Propane and the like are preferred.

On the other hand, when the malonic acid (malonate)-based compound of the present invention is used, it is possible to prepare a polymer that provides high hydrogen reactivity and has a molecular weight distribution level equal to or greater than that of the phthalate-based compound. In addition, the structure of the compound of Formula 2 can impart excellent stereoregularity and high melt index characteristics.

On the other hand, since the ether structure in the diether-based compound of Formula 1 can also impart excellent stereoregularity and high melt index characteristics, the internal electron donor including the compound of Formula 2 together with Formula 1 is a polyolefin It is possible to more effectively increase the activity of the catalyst in the polymerization reaction, to prepare a polyolefin having a high molecular weight distribution and excellent stereoregularity.

Preferred internal electron donors of the compound of formula 2 of the present invention include, for example, dineopentyl 2-isopropylmalonate, diisobutyl 2-isopropylmalonate, di-n-butyl 2-isopropylmalonate, dimethyl 2-n-Butyl-2-isobutylmalonate, diethyl 2-n-butyl-2-isobutylmalonate, diethyl 2-methyl-2-isopropylmalonate, diethyl 2-isopropyl-2- and isobutylmalonate, diethyl 2-methyl-2-isobutylmalonate, and the like, and among them, one type or a mixture of two or more types may be used as the internal electron donor.

In addition, the structure of the compound of Formula 1 and the compound of Formula 2 is an environmentally friendly material that is not harmful to the environment and the human body.

The compound represented by Formula 1 and the compound represented by Formula 2 are each preferably in an amount of 0.001 to 0.005 moles based on 1 mole of the transition metal compound, for example, more preferably in a content of 0.002 to 0.003 moles. Do. If the content of the compound represented by Formula 1 and the compound represented by Formula 2 is less than 0.001 mol based on 1 mol of the transition metal compound, respectively, the activity of the catalyst and the stereoregularity of the polymer may be lowered, and if it exceeds 0.005 mol, the catalyst It is undesirable to lower the activity of

Meanwhile, among the internal electron donors, the diether-based compound of Formula 1 and the malonate-based compound of Formula 2 have a molar ratio of 2:1 to 1:2, for example, 1.2:1 to 1:1.2. It is preferably included in a molar ratio, and more preferably, the compound represented by Formula 1 and the compound represented by Formula 2 are included in a molar ratio of 1:1. When the molar ratio of the diether-based compound to the malonic acid-based compound is out of the above range, the molecular weight distribution may be lowered or catalyst activity may be lowered.

In addition, the catalyst of the present invention may include, in addition to the compound represented by Formula 1 and the compound represented by Formula 2, various previously known internal electron donor compounds, such as a succinate compound, a silane compound, a fluorene-based compound, or a mixture thereof. may further include.

The catalyst may be supported on a carrier, and the carrier is preferably a carrier known to be commonly used in the preparation of a general Ziegler-Natta-based catalyst, without particular limitation, it can be prepared or commercially purchased and used. Preferably, the carrier may use at least one component selected from the group consisting of silica, alumina, zeolite and magnesium compound, a mixture thereof or a hybrid carrier thereof may also be used, and more preferably a magnesium compound may be used. can The hybrid carrier refers to a state in which two or more types of silica, alumina, zeolite and magnesium compounds are reacted or combined.

Specific examples of the magnesium compound include magnesium dihalide, dialkoxy magnesium, alkylmagnesium halide, alkoxymagnesium halide, or aryloxymagnesium halide. and the stereoregularity of the polyolefin to be polymerized may be further improved.

The internal electron donor may be supported on the carrier in a ratio of 0.05 to 1 mole, preferably 0.1 to 0.2 mole, based on 1 mole of the carrier. The internal electron donor serves to increase the activity of the catalyst in the polymerization reaction and to improve the stereoregularity of the polymerized polyolefin. When the content of the internal electron donor is too small compared to the content of the carrier, the stereoregularity is cannot be controlled, and if the content of the internal electron donor is too large, the activity of the catalyst may be low.

Meanwhile, the transition metal compound may be supported on the carrier in a ratio of 3 to 30 moles, preferably 9 to 20 moles, based on 1 mole of the carrier. When the content of the transition metal compound is too small compared to the content of the carrier, the catalytic performance may be reduced due to the small amount of the transition metal compound exhibiting catalytic activity. When the content of the transition metal compound is too large compared to the content of the carrier, the magnesium compound, etc. An excessively large number of transition metal components exist compared to the carrier, which is undesirable in terms of process economy.

As a specific example of the transition metal compound that can be used in the present invention, any transition metal compound known to be used as a Ziegler-Natta catalyst for polyolefin polymerization can be used without limitation. In particular, preferred examples of the transition metal compound include a compound represented by the following formula (3).

In Formula 3, M is selected from the group consisting of transition metal elements of groups IVB, VB and VIB of the periodic table, and preferred examples thereof include Ti, Zr, Hf, Rf, V, Nb, Ta, Db, Cr, Mo, W, Sg etc. are mentioned. In Formula 3, X is halogen, and may be fluorine, chlorine, bromine, or iodine. In Formula 3, R ⁷ is a (C ₁ -C ₂₀ )alkyl group, and m is an integer of 0 to 4.

Specific examples of the transition metal compound of Formula 3 include titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, tetrabutoxy titanium, tetraethoxy titanium, diethoxy titanium dichloride, zirconium tetrachloride, chromium chloride or ethoxy titanium trichloride. and the like, and it is preferable to use zirconium tetrachloride [Zirconium (IV) chloride], chromium chloride [Chromium (III) chloride], titanium tetrachloride, or a combination thereof.

Meanwhile, the halogen X may be fluorine, chlorine, bromine, or iodine.

The transition metal compound may be included in an amount of 0.1 wt% to 10 wt%, for example, 2.1 wt% to 10 wt% based on the total weight of the catalyst. When the content of the transition metal compound is less than 0.1% by weight, the activity of the catalyst for polymerization of polyolefin may decrease, and when the transition metal compound is included in excess of 10% by weight, the content of the internal electron donor is reduced and steric regulation There is a problem of lowering the sex.

In addition, the catalyst may further include a cocatalyst, an external electron donor, or both.

The cocatalyst may reduce the transition metal compound to form an active site, thereby increasing catalytic activity. The cocatalyst according to an embodiment is not particularly limited, and any organometallic compound known to be used in the preparation of a general catalyst for polyolefin polymerization may be used without limitation. Among them, it is preferable to use an alkylaluminum compound represented by the following formula (4).

In Formula 4, R ⁸ is a (C ₁ -C ₈ )alkyl group, X is a halogen, and n is 0 to 3.

The alkylaluminum compound is a promoter, and specific examples include trimethylaluminum, triethylaluminum, triisobutylaluminum, tributylaluminum, diethylaluminum dichloride, ethylaluminum dichloride, ethylaluminum sescuchloride, tripropylaluminum, and tri butylaluminum, tripentylaluminum, trihexylaluminum, trioctylaluminum, and the like, and at least one of them may be selected and used.

In addition, the co-catalyst may be in an amount of 0.01 to 10 moles per mole of the transition metal compound, preferably 0.01 to 2 moles per mole of the transition metal compound. If the amount of the cocatalyst is too small or too large, the activity of the catalyst may be reduced.

In addition, the catalyst for polyolefin polymerization may further include an external electron donor, and the external electron donor can be used without any particular limitation as long as the external electron donor is an external electron donor commonly used for polyolefin polymerization, but the catalyst for polyolefin polymerization of the present invention may further include a silane-based external electron donor represented by the following formula (5).

In Formula 5, R ⁹ and R ¹⁰ are each independently hydrogen, a linear or branched (C ₁ -C ₁₀ )alkyl group, (C ₃ -C ₁₀ )cycloalkyl group, (C ₆ -C ₂₀ )aryl group, It is selected from the group consisting of (C ₁ -C ₁₀ )aminoalkyl group and (C ₂ -C ₁₀ )alkoxyalkyl group, and p is 0 to 4.

Specific examples of the external electron donor include cyclohexylmethyldimethoxysilane, dicyclopentyldimethoxysilane, diisopropyldimethoxysilane, vinyltriethoxysilane, triethylmethoxysilane, trimethylethoxysilane, dicyclopentyl diethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, diphenyldiethoxysilane, phenylpropyldimethoxysilane, phenyltrimethoxysilane, tert-butyltrimethoxysilane, cyclohexylethyldimethoxysilane, cyclo Hexylmethyldimethoxysilane, cyclopentyltriethoxysilane, diisobutyldiethoxysilane, isobutyltriethoxysilane, normalpropyltrimethoxysilane, isopropyltrimethoxysilane, cycloheptylmethyldiethoxysilane, dicyclo and heptyldiethoxysilane, and one or more of them may be selected and used.

In the catalyst for polyolefin polymerization, the internal electron donor reacts with the promoter as shown in Chemical Formula 4 to remove a portion thereof, and the external electron donor binds the vacant site to proceed with the polymerization reaction. Accordingly, the role of the external electron donor in the catalyst for polyolefin polymerization is similar to that of the internal electron donor. That is, it is possible to effectively increase the activity of the catalyst in the polyolefin polymerization reaction, and to increase the stereoregularity in the polyolefin polymerization.

The external electron donor may be in an amount of 0.01 to 10 moles per mole of the transition metal compound, preferably 0.01 to 2 moles per mole of the transition metal compound. When the amount of the external electron donor used is too small outside the above range, the activity and stereoregularity supplementation may be insignificant, and when the amount of the external electron donor is excessively large, the activity of the catalyst may be deteriorated.

The cocatalyst or the external electron donor may be reacted by dispersing it in a hydrocarbon solvent if necessary. Specific examples of the hydrocarbon solvent include aliphatic or alicyclic (C ₅ -C ₂₀ ) hydrocarbons, and among them, aliphatic or alicyclic (C ₆ -C ₁₇ ) hydrocarbon solvents are preferable. More specific examples include aliphatic hydrocarbons such as hexane, heptane, octane, decane, dodecane, tetradecane, and mineral oil; alicyclic hydrocarbons such as cyclohexane, cyclooctane, methyl cyclopentane and methyl cyclohexane; and aromatic hydrocarbons such as benzene, toluene, xylene, ethylbenzene and cumene. In order for the prepared solid catalyst to have a uniform particle size distribution and a smooth spherical shape on the surface of the catalyst particles, it is more preferable to use hexane.

The catalyst for polyolefin polymerization of the present invention may be a catalyst in a solid form, and may have an average diameter of 5 μm to 100 μm, or 5 μm to 70 μm. The average diameter of the catalyst for polyolefin polymerization means the average diameter of a plurality of solid particles of the catalyst for polymerization of polyolefin.

When the average diameter of the catalyst for polyolefin polymerization is reduced to less than 5 μm, the size of the catalyst for polyolefin polymerization is not sufficiently secured, so it is difficult to secure smooth flow in the reactor, and small finely divided catalyst particles pass over the top of the reactor. The operation stability of the reactor may be reduced.

Furthermore, the catalyst for polymerization of polyolefin of the present invention includes, in addition to the above-described internal electron donor, transition metal compound, carrier, cocatalyst, external electron donor, etc., excipients or additives commonly employed in the art to which the present invention pertains. can be included as

According to another aspect of the present invention, there is provided a method for preparing the catalyst for polymerization of polyolefin of the present invention as described above.

More specifically, the method for preparing a catalyst for polyolefin polymerization of the present invention comprises the steps of supporting a transition metal compound on a carrier; and supporting the compound represented by Formula 1 and the compound represented by Formula 2 on a carrier as an internal electron donor.

The content related to the composition of the catalyst, that is, the components and content of the catalyst, is the same as that mentioned in relation to the catalyst, and therefore, the content related to the preparation method will be mainly described below.

The carrier that can be used in the preparation of the catalyst for polyolefin polymerization of the present invention is to fix or support the transition metal compound and the internal electron donor, and in the present invention, the steps of supporting the transition metal compound on the carrier; And the step of supporting the internal electron donor compound represented by the following formula (1) on the carrier may be performed sequentially, in reverse order, or simultaneously. On the other hand, when a transition metal compound is first supported on the carrier to form an active site, and then supported by introducing an internal electron donor, it is more preferable to increase catalytic activity.

On the other hand, the step of supporting the internal electron donor comprising the compound represented by Formula 1 and the compound represented by Formula 2 on a carrier is the step of supporting the compound represented by Formula 1 on a carrier, and Formula 2 on the carrier It may include a step of supporting the compound represented by , these steps may be performed sequentially, in reverse order, or simultaneously.

For example, in one embodiment of the present invention, the reactant comprising the transition metal compound and the internal electron donor is selected from the group consisting of a magnesium compound, silica, alumina, silica-alumina, zeolite, and a hybrid carrier thereof. It can be supported on more than one kind of carrier.

In the step of supporting the transition metal compound on the carrier, it is preferable to slowly add the transition metal compound to the carrier over 10 minutes to 2 hours. On the other hand, the step of supporting the transition metal compound on the carrier is preferably carried out at -30 to 50 ℃, for example, -25 to -10 ℃. If the temperature is less than -30°C, the supporting temperature is too low to complete the reaction, and if it exceeds 50°C, the particle shape of the catalyst may be destroyed and process stability may be lowered. On the other hand, the temperature of the step of supporting the carrier and the transition metal compound may be gradually increased from a temperature of -30 ℃ starting.

In addition, the step of supporting the internal electron donor compound represented by Chemical Formulas 1 and 2 on the carrier is preferably performed at a temperature of -20 to 150°C. If the temperature is less than -20°C, it is difficult to complete the reaction, and if it exceeds 150°C, polymerization activity and stereoregularity of the resulting catalyst may be lowered due to side reactions, which is not preferable.

The internal electron donor, from the reaction temperature of the step of supporting the transition metal compound on the carrier to the temperature of the step of supporting the internal electron donor on the carrier on which the transition metal compound is supported During the process of raising the temperature, or to be added after raising the temperature can At this time, the input temperature, the number of input and the input time are not significantly limited.

On the other hand, in the case of performing the step of fixing the transition metal compound and the internal electron donor compound to the carrier by mixing, the process temperature may start at -50°C and gradually increase to 50°C, and the reaction temperature in the above step is It may be 80 °C or higher.

Polyolefin can be polymerized in the presence of a catalyst prepared using the method for preparing a catalyst for polyolefin polymerization of the present invention, and polyolefin is polymerized in the presence of a catalyst system further comprising a cocatalyst or an external electron donor in the catalyst. can

The timing of adding the cocatalyst is not particularly limited, but it is preferable to add the catalyst after the step of supporting the transition metal compound and the internal electron donor on the carrier because it can increase the activity of the catalyst.

On the other hand, the timing of input of the external electron donor is also not particularly limited, but like the promoter, it is preferable to add after the step of supporting the transition metal compound and the internal electron donor on the carrier as it can increase the activity of the catalyst.

The step of reacting with the co-catalyst may be carried out at -30 to 100°C, particularly preferably at 0 to 30°C. In addition, it is preferable that the contact time is sufficiently contacted for 0.5 to 24 hours from the time the reaction takes place.

The reaction with the external electron donor may be carried out at -30 to 100°C, and particularly preferably at 0 to 30°C. In addition, it is preferable that the contact time is sufficiently contacted for 0.5 to 24 hours from the time the reaction takes place.

According to another aspect of the present invention, in the presence of the catalyst of the present invention as described above, there is provided a method for producing a polyolefin, comprising the step of polymerizing an olefinic monomer. The polymerization is meant to include both a polymerization process using one type of monomer and a copolymerization process using two or more types of monomers.

Polyolefin polymerized in this way does not use phthalate-based compounds that are harmful to the human body and the environment as internal electron donors in the manufacturing process, so it is an eco-friendly polymer with improved physical properties in which phthalate compounds do not remain in the polymer.

In this case, the polyolefin polymerization reaction may be performed in bulk, slurry, or gas phase. In bulk polymerization, olefin itself can be used as a monomer and a solvent, in slurry polymerization, an olefin monomer is added while using a hydrocarbon solvent, and in gas polymerization, a monomer and an inert gas are introduced in a gas phase.

The polymerization temperature may be 0 to 200°C, preferably in the range of 30 to 150°C. When the polymerization temperature is less than 0°C, the catalyst activity is not good, and when it exceeds 200°C, the stereoregularity is deteriorated, which is not preferable. The polymerization pressure may be carried out at 1 to 100 atmospheres, and it is preferable to proceed under the conditions of 2 to 40 atmospheres. When the polymerization pressure exceeds 100 atm, it is not preferable from an industrial and economic point of view. The polymerization reaction can be carried out by any of batch, semi-continuous, and continuous methods.

On the other hand, polyolefins prepared using the solid catalyst according to the present invention may contain heat stabilizers, light stabilizers, flame retardants, carbon black, pigments, antioxidants, etc. which are usually added. In addition, the prepared polyolefin may be mixed with linear low-density polyethylene (LLDPE), low-density polyethylene (LDPE), high-density polyethylene (HDPE), EP (ethylene/propylene) rubber, and the like.

In the present invention, the olefinic monomer is ethylene, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-aitocene, norbornene, norbornadiene, ethylidene noboden, phenyl noboden, vinyl noboden, dicyclopentadiene, 1,4-butadiene , 1,5-pentadiene, 1,6-hexadiene, styrene, alpha-methyl styrene, divinylbenzene and 3-chloromethyl styrene may include at least one selected from the group consisting of.

As described above, the catalyst according to the present invention not only exhibits excellent catalytic activity in the polyolefin polymerization reaction, but also enables to obtain excellent stereoregularity, high melt index, and wide molecular weight distribution of the polyolefin to be prepared, and thus the wide molecular weight of polyolefin It is possible to obtain a catalyst for polyolefin polymerization capable of producing various molded articles by distribution, a method for producing the same, and further, a method for producing polyolefin using the same.

Hereinafter, the present invention will be described in more detail through specific examples. The following examples are merely examples to help the understanding of the present invention, and the scope of the present invention is not limited thereto.

Example

[ Example One]

1. Preparation of solid catalyst

120 mL of titanium tetrachloride was put into a reactor circulated with nitrogen, and after cooling to a low temperature of -20°C or less _{, 10 g of a magnesium carrier (MgCl 2} ·2.6EtOH) was added and stirred. After maintaining at the same temperature for about 1 hour, the temperature of the reactor was gradually increased. After the temperature was raised to 80° C., 2.3 mmol of 2-isopropyl-2-isobutyl-1,3-dimethoxypropane and 2.3 mmol of diethyl isopropyl malonate were mixed and added. After the temperature was raised to 120 °C, and stirred at the same temperature for 1 hour, stirring was stopped and the supernatant was removed. After washing twice using 120 mL of titanium tetrachloride at the same temperature, and then washing 5 times using 200 mL of hexane at 70 °C each time, a solid catalyst was obtained.

2. Polypropylene Polypropylene

This polymerization was carried out as bulk polymerization. A 2 L high-pressure reactor heated to 120° C. was purged with nitrogen for 1 hour so that the state of the high-pressure reactor was a nitrogen atmosphere. The temperature of the reactor was lowered to 25° C. under a nitrogen atmosphere and the propylene was purged to maintain the reactor in a propylene atmosphere. In a reactor maintained in a propylene gas atmosphere, triethylaluminum Al/Ti diluted in a decane solvent at a 1 molar concentration was added in an 800 molar ratio, and cyclohexylmethyldimethoxysilane external electron donor diluted in a decane solvent was added in a Si/Ti molar ratio It injected so that it might become this 30. 5 mg of the solid catalyst, 1000 ml of hydrogen, and 500 g of propylene were added, and pre-polymerization was performed for 5 minutes by operating a stirrer. After pre-polymerization, the temperature of the reactor was heated to 70° C. and polymerization was performed at 70° C. for 1 hour. Table 1 shows the results of measuring the properties of the catalyst after polymerization.

[ Example 2]

The same as in Example 1, except that 3.5 mmol of 2-isopropyl-2-isobutyl-1,3-dimethoxypropane and 3.5 mmol of diethyl isopropyl malonate were used as internal electron donors in different amounts from Example 1 A solid catalyst was prepared, and polypropylene was polymerized using this.

[ comparative example One]

A solid catalyst was prepared in the same manner as in Example 1, except that only 9.3 mmol of 2-isopropyl-2-isobutyl-1,3-dimethoxypropane was used as the internal electron donor, and polypropylene polymerization was performed using this.

[ comparative example 2]

A solid catalyst was prepared in the same manner as in Example 1, except that only 4.6 mmol of diethyl isopropyl malonate was used as an internal electron donor, and polypropylene polymerization was performed using this.

[ comparative example 3]

In the same manner as in Example 1, except that 5.0 mmol of diisobutyl phthalate was used instead of 2-isopropyl-2-isobutyl-1,3-dimethoxypropane and diethyl isopropyl malonate as internal electron donors. A solid catalyst was prepared, and polypropylene polymerization was performed using this.

[ comparative example 4]

23.2 mmol of 9,9-bis(methoxymethyl)fluorene and diethyl-2-tert instead of 2-isopropyl-2-isobutyl-1,3-dimethoxypropane and diethyl isopropyl malonate as internal electron donors - A solid catalyst was prepared in the same manner as in Example 1, except that 17.4 mmol of butylmalonate was used, and polypropylene polymerization was performed using this.

[ comparative example 5]

Same as Example 1, except that 3.3 mmol of 2-isopropyl-2-isobutyl-1,3-dimethoxypropane and 1.4 mmol of diethyl isopropyl malonate were used as internal electron donors in different amounts from Example 1 A solid catalyst was prepared, and polypropylene was polymerized using this.

[ comparative example 6]

Same as Example 1, except that 1.4 mmol of 2-isopropyl-2-isobutyl-1,3-dimethoxypropane and 3.3 mmol of diethyl isopropyl malonate were used as internal electron donors in different amounts from Example 1 A solid catalyst was prepared, and polypropylene was polymerized using this.

Experimental example : Measurement of properties of catalyst and polypropylene

The physical properties of the catalyst and polypropylene prepared in Examples and Comparative Examples were measured in the following manner and are shown in Table 1.

1. Catalytic activity measurement

The weight (kg) of the polymer prepared for 1 hour per weight (g) of the catalyst used in Examples and Comparative Examples was measured.

2. Measurement of stereoregularity of polypropylene

Prepare 200 ml xylene in a flask, and filter with 200mm No.4 extraction paper. The aluminum pan was dried in an oven at 150° C. for 30 minutes and cooled in a desicator to determine the mass. Next, 100 ml of filtered o-xylene was collected with a pipette, transferred to an aluminum pan, and heated to 145 to 150° C. to evaporate all of o-xylene. Thereafter, the aluminum pan was vacuum dried at a temperature of 100±5° C. and under a pressure of 1 hr and 13.3 kPa for 1 hour. After cooling the aluminum pan in a desiccator, the above process was repeated twice, thereby completing the blank test of only o-xylene within a weight error of 0.0002 g.

Next, after drying each polymer obtained in Examples and Comparative Examples (70° C., 13.3 kPa, 60 minutes, vacuum drying), 2 g±0.0001 g of a polymer sample cooled in a desiccator is placed in a 500 ml flask, 200ml o-xylene was added. Nitrogen and cooling water were connected to this flask, and the flask was heated for 1 hour to continuously reflux o-xylene. After that, the flask was placed in the air for 5 minutes to cool it to 100°C or less, the flask was shaken and the insoluble matter was precipitated by putting it in a constant temperature bath (25±0.5°C for 30 minutes). After drying at 150° C. for 30 minutes, cooling in a desiccator, 100 ml of the filtered solution was added to a previously weighed aluminum pan, and heating the aluminum pan to 145 to 150° C. to o- After evaporation, the aluminum pan was vacuum dried for 1 hour at a temperature of 70±5℃ and a pressure of 13.3kP, and the cooling process was repeated twice in a desiccator to measure the weight within an error of 0.0002g. As shown in Equation 1 below, the weight % (Xs) of the portion dissolved in o-xylene in the resulting polymer was obtained.

3. Measurement of melt index

According to ASTM1238, the amount of resin extruded at 230°C and 2.16 kg for 10 minutes was expressed in g.

4. Molecular Weight Distribution (Polydispersity Index, PI) Measurement

Diameter 25.0 mm and Gap using a Geometry Type (Parallel Plates) measuring tool by the Dynamic frequency sweep test method using a rheometer (ARES, manufactured by TA Instruments) ) under the 2.000 mm setting. The measurement temperature was 230°C, and the measurement condition frequency range was 0.01 to 500 s ⁻¹ .

Activity (kg-PP/g-cat,hr) diether
(wt%) malonate
(wt%) phthalates
(wt%) melt index
(g/10 min) XS (wt%) PI Example 1 37 5.2 5.2 - 22 3.5 4.5 Example 2 39 6.0 6.1 - 19 1.9 4.6 Comparative Example 1 30 14.0 - - 14 1.4 3.5 Comparative Example 2 33 - 12.5 - 26 4.3 4.8 Comparative Example 3 40 - - 10.0 15 2.5 4.0 Comparative Example 4 35 12.5 10.2 - 18 2.0 4.0 Comparative Example 5 36 6.0 4.8 - 24 3.2 3.9 Comparative Example 6 32 5.0 6.1 - 20 3.8 4.2

As shown in Table 1, the solid catalysts of Examples 1 and 2 according to the present invention had superior catalytic activity compared to the case of using only one internal electron donor in Comparative Examples 1 and 2, and the phthalate of Comparative Example 3 It was possible to polymerize a polymer having a wider molecular weight distribution than in the case of using the type compound. In addition, the present invention has a similar stereoregularity and a wide molecular weight distribution just by adding about 20% of a donor than the internal electron donor used in the Basel catalyst of Comparative Example 4, and it was confirmed that the catalytic activity was excellent. In addition, as in Comparative Examples 5 and 6, when the molar ratio of the diether-based compound and the malonic acid-based compound was out of the range of 1:1.2 to 1.2:1, it was confirmed that the molecular weight distribution was lowered or the catalytic activity was lowered.

As described above, in the case of the catalyst of the present invention, it has excellent catalytic activity and shows the characteristics of forming a polymer having a wide molecular weight distribution. Using the catalyst of the present invention, various polymers can be prepared, and molding and molding using the polymer can be performed. The production cost can be reduced during the processing process. In addition, it can be seen that the catalyst of the present invention has catalytic performance equal to or higher than that of a catalyst using a conventional phthalate-based internal electron donor without using a phthalate-based internal electron donor, which is an environmentally harmful substance.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and variations are possible within the scope without departing from the technical spirit of the present invention described in the claims. It will be apparent to those of ordinary skill in the art.

Claims (6)

an internal electron donor comprising a compound represented by the following formula (1) and a compound represented by the following formula (2); And a catalyst for polyolefin polymerization, comprising a transition metal compound:
[Formula 1]

(In Formula 1, R ¹ and R ⁴ are each independently selected from the group consisting of hydrogen, and a straight-chain or branched (C ₁ -C ₂₀ ^{)alkyl group, R 2} and R ³ are each independently hydrogen, straight-chain or straight-chain (C 1 -C 20 ) Chain or branched (C ₁ -C ₂₀ )alkyl group, (C ₂ -C ₂₀ )alkenyl group, (C ₃ -C ₂₀ )cycloalkyl group, (C ₆ -C ₂₀ )aryl group, (C ₁ -C ₂₀ ) Alkylsilyl group, (C ₇ -C ₂₀ )arylalkyl group, (C ₇ -C ₂₀ )alkylaryl group, heteroatom substituted (C ₂ -C ₂₀ )heteroalkyl group and hetero atom substituted (C ₅ -C ₂₀ ) selected from the group consisting of heteroaryl groups),
[Formula 2]

(In Formula 2, R ⁵ and R ⁶ are each independently hydrogen, a linear or branched (C ₁ -C ₂₀ )alkyl group, (C ₂ -C ₂₀ )alkenyl group, (C ₃ -C ₂₀ )cycloalkyl group , (C ₆ -C ₂₀ )aryl group, (C ₁ -C ₂₀ )alkylsilyl group, (C ₇ -C ₂₀ )arylalkyl group, (C ₇ -C ₂₀ )alkylaryl group, hetero atom-substituted (C _{2 )} -C ₂₀ )heteroalkyl group and a hetero atom-substituted (C ₅ -C ₂₀ )heteroaryl group).
The method according to claim 1, wherein in the compound represented by Formula 1, R ¹ and R ⁴ are each independently selected from the group consisting of a straight-chain (C ₁ -C ₁₀ )alkyl group, and R ² and R ³ are each independently Branched (C ₁ -C ₁₀ ) selected from the group consisting of alkyl groups, R ² and R ³ are different substituents from each other, a catalyst for polymerization of polyolefins.
According to claim 1, wherein the compound represented by Formula 2 is contained in an amount of 0.1 to 10 moles based on 1 mole of the compound represented by Formula 1, the catalyst for polymerization of polyolefin.
The catalyst for polyolefin polymerization according to claim 1, wherein the compound represented by Formula 1 and the compound represented by Formula 2 are included in a molar ratio of 1:1.2 to 1.2:1.
The catalyst for polyolefin polymerization according to claim 1, wherein the catalyst is supported on at least one carrier selected from the group consisting of silica, alumina, silica-alumina, zeolite and magnesium compounds.
The catalyst for polyolefin polymerization according to claim 1, wherein the transition metal compound is represented by the following Chemical Formula 3:
[Formula 3]
MX _m (OR ⁷ ) _{4 -m}
(In Formula 3, M is selected from the group consisting of transition metal elements of groups IVB, VB and VIB of the periodic table;
X is halogen;
R ⁷ is a (C ₁ -C ₂₀ )alkyl group;
m is an integer from 0 to 4).