WO2018009016A2

WO2018009016A2 - Method for preparing metallocene catalyst for preparing polyolefin

Info

Publication number: WO2018009016A2
Application number: PCT/KR2017/007280
Authority: WO
Inventors: 박희광; 이혜경; 김병석; 정재엽; 전상진
Original assignee: 주식회사 엘지화학
Priority date: 2016-07-07
Filing date: 2017-07-07
Publication date: 2018-01-11
Also published as: WO2018009016A3

Abstract

The present invention relates to a method for preparing a high-purity metallocene catalyst capable of providing varying selectivity and high activity to a polyolefin copolymer and, particularly, can prepare a high-purity metallocene catalyst by adding, after forming a metallocene compound by reacting a ligand compound and a zirconium compound, a step of converting lithium chloride, which is contained as a reaction by-product in the metallocene compound, into a complex form, thereby effectively removing the same in the next step of extracting a catalyst.

Description

【Specification】

[Name of invention]

Method for preparing metallocene catalyst for polyolefin production

Technical Field

Cross Citation with Related Applications

This application claims the benefit of priority based on Korean Patent Application No. 10-2016-0086256 filed on July 7, 2016 and Korean Patent Application No. 10-2017—0085739 filed on July 6, 2017. All content disclosed in the literature is included as part of this specification.

The present invention relates to a method for effectively preparing a high purity metallocene catalyst capable of high activity in preparing high molecular weight polyolefin.

Background Art

Olefin polymerization catalyst systems can be classified into Ziegler-Natta and metallocene catalyst systems, and these two highly active catalyst systems have been developed for their respective characteristics. Ziegler-Natta catalysts have been widely applied to existing commercial processes since the invention in the 50's, but are characterized by a wide molecular weight distribution of polymers because they are multi- active catalysts with multiple active sites. There is a problem that there is a limit in securing the desired physical properties because the composition distribution of the monomer is not uniform.

The metallocene catalyst is composed of a combination of a main catalyst composed mainly of transition metal compounds and a cocatalyst composed of an organic metal compound composed mainly of aluminum. Such a catalyst is a homogeneous complex catalyst, which is a single-site catalyst. ， According to the characteristics of single active site, the polymer has narrow molecular weight distribution and homogeneous comonomer composition distribution, and the stereoregularity of copolymer, copolymerization characteristic, molecular weight, crystallinity according to ligand structure modification and change of polymerization conditions of catalyst It has the property to change the back. ^'

Meanwhile, ansa-metallocene compound is an organometallic compound including two ligands connected to each other by a bridging group, and the rotation of the ligand is prevented by the bridging group. Center of Activity and structure are determined.

Such ansa-metallocene compounds have been used as catalysts in the preparation of ellepin-based homopolymers or copolymers. In particular, ansa-metallocene compounds comprising cyclopentadienyl (eye 1 opent adienyl; f luoreny 1) ligands can produce high molecular weight polyethylene, thereby controlling the microstructure of polypropylene. It is also known that the ansa-metallocene compound containing an indenyl ligand can produce a polyolefin having excellent activity and improved stereoregularity.

The present inventors have disclosed an ansa-metallocene compound of a novel structure capable of providing various selectivity and activity to a polyolefin copolymer in Korean Patent Publication No. 10-2013-0125311.

On the other hand, in the case of bis-indenyl-ligand in the ansa-metallocene catalyst, according to the three-dimensional arrangement of the two ligands, there are two forms, namely racemate debris-symmetric meso diastereomers (mirror -symmetric meso di astereomer) can be formed. Racemates are preferred because they produce isotact ic polymers with high crystallinity, high melting point, high specific gravity and mechanical strength, while mirror-symmetric meso diastereomers are preferred for atactic ic. It is a catalyst that should be avoided because it manufactures polymer). However, since the racemates and the mirror-symmetric meso diastereomers are prepared simultaneously in the process of preparing the ansa-metallocene catalyst, the structure of the ansa-metallocene catalyst that can generate excessive amounts of the racemates is important. Should be considered. There is also a need for an ansa-metallocene catalyst that can produce higher molecular weight polyolefins.

In particular, the existing metallocene catalyst is one of the by-products generated during synthesis

In the filtration process to remove LiCl is passed without being removed to exist with the metallocene catalyst to reduce the purity, there is a problem that inhibits the activity during polymer polymerization.

Therefore, there is a need for a process development for producing an ansa-metallocene compound capable of producing high molecular weight polyolefin with high activity. [Content of invention]

[Problem to solve]

The present invention is to provide a high purity metallocene catalyst capable of producing high molecular weight polyolefin with high activity.

[Measures of problem]

The present invention comprises the steps of reacting a ligand compound and a zirconium compound represented by Formula 1 to form a metallocene compound; Forming a lithium chloride complex compound by adding a solvent for forming a lithium chloride complex compound to the reaction product including the metallocene compound; And adding a solvent for extracting a lithium chloride complex to a reaction product including the lithium chloride complex and the metallocene compound, and filtering the same.

In Chemical Formula 1,

¾ is a C ₆ alkyl substituted with CWQ - A ₂₀ aryl,

, And R ₃ are each independently hydrogen, halogen, d- ₂₀ alkyl, C ₂ - ₂₀ alkenyl, d-20-alkyl silyl, alkyl silyl d- _20, d-20 alkoxysilyl, d- ₂₀ ether, silyl ether, d- ₂₀ alkoxy, C ₆ - ₂₀ aryl, C ₇ - ₂₀ alkylaryl, or C ₇ - ₂₀ Arylalkyl,

A is carbon, silicon or germanium,

¾ is C-20 alkyl substituted with C0 alkoxy,

R ₆ is hydrogen, d- ₂₀ alkyl or C ₂ - ₂₀ alkenyl is.

The present invention also provides a metallocene catalyst prepared by the method as described above.

Hereinafter, a method of preparing a metallocene catalyst and a metallocene catalyst prepared therefrom according to an exemplary embodiment of the present invention will be described in more detail.

In the present invention, the terms first, crab, etc. are used to describe various components, and the terms are used only for the purpose of distinguishing one component from other components.

In addition, the terminology used herein is for the purpose of describing example embodiments only and is not intended to be limiting of the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. As used herein, the terms "comprise", "comprise ¹ " or "have ¹ " and the like are intended to indicate that there are features, features, steps, components, or a combination thereof that are implemented, one or more other It should be understood that it does not exclude in advance the possibility of the presence or addition of features or figures ", steps, components, or combinations thereof.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated and described in detail below. However, this is not intended to limit the present invention to a specific disclosed form, it should be understood to include all changes, equivalents, and substitutes included in the spirit and scope of the present invention.

According to an embodiment of the present invention, forming a metallocene compound by reacting a ligand compound and a zirconium compound represented by Formula 1 below; Forming a lithium chloride complex compound by adding a solvent for forming a lithium chloride complex compound to the reaction product including the metallocene compound; And adding a solvent for extracting a lithium chloride complex to the reaction product including the lithium chloride complex and the metallocene compound, and filtering the metallocene.

In Chemical Formula 1,

Ri is a C ₆ alkyl substituted with _CQ-20, and aryl,

, R ₃ and R ₄ are each independently hydrogen, halogen, d- ₂₀ alkyl, C ₂ - ₂₀ alkenyl, CHO alkylsilyl, C ₂₀ alkyl silyl group, alkoxysilyl group, d-20 ether, silyl ether, CO alkoxy, C ₆ - _20, and arylalkyl, - ₂₀ aryl, C ₇ - ₂₀ alkylaryl, or C ₇

A is carbon, silicon or germanium,

R ₅ is alkyl substituted with Cwo alkoxy,

¾ is hydrogen, d-20 alkyl or C ₂ - ₂₀ alkenyl is.

In particular, the present invention provides a ring structure including a solvent capable of forming a lithium chloride complex, for example, two or more oxygen atoms so as to effectively remove LiCl produced as a by-product in the reaction of the ligand compound and the transition metal compound. In addition to the step of reacting with a specific solvent having, it is characterized by using a specific aprotic solvent that can selectively extract the organometallic compound and the lithium chloride complex. That is, it acts as a non-solvent for removing LiCl, by using a solvent having a ring structure containing two or more oxygen atoms such as 1,4-dioxane as a solvent for forming a lithium chloride complex Ultimately, a high purity organometallic compound is prepared, and polypropylene is produced with high activity.

In the present invention, the ligand compound includes an indene compound as shown in Chemical Formula 1.

In particular, the method for preparing a metallocene catalyst of the present invention includes the steps of preparing a ligand compound represented by the following Chemical Formula 1 by reacting the indene compound represented by the following Chemical Formula 2 and the compound represented by the following Chemical Formula 3; Forming a metallocene compound by reacting a ligand compound and a zirconium compound represented by Formula 1 below; Forming a lithium chloride complex compound by adding a solvent for forming a lithium chloride complex compound to the reaction product including the metallocene compound; And adding a solvent for extracting the lithium chloride complex compound to the reaction product including the lithium chloride complex and the metallocene compound, and filtering.

In Chemical Formula 1,

Ri is an optionally substituted C ₆ to C o alkyl-aryl and _20,

¾, ¾, and are each independently hydrogen, halogen, d-20 alkyl, C ₂ - ₂₀ alkenyl, (^ -20 alkylsilyl, d- ₂₀ alkyl silyl group, alkoxysilyl ₂₀ d-, d- ₂₀ ether, a silyl ether , d- ₂₀ alkoxy, C ₆ - ₂₀ aryl, C ₇ - ₂₀ alkylaryl, or C ₇ - ₂₀ Arylalkyl,

A is carbon, silicon or germanium,

¾ is d-20 alkyl substituted with CWQ alkoxy,

¾ is hydrogen, d-20 alkyl or C ₂ - ₂₀ alkenyl, and,

[Formula 2]

In Chemical Formula 2,

Ri is - a C ₆ alkyl substituted with ₂₀ - ₂₀ aryl

, ¾ and are each independently hydrogen, halogen, alkyl, C ₂ - ₂₀ alkenyl, d- ₂₀ alkylsilyl, d-20 alkyl silyl group, alkoxysilyl ₂₀ d-, d- ₂₀ ether, silyl ether ₂₀ d-, CO and ₂₀ arylalkyl, alkoxy, C ₆ - ₂₀ aryl, C ₇ - ₂₀ alkylaryl, or C ₇

[Formula 3]

In Chemical Formula 3,

A is carbon, silicon or germanium,

R ₅ is d-20 alkyl substituted with CQ alkoxy,

R ₆ is hydrogen, alkyl, CHO, or C ₂ - ₂₀ alkenyl, and,

X 'is the same or different halogen from each other,

[Formula 4]

ZrX ₄

In Chemical Formula 4, X is the same or different halogen from each other.

In addition, the present invention provides a method for producing a metallocene catalyst for minimizing reaction by-products and producing a metallocene compound with high purity as an olefin catalyst. The metallocene catalyst may include, in particular, a metallocene compound of Formula 5 below.

[Formula 5]

In Chemical Formula 5,

X is the same or different halogen from each other,

¾ is substituted with a C ₆ Cuo alkyl-aryl and _20,

R _2, R ₃ and R4 are each independently hydrogen, halogen, d-20 alkyl, C ₂ - ₂₀ alkenyl, CHO alkylsilyl, silyl Cwo alkyl, d-20 alkoxysilyl, d- ₂₀ ether, silyl ether, alkoxy and ₂₀ alkylaryl, or C ₂₀ aryl that, -, C ₆ - ₂₀ aryl, C ₇

A is carbon, silicon or germanium,

¾ is d-20 alkyl substituted with CHO alkoxy,

R ₆ is hydrogen, alkyl or C ₂ - ₂₀ alkenyl is.

The compound of Formula 5 has an ansa-metallocene structure and includes two indenyl groups as ligands. In particular, the ligand The bridge group (br idge group) to link with the oxygen-donor (oxygen-donor) is substituted with a functional group that can act as a Lewis base has the advantage of maximizing the activity as a catalyst. In addition, since a bulky group such as C6-20 aryl (R1) substituted with C1-20 alkyl in the indenyl group is substituted, steric hindrance is imparted to suppress mesoform formation. Accordingly, when the indene compound represented by Chemical Formula 1 is used on its own or in a carrier to be used as a catalyst for the production of polyolefins, polyolefins having desired physical properties can be more easily prepared. In addition, the inclusion of zirconium (Hf) as a metal atom enhances the activity of the catalyst and enables polymerization of higher molecular weight polyolefins. Preferably, Ri is phenyl substituted with tert-butyl. More preferably, it is Rr 4- (t-butyl) -phenyl.

Also preferably, ¾ and ¾ are hydrogen.

Also preferably, A is silicon.

Also preferably, ¾ is 3- (t-buroxy) -propyl and R ₆ is methyl.

Representative examples of compounds represented by 5 are as follows:

In particular, the method for producing a metallocene catalyst according to the present invention may be carried out in one embodiment, such as the following reaction.

[Banungsik 1]

Step 1 is a step of preparing a ligand compound represented by Formula 3 by reacting the indene compound represented by Formula 1 and the compound represented by Formula 2. It is preferable to use alkyllilium (eg, η-butyllithium) in the reaction, and the reaction temperature is -200 to 0 ^° C., more preferably -150 to 0 ^° C. As the solvent, toluene, tetrahydrofuran (THF: tetrahydrofuran) and the like can be used. At this time, after separating the organic layer from the product, the step of vacuum drying the separated organic layer and removing the excess reactant may be further performed.

Step 2 is a step of preparing a compound represented by Chemical Formula 5 by reacting the ligand compound represented by Chemical Formula 3 with the zirconium compound represented by Chemical Formula 4. Is ₇₈ to 0 ° c - is preferred to use an alkyllithium (e.g., n- butyl lithium) to the reaction, and banung temperature is from -20 to 0 ^° C, more preferably. As the solvent for the reaction, at least one selected from the group consisting of diethyl ether, nucleic acid, toluene, and 1,4-dioxane can be used.

In particular, according to the present invention, the reaction product is removed after the reaction and the reaction product including the obtained metallocene compound is added to form a lithium chloride complex by adding a solvent for forming a lithium chloride complex. Here, the solvent for forming a lithium chloride complex has a property of dissolving both the produced lithium chloride complex and the metallocene compound while being able to react with lithium chloride to form a complex. In general, Li atoms in the members of LiCl have a high oxygen affinity (oxophi lic), and thus LiCl can easily form a complex with oxygen atoms included in the solvent. but, Included together as impurities in a reaction product comprising a metallocene compound

For more effective complex formation with LiCl, it is preferable to use an organic solvent containing two or more oxygen atoms and having a cyclic structure. In particular, the organic solvent containing more than two oxygen atoms increases the reaction properties with LiCl according to the high oxygen affinity (oxophilicity), the shielding effect of the oxygen atoms by the surrounding carbon atoms in the case of having a cyclic structure (Shielding Due to its low effect, it is possible to form complexes with LiCl with high oxygen affinity (oxophi 1 ici ty). The solvent for forming the lithium chloride complex compound may be at least one selected from the group consisting of 1,4-dioxane and 1,3-dioxolane (1,3-Dioxolane).

The lithium chloride complex forming solvent is added in an amount of about 3 to 20 times, preferably about 5 to 15 times, most preferably about 8 to 12 times, based on the weight of the indene compound of Formula 2, and about 1 hour The above can be stirred.

The lithium chloride complex thus produced may be LiCl / dioxane 1: 1 complex as lithium chloride-1,4-dioxane complex.

The lithium chloride complex forming solvent may be removed by distillation under reduced pressure under the conditions of pressure 0.5 to 2.0 mbar and temperature 30 to 45 ^° C.

In addition, the reaction product obtained by adding and stirring the lithium chloride complex ^' forming solvent and then removing the solvent for forming a lithium chloride complex such as 1,4' dioxane includes a lithium chloride complex and a metallocene compound. The reaction product containing the lithium chloride complex and the metallocene compound may be added with a solvent for extracting the lithium chloride complex and filtered. Here, the solvent for extracting the lithium chloride complex is to dissolve only the lithium chloride complex in the reaction product, so that only the solid metallocene compound can be obtained through the filtration process. The solvent for extracting the lithium chloride complex compound may be an aprotic solvent containing no oxygen atom. In particular, when an organic solvent containing oxygen balls is used in the reaction product containing the lithium chloride complex and the metallocene compound, a problem may occur in that the metallocene compound, which is a product, is dissolved together. solvent) proton solvents such as alcohols If used, problems may occur that decompose the metallocene compound as a product. For example, the solvent for extracting the lithium chloride complex compound is selected from the group consisting of dichloromethane, chloroform, carbon tetrachl or ide, benzene, and toluene. The above is mentioned.

The solvent for extracting the lithium chloride complex compound is added in an amount of about 3 to 20 times, preferably about 4 to 15 times, and most preferably about 5 to 12 times, based on the weight of the indene compound of Chemical Formula 2, and about 1 hour. The above can be stirred.

In the method for producing a metallocene catalyst according to the present invention, it is the addition of such an extraction solvent, and the solvent removed from the filtrate obtained after the filtration, and preferably may be prepared by reduced pressure distillation, adding performed in the ^{recrystallization,} phase . In the recrystallization step, one or more solvents selected from the group consisting of dichloromethane and nucleic acid may be used.

On the other hand, according to another embodiment of the invention, there is provided a metallocene catalyst prepared by the method as described above. In particular, the metallocene catalyst prepared according to the present invention may exhibit high purity by removing LiCl, which is a reaction impurity, as much as possible. In particular, the content of LiCl included in the prepared metallocene catalyst may be 200 ppm or less and 150 ppm. Or less, 100 ppm or less, or 75 ppm or less.

In the metallocene catalyst of the present invention, the compound represented by Chemical Formula 5 may be used as a catalyst for olefin polymerization by itself or with a promoter as a catalyst precursor.

The metallocene catalyst may be a catalyst supported on a carrier. The carrier is not particularly limited since the conventional one can be used in the art to which the present invention pertains. Preferably, one or more carriers selected from the group consisting of silica, silica-alumina and silica-magnesia may be used. On the other hand, when supported on a carrier such as silica, since the silica carrier and the functional group of the compound represented by Chemical Formula 1 are supported by chemical bonding, there are almost no catalysts liberated from the surface in the olefin polymerization process. There is no fouling on the wall or the polymer particles that get entangled in the process. In addition, the polyolefin prepared in the presence of a catalyst comprising such a silica carrier is excellent in the particle shape and apparent density of the polymer can be suitably used in conventional slurry or gas phase polymerization process. Therefore, it is preferable to use a carrier having a high banung siloxane group on the surface by drying at a high temperature.

Specifically, silica, silica-alumina and the like dried at a high temperature may be used, and they may typically contain oxides, carbonates, sulfates, nitrates, such as Na ₂ O, K ₂ CO 3, BaS0 ₄ , and Mg (N0 ₃ ) ₂ . have.

In addition, the metallocene catalyst may further include a promoter composed of alkylaluminoxane. In the case of using such a promoter, X bonded to the metal element (Hf) of the compound represented by Chemical Formula 5 may be used as a catalyst in a form substituted with an alkyl group, such as CHO alkyl.

The promoter is not particularly limited as it may be used in the art to which the present invention pertains. Preferably, one or more promoters selected from the group consisting of silica, silica-alumina, and organoaluminum compounds may be used.

On the other hand, according to another embodiment of the invention, there is provided a polymer polymerization method using the metallocene catalyst. In particular, in the presence of the metallocene catalyst, there is provided a process for producing a polyolefin comprising the step of polymerizing at least one olefin monomer. The olefin monomers are ethylene, propylene, 1-butene, 1-pentene, 1-nuxene, 4-methyl-1-pente, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-nuxadecene It may be one or more selected from the group consisting of, 1-octadecene, 1-eicosene and combinations thereof.

Here, the polymerization of the polyolefin may be performed by reacting for 1 to 24 hours under a silver degree of 25 to 500 ^° C and a pressure of 1 to 100 kgf / cuf. At this time, the polymerization reaction temperature is preferably 25 to 200 ^° C., more preferably 50 to 100 ° C. Further, the polymerization banung pressure of 1 to 70 kgf / cuf is preferable, more preferably 5 to 40 kgf / cin ^2. The polymerization reaction time is preferably 1 to 5 hours.

The polymerization process can control the molecular weight range of the resulting polymer product in accordance with hydrogenation or no addition conditions. In particular, hydrogen Under the conditions without addition, high molecular weight polyolefin can be produced, and if hydrogen is added, a low molecular weight polyolefin can be produced even with a small amount of hydrogen. At this time, the hydrogen content added to the polymerization process is in the range of 0.07 L to 4 L under 1 atmosphere of semi-aqueous conditions, or is supplied at a pressure of 1 bar to 40 bar or 168 ppm to 8,000 ppm in the range of molar hydrogen content relative to the olefin monomer. Can be supplied.

In the process for preparing polyolefin using the metallocene catalyst prepared according to the present invention, the activity of the catalyst is determined based on the weight of the polymer produced per unit weight content (g) of catalyst based on unit time (h) ( kg), 8.0 kg / gCat. hr or more or 8.0 to 30 kg / dl ol. hr, preferably 10.0 kg / mmol.hr or more, and more preferably 12.0 kg / dol.hr or more.

Polyolefin prepared using the compound of Formula 5 as a catalyst according to the present invention, may have a higher molecular weight than when using a conventional metallocene catalyst. For example, the melt index (MFR, 2.16 kg) measured according to the method of ASTM D 1238 for the polyolefin is 25 g / 10 min or less, preferably 18 g / 10 min or less, most preferably 15 It can be significantly lowered to g / 10 min or less, thereby securing a polylefin having a high molecular weight.

In particular, the present invention is characterized by producing a catalyst of higher purity by adding a step of distillation under reduced pressure after dissolving in a solvent for forming a lithium chloride complex such as 1,4-dioxane in the existing catalyst production process. Moreover, the present invention is very effective in removing by-products such as LiCl, and it is possible to achieve the effect of increasing the filtration efficiency due to the increase in particle size. For example, the polyolefin prepared using the metallocene catalyst prepared according to the present invention may have an average particle diameter of 500 i or more or 500 to 1200, preferably 600 m or more, and more preferably 700 im or more.

In addition, when used for the same purpose as the film, since the gel due to the residual inorganic material increases, when applying the metallocene catalyst prepared according to the present invention can produce a high-purity polymer, when used in film applications It is possible to significantly improve workability. 【Effects of the Invention】

According to the present invention, the high purity metallocene catalyst which effectively removes LiCl, which is a by-product of catalyst synthesis, has a higher activity as a catalyst in olefin polymerization reaction than the conventional metallocene compound, and a high molecular weight when preparing polyolefin using the same Polyolefins having properties can be easily produced.

[Brief Description of Drawings]

1 is a photograph showing the particle size and distribution produced after the polymerization process according to Example 1 and Comparative Example 1 of the present invention.

[Specific contents to carry out invention]

Hereinafter, preferred embodiments of the present invention are provided to aid in understanding 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 thereto.

Step 1) Preparation of (3-t-butoxypropyl) (methyl) -bis (2-methyl-4- (4-t-butylphenyl) indenyl)) silane

15 Alternative Paper (Article 126 of the Rules) 150 g of 2-methyl 쉬 4- (4-t-butylphenyl) -indene was added to a 3 L Schlenk flask, and a solution of toluene / THF (5: 1, 715 mL) was added and dissolved at room temperature. I was. After the solution was cooled to -20 ^° C, 240 mL of n-butyllithium solution (n-BuLi, 2.5 M in hexane) was slowly added dropwise and stirred at room temperature for about 15 hours. Thereafter, the reaction mixture was cooled to -20 ^° C, and then 82 g of (3-t-butoxypropyl) dichloromethylsilane and 512 mg of CuCN were slowly added dropwise. The reaction mixture was warmed to room temperature, stirred for about 15 hours, and 500 mL of water was added. Thereafter, the organic layer was separated, dehydrated with MgSO ₄ and filtered. The filtrate was distilled under reduced pressure to give a yellow oil.

¾ NMR (500 MHz, CDC1 ₃ , 7.26 ppm): -0.09--0.05 (3H, m), 0.40-

0.60 (2H, m), 0.80-1.51 (26H, m), 2.12-2.36 (6H, m), 3.20-3.28 (2H, m), 3.67-3.76 (2H, m), 6.81-6.83 (2H, m ), 7.10-7.51 (14H, m) step 2) rac _ [(3-t-butoxypropylmethylsilanediyl) —bis (2-methyl-4- (4—t-butylphenyl) indenyl)] zirconium Preparation of Dichloride

Into a 3 L schlenk flask was prepared (3-t-butoxypropyl) (methyl) bis (2-methyl-4- (4-t_butylphenyl)) indenylsilane, prepared previously. 1 L of luene / diethyl ether (volume ratio, 10: 1) was added and dissolved at room temperature. After the solution was cooled down to -20 ^° C., 240 mL of n-butyllithium solution (n—BuLi, 2.5 M in hexane) was slowly added dropwise and stirred at room temperature for about 3 hours. After that, the reaction solution was cooled to -20 ^° C, and then 92 g of zirconium chloride was added thereto. The reaction solution was raised to room temperature, stirred for about 15 hours, and the solvent was removed under reduced pressure. The reaction mixture was distilled under reduced pressure, and 1,4-dioxane (1,4-dioxane) was about 750, which was about 5 times based on the weight of 2-methyl-4- (4_t-butylphenyl) -indene. g was added and stirred for about 1 hour, and the solvent was removed under reduced pressure to obtain a solid mixture of the lithium chloride-1,4-dioxane complex and the organometallic compound. About 1 L of dichloromethane was added to the reaction container containing the solid mixture thus obtained, and the insoluble inorganic salts were filtered out. The filtrate was dried under reduced pressure, and 300 mL of dichloromethane was added again to precipitate crystals. The precipitated crystals were filtered and dried to rac _ [(3-t- appendoxypropylmethylsilanediyl) -bis (2-methyl-4- (4-t-butylphenyl) indenyl)] zirconium 80 g of dichloride were obtained (yield 31.7%, racmeso = 50: 1).

¾ 證 (500 MHz, CDCls, 7.26 ppm): 1.19-1.78 (37H, m), 2.33 (3H, s), 2.34 (3H, s), 3.37 (2H, t), 6.91 (2H, s), 7.05 7.71 (14 H, m)

The metallocene catalyst obtained by performing high frequency inductively coupled plasma (ICP) analysis on the obtained metallocene catalyst was measured to have a high purity of 75 ppm. It was confirmed that was prepared. Step 3) Preparation of Supported Catalyst

3 g of silica was pre-weighed in a shrink flask, and 10 ml of methylaluminoxane (MA0) was added thereto and reacted at 90 ^° C. for about 24 hours. After precipitation, the upper layer was removed and washed once with toluene. Ansa-metallocene compound synthesized in step 2 rac-[(3-t-butoxypropylmethylsilanediyl) -bis (2-methyl-4- (4-t-butylphenyl) indenyl)] zirconium After dissolving 60 yi l of dichloride in toluene, it was reacted at about 70 ^° C. for about 5 hours. After the completion of the reaction, when the precipitation was completed, the supernatant solution was removed and the remaining reaction product was washed with toluene. The next day, borate (AB) was dissolved 48 un l in toluene, and then reacted at about 70 ^° C for about 5 hours. After the completion of the reaction, when the precipitation was completed, the supernatant solution was removed and the remaining reaction product was washed with toluene. After washing with hexane again and dried under vacuum to obtain 5 g of a silica supported metallocene catalyst in the form of solid particles. Example 2

After the reaction by adding zirconium chloride, all the reaction solvents are removed by distillation under reduced pressure, and 1,4-dioxane (1,4- ^ 0 31) is removed from 2-methyl- (4- (4-t-butylphenyl) -indene. Metallocene catalyst rac-[(3-t-butoxypropylmethylsilanediyl)-in the same manner as in Example 1, except that about 1,500 g, which was about 10 times by weight, was added. 78 g of bis (2-methyl-4- (4-t-butylphenyl) indenyl)] zirconium dichloride were prepared (yield 30.9%, rac: meso = 50: 1) and the LiCl content was measured.

At this time, the content of LiCl measured for the produced metallocene catalyst is 30 It was confirmed that a metallocene catalyst was prepared in which impurities were removed with a very high purity. Example 3

After the reaction by adding zirconium chloride, all reaction solvents are removed by distillation under reduced pressure, and 1,4-dioxane (1,4-dioxane) is about based on the weight of 2-methyl-4- (4_t_butylphenyl) -indene. Metallocene catalyst rac-[(3-t_butoxypropylmethylsilanediyl) -bis (2-methyl in the same manner as in Example 1, except that about 2,250 g, which is about 15 times as much content was added. -4- (4-t_

Butylphenyl) indenyl)] zirconium dichloride 80 g was prepared (yield 31.7%, rac: meso = 50: 1) and the LiCl content was measured.

At this time, the content of LiCl measured for the produced metallocene catalyst was 50 ppm to confirm that the metallocene catalyst from which impurities were removed with high purity was prepared. Comparative Example 1

Step 1) Preparation of (3-t-butoxypropyl) (methyl) -bis (2-methyl-4- (4-t-butylphenyl) indenyl)) silane.

150 g of 2-methyl-4- (4-t-butylphenyl) -indene was added to a 3 L Schlenk flask and the solution of toluene / THF (5: 1, 715 mL) was dissolved at room temperature. I was. After the solution was cooled to -20 ^° C, 240 mL of n-butyllithium solution (n-BuLi, 2.5 M in hexane) was slowly added dropwise and stirred at room temperature for about 3 hours. Thereafter, the reaction solution was stirred at -20 ^° C, and then 82 g of (3-t-butoxypropyl) dichloromethylsilane and 512 mg of CuCN were slowly added dropwise. The reaction liquid was raised to room temperature, stirred for about 15 hours, and 500 mL of water was added. Thereafter, the organic layer was separated, dehydrated with MgSO ₄ and filtered. The filtrate was distilled under reduced pressure to give a yellow oil.

¾ 匪 R (500 MHz, CDC1 ₃ , 7.26 ppm): -0.09--0.05 (3H, m), 0.40-0.60 (2H, m), 0.80-1.51 (26H, m), 2.12-2.36 (6H, m ), 3.20-3.28 (2H, m), 3.67-3.76 (2H, m), 6.81-6.83 (2H, m), 7.10-7.51 (14H, m) Step 2) Preparation of rac-[(3-t-butoxypropylmethylsilanediyl) -bis (2 ᅳ methyl-4- (4-t-butylphenyl) indenyl)] zirconium dichloride

3 L of shrink flask manufactured prior to _(schlenk. Flask) (Appendix 3_t- during propyl) (methyl) inde-bis (2-methyl -4- (4-t-butylphenyl eu)) into a carbonyl silane, a toluene 1 L of diethyl ether (10: 1) was added and dissolved at room temperature. After the solution was cooled down to -20 ^° C., 240 mL of n-butyllithium solution (n—BuLi, 2.5 M in hexane) was slowly added dropwise and stirred at room temperature for about 3 hours. After that, the reaction mixture was cooled to -20 ^° C, and then 92 g of zirconium chloride was added thereto. The reaction mixture was raised to room temperature, stirred for about 15 hours, and the reaction solvent was removed under reduced pressure. About 1 L of dichloromethane was added without treating a solvent for forming a lithium chloride complex, and then an insoluble inorganic salt was filtered off. The filtrate was dried under reduced pressure, and 300 mL of dichloromethane was added again to precipitate crystals. The precipitated crystals were filtered and dried to obtain 80 g of rac-[(3-t- appendoxypropylmethylsilanediyl) -bis (2-methyl-4- (4-t_butylphenyl) indenyl)] zirconium dichloride (Yield 31.7%, rac: meso = 50: 1).

¾ NMR (500 MHz, CDC1 ₃ , 7.26 ppm): 1.19-1.78 (37H, m), 2.33 (3H, s), 2.34 (3H, s), 3.37 (2H, t), 6.91 (2H, s), 7.05-7.71 (14H, m)

The high frequency inductively coupled plasma (ICP) analysis of the metallocene catalyst thus obtained was carried out to measure the content of LiCl, which is a reaction impurity, and was found to be 2110 ppm. . Step 3) Preparation of Supported Catalyst

3 g of silica was previously weighed into a shrink flask, and 10 ml of methylaluminoxane (MA0) was added thereto, followed by reaction at 90 ^° C. for about 24 hours. After precipitation, the upper layer was removed and washed once with toluene. Ansa-metallocene compound synthesized in step 2 rac-[(3-t- appendoxypropylmethylsilanediyl) -bis (2-methyl-4- (4-t-butylphenyl) indenyl)] zirconium 60 ymol of dichloride was dissolved in toluene and reacted at about 70 ^° C. for about 5 hours. After the completion of the reaction, when the precipitation was completed, the supernatant solution was removed and the remaining reaction product was washed with toluene. Next day borate (AB) 48 umol After dissolving in toluene, it was reacted for about 5 hours at about 70 ° C. After the reaction was completed, the precipitate was finished, the supernatant solution was removed, and the remaining reaction product was washed with toluene. After washing with nucleic acid again and dried under vacuum to obtain 5 g of a silica supported metallocene catalyst in the form of solid particles. Comparative Example 2

After reaction by adding zirconium chloride, all reaction solvents were removed by distillation under reduced pressure, and tetrahydrofuran (THF: tetrahydrofuran) was substituted with 2-methyl-4_ (4-t instead of 1,4-dioxane). _Butylphenyl)-A metallocene catalyst was prepared in the same manner as in Example 1 except that about 1,500 g of about 10 times by weight of indene was added, and the LiCl content was measured.

At this time, the content of LiCl measured for the produced metallocene catalyst was found to be 450 ppm to confirm that the impurities contained in a high content. Comparative Example 3

After reaction by adding zirconium chloride, all the reaction solvents were removed by distillation under reduced pressure, and methyl tertiary butyl ether was substituted with 2-methyl-4- instead of 1,4-dioxane. (4_t_Butylphenyl)-A metallocene catalyst was prepared in the same manner as in Example 1 except that about 1,500 g of about 10 times by weight of indene was added, and the LiCl content was increased. Measured.

At this time, the content of LiCl measured for the produced metallocene catalyst was found to be 1,730 ppm, indicating that the impurities were contained in a high content. Comparative Example 4

After reaction by adding zirconium chloride, the reaction mixture was removed by distillation under reduced pressure, and diethyl ether was used instead of 1,4-dioxane.

Example 1, except that about 1,500 g of (Et ₂ 0) was added in an amount of about 10 times by weight of 2-methyl-4- (4-t-butylphenyl) -indene In the same manner as the metallocene catalyst was prepared and the LiCl content was measured. At this time, the content of LiCl measured for the produced metallocene catalyst was found to be 1,850 ppm, indicating that the impurities were contained in a high content. Comparative Example 5

After reaction by adding zirconium chloride, all the reaction solvents were removed by distillation under reduced pressure, and the weight of 1,4-dioxane (1,4-0110 31) was 2-methyl-4- (4-t-butylphenyl) -indene About 750 g of about 5 times the amount was added, and then the undissolved solids were filtered and dried to obtain rac _ [(3-t-subspecificpropylmethylsilanediyl) -bis (2-methyl-4). 8 g of-(4-t-butylphenyl) indenyl)] zirconium dichloride was obtained (yield 3.2%).

A high-frequency inductively coupled plasma (ICP) analysis was performed on the obtained metallocene catalyst to measure the content of LiCl, which is a reaction impurity, and was found to be 1080 ppm, which contained a high content of impurities, 3.2% It was found that the low yield of the product made it difficult to use industrially. Comparative Example 6

After reaction by adding zirconium chloride, all reaction solvents were removed by distillation under reduced pressure, and 1,4-dioxane (1,4- (0 31) was removed from 2-methyl- (4- (t-butylphenyl) -indene). Metallocene catalyst rac- [(3-t-butoxypropylmethylsilanediyl) in the same manner as in Comparative Example 5 except that about 1,500 g of about 10 times by weight was added. ) -Bis (2-methyl-4- (4_t—

Butylphenyl) indenyl)] zirconium dichloride 5 g was prepared (yield 2.0%) and the LiCl content was measured.

At this time, the content of C1 measured for the produced metallocene catalyst was found to be 1415 ppm, which contained a high content of impurities, and it was confirmed that it was difficult to use industrially with a low yield of 3.2%. Comparative Example 7

After reaction by adding zirconium chloride, all the reaction solvents were removed by distillation under reduced pressure, and 1,4-dioxane (1,4-dioxane) was 2-methyl-4- (4_t_). Butylphenyl) -Metallocene catalyst was prepared in the same manner as in Comparative Example 1 except that about 2,250 g of about 15 times by weight of indene was added. All were dissolved to obtain an organometallic compound (yield 0%), and the content detection of LiCl could not be performed. In the preparation of the catalysts according to Examples 1 to 3 and Comparative Examples 1 to 7, after the reaction by the addition of zirconium chloride, the main process conditions and the LiCl content contained in the resulting catalyst were measured as shown in Table 1 below. .

TABLE 1

Experimental Example

1) Homopolymerization of propylene

Vacuum dry 2 L stainless reactor at 65 ^° C Triethylaluminum 3.0 Pa was added at room temperature, about 2 bar of hydrogen was added, and about 770 g of propylene was sequentially added.

Thereafter, after stirring for about 10 minutes, 0.060 g of each of the supported metallocene catalysts prepared in Examples 1 to 3 and Comparative Examples 1 to 6 was dissolved in 20 mL of TMA-prescribed nucleic acid, and added to the reactor under nitrogen pressure. . After the reaction temperature was slowly raised to about 70 ^° C. and then polymerized for about 1 hour. After reaction, unreacted propylene was vented.

2) measuring properties of polymers

(1) Catalyst activity: calculated as the ratio of the weight of polymer produced (kg PP) per catalyst content (함량 ol and g of catalyst) used, based on unit time (h).

(2) Melting point (Tm) of the polymer: The melting point of the polymer was measured using a differential scanning calorimeter (DSC, device name: DSC 2920, manufacturer: TA instrument). After heating to the particular polymer to 220 ^° C was maintained at that temperature for 5 minutes, ^again, was increased the temperature again lowered to 20 ^° C, wherein the rising speed and the descending speed of the temperature of each of 10 ^° C / min Adjusted to. (3) Silver crystallization degree of polymer (Tc): It was crystallization silver content from the curve which shows temperature decreasing on the conditions similar to melting | fusing point using DSC.

(4) Melt index (MFR, 2.16 kg): measured at 2.16 kg load at 230 ^° C according to ASTM D1238 and expressed as weight (g) of polymer melted for 10 minutes.

3) Measurement results of the physical properties of the polymer

Homopolymerization process of Preparation Examples 1 to 3 and Comparative Preparation Examples 1 to 6 using the respective metallocene supported catalysts prepared in Examples 1 to 3 and Comparative Examples 1 to 6: Measurement results of the properties of the dry and the resulting polypropylene Table 2 (Homo Polymerization).

TABLE 2

In addition, a scanning electron microscope (SEM) photograph of the particle size and distribution generated after the polymerization process according to Example 1 and Comparative Example 1 of the present invention is shown in FIG. 1. As shown in Figure 1 it can be seen that by increasing the particle size of the polymer produced by about 25% to suppress the generation of fine particles to ensure process stability.

As shown in Table 2, the metallocene compound according to the present invention Production Examples 1 to 3 used as supported catalysts showed a high activity increasing effect in the production of polypropylene. In particular, Preparation Examples 1 to 3 had a catalytic activity of 15.3 to 15.9 k ^' g / g. very good in hr. On the other hand, no extraction drying step with the addition of a separate LiCl complex solvent is carried out according to existing methods or using conventional ether solvents. Comparative Preparation Examples 1 to 4 have a catalytic activity of 0.9 to 2.5 kg / g at random polymerization. It can be seen that the hr falls markedly. In particular, Preparation Examples 1 to 3 of the present invention significantly improved the purity of the metallocene catalyst produced as compared to the conventional method, thereby improving the polymerization activity by about 17 times compared to Comparative Preparation Example 1 according to the conventional method. It can be seen that. When the activity is low as in Comparative Preparation Example 1, the catalyst input should be increased in order to control the slurry densi ty of the polymerization process, but when the activity is low, it is difficult to commercially produce the limit. On the contrary, when the activity is high, as in Preparation Examples 1 to 3 according to the present invention, it is advantageous in commercial production because it can be controlled by a small amount of catalyst.

Furthermore, in the case of Preparation Examples 1 to 3 using the high purity metallocene catalyst according to the present invention, the average particle diameter of the produced polypropylene particles is about three times that of Comparative Preparation Examples 1 to 6, in particular, Comparative Preparation Example Since it is about 4.5 times larger than 1, it has the advantage of being able to stably produce long-term without fouling in a continuous process produced industrially. In particular, when the average particle diameter of the produced polyolefin is significantly small, as in Comparative Preparation Examples 1, 3, 4, etc., the possibility of fine powder is increased, or a sheet is generated in the process to generate fouling to increase the overall process efficiency. Can be reduced.

In addition, in the case of the embodiment according to the present invention, it was confirmed that the MFR value is significantly low, which can be seen that the molecular weight of the polypropylene prepared by using the metallocene compound according to the present invention as a supported catalyst. .

Claims

[Claim]

[Claim 1]

Reacting a zirconium compound with a ligand compound represented by Formula 1 to form a metallocene compound;

Forming a lithium chloride complex compound by adding a solvent for forming a lithium chloride complex compound to the reaction product including the metallocene compound; And

Adding a solvent for extracting a lithium chloride complex to a reaction product including the lithium chloride complex and a metallocene compound, and filtering the result;

Method for producing a metallocene catalyst comprising a.

In Chemical Formula 1,

¾ is Ce-20 aryl substituted with 0, -20 alkyl,

, ¾ and ¾ are each independently hydrogen, halogen, ₍₂₀ alkyl, C ₂ - ₂₀ alkenyl, C - ₂₀ alkylsilyl, d-20 silyl-alkyl, d-20, alkoxysilyl, d-20 ether, d-20 silyl ether, d- ₂₀ alkoxy C ₆ - ₂₀ aryl, C ₇ - ₂₀ aryl and the alkyl, - ₂₀ alkylaryl or C ₇

A is carbon, silicon or germanium,

R ₅ is a d- ₂₀ alkyl substituted with d-20-alkoxy,

R ₆ is hydrogen, C o alkyl, C ₂ - ₂₀ alkenyl is.

[Claim 2]

The method of claim 1,

Reacting an indene compound represented by Chemical Formula 2 with a compound represented by Chemical Formula 3 to prepare a ligand compound represented by Chemical Formula 1;

Method for producing a metallocene catalyst further comprising:

In Chemical Formula 2,

¾ is C _{6 20} aryl substituted with CO alkyl,

, And R ₃ are each independently hydrogen, halogen, alkyl, C ₂ - ₂₀ alkenyl, ₍₂₀ alkylsilyl, d- ₂₀ silyl-alkyl, d-2 ₀ alkoxysilyl, ether, d-20 silyl ether, d- ₂₀ and ₂₀ arylalkyl, alkoxy, C ₆ - ₂₀ aryl, C ₇ - ₂₀ alkylaryl, or C ₇

[Formula 3]

In Chemical Formula 3

Carbon, silicon or germanium

¾ is d- ₂₀ alkyl substituted with ₂₀ alkoxy,

R ₆ is hydrogen, d- ₂₀ alkyl or C ₂ - ₂₀ alkenyl, and,

X 'is the same or different halogen from each other. [Claim 3]

In U,

The zirconium compound is a method for producing a metallocene catalyst represented by the following formula (4):

[Formula 4]

Zr

In Chemical Formula 4,

X is the same or different halogen from each other.

[Claim 4]

The method according to claim 1 or 2,

¾ is a method for preparing a metallocene catalyst wherein phenyl is substituted with t-butyl.

[Claim 5]

According to claim 1 or 2,

¾ is a 4- (t-butyl) -phenyl process for producing a metallocene catalyst.

[Claim 6]

The method according to claim 1 or 2,

R ₂ , Rs and ¾ are hydrogen.

[Claim 7]

The method according to claim 1 or 2,

A is a method for producing a metallocene catalyst, which is silicon.

[Claim 8]

According to claim 5 or 2,

¾ is 3- (t-subsidiary) -propyl and R ₆ is methyl.

[Claim 9]

The method of claim 1,

The solvent for forming the lithium chloride complex is 1, 4-dioxane and 1,3_ dioxolane (1, 3-Dioxolane) A method for producing a metallocene catalyst selected from the group consisting of.

[Claim 10]

The method of claim 2,

Method for producing a metallocene catalyst to add a solvent for forming a lithium chloride complex compound in an amount of 3 to 20 times based on the weight of the compound of Formula 2.

[Claim 11]

The method of claim 1,

Method for producing a metallocene catalyst to which the lithium chloride complex forming solvent is added and stirred for at least 1 hour.

[Claim 12]

The method of claim 1,

Method for producing a metallocene catalyst to remove the lithium chloride complex formation solvent by distillation under reduced pressure under the conditions of pressure 0.5 to 2.0 mbar and temperature 30 to 45 ^° C.

[Claim 13]

The method of claim 1,

The solvent for extracting the lithium chloride complex is dichloropentane, chloroform, carbon tetrachloride, benzene, toluene and a method for producing a metallocene catalyst selected from the group consisting of.

[Claim 14]

According to claim 2,

In an amount of 3 to 20 times based on the weight of the compound of Formula 2 A method for producing a metallocene catalyst comprising adding a solvent for extracting a lithium chloride complex.

[Claim 15]

The method of claim 1,

Preparation of the metallocene catalyst further comprising the step of removing the solvent from the filtrate obtained by adding and filtering the lithium chloride complex extraction solvent and recrystallization using at least one solvent selected from the group consisting of dichloromethane and nucleic acid. Way .

[Claim 16]

Metallocene catalyst prepared by the process according to claim U or 2.

[Claim 17]

The method of claim 16,

The content of lithium chloride contained in the catalyst is 200 ppm or less metallocene catalyst.