KR100205735B1 - Dinuclear metallocene compound useful as a catalyst for producingpolyolefins - Google Patents

Abstract

The present invention relates to a bimetallic metallocene compound having a heteroatom bridge, useful as a catalyst for producing a polyolefin-based polymer, and is mainly classified into three kinds, that is, a neutral metallocene compound, a cationic metallocene compound, and these Compounds are classified as supported catalysts. The catalyst according to the present invention is a novel bimetallic metallocene compound, and has a specific structure and polymerization properties, thereby producing polyethylene having a unique structure and properties.

Description

Bimetalmetallocene Compounds Useful as Catalysts for the Preparation of Polyolefin Polymers

The present invention relates to a diuclear metallocene compound having a heteroatom bridge, which is useful as a catalyst for preparing polyolefin-based polymers.

Although many types of metallocene compounds for producing polymers have been known so far, the compounds of the present invention are catalysts of a completely new structure in that they have new types of heteroatomic bridges and bimetals. In other words, the present invention is an indenyl that produces a π-electron cyclopentadienyl (Cp), substituted Cp (Cp ^* ) and η ⁵ -bonds to which the transition metal element of the metallocene is directly bonded. ), A bridge containing heteroatoms is connected between two similar compounds, such as fluorenyl and their substituents, in particular a metal having one transition metal element bonded to each of the above two ligands. Heteroatom Bridged Dinuclear Titanocene (HBDT), especially when this metal is titanium, and Heteroatom Bridged Dinuclear Zirconocene (HBDZ) when this metal is zirconium. to be. In particular, the HBDT compound and the HBDZ compound are very effective catalysts for the production of polyethylene (hereinafter, referred to as "PE"), and include neutral HBDT and HBDZ compounds, cationic HBDT and HBDZ compounds, and HBDT and HBDZ compounds. The supported compound of the form obtained by carrying out the ligand bonded by hetero atom, and then synthesize | combined is contained.

The HBDT compound of the present invention has the following structure.

or

The HBDZ compound of the present invention has the following structure.

In the above formula,

M is a metal of Group 3 to 10 and a transition metal element, preferably a lanthanum element, more preferably titanium or zirconium,

Y1, Y2, Y3 and Y4 independently of one another are cyclopentadienyl, cyclopentadienyl derivatives or indenyl, fluorenyl or derivatives thereof capable of η ⁵ -bonding with M,

A1, A2, A3 are independently of each other the group 1 to 4 elements, the spacer Sp may be sandwiched between A1 and Y1 or A3 and Y2, the spacer Sp is preferably carbon, oxygen, nitrogen, phosphorus,

E1 and E2 are heteroatoms preferably nitrogen, oxygen, phosphorus, sulfur and independently of each other form a site between the Y1, Y2, Y3 and Y4 ligands,

R1 to R6 are independently of each other hydrogen, alkyl, aryl, silyl, alkoxy, aryloxy, siloxy, halogen, a group formed from a combination thereof, or -Sp-Sup, where Sp is as described above and Sup is a support ,

X is a group formed of hydrogen, alkyl, aryl, silyl, alkoxy, aryloxy, siloxy, halogen or a combination thereof,

n may have a value from 0 to 4 depending on the type and valency of the metal.

In the above formulas (II) and (IV), Z is a non-coordinating anion, which is not or very weakly coordinated with the metal cation moiety containing Y so that other Lewis bases contain Y of the cation. An anion that does not interfere with the action of the metal moiety, preferably [BQ ₁ Q ₂ Q ₃ ] ^- , where B is boron in the trivalent valence, Q _{1 to} Q ₄ are each independently hydrogen anion ( Selected from the group consisting of Hydride, Dialkylamido, Alkoxide, Aryl oxide, Hydrocarbyl, Substituted Hydrocarbyl, Organometalloid, etc. It is a radical and one of Q <_1> -Q <_4> may be halide.

The HBDT compound is prepared in three steps as follows:

Wherein A1, A2, A3, E1, E2, R1, R2, R3, R4, R5, R6 and Sp are as defined above, Y is Y1 or Y2, H is a halogen element, Y is Y1 as defined above Or an anion of Y 2 and T is an alkali metal cation.

next

R is alkyl, alkoxy and T is an alkali metal or thallium.

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The HBDZ compound is prepared as follows using compound (2) and YMXn.

In order to use the compound of the present invention as a polymerization catalyst, it is usually supported on a support. For example, the compound of formula (I), (II), (III) or (IV) of the present invention is directly supported on a dehydrated carrier. Examples of the carrier include silica, alumina, magnesium chloride (MgCl ₂ ), zeolite, zeolite, aluminum phosphate (AlPO ₄ ), or zirconia (Zirconia). It is prepared by immersion in the solvent of the compound of (II), (III) or (IV). The cationic HBDT compound (formula (II)) and HBDZ compound (formula (IV)) supported catalyst is a compound in which the compounds of formulas (II) and (IV) are supported on a dehydrated carrier, and non-aluminum ) In addition to the method of directly supporting the carrier by activating with a promoter, the neutral HBDT compound (formula (I)) and HBDZ compound (formula (IV)) are supported on a carrier and then activated by a non-aluminum promoter. can do. Here, the non-aluminum promoter [R ₁ R ₆ R ₇ ] [BQ ₁ Q ₂ Q ₃ Q ₄ ] or [HNR ₈ R ₉ R ₁₀ ] [BQ ₁ Q ₂ Q ₃ Q ₄ ], and R ₅ to R ₁₀ Is a group consisting of hydrogen, alkyl, aryl, alkoxy, silyl, siloxy and the like, and B and Q _{1 to} Q ₄ are as defined above.

Another method of making the polymerization catalyst of the present invention is to directly form the bimetalmetallocene compound of the present invention together with the carrier by modifying the carrier as in the following reaction.

Wherein A, E, M, Y1, Y2, Y3, Y4, (X) n and the like are as described above, Sp is a spacer connecting the ligand Y with the surface of the carrier, carbon, oxygen, nitrogen, Phosphorus etc. And these Sp can be connected to each other by chemical bonds including carbon, oxygen, nitrogen, phosphorous. The neutral supported catalyst obtained above may be used by treating with a non-aluminum promoter.

In addition to the various catalysts of the present invention, an organometallic compound may be used as a promoter. The organometallic compound is preferably an alkylaluminoxane or an organoaluminum compound, and the alkylaluminoxane is more preferably methylaluminoxane (MAO) or modified aluminoxane (Modified Methylalumino xane: MMAO). ) And the organoaluminum compound is more preferably AlR _n X _3n . Wherein R is C1 to C10 alkyl or aryl, X is halogen, n is 1,2 or 3;

Styrene can be polymerized using a catalyst prepared by modifying the catalyst or support supporting the HBDT compound or the HBDZ compound of the present invention and bonding the HBDT compound to the surface thereof. The amount of the polymerization and, based on the styrene is 10 ^-7 to 10 ^-3 mol / L, and preferably 10 ^-6 to 10, more preferably ^-4 mol / L, the polymerization temperature of the catalyst is 0~80 ℃ preferably from 20 to 60 ℃.

Example

Hereinafter, although an Example demonstrates this invention, this invention is not limited to an Example.

(1) Structure and composition of catalyst

The structure of the catalyst was investigated by hydrogen and carbon nuclear magnetic resonance analyzers (H-NMR and C-NMR), and the catalyst components and composition were analyzed by inductive plasma spectroscopy (ICP).

(2) Polymerization and Copolymerization of Ethylene

The polymerization and copolymerization of ethylene was carried out in an external temperature controller, a magnetic stirrer, and an organic reactor with a valve capable of supplying monomer and nitrogen. In the nitrogen-substituted glass reactor, the required amount of purified toluene and MAO as a cocatalyst were added, stirred sufficiently, and then the required amount of catalyst was injected to initiate polymerization. After some time, a little methanol was added to terminate the polymerization. The resulting mixture was poured into a large amount of methanol added with hydrochloric acid to obtain a polymer, washed with water and ethanol and then dried in vacuo.

(3) catalytic activity

The weight of PE obtained in the polymerization was measured and the catalytic activity was expressed in kg PE / mol M-h.

(4) melting point and crystallization temperature

Melting point and crystallization temperature of the polymer was measured by differential thermal analyzer (DSC), and the specimen was heated to 200 ° C. and left for 5 minutes, and then cooled and warmed up to 20 ° C./min.

Example 1 Synthesis of Hexamethyltrisiloxane Bis (η ⁵ -cyclopentadienyltitanium Trichloride)

(a) Synthesis of 1,5-dicyclopentadienylhexamethyltrisiloxane

10 mmol of 1,5-dichlorohexamethyltrisiloxane was dissolved in 50 mL of THF, and then 200 mmol of sodium cyclopentadiene (2.0 M THF solution) was slowly added at -78 ° C, and the mixture was allowed to react at room temperature for about 5 hours. After the reaction, the solvent was removed, hexane was added, and then filtered to remove LiCl generated during the reaction. Removal of the solvent from the filtered solution yields the desired product as a yellow liquid in 90% yield.

(b) Synthesis of hexamethyltrisiloxane bis (η ⁵ -cyclopentadienyltitanium trichloride)

10 mmol of the synthesized 1,5-dicyclopentadienylhexamethyltrisiloxane was dissolved in 50 mL of THF, and then 200 mmol of TiOEt was added at -78 ° C, and stirred for 3 to 5 hours at room temperature to form thallium dianion. . The solution is mixed with a TiCl ₄ (20 mmol) toluene solution prepared at -78 ° C, and the mixed solution is reacted at room temperature for 10 to 15 hours, and then the solvent is removed. Here, 30 ml of CH ₂ Cl ₂ was added, filtered to remove TICl, and then 50 ml of hexane was added to the filtered solution to recrystallize the product. The recrystallized solid product is recrystallized again in CH ₂ Cl ₂ or toluene solution to give the desired product in 50% yield.

Example 2 Polymerization Behavior of Ethylene and Thermal Properties and Molecular Weight of PE Polymer

(1) Characteristics of this patent catalyst

In order to investigate the properties of the catalysts (HBDT and HBDZ) prepared in this patent, the catalytic activity of polymers of ethylene, several metallocene polymerization catalysts which can be used in general, HBDT or HBDZ, and the resulting polyethylene (PE) The melting temperature and crystallization temperature of were investigated, and the results are shown in Table 1 below.

The polymerization activity of ethylene using HBDT compounds was slightly smaller than that of CpTiCl ₃ or Cp ₂ TiCl ₂ , but the melting and crystallization temperatures of polymerized PE are similar to those of polymers obtained from other catalysts. . Depending on the catalyst, such as varying the component ratio or the polymerization temperature, and can adjust the molecular weight of PE 10 ^{4-10 6,} particularly over the 100,000 to 1,000,000, wherein the molecular weight distribution (polydispersity index) is shown relatively wide as 3.0 to 8.0.

The catalytic activity and thermal properties were changed according to the amount of cocatalyst used. That is, as the number of cocatalysts increased to some extent, the catalytic activity increased and the melting and crystallization temperatures of PE slightly increased. However, as the polymerization temperature increases, the catalytic activity decreases, and the melting temperature and crystallization temperature of PE are low.

In the case of polymerization of ethylene using HBDZ compound, the polymerization activity was almost the same as that of Cp ₂ ZrCl ₂ or Ind ₂ ZrCl ₂ , and the melting temperature and crystallization temperature of PE were similar. The molecular weight of PE was relatively high and appeared to be 100,000 or more, especially the molecular weight distribution was found to be higher than 4.0.

Table 1. Polymerization Activity of Ethylene and Thermal Properties and Molecular Weight of Polymer PE

Catalyst Catalytic activity Molecular Weight (Mw) Melting temperature (℃) Crystallization temperature (℃) CpTiCl ₃ -MAO 12.3 635000 129.4 107.3 Cp ₂ TiCl ₂ -MAO 25.5 525000 135.8 114.7 HBDT-MAO 1.9 899000 131.3 115.3 Cp ₂ ZrCl ₂ -MAO 2422 52000 134.3 115.0 Ind ₂ ZrCl ₂ -MAO 2254 58000 135.9 114.7 HBDZ-MAO 2187 250000 134.4 114.9

Polymerization conditions: [A1] / [Ti] = 1,000; [A1] / [Zr] = 10,000; 40 ° C .;

Catalytic activity: kg polymer M mol-h-atm.

As can be seen from the table above, the polymerization behavior of the HBDT compound as a catalyst showed lower catalytic activity than that of the catalyst which can be used normally, but it showed a much higher molecular weight than CpTiCl ₃ having a structure similar to that of the HBDT compound. have. Compared with the general Cp ₂ ZrCl ₂ and Ind ₂ ZrCl ₂ , the activity was obtained with HBDZ, and the molecular weight of PE was significantly increased.

(2) Thermal Properties of Polymers under Polymerization Conditions

The previously prepared catalyst HBDZ can be used together with the MAO cocatalyst to polymerize ethylene, and the effects of the amount of MAO and the catalyst and the polymerization temperature on the catalytic activity and the enthusiasm of the polymer are shown in Table 2.

Table 2. Catalytic Activity and Polymer Thermal Properties According to Catalyst Content and Polymerization Temperature in HBDZ

[A1] / [Zr] Temperature (℃) Catalytic activity Molecular Weight (Mw) Melting temperature (℃) Crystallization temperature (℃) 10000 30 2150 312000 135.4 114.8 20000 30 2850 148000 135.7 114.0 10000 40 2187 250000 134.4 114.9 20000 40 2245 86000 136.3 113.5

Catalytic Activity: ㎏ PE / mol Zr-atm-h

As can be seen above, as the amount of the cocatalyst MAO increases, the melting temperature and crystallization temperature do not change significantly, but the catalytic activity tends to increase. However, the degree of increase in catalytic activity was different depending on the polymerization temperature, so the increase in catalytic activity was more pronounced at 40 ° C. The molecular weight decreased as the amount of MAO or polymerization temperature increased.

The catalyst according to the present invention is a novel bimetallic metallocene compound, and has a specific structure and polymerization properties, thereby producing polyethylene having a unique structure and properties.

Claims (3)

Bimetalmetallocene compound represented by the following structural formula: In the above formula, M is a group 3-10 metal and transition metal element, Y 1, Y 2, Y 3 and Y 4 are independently of each other cyclopentadienyl, a cyclopentadienyl derivative capable of bonding M and η ⁵ , indenyl or fluorenyl, A1, A2 and A3 are each independently a group 1 to 4 element, and the spacer Sp may be interposed between A1 and Y1 or A3 and Y2, E1 and E2 are heteroatoms that independently form a site between Y1 and Y2 ligand, R1 to R6 are independently of each other a group formed of hydrogen, alkyl, aryl, silyl, alkoxy, aryloxy, siloxy, halogen or a combination thereof or -Sp-Sup where Sp is as described above and Sup is a support , X is a group formed of hydrogen, alkyl, aryl, silyl, alkoxy, aryloxy, siloxy, halogen, or a combination thereof, n may have a value of 0 to 4 depending on the type and valence of the metal. 2. A compound according to claim 1, wherein M is a lanthanum element; Sp is carbon, oxygen, nitrogen or phosphorus as spacer; E1 and E2 are bimetallic metallocene compounds each being nitrogen, oxygen, phosphorus or sulfur. The bimetallic metallocene compound according to claim 2, wherein M is titanium or zirconium.