KR102089057B1 - Transition metal compound, catalyst composition comprising the same, and method for preparing olefin polymer using the same - Google Patents

Abstract

According to the present invention, as well as exhibiting high activity in the olefin polymerization reaction, a transition metal compound capable of easily controlling the properties of the synthesized olefin polymer, a catalyst composition comprising the same, and a method for producing the olefin polymer using the catalyst composition This can be provided. When the transition metal compound is used, it is possible to provide an olefin polymer having high catalytic activity and having a high apparent density within various molecular weight ranges.

Description

A transition metal compound, a catalyst composition comprising the same, and a method for producing the olefin polymer using the same {TRANSITION METAL COMPOUND, CATALYST COMPOSITION COMPRISING THE SAME, AND METHOD FOR PREPARING OLEFIN POLYMER USING THE SAME}

The present invention relates to a transition metal compound, a catalyst composition comprising the transition metal compound, and a method for producing an olefin polymer using the catalyst composition.

Ziegler-Natta catalysts of titanium or vanadium compounds have been widely used in the commercial production process of conventional polyolefins. Although the Ziegler-Natta catalyst has a high activity, the molecular weight distribution of the resulting polymer is wide and the comonomer is a multi-activation catalyst. Since the composition distribution of was not uniform, there was a limit to securing desired physical properties.

Accordingly, recently, a metallocene catalyst in which a transition metal such as titanium, zirconium, and hafnium is combined with a ligand including a cyclopentadiene functional group has been developed and widely used. Metallocene compounds are generally activated by using aluminoxane, borane, borate or other activators. For example, a metallocene compound having a ligand including a cyclopentadienyl group and two sigma chloride ligands uses aluminoxane as an activator. The metallocene catalyst is a single active point catalyst having one kind of active point and has a narrow molecular weight distribution of the resulting polymer. Accordingly, there is a need to develop various metallocene catalysts that can easily control properties such as molecular weight, molecular weight distribution, and comonomer composition of the olefin polymer.

The present invention provides a transition metal compound capable of providing an olefin polymer exhibiting excellent catalytic activity and having a high apparent density within various molecular weight ranges.

In addition, the present invention provides a catalyst composition comprising the transition metal compound and a method for producing an olefin polymer using the catalyst composition.

According to one embodiment of the invention, a transition metal compound represented by Formula 1 is provided.

[Formula 1]

In Chemical Formula 1,

M ¹ is any ^one of a group 3 transition metal, a group 4 transition metal, a group 5 transition metal, a lanthanide-based transition metal, and an actanide-based transition metal,

X ¹ and X ² are the same or different from each other, and each independently is one of halogen and alkyl having 1 to 20 carbons,

A is any one of elements of group 14, n is an integer from 1 to 20,

R ¹ is any one of alkyl having 1 to 20 carbons, alkenyl having 2 to 20 carbons, alkylaryl having 7 to 30 carbons, arylalkyl having 7 to 30 carbons, and aryl having 6 to 30 carbons,

R ² is hydrogen, alkyl having 1 to 20 carbons, alkenyl having 2 to 20 carbons, alkylaryl having 7 to 30 carbons, arylalkyl having 7 to 30 carbons or aryl having 6 to 30 carbons,

R ³ and R ⁴ are each independently hydrogen, alkyl having 1 to 20 carbon atoms, which is unsubstituted or substituted with a hetero atom,

,

및

중 어느 하나이고,C ¹ is -NR ^5- ,

,

And

Is either

R ⁵ is any one of alkyl having 1 to 20 carbons,

R ⁶ to R ²¹ are each independently hydrogen or alkyl having 1 to 20 carbons.

이고, 상기 R⁶ 내지 R¹³은 각각 독립적으로 수소 및 탄소수 1 내지 4의 직쇄 알킬 중 어느 하나일 수 있다. 상기 화학식 1에서 R¹은 탄소수 4 내지 6의 분지쇄 알킬 중 어느 하나이고, n은 4 내지 8 사이의 정수일 수 있다. 상기 화학식 1에서 R²는 탄소수 1 내지 6의 직쇄 알킬 중 어느 하나일 수 있다. 상기 화학식 1에서 M¹은 4족 전이 금속 중 어느 하나일 수 있다. Specifically, in Chemical Formula 1, R ³ and R ⁴ may be each independently hydrogen or straight chain alkyl having 1 to 5 carbon atoms. In Formula 1, C ¹ is -NR ^5- , and R ⁵ may be any one of 4 to 8 branched chain alkyl. In Formula 1, C ¹ is

, And R ⁶ to R ¹³ may each independently be hydrogen or straight chain alkyl having 1 to 4 carbon atoms. In Formula 1, R ¹ is any one of a branched chain alkyl having 4 to 6 carbon atoms, and n may be an integer between 4 and 8. In Formula 1, R ² may be any one of straight-chain alkyl having 1 to 6 carbon atoms. In Formula 1, M ¹ may be any one of Group 4 transition metals.

Meanwhile, according to another embodiment of the present invention, a catalyst composition comprising a transition metal compound represented by Chemical Formula 1 is provided.

The catalyst composition may include one or more cocatalysts selected from the group consisting of compounds represented by the following Chemical Formulas 2 to 4.

[Formula 2]

R ^23- [Al (R ²² ) -O] _m -R ²⁴

In Chemical Formula 2,

R ²² , R ²³ and R ²⁴ are each independently hydrogen, halogen, a hydrocarbyl group having 1 to 20 carbon atoms or a hydrocarbyl group having 1 to 20 carbon atoms substituted with halogen,

m is an integer greater than or equal to 2,

[Formula 3]

D (R ²⁵ ) ₃

In Chemical Formula 3,

D is aluminum or boron,

R ²⁵ is each independently halogen, a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbyloxy group having 1 to 20 carbon atoms, or a hydrocarbyl group having 1 to 20 carbon atoms substituted with halogen,

[Formula 4]

^{[LH] + [W (J} ) 4] - or ^{[L] + [W (J} ) 4] -

In Chemical Formula 4,

L is a neutral or cationic Lewis base,

W is a group 13 element, J is each independently a hydrocarbon group having 1 to 20 carbon atoms; A hydrocarbyloxy group having 1 to 20 carbon atoms; And one or more substituents in which one or more hydrogen atoms of these substituents are substituted with one or more substituents among halogen, a hydrocarbyloxy group having 1 to 20 carbon atoms and a hydrocarbyl (oxy) silyl group having 1 to 20 carbon atoms.

Meanwhile, the catalyst composition may further include a carrier that carries the transition metal compound. Silica, alumina, magnesia or mixtures thereof may be used as the carrier.

The catalyst composition may provide an olefin polymer having high catalytic activity and high apparent density within various molecular weight ranges due to the unique steric structure of the transition metal compound of Formula 1.

On the other hand, according to another embodiment of the invention, in the presence of the catalyst composition, a method for producing an olefin polymer comprising the step of polymerizing an olefin monomer is provided.

The olefin 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 novoden, phenyl novoden, vinyl novoden, dicyclopentadiene, 1,4-butadiene, 1,5- Pentadiene, 1,6-hexadiene, styrene, alpha-methylstyrene, divinylbenzene, and 3-chloromethylstyrene.

According to the present invention, as well as exhibiting high activity in the olefin polymerization reaction, a transition metal compound capable of easily controlling the properties of the synthesized olefin polymer, a catalyst composition comprising the same, and a method for producing the olefin polymer using the catalyst composition This can be provided. When the transition metal compound is used, it is possible to provide an olefin polymer having high catalytic activity and having a high apparent density within various molecular weight ranges.

Hereinafter, a transition metal compound according to a specific embodiment of the present invention, a catalyst composition comprising the same, and a method of manufacturing the olefin polymer using the above will be described.

According to one embodiment of the invention, a transition metal compound represented by Formula 1 is provided.

[Formula 1]

In Chemical Formula 1,

M ¹ is any ^one of a group 3 transition metal, a group 4 transition metal, a group 5 transition metal, a lanthanide-based transition metal, and an actanide-based transition metal,

X ¹ and X ² are the same or different from each other, and each independently is one of halogen and alkyl having 1 to 20 carbons,

A is any one of elements of group 14, n is an integer from 1 to 20,

R ¹ is any one of alkyl having 1 to 20 carbons, alkenyl having 2 to 20 carbons, alkylaryl having 7 to 30 carbons, arylalkyl having 7 to 30 carbons, and aryl having 6 to 30 carbons,

R ² is hydrogen, alkyl having 1 to 20 carbons, alkenyl having 2 to 20 carbons, alkylaryl having 7 to 30 carbons, arylalkyl having 7 to 30 carbons or aryl having 6 to 30 carbons,

R ³ and R ⁴ are each independently hydrogen, alkyl having 1 to 20 carbon atoms, which is unsubstituted or substituted with a hetero atom,

,

및

중 어느 하나이고,C ¹ is -NR ^5- ,

,

And

Is either

R ⁵ is any one of alkyl having 1 to 20 carbons,

R ⁶ to R ²¹ are each independently hydrogen or alkyl having 1 to 20 carbons.

The following terms may be defined as follows, unless otherwise specified.

Halogen may be fluorine (F), chlorine (Cl), bromine (Br) or iodine (I).

The alkyl having 1 to 20 carbons may be straight chain, branched chain or cyclic alkyl. Specifically, alkyl having 1 to 20 carbons is linear alkyl having 1 to 20 carbons; Straight-chain alkyl having 1 to 10 carbon atoms; Straight-chain alkyl having 1 to 5 carbon atoms; Branched or cyclic alkyl having 3 to 20 carbon atoms; Branched or cyclic alkyl having 3 to 15 carbons; Or it may be a branched or cyclic alkyl having 3 to 10 carbon atoms. More specifically, alkyl having 1 to 20 carbon atoms is methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, tert-butyl group, n-pentyl group, iso-pentyl group or It may be a cyclohexyl group.

Alkyl having 1 to 20 carbon atoms substituted with a hetero atom is a radical in which one or more -CH ₂ -is replaced by -O-, -NH- -S- so that the hetero atoms are not directly connected, or a radical in which one or more H is substituted by halogen. .

The alkenyl having 2 to 20 carbon atoms may be straight chain, branched chain or cyclic alkenyl. Specifically, alkenyl having 2 to 20 carbon atoms includes straight alkenyl having 2 to 20 carbon atoms, straight alkenyl having 2 to 10 carbon atoms, straight alkenyl having 2 to 5 carbon atoms, branched alkenyl having 3 to 20 carbon atoms, and 3 carbon atoms. It may be a branched chain alkenyl having 15 to 15, a branched chain alkenyl having 3 to 10 carbons, a cyclic alkenyl having 5 to 20 carbons, or a cyclic alkenyl having 5 to 10 carbons. More specifically, the alkenyl having 2 to 20 carbon atoms may be ethenyl, propenyl, butenyl, pentenyl or cyclohexenyl.

Aryl having 6 to 30 carbon atoms may mean a monocyclic, bicyclic or tricyclic aromatic hydrocarbon. Specifically, aryl having 6 to 30 carbon atoms may be a phenyl group, a naphthyl group, or anthracenyl group.

The alkylaryl having 7 to 30 carbon atoms may mean a substituent in which one or more hydrogens of aryl are substituted by alkyl. Specifically, the alkylaryl having 7 to 30 carbon atoms may be methylphenyl, ethylphenyl, n-propylphenyl, iso-propylphenyl, n-butylphenyl, iso-butylphenyl, tert-butylphenyl or cyclohexylphenyl.

Arylalkyl having 7 to 30 carbon atoms may mean a substituent in which one or more hydrogens of alkyl are substituted by aryl. Specifically, arylalkyl having 7 to 30 carbon atoms may be a benzyl group, phenylpropyl or phenylhexyl.

The transition metal compound represented by Chemical Formula 1 includes a benzoindenyl group, a ligand combined with an amino group, a fluorenyl group, an indenyl group, or a cyclopentadiene group, and oxygen to a bridge group connecting the two ligands -It has a structure that contains a functional group that can act as a Lewis base as an oxygen-donor. For example, when a transition metal compound having a specific structure is activated by an appropriate method and used as a polymerization catalyst for an olefin monomer, an olefin polymer exhibiting high catalytic activity and having a high apparent density within various molecular weight ranges can be prepared.

Specifically, in the transition metal compound represented by Formula 1, the benzoindenyl ligand may be unsubstituted or substituted with a substituent having little steric hindrance. Thereby, an olefin polymer having a desired steric structure can be easily produced while exhibiting good catalytic activity. For example, R ³ and R ⁴ in Formula 1 may be each independently hydrogen or straight-chain alkyl having 1 to 5 carbon atoms.

The benzoindenyl ligand can be combined with an amino group, fluorenyl group, indenyl group or cyclopentadiene group. For example, in the transition metal compound represented by Chemical Formula 1, C ¹ is -NR ^5- , and R ⁵ may be any one of 4 to 8 branched chain alkyl. The transition metal compound having such a structure is suitable for providing a high molecular weight olefin polymer, and can exhibit high copolymerizability.

이고, 상기 R⁶ 내지 R¹³은 각각 독립적으로 수소 및 탄소수 1 내지 4의 직쇄 알킬 중 어느 하나일 수 있다. 이러한 구조를 가지는 전이 금속 화합물은 저분자량의 올레핀 중합체를 제공하는데 적합하다.Also, as another example, C ¹ is

, And R ⁶ to R ¹³ may each independently be hydrogen or straight chain alkyl having 1 to 4 carbon atoms. The transition metal compound having such a structure is suitable for providing a low molecular weight olefin polymer.

In addition, in Formula 1, a bridge group connecting a benzoindenyl ligand and an amino group, a fluorenyl group, an indenyl group, or a cyclopentadiene group may affect catalytic activity and loading stability of a transition metal compound. For example, for improved catalytic activity and loading efficiency, R ¹ in Formula 1 may be any one of branched chain alkyl having 4 to 6 carbon atoms, and n may be an integer between 4 and 8. In addition, R ² in Formula 1 may be any one of straight-chain alkyl having 1 to 6 carbon atoms, and A may be C or Si.

Particularly, as a result of experiments conducted by the present inventors, olefin polymers exhibiting excellent catalytic efficiency and having a high apparent density within various molecular weight ranges are prepared, and changes in ligands within the range of Chemical Formula 1 realize easy physical property changes of olefin polymers. In order to do so, as in Formula 1, it was confirmed that the ligand of the above-described structure should be linked to the bridge group of the above-described structure. That is, it was confirmed that the olefin polymer desired in the present invention cannot be produced through a transition metal compound in which the ligand is not linked to the bridge group of the above-described structure, even if the ligand of the above-described structure is included.

On the other hand, M ¹ of Formula 1 is any one of a Group 4 transition metal; Alternatively, storage stability of the metal complex may be improved by using any one of Ti, Zr, and Hf. In addition, X ¹ and X ² are the same as or different from each other, and each independently is one of halogen and alkyl having 1 to 20 carbons; Or each independently halogen or alkyl having 1 to 10 carbons; Or each independently halogen.

The transition metal compound represented by Chemical Formula 1 may be synthesized by applying known reactions. For more detailed synthesis methods, reference may be made to Preparation Example 1, etc., described later.

Meanwhile, according to another embodiment of the present invention, a catalyst composition comprising a transition metal compound represented by Chemical Formula 1 is provided.

The catalyst composition may further include a cocatalyst capable of activating the transition metal compound. As such a co-catalyst, what is commonly used in the art to which the present invention pertains can be used without particular limitation. As a non-limiting example, the cocatalyst may be one or more compounds selected from the group consisting of compounds represented by the following Chemical Formulas 2 to 4.

[Formula 2]

R ^23- [Al (R ²² ) -O] _m -R ²⁴

In Chemical Formula 2,

R ²² , R ²³ and R ²⁴ are each independently hydrogen, halogen, a hydrocarbyl group having 1 to 20 carbon atoms or a hydrocarbyl group having 1 to 20 carbon atoms substituted with halogen,

m is an integer greater than or equal to 2,

[Formula 3]

D (R ²⁵ ) ₃

In Chemical Formula 3,

D is aluminum or boron,

R ²⁵ is each independently halogen, a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbyloxy group having 1 to 20 carbon atoms, or a hydrocarbyl group having 1 to 20 carbon atoms substituted with halogen,

[Formula 4]

^{[LH] + [W (J} ) 4] - or ^{[L] + [W (J} ) 4] -

In Chemical Formula 4,

L is a neutral or cationic Lewis base,

W is a group 13 element, J is each independently a hydrocarbon group having 1 to 20 carbon atoms; A hydrocarbyloxy group having 1 to 20 carbon atoms; And one or more substituents in which one or more hydrogen atoms of these substituents are substituted with one or more substituents among halogen, a hydrocarbyloxy group having 1 to 20 carbon atoms and a hydrocarbyl (oxy) silyl group having 1 to 20 carbon atoms.

The following terms may be defined as follows, unless otherwise specified.

The hydrocarbyl group is a monovalent functional group in which hydrogen atoms are removed from the hydrocarbon, and an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an aralkyl group, an alkenyl group, an alkynyl group, an alkylaryl group, an alkenylaryl group, and an alkyl group And a nilaryl group. Further, the hydrocarbyl group having 1 to 20 carbon atoms may be a hydrocarbyl group having 1 to 15 carbon atoms or 1 to 10 carbon atoms. Specifically, the hydrocarbyl group having 1 to 20 carbon atoms is a methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, tert-butyl group, n-pentyl group, n-hexyl group , n-heptyl group, cyclohexyl group, such as a straight chain, branched chain or cyclic alkyl group; Or it may be an aryl group such as a phenyl group, naphthyl group, or anthracenyl group.

The hydrocarbyloxy group is a functional group in which the hydrocarbyl group is bonded to oxygen. Specifically, the hydrocarbyloxy group having 1 to 20 carbon atoms may be a hydrocarbyloxy group having 1 to 15 carbon atoms or 1 to 10 carbon atoms. More specifically, the hydrocarbyloxy group having 1 to 20 carbon atoms has a methoxy group, an ethoxy group, an n-propoxy group, an iso-propoxy group, an n-butoxy group, an iso-butoxy group, a tert-butoxy group, and an n-pentoxy group. , straight-chain, branched-chain or cyclic alkoxy groups such as n-hexoxy group, n-heptoxy group and cyclohexoxy group; Or it may be an aryloxy group such as a phenoxy group or a naphthalenoxy group.

The hydrocarbyl (oxy) silyl group is a functional group in which 1-3 hydrogens of -SiH ₃ are substituted with 1 to 3 hydrocarbyl groups or hydrocarbyloxy groups. Specifically, the hydrocarbyl (oxy) silyl group having 1 to 20 carbon atoms may be a hydrocarbyl (oxy) silyl group having 1 to 15 carbon atoms, 1 to 10 carbon atoms, or 1 to 5 carbon atoms. More specifically, hydrocarbyl (oxy) silyl groups having 1 to 20 carbon atoms include alkyls such as methylsilyl group, dimethylsilyl group, trimethylsilyl group, dimethylethylsilyl group, diethylmethylsilyl group and dimethylpropylsilyl group. Silyl group; Alkoxysilyl groups such as methoxysilyl group, dimethoxysilyl group, trimethoxysilyl group and dimethoxyethoxysilyl group; And alkoxyalkylsilyl groups such as methoxydimethylsilyl group, diethoxymethylsilyl group, and dimethoxypropylsilyl group.

Non-limiting examples of the compound represented by Formula 2 in the above include methyl aluminoxane, ethyl aluminoxane, isobutyl aluminoxane or tert-butyl aluminoxane. In addition, non-limiting examples of the compound represented by Formula 3 include trimethyl aluminum, triethyl aluminum, triisobutyl aluminum, tripropyl aluminum, tributyl aluminum, dimethylchloro aluminum, triisopropyl aluminum, tri-sec-butyl aluminum, To tricyclopentyl aluminum, tripentyl aluminum, triisopentyl aluminum, trihexyl aluminum, trioctyl aluminum, ethyl dimethyl aluminum, methyl diethyl aluminum, triphenyl aluminum, tri-p-tolyl aluminum, dimethyl aluminum methoxide or dimethyl aluminum And thoxide. Finally, non-limiting examples of compounds represented by Formula 4 include trimethylammonium tetrakis (pentafluorophenyl) borate, triethylammonium tetrakis (pentafluorophenyl) borate, N, N-dimethylanilinium tetrakis ( Pentafluorophenyl) borate, N, N-dimethylanilinium n-butyltris (pentafluorophenyl) borate, N, N-dimethylanilinium benzyltris (pentafluorophenyl) borate, N, N-dimethylanilinium Tetrakis (4- (t-butyldimethylsilyl) -2,3,5,6-tetrafluorophenyl) borate, N, N-dimethylanilinium tetrakis (4- (triisopropylsilyl) -2,3 , 5,6-tetrafluorophenyl) borate, N, N-dimethylanilinium pentafluorophenoxytris (pentafluorophenyl) borate, N, N-dimethyl-2,4,6-trimethylanilinium tetrakis (Pentafluorophenyl) borate, trimethylammonium tetrakis (2,3,4,6-tetrafluorofe ) Borate, N, N-dimethylanilinium tetrakis (2,3,4,6-tetrafluorophenyl) borate, hexadecyldimethylammonium tetrakis (pentafluorophenyl) borate, N-methyl-N-dodecyl Anilium tetrakis (pentafluorophenyl) borate or methyl di (dodecyl) ammonium tetrakis (pentafluorophenyl) borate, etc. are mentioned.

The catalyst composition may be a supported catalyst in which the aforementioned transition metal compound is supported on a carrier. The transition metal compound represented by Chemical Formula 1 has the above-described structural characteristics and can be stably supported on a carrier. In addition, the supported catalyst on which the transition metal compound is supported exhibits high activity for olefin polymerization and can easily provide an olefin polymer having a high apparent density within various molecular weight ranges.

As the carrier, a carrier containing a hydroxy group or a siloxane group on the surface can be used. Specifically, as the carrier, a carrier containing a hydroxy group or a siloxane group having high reactivity may be used by drying at high temperature to remove moisture on the surface. More specifically, as the carrier, silica, alumina, magnesia or mixtures thereof may be used. The carrier may be dried at a high temperature, and these may generally include oxides, carbonates, sulfates, and nitrate components such as Na ₂ O, K ₂ CO ₃ , BaSO ₄ and Mg (NO ₃ ) ₂ .

The above-described catalyst composition is used in the polymerization reaction of an olefin monomer, exhibits high catalytic activity, and can provide an olefin polymer having a high apparent density within various molecular weight ranges.

On the other hand, according to another embodiment of the invention, in the presence of the catalyst composition, a method for producing an olefin polymer comprising the step of polymerizing an olefin monomer is provided.

As described above, the catalyst composition provides an olefin polymer having a high apparent density within various molecular weight ranges compared to a polyolefin polymerized using a conventional metallocene catalyst due to a specific structure, and is higher in polymerization of olefin monomers. Activity.

Examples of the olefin monomer polymerizable with the catalyst composition include ethylene, alpha-olefin, and cyclic olefin, and a diene olefin monomer or triene olefin monomer having two or more double bonds may also be polymerized. Specific examples of the monomers are ethylene, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dode Sen, 1-tetradecene, 1-hexadecene, 1-atocene, norbornene, norbornene, ethylidene norbornene, phenyl norbornene, vinyl norbornene, dicyclopentadiene, 1,4-butadiene, 1, 5-pentadiene, 1,6-hexadiene, styrene, alpha-methylstyrene, divinylbenzene, 3-chloromethylstyrene, and the like, and two or more of these monomers may be mixed and copolymerized.

For the polymerization reaction of the olefin monomer, various polymerization processes known as polymerization reactions of olefin monomers, such as a continuous solution polymerization process, a bulk polymerization process, a suspension polymerization process, a slurry polymerization process, or an emulsion polymerization process, can be employed.

Specifically, the polymerization reaction may be performed under a temperature of about 50 to 110 ° C or about 60 to 100 ° C and a pressure of about 1 to 100kgf / cm ² .

In addition, in the polymerization reaction, the catalyst composition may be used in a dissolved or diluted state in a solvent such as pentane, hexane, heptane, nonane, decane, toluene, benzene, dichloromethane, chlorobenzene, and the like. At this time, by treating the solvent with a small amount of alkyl aluminum or the like, a small amount of water or air, which may adversely affect the catalyst, can be removed in advance.

The olefin polymer prepared by the above method may exhibit a high apparent density within various molecular weight ranges as it is prepared using the catalyst composition described above.

Hereinafter, the operation and effects of the invention will be described in more detail through specific examples of the invention. However, this is provided as an example of the invention, and the scope of the invention is not limited in any way.

Manufacturing example  1: Preparation of transition metal compound and supported catalyst

Step 1: Preparation of 1H-cyclopenta [a] naphthalene

Naphthalene solution was prepared by dissolving 10 mmol of naphthalene in methylene chloride (MC). 10 mmol of AlCl ₃ was dispersed in MC, and the obtained AlCl ₃ solution was cooled. To the cooled AlCl ₃ solution, 10 mmol of the naphthalene solution and 3-chloropropanoyl chloride were injected. The temperature of the obtained reaction mixture was gradually raised to room temperature, and then stirred overnight.

Then, ice water was added to the stirred reaction mixture overnight to complete the reaction, and the organic layer was extracted with ether to obtain 3-chloro-1- (naphthalen-2-yl) propan-1-one in a yield of 100%.

¹ H NMR (500 MHz, CDCl ₃ ): 3.54 (2H, t), 3.97 (2H, t), 7.50-8.65 (7H, m)

10 mmol of 3-chloro-1- (naphthalen-2-yl) propan-1-one was dissolved in 50 mL of H ₂ SO ₄ and reacted at 90 ° C. for 5 hours. Then, ice water was added to the obtained reaction product to terminate the reaction, and the organic layer was extracted with ether to obtain 1,2-dihydro-3H-cyclopenta [a] naphthalen-3-one in a yield of 80% (isomer present).

¹ H NMR (500 MHz, CDCl ₃ ): 2.79 (1H, t), 2.84 (2H, t), 3.45 (1H, t), 3.74 (2H, t), 7.50 ~ 9.15 (6H, m)

10-mmol of 1,2-dihydro-3H-cyclopenta [a] naphthalen-3-one was dissolved in methanol and cooled. To the cooled solution, 25 mmol of NaBH ₄ was slowly added dropwise and stirred for 2 hours. Then, ice water was added to the obtained reaction product to complete the reaction, and the organic layer was extracted with ether to obtain 2,3-dihydro-1H-cyclopenta [a] naphthalene-3-ol in a yield of 100% (isomer present).

¹ H NMR (500 MHz, CDCl ₃ ): 2.12 (1H, m), 2.18 (1H, m), 2.59 (1H, m), 2.67 (1H, m), 2.97 (1H, m), 3.12 (1H, m), 3.27 (1H, m), 3.43 (1H, m), 5.43 (1H, s), 5.78 (1H, s), 7.37 to 8.16 (12H, m)

2,3-dihydro-1H-cyclopenta [a] naphthalene-3-ol was dissolved in THF, and a 1N HCl solution was added dropwise. The reaction mixture thus obtained was stirred at reflux for 2 hours. Then, water was added to the obtained reaction product to terminate the reaction, and the organic layer was extracted with ether to obtain 1H-cyclopenta [a] naphthalene in a yield of 70% (isomer present).

¹ H NMR (500 MHz, CDCl ₃ ): 3.56 (2H, s), 3.71 (1H, s), 6.64 (0.5H, d), 6.73 (1H, d), 6.97 (0.5H, d), 7.36 ~ 8.13 (9H, m)

Step 2: Preparation of (6-t-butoxyhexyl) dichloromethylsilane

Into a 1 L flask, 95 g of Mg was added, washed three times with 1.0M HCl three times with MeOH and three times with acetone, and then dried under reduced pressure at 25 ° C. for 3 hours. Into a reactor containing Mg, THF 1.0L and 1,2-DBE (1,2-dibromoethane) 5.0 mL were sequentially added and stirred. After adding 500 g of t-butoxyhexyl chloride to the dropping funnel, about 5% of them were added to the reactor for 5 minutes. Thereafter, the temperature of the reactor was raised to 70 ° C., and the reaction mixture was stirred for 30 minutes. Subsequently, the remaining amount of t-butoxyhexyl chloride was slowly added to the reactor over about 3 hours, and the reaction mixture was stirred at a temperature of 70 ° C. for about 15 hours. Then, the temperature of the reactor was cooled to 25 ° C, and the reaction mixture was filtered to remove excess Mg, and the filtrate was transferred to a 3L flask.

Meanwhile, after washing and drying under reduced pressure, 583 g of trichloromethylsilane and 3.3 L of THF were added to the reactor, and the temperature of the reactor was cooled to -15 ° C. Thereafter, the filtrate prepared above was gradually added dropwise to the reactor while maintaining it at -5 ° C for 2 hours. The temperature of the reactor was raised to 25 ° C. and stirred at about 130 rpm for 16 hours. Thereafter, the reaction mixture was distilled under reduced pressure at 25 ° C., dispersed in 4.3 L of hexane, and then stirred for 30 minutes. Thereafter, the solid was filtered from the reaction mixture, then washed and filtered with 1.0 L of hexane, and the filtrate was distilled under reduced pressure at 25 ° C. to obtain (6-t-butoxyhexyl) dichloromethylsilane in 85% yield.

¹ H NMR (500 MHz, CDCl ₃ , 7.24 ppm): 0.76 (3H, s), 1.11 (2H, t), 1.18 (9H, s), 1.32 ~ 1.55 (8H, m), 3.33 (2H, t)

Step 3: Preparation of 1- (6- (t-butoxy) hexyl) -N- (t-butyl) -1-chloro-1-methylsilaneamine

In 120 mL schlenk flask, 120 mmol of t-butylamine and 20 mL of ether solvent were added, and in 60 mL of (6-t-butoxyhexyl) dichloromethylsilane and 40 mL of ether solvent in another flask and 250 mL schlenk flask, t-butylamine solution and ( 6-t-butoxyhexyl) dichloromethylsilane solution was prepared, respectively. Then, the t-butylamine solution was cooled to -78 ° C, and (6-t-butoxyhexyl) dichloromethylsilane solution was slowly injected into the cooled solution, which was stirred at room temperature for about 2 hours. The resulting white suspension was filtered to give an ivory color, and liquid 1- (6- (t-butoxy) hexyl) -N- (t-butyl) -1-chloro-1-methylsilaneamine was obtained. .

¹ H NMR (CDCl ₃ ): 3.29 (t, 2H), 1.52-1.29 (m, 10H), 1.20 (s, 9H), 1.16 (s, 9H), 0.40 (s, 3H)

Step 4: Preparation of 1- (6- (t-butoxy) hexyl) -N- (t-butyl) -1- (1H-cyclopenta [a] naphthalen-1-yl) -1-methylsilaneamine

8.6 mmol of 1H-cyclopenta [a] naphthalene was dissolved in a mixed solvent of 101 mL of toluene and 10.1 mL of THF. Thereafter, the reaction mixture was cooled to -25 ° C, and 3.6 mL (9.1 mmol) of n-butyllithium solution (2.5M solution in hexane) was slowly added dropwise to the reaction mixture. Then, the resulting reaction mixture was stirred at room temperature for 3 hours. Then, 9.9 mg of CuCN was dissolved in a small amount of toluene, added to the reaction mixture in the form of a slurry, and stirred for 30 minutes. Subsequently, 1- (6- (t-butoxy) hexyl) -N- (t-butyl) -1-chloro-1-methylsilaneamine prepared above is added to the reaction mixture, and the obtained reaction mixture is at room temperature. Stir for one day. Thereafter, an organic layer was extracted from the obtained reaction product using water and ether, and dried to 1- (6- (t-butoxy) hexyl) -N- (t-butyl) -1- (1H-cyclopenta [a ] Naphthalen-1-yl) -1-methylsilaneamine was obtained.

¹ H NMR (500 MHz, CDCl ₃ , 7.24 ppm): 0.14 (3H, s), 1.15 (9H, s), 1.24 (9H, s), 0.60 to 1.49 (10H, m), 3.30 (2H, t) , 3.56 (1H, s), 6.47 (1H, d), 6.96 (1H, d), 7.32 ~ 7.86 (6H, m)

Step 5: Preparation of (1H-cyclopenta [a] naphthalen-1-yl) (t-butylamino) (6- (t-butoxy) hexyl) (methyl) silane titanium dichloride

8.6 mmol of the previously prepared 1- (6- (t-butoxy) hexyl) -N- (t-butyl) -1- (1H-cyclopenta [a] naphthalen-1-yl) -1-methylsilaneamine was prepared. After dissolving in 14 mL of toluene and 1.7 mL of n-hexane, 7.3 mL (18 mmol) of n-butyllithium solution (2.5M solution in hexane) was slowly added dropwise to the solution at -78 ° C. Then, the resulting reaction mixture was stirred at room temperature for about 12 hours. Then, the reaction mixture was added to a reaction vessel containing 8.6 mmol of TiCl ₄ (THF) ₂ at -78 ° C and stirred at room temperature for one day. Thereafter, the reaction mixture was dried to remove the solvent, and then toluene was injected. Then, the obtained mixed solution was filtered and the filtrate was dried to obtain a transition metal compound represented by the following Chemical Formula 1a.

[Formula 1a]

¹ H NMR (500 MHz, CDCl ₃ , 7.24 ppm): 1.16 (9H, s), 1.35 (9H, s), 1.49 (3H, s), 0.79 to 1.83 (10H, m), 3.32 (2H, t) , 6.39 (1H, d), 6.58 (1H, d), 7.39 to 7.92 (6H, m).

Step 6: Preparation of supported catalyst

Methyl aluminoxane (MAO) 8 mmol / gSiO ₂ was added to a shrink flask containing 9.1 g of silica and reacted at 60 ° C. for 12 hours. After completion of the reaction, when the reaction product subsided, the upper layer solution was removed and the remaining precipitate was washed once with toluene. Then, 0.1 mmol / gSiO ₂ of the transition metal compound prepared above was dissolved in toluene and injected into the flask, and reacted at 40 ° C. for 2 hours. After completion of the reaction, when the reaction product subsided, the upper layer solution was removed and the remaining precipitate was washed once with toluene. Subsequently, 0.15 mmol / gSiO ₂ of dimethylanilininium tetrakis (pentafluorophenyl) borate was added to the flask, and the mixture was reacted at 50 ° C. for 5 hours. After the reaction was completed, washing was performed with toluene, washed again with hexane, and dried under vacuum to obtain a silica-supported metallocene catalyst in the form of solid particles.

Manufacturing example  2: Preparation of transition metal compound and supported catalyst

1- (6- (t-butoxy) hexyl) -1- (9H-fluoren-9-yl) -1-chloro-1 using fluorene instead of t-butylamine in Step 3 of Preparation Example 1 -Methylamine was prepared, and the transition metal compound of Formula 1b and the supported catalyst were prepared in the same manner as in Preparation Example 1, except that ZrCl ₄ (THF) ₂ was used instead of TiCl ₄ (THF) ₂ in step 5.

[Formula 1b]

¹ H NMR (500 MHz, CDCl ₃ , 7.24 ppm): 1.10 (9H, m), 0.60 to 1.52 (10H, m), 3.31 (2H, m), 6.21 (1H, d), 6.52 (1H, d) , 7.08 ~ 7.85 (6H, m).

Manufacturing example  3: Preparation of transition metal compound and supported catalyst

2-methyl-1H-cyclo by replacing step 1 of the preparation example 1 (preparation of 1H-cyclopenta [a] naphthalene) with step 1 described below (preparation of 2-methyl-1H-cyclopenta [a] naphthalene) A penta [a] naphthalene was prepared, and a transition metal compound of Formula 1c and a supported catalyst were prepared in the same manner as steps 2 to 6 of Preparation Example 1 using the same.

[Formula 1c]

¹ H NMR (500 MHz, CDCl ₃ , 7.24 ppm): 1.16 (9H, s), 1.35 (9H, s), 1.41 (3H, s), 0.55-1.45 (10H, m), 1.92 (3H, s) , 3.29 (2H, t), 7.14 (1H, d), 7.39 to 7.92 (6H, m).

Step 1: Preparation of 2-methyl-1H-cyclopenta [a] naphthalene

Naphthalene solution was prepared by dissolving 10 mmol of naphthalene in methylene chloride (MC). 10 mmol of AlCl ₃ was dispersed in MC, and the obtained AlCl ₃ solution was cooled. The cooled AlCl ₃ solution The naphthalene solution and 10 mmol of 3-chloro-2-methylpropanoyl chloride were injected. The temperature of the obtained reaction mixture was gradually raised to room temperature, and then stirred overnight. Then, ice water was added to the reaction mixture stirred overnight, and the organic layer was extracted with ether to obtain 3-chloro-2-methyl-1- (naphthalen-2-yl) propan-1-one.

¹ H NMR (500 MHz, CDCl ₃ ): 1.25 (3H, d), 3.20 (2H, m), 3.45 (1H, m), 7.60 to 8.60 (7H, m)

10 mmol of 3-chloro-2-methyl-1- (naphthalen-2-yl) propan-1-one was dissolved in 50 ml of H ₂ SO ₄ and reacted at 90 ° C. for 5 hours. Then, ice water was added to the obtained reaction product, and the organic layer was extracted with ether to obtain 2-methyl-1,2-dihydro-3H-cyclopenta [a] naphthalen-3-one.

¹ H NMR (500 MHz, CDCl ₃ ): 1.30 (3H, d), 3.28 (2H, d), 3.50 (1H, m), 7.50 to 9.20 (6H, m)

10 mmol of 2-methyl-1,2-dihydro-3H-cyclopenta [a] naphthalen-3-one was dissolved in methanol and then cooled. To the cooled solution, 25 mmol of NaBH ₄ was slowly added dropwise and stirred for 2 hours. Then, water was added to the obtained reaction product, and the organic layer was extracted with ether to obtain 2-methyl-2,3-dihydro-1H-cyclopenta [a] naphthalene-3-ol.

¹ H NMR (500 MHz, CDCl ₃ ): 1.27 (3H, d), 3.22 (2H, m), 3.48 (1H, s), 7.27-8.20 (6H, m)

After dissolving 10 mmol of 2-methyl-2,3-dihydro-1H-cyclopenta [a] naphthalene-3-ol in toluene, 1 mmol of p-doluenesulfonic acid was added dropwise. The reaction mixture thus obtained was stirred at reflux for 2 hours. Then, water was added to the obtained reaction product, and the organic layer was extracted with ether to obtain 2-methyl-1H-cyclopenta [a] naphthalene.

¹ H NMR (500 MHz, CDCl ₃ ): 2.27 (3H, s), 3.45 (2H, s), 7.08 (1H, s), 7.40 to 8.05 (6H, m).

Manufacturing example  4: Preparation of transition metal compound and supported catalyst

1- (6- (t-butoxy) hexyl) -1- (9H-fluoren-9-yl) -1-chloro-1 using fluorene instead of t-butylamine in step 3 of Preparation Example 3. -Methylamine was prepared, and a transition metal compound of Formula 1d and a supported catalyst were prepared in the same manner as in Preparation Example 3, except that ZrCl ₄ (THF) ₂ was used instead of TiCl ₄ (THF) ₂ in step 5.

[Formula 1d]

¹ H NMR (500 MHz, CDCl ₃ , 7.24 ppm): 1.05 (9H, m), 0.72-1.61 (10H, m), 1.38 (3H, s), 3.21 (2H, m), 5.88 (2H, d) , 6.96 ~ 7.85 (6H, m).

Example  1: Polymerization of olefin monomer

A 600 mL metal alloy reactor was prepared, which is equipped with a mechanical stirrer, is capable of temperature control, and can be used for a high pressure reaction.

On the other hand, the supported catalyst prepared in Preparation Example 1 was quantified in a dry box and placed in a 50 mL glass bottle, and then the inlet of the glass bottle was sealed with a rubber septum.

Then, 400 mL of hexane containing 1.0 mmol of triethyl aluminum and the previously prepared supported catalyst were added to the 600 mL metal alloy reactor without air contact. Subsequently, the temperature of the reactor was raised to about 80 ° C., and ethylene gas was injected into the reactor to polymerize ethylene for about 1 hour. At this time, ethylene gas was continuously injected so that the pressure in the reactor was maintained at about 9 kgf / cm ² .

Thereafter, when ethylene was polymerized to a desired level, stirring of the reactor was stopped, and unreacted ethylene gas was removed by evacuation. Then, the solvent was removed from the reaction product, and the obtained solid was dried in a vacuum oven at about 80 ° C. for about 4 hours to obtain an ethylene homopolymer.

Example  2: Polymerization of olefin monomer

Ethylene homopolymer was obtained in the same manner as in Example 1, except that the supported catalyst of Preparation Example 2 was used in Example 1.

Example  3: Polymerization of olefin monomer

Ethylene homopolymer was obtained in the same manner as in Example 1, except that the supported catalyst of Preparation Example 3 was used in Example 1.

Example  4: Polymerization of olefin monomer

Ethylene homopolymer was obtained in the same manner as in Example 1, except that the supported catalyst of Preparation Example 4 was used in Example 1.

Comparative example  1: Polymerization of olefin monomer

A supported catalyst was prepared in the same manner as in Step 6 of Preparation Example 1 using the transition metal compound represented by the following Chemical Formula P-1.

[Formula P-1]

Ethylene homopolymer was obtained in the same manner as in Example 1, except that the supported catalyst of Formula P-1 was used in Example 1.

Comparative example  2: Polymerization of olefin monomer

A supported catalyst was prepared in the same manner as in Step 6 of Preparation Example 1 using the transition metal compound represented by the following Chemical Formula P-2.

[Formula P-2]

Ethylene homopolymer was obtained in the same manner as in Example 1, except that the supported catalyst of Formula P-2 was used in Example 1.

Test example : Olipine  Evaluation of polymer properties

The physical properties of the olefin polymers prepared in Examples 1 to 4 and Comparative Examples 1 to 2 were evaluated as follows, and the results are shown in Table 1 below.

(1) Catalytic activity: The mass of the catalyst used in the polymerization reaction and the mass of the polymer calculated per hour from the reaction were measured to calculate the activity of the catalyst used in each example and comparative examples.

(2) Weight average molecular weight and molecular weight distribution: The weight average molecular weight (Mw) and molecular weight distribution (PDI) were calculated through GPC analysis by taking 10 mg as a sample from the polymers prepared in each Example and Comparative Examples.

(3) Bulk Density: It was obtained by measuring the weight (g) of an olefin polymer in a 100 mL container using IPT model 1132.

(4) Copolymerization: Before injecting ethylene gas into each polymerization reaction of Examples 1 to 4, 5 mL of 1-hexene was injected to perform a copolymerization reaction. The content of the ¹ -hexene-derived repeating unit (branch) contained in the ethylene-1-hexene copolymer prepared through the copolymerization reaction is calculated through ¹ H-NMR and ¹³ C-NMR to promote the degree of catalyst to promote the copolymerization reaction. Was evaluated. Table 1 shows the repeating unit (branch) content derived from 1-hexene compared to the total number of moles of the copolymer.

Catalytic activity
[kgPol./(gCat.*hr)] Weight average molecular weight Molecular weight distribution Apparent density
[g / cm ³ ] Aerial synthesis
[1-hexene mol%] Example 1 3.2 1,297,000 2.27 0.38 10.2 Example 2 4.5 266,000 3.11 0.36 8.9 Example 3 2.8 1,255,000 2.01 0.37 10.8 Example 4 4.8 424,000 4.27 0.36 9.2 Comparative Example 1 0.5 210,000 3.20 0.31 Comparative Example 2 0.8 325,000 3.80 0.32

Referring to Table 1, the polymerization reaction of the olefin monomers according to Comparative Examples 1 and 2 shows very low catalytic activity, whereas the catalysts used in the polymerization reactions of Examples 1 to 4 exhibited very good catalytic activity.

Further, referring to Examples 1 to 4, when using the transition metal compound according to an embodiment of the present invention, the molecular weight of the olefin polymer can be easily adjusted by varying the C ¹ ligand of Chemical Formula 1, and in various molecular weight ranges. It is confirmed that an olefin polymer having a high bulk density can provide the polymer. On the other hand, Comparative Examples 1 and 2, it is confirmed that even if the ligand is changed, the molecular weight is not easily adjusted, and the morphology of the prepared olefin polymer is poor and thus has a low bulk density.

On the other hand, when comparing Examples 1 and 3 with Examples 2 and 4, it is confirmed that the copolymerization can be easily controlled by varying the C ¹ ligand of Chemical Formula 1.

Claims (13)

Transition metal compound represented by the following formula (1):
[Formula 1]

In Chemical Formula 1,
M ¹ is any ^one of a group 3 transition metal, a group 4 transition metal, a group 5 transition metal, a lanthanide-based transition metal, and an actanide-based transition metal,
X ¹ and X ² are the same or different from each other, and each independently is one of halogen and alkyl having 1 to 20 carbons,
A is any one of elements of group 14, n is an integer from 1 to 20,
R ¹ is any one of alkyl having 1 to 20 carbons, alkenyl having 2 to 20 carbons, alkylaryl having 7 to 30 carbons, arylalkyl having 7 to 30 carbons, and aryl having 6 to 30 carbons,
R ² is hydrogen, alkyl having 1 to 20 carbons, alkenyl having 2 to 20 carbons, alkylaryl having 7 to 30 carbons, arylalkyl having 7 to 30 carbons or aryl having 6 to 30 carbons,
R ³ and R ⁴ are each independently hydrogen, alkyl having 1 to 20 carbon atoms, which is unsubstituted or substituted with a hetero atom,
C ¹ is -NR ⁵ -and

Is either
R ⁵ is any one of 4 to 8 branched chain alkyl,
R ⁶ to R ¹³ are each independently hydrogen or 1 to 4 carbon atoms.
The transition metal compound according to claim 1, wherein R ³ and R ⁴ are each independently hydrogen or straight-chain alkyl having 1 to 5 carbon atoms.
delete delete The transition metal compound according to claim 1, wherein R ¹ is any of branched chain alkyl having 4 to 6 carbon atoms, and n is 4 to 8.
The transition metal compound according to claim 1, wherein R ² is any one of straight chain alkyl having 1 to 6 carbon atoms.
The transition metal compound according to claim 1, wherein M ¹ is any one of a Group 4 transition metal.
A catalyst composition comprising the transition metal compound represented by Chemical Formula 1 of claim 1.
The catalyst composition according to claim 8, comprising at least one cocatalyst selected from the group consisting of compounds represented by the following Chemical Formulas 2 to 4:
[Formula 2]
R ^23- [Al (R ²² ) -O] _m -R ²⁴
In Chemical Formula 2,
R ²² , R ²³ and R ²⁴ are each independently hydrogen, halogen, a hydrocarbyl group having 1 to 20 carbon atoms or a hydrocarbyl group having 1 to 20 carbon atoms substituted with halogen,
m is an integer greater than or equal to 2,
[Formula 3]
D (R ²⁵ ) ₃
In Chemical Formula 3,
D is aluminum or boron,
R ²⁵ is each independently halogen, a hydrocarbon group having 1 to 20 carbon atoms, a hydrocarbyloxy group having 1 to 20 carbon atoms, or a hydrocarbyl group having 1 to 20 carbon atoms substituted with halogen,
[Formula 4]
^{[LH] + [W (J} ) 4] - or ^{[L] + [W (J} ) 4] -
In Chemical Formula 4,
L is a neutral or cationic Lewis base,
W is a group 13 element, J is each independently a hydrocarbon group having 1 to 20 carbon atoms; A hydrocarbyloxy group having 1 to 20 carbon atoms; And one or more substituents in which one or more hydrogen atoms of these substituents are substituted with one or more substituents among halogen, a hydrocarbyloxy group having 1 to 20 carbon atoms and a hydrocarbyl (oxy) silyl group having 1 to 20 carbon atoms.
The catalyst composition according to claim 8, further comprising a carrier supporting the transition metal compound.
The catalyst composition according to claim 10, wherein the carrier is silica, alumina, magnesia or a mixture thereof.
A method for producing an olefin polymer comprising the step of polymerizing an olefin monomer in the presence of the catalyst composition of claim 8.
The method of claim 12, wherein the olefin 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 novoden, phenyl novoden, vinyl novoden, dicyclopentadiene, 1,4- A method for producing an olefin polymer comprising at least one member selected from the group consisting of butadiene, 1,5-pentadiene, 1,6-hexadiene, styrene, alpha-methylstyrene, divinylbenzene and 3-chloromethylstyrene.