KR20150058065A - Method for preparing propylene-based polymer - Google Patents

Abstract

The present invention relates to a preparation method of a propylene-based polymer. The preparation method of a propylene-based polymer according to the present invention can effectively prepare a propylene-based polymer having a large molecular weight and balanced properties by using a metallocene catalyst for excellent propylene homo polymerization activation and alpha olefin copolymerization activation. The method includes polymerizing propylene or propylene and alpha-olefin having at least four carbon atoms in presence of a catalyst composition having a transition metal compound represented by the following chemical formula 1.

Description

METHOD FOR PREPARING PROPYLENE-BASED POLYMER [0002]

The present invention relates to a process for producing a propylene-based polymer.

In general, metallocene catalysts are more easily used to control the molecular weight and molecular weight distribution of polyolefins than conventional Ziegler-Natta catalysts, and can control the distribution of comonomers in the polymer, and are used to produce polyolefins and the like that have improved mechanical properties and processability simultaneously come. However, polyolefins prepared using metallocene catalysts suffer from poor processability due to their narrow molecular weight distribution.

Generally, the wider the molecular weight distribution, the higher the degree of decrease in viscosity with shear rate, and the better the workability in the machining area. The polyolefin prepared with the metallocene catalyst, due to the relatively narrow molecular weight distribution, There is a disadvantage in that the extrusion productivity and the blowing productivity are lowered. In particular, the bubble stability is significantly lowered during the blow molding process, and the surface of the produced molded article is uneven, resulting in lower transparency.

Accordingly, there is a continuing need to develop a technique capable of more effectively producing a polyolefin having a large molecular weight and balanced physical properties.

The present invention is to provide a process for efficiently producing a propylene polymer or a propylene / alpha olefin copolymer having a large molecular weight and excellent physical properties.

According to the present invention, there is provided a process for producing a propylene-based polymer comprising the step of polymerizing propylene or propylene with an alpha-olefin having 4 or more carbon atoms in the presence of a catalyst composition comprising a transition metal compound represented by the following formula :

[Chemical Formula 1]

In Formula 1,

M is a Group 4 transition metal;

Each X is independently halogen, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group having 7 to 20 carbon atoms, or an arylalkyl group having 7 to 20 carbon atoms;

Each of R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ and R ¹¹ is independently hydrogen, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms , An aryl group having 6 to 20 carbon atoms, an alkylaryl group having 7 to 20 carbon atoms, or an arylalkyl group having 7 to 20 carbon atoms; Any one of R ³ and R ⁴ and any one of R ⁹ and R ¹⁰ is independently an aryl group having 10 to 20 carbon atoms which is substituted or unsubstituted with an alkyl group having 1 to 10 carbon atoms;

R ⁶ and R ¹² are each independently an alkyl group having 1 to 5 carbon atoms;

Q is carbon (C), silicon (Si), germanium (Ge), or tin (Sn);

R ¹³ and R ¹⁴ are each independently an alkyl group having 1 to 10 carbon atoms.

According to the present invention, in Formula 1, M is titanium (Ti), zirconium (Zr), or hafnium (Hf); X is halogen; Any one of R ³ and R ⁴ and any one of R ⁹ and R ¹⁰ is independently a naphthyl group substituted or unsubstituted with an alkyl group having 1 to 10 carbon atoms; R ⁶ and R ¹² are each independently an alkyl group having 1 to 3 carbon atoms; Each of R ¹³ and R ¹⁴ may independently be an alkyl group having 1 to 10 carbon atoms.

According to the present invention, there is provided a process for producing a propylene-based polymer, wherein the propylene homopolymer having a weight average molecular weight of 200,000 to 2,000,000 g / mol is obtained through the polymerization reaction.

Further, according to the present invention, there is provided a process for producing a propylene-based polymer, wherein a propylene / alpha olefin copolymer having excellent impact strength, transparency and processability is obtained through the polymerization reaction.

The process for producing a propylene-based polymer according to the present invention is to more effectively produce a propylene-based polymer having a large molecular weight and a balanced physical property by using a metallocene catalyst having excellent propylene homopolymerization activity and propylene / alpha olefin copolymerization activity It is possible.

Hereinafter, a method for producing a propylene-based polymer according to an embodiment of the present invention will be described in detail.

Prior to that, the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. And, the singular forms used herein include plural forms unless the phrases expressly have the opposite meaning. Also, as used herein, the term " comprises " embodies specific features, regions, integers, steps, operations, elements or components, and does not exclude the presence of other specified features, regions, integers, steps, operations, elements, It does not.

On the other hand, according to the research results of the present inventors, it has been confirmed that a propylene polymer having a larger molecular weight can be produced more efficiently than when a catalyst composition comprising a transition metal compound represented by the following formula (1) is used for propylene homopolymerization. Furthermore, the transition metal compound represented by the following formula (1) can exhibit excellent activity in the copolymerization reaction of propylene with an alpha olefin (in particular, an alpha olefin having a large steric hindrance), and thus provides a propylene / alpha olefin copolymer .

According to one embodiment of the present invention, there is provided a process for producing a propylene-based polymer comprising the step of polymerizing propylene or propylene with an alpha-olefin having 4 or more carbon atoms in the presence of a catalyst composition comprising a transition metal compound represented by the following formula Is provided:

[Chemical Formula 1]

In Formula 1,

M is a Group 4 transition metal;

Each X is independently halogen, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group having 7 to 20 carbon atoms, or an arylalkyl group having 7 to 20 carbon atoms;

Each of R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ and R ¹¹ is independently hydrogen, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms , An aryl group having 6 to 20 carbon atoms, an alkylaryl group having 7 to 20 carbon atoms, or an arylalkyl group having 7 to 20 carbon atoms; Any one of R ³ and R ⁴ and any one of R ⁹ and R ¹⁰ is independently an aryl group having 10 to 20 carbon atoms which is substituted or unsubstituted with an alkyl group having 1 to 10 carbon atoms;

R ⁶ and R ¹² are each independently an alkyl group having 1 to 5 carbon atoms;

Q is carbon (C), silicon (Si), germanium (Ge), or tin (Sn);

R ¹³ and R ¹⁴ are each independently an alkyl group having 1 to 10 carbon atoms.

The transition metal compound represented by the formula (1) includes two indenyl groups, and the two indenyl groups are symmetrically connected by a bridge of carbon, silicon and the like.

In particular, the transition metal compound has a structure in which an aryl group (preferably a naphthyl group) having 10 to 20 carbon atoms and an alkyl group are introduced at specific positions of the indenyl group. Due to such a chemical structure, the transition metal compound is excellent in the homopolymerization activity of propylene through control of the surrounding electronic environment and steric environment, and thus it is possible to provide a polypropylene having a large molecular weight. Furthermore, the transition metal compound has a high activity for the copolymerization reaction of propylene and an alpha-olefin, and exhibits excellent polymerization activity even for an alpha-olefin having a large steric hindrance such as 1-hexene, Olefin < / RTI > copolymer.

According to an embodiment of the present invention, M in the formula (1) may be a transition metal of Group 4, preferably titanium (Ti), zirconium (Zr) or hafnium (Hf).

In Formula 1, X is independently selected from the group consisting of halogen, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group having 7 to 20 carbon atoms, An arylalkyl group having 7 to 20 carbon atoms; Preferably each may be halogen. Here, the alkylaryl group means a functional group in which at least one linear or branched alkyl group having at least 1 carbon atom is introduced into an aryl group having 6 or more carbon atoms. The arylalkyl group means a functional group in which an aryl group having 6 or more carbon atoms is introduced into at least one linear or branched alkyl group having at least 1 carbon atom.

In Formula 1, Q may be carbon (C), silicon (Si), germanium (Ge), or tin (Sn); Preferably carbon or silicon.

R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ and R ¹¹ are each independently selected from the group consisting of hydrogen, An alkyl group, a cycloalkyl group having 3 to 8 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group having 7 to 20 carbon atoms, or an arylalkyl group having 7 to 20 carbon atoms.

In particular, any one of R ³ and R ⁴ , and any one of R ⁹ and R ¹⁰ may be independently an aryl group having 10 to 20 carbon atoms, which is substituted or unsubstituted with an alkyl group having 1 to 10 carbon atoms. According to an embodiment of the present invention, an aryl group having 10 to 20 carbon atoms is introduced at any one of R ³ and R ^{4 and} at any one of R ⁹ and R ¹⁰ , so that a more effective electronic environment and three-dimensional Environment control is possible. Accordingly, such transition metal compounds can exhibit high activity for the copolymerization of alpha olefins and propylene, which are not only homopolymerization of propylene but also steric hindered amines, and can form a propylene-based copolymer having high long-chain branching (LCB) . Further, the polymer obtained by using the transition metal compound may have a large molecular weight and a high melting point (Tm).

According to an embodiment of the present invention, the aryl group introduced into any one of R ³ and R ⁴ , and either R ⁹ or R ¹⁰ in Formula 1 may be a naphthyl group, an anthracenyl group, or a pyridyl group, Among them, a naphthyl group may be preferable for attaining the above-mentioned effect. For reference, when an aryl group having less than 10 carbon atoms (that is, a phenyl group) is introduced at the above position, the electron / stereoscopic environment control effect hardly appears, and it is difficult to obtain a copolymer having low catalytic activity or high LCB.

In Formula 1, R ⁶ and R ¹² each independently represent an alkyl group having 1 to 5 carbon atoms or an alkyl group having 1 to 3 carbon atoms.

In Formula 1, R ¹³ and R ¹⁴ bonded to Q may each independently be an alkyl group having 1 to 10 carbon atoms, an alkyl group having 1 to 5 carbon atoms, or an alkyl group having 1 to 3 carbon atoms.

The transition metal compound represented by the formula (1) includes an aryl group (preferably a naphthyl group) at any one of R ³ and R ⁴ , and R ⁹ and R ¹⁰ ; An alkyl group at the position of R ⁶ and R ¹² ; Since it has a structure containing an alkyl group at the positions of R ¹³ and R ¹⁴ , it can show not only the homopolymerization activity of propylene but also the copolymerization reaction of propylene and an alpha olefin.

As a non-limiting example, specific examples of the transition metal compound represented by the above formula (1) include compounds represented by the following structural formulas:

,

,

,

,

,

.

,

.

The transition metal compound of the above formula (1) can be synthesized by applying known reactions, and a more detailed synthesis method will be described in the examples.

On the other hand, according to one embodiment, the catalyst composition may further comprise a cocatalyst compound.

Herein, as the above-mentioned co-catalyst compound, those which are common in the technical field of the present invention can be applied without particular limitation. However, as a non-limiting example, the promoter compound may be at least one compound selected from the group consisting of compounds represented by the following formulas (2), (3) and (4)

(2)

R ¹⁵ - [Al (R ¹⁵ ) -O] _a --R ¹⁷

In Formula 2,

R ¹⁵ , R ¹⁶ and R ¹⁷ 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,

a is an integer of 2 or more;

(3)

D (R ¹⁸⁾ ₃

In Formula 3,

D is aluminum or boron;

R ¹⁸ is each independently halogen, a hydrocarbyl group having 1 to 20 carbon atoms, or a hydrocarbyl group having 1 to 20 carbon atoms substituted with halogen;

[Chemical Formula 4]

^{[LH] + [Z (A} ) 4] - or ^{[L] + [Z (A} ) 4] -

In Formula 4,

L is a neutral or cationic Lewis base;

[LH] + or [L] ⁺ is a Bronsted acid;

H is a hydrogen atom;

Z is a Group 13 element;

A is independently at each occurrence one or more hydrogen atoms independently selected from the group consisting of halogen, a hydrocarbyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms substituted with an alkoxy or phenoxy radical having 1 to 20 carbon atoms, or an alkyl group having 1 to 20 carbon atoms.

In the above Chemical Formulas 2 and 3, "hydrocarbyl" is a monovalent functional group having a hydrogen atom removed from a hydrocarbon, and may include ethyl, phenyl, and the like.

As a non-limiting example, the compound represented by Formula 2 may be methylaluminoxane, ethylaluminoxane, isobutylaluminoxane, butylaluminoxane, or the like.

In addition, as a non-limiting example, the compound represented by the above-mentioned general formula (3) may be used in combination with one or more compounds selected from the group consisting of trimethylaluminum, triethylaluminum, triisobutylaluminum, tripropylaluminum, tributylaluminum, dimethylchloroaluminum, triisopropylaluminum, 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, dimethyl aluminum Ethoxide and the like.

In addition, as a non-limiting example, the compound represented by the general formula (4) may be at least one compound selected from the group consisting of trimethylammonium tetrakis (pentafluorophenyl) borate, triethylammonium tetrakis (pentafluorophenyl) borate, N, N-dimethylanilinium tetrakis N, N-dimethylanilinium benzyltris (pentafluorophenyl) borate, N, N-dimethylanilinium n-butyltris (pentafluorophenyl) Tetrakis (4- (t-butyldimethylsilyl) -2,3,5,6-tetrafluorophenyl) borate, N, N-dimethylanilinium tetrakis (4- (triisopropylsilyl) , 5,6-tetrafluorophenyl) borate, N, N-dimethylanilinium pentafluorophenoxy tris (pentafluorophenyl) borate, N, N-dimethyl- 2,4,6- trimethylanilinium tetrakis (Pentafluorophenyl) borate, trimethylammonium tetrakis (2,3,4,6-tetrafluorophenyl) N, N-dimethylanilinium tetrakis (2,3,4,6-tetrafluorophenyl) borate, hexadecyldimethylammonium tetrakis (pentafluorophenyl) borate, N-methyl-N-dodecyl anil (Pentafluorophenyl) borate, methyldi (dodecyl) ammonium tetrakis (pentafluorophenyl) borate, and the like.

According to one embodiment, when the compound of Formula 4 is used as the co-catalyst compound, about 1 to 20 moles, or 1 to 18 moles of the co-catalyst compound per mole of the transition metal compound of Formula 1, Or 1 to 15 moles. According to one embodiment, when the compound of Formula 2 or Formula 3 is used as the co-catalyst compound, about 500 to 20,000 moles of the co-catalyst compound, or 2,000 to 20,000 moles of the co-catalyst compound per mole of the transition metal compound of Formula 1, 20,000 mole, or 5,000 to 20,000 mole of the transition metal compound. That is, in order to allow the alkylation of the transition metal compound to proceed sufficiently, it is preferable that the co-catalyst compound is contained at a molar ratio of the minimum content or more. However, when the above-mentioned co-catalyst compound is added in an excess amount, the physical properties of the polymer may be difficult to control, and in particular, the activation of the alkylated transition metal compound may not be completely achieved. Therefore, in order to prevent this, the above-mentioned co-catalyst compound is preferably contained at a molar ratio of not more than the above maximum content.

According to an embodiment of the present invention, the method for producing the propylene-based polymer may include the step of polymerizing propylene or propylene with an alpha-olefin having 4 or more carbon atoms in the presence of the catalyst composition described above.

The catalyst composition can be used for the polymerization of various olefin monomers, but it is possible to provide a polypropylene having a particularly high activity for homopolymerization of propylene and having a large molecular weight. The catalyst composition can exhibit high activity in the copolymerization reaction of propylene and an alpha olefin, and exhibits excellent polymerization activity even for an alpha-olefin having a large steric hindrance such as 1-hexene and the like. Thus, a propylene / alpha olefin Thereby making it possible to provide a copolymer.

According to the above production process, propylene polymer or propylene / alpha olefin copolymer may be provided. Wherein the alpha olefin is selected from the group consisting of 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, Dodecene, and the like.

Through the polymerization step, a propylene homopolymer having a weight average molecular weight of 200,000 to 2,000,000 g / mol, or 400,000 to 1,800,000 g / mol, or 500,000 to 1,500,000 g / mol can be obtained.

Through the polymerization reaction step, a propylene / alpha olefin copolymer having excellent impact strength, transparency and processability can be provided. In addition, the propylene / alpha-olefin copolymer has a low haze, high transparency, and high elongation so that it can exhibit excellent elasticity.

According to an embodiment of the present invention, the polymerization reaction may be carried out according to a process of solution polymerization.

At this time, the catalyst composition may be added at a concentration of about 1 X 10 ^-7 to about 1 X 10 ^-4 mol, or about 1 X 10 ^-6 to about 1 X 10 ^-5 mol per mol of the monomer to be polymerized.

Further, in the above polymerization reaction, the catalyst composition may be used in a state of being dissolved or diluted in a solvent such as pentane, hexane, heptane, nonane, decane, toluene, benzene, dichloromethane, chlorobenzene and the like. At this time, it is preferable to treat the solvent with a small amount of alkylaluminum or the like to remove a small amount of water or air that can act as a catalyst poison beforehand.

And wherein the polymerization reaction is conducted at a temperature of from about 10 to about 110 캜, or from about 80 to about 100 캜; And from about 1 to about 50 bar, or from about 5 to about 20 bar.

The propylene polymer produced by such a method has high heat distortion temperature and flexural strength and is excellent in impact strength and is suitable for manufacturing various products in various fields such as automobile parts, interior materials, food containers, medical instruments, etc. .

Hereinafter, preferred embodiments of the present invention will be described in order to facilitate understanding of the present invention. However, the following examples are intended to illustrate the present invention without limiting it thereto.

Synthetic example : Metallocene  Synthesis of compounds

(1) Synthesis of 2-methyl-4- (1-naphthyl) -indene

: 500 ml round bottom flask 2-methyl-4-bromo- indene (10 g, 47.8 mmol), 1-naphthyl boronic acid (9.85 g, 57.3 mmol), sodium carbonate (7.6 g, 71.7 mmol), Pd (PPh 3 ) ₄ (1.1 g, 0.956 mmol), and the mixture was dissolved by adding a mixed solvent (toluene: EtOH: H ₂ O = 2: 1: 1, 200 ml). The reaction was stirred at 80 < 0 > C for 6 hours, then cooled to room temperature and diluted with H ₂ O (100 ml) and ethyl acetate (EtOAc, 100 ml). The organic layer was separated, the aqueous layer re-chulchulhan in EtOAc (150 ml), followed by dehydrating the organic layer with MgSO ₄ and filtered. The filtrate was distilled off under reduced pressure, toluene (15 ml) and MeOH (80 ml) were added, stirred at room temperature, and crystals were precipitated at -20 ° C for 2 hours. The precipitated crystals were filtered under reduced pressure, washed with MeOH (50 ml) and the separated crystals were dried under reduced pressure at 30 ° C for 8 hours to obtain 2-methyl-4- (1-naphthyl) 42.9 mmol, yield 90%).

(2) Synthesis of Dimethylbis (2-methyl-4- (naphthalen-1-yl) -1H-inden-1-yl) silane ligand

: 2-methyl-4- (1-naphthyl) -indene (10 g, 39.0 mmol) was added to a 500 ml round-bottomed flask and toluene / THF (10: 1, 121 ml) was added and dissolved at room temperature. The solution was cooled to -20 C and n- BuLi (2.5 M in hexane, 16.4 ml, 41.0 mmol) was slowly added dropwise and stirred at room temperature for 16 hours. The solution was cooled to -20 ° C and a solution of Me ₂ SiCl ₂ (2.77 g, 21.5 mmol) and CuCN (175 mg, 1.95 mmol) in toluene (5 ml) was slowly added dropwise. The solution was warmed to room temperature, stirred for 16 hours, and diluted with H ₂ O (100 ml) and ethyl acetate (EtOAc, 100 ml). The organic layer was separated, it was dehydrated for re chulchulhan the organic layer the aqueous layer with EtOAc (100 ml) with MgSO ₄ and filtered. The filtrate was distilled off under reduced pressure and the residue was purified by column chromatography (EtOAc: Hex = 0: 1 to 1:50) to obtain powdery dimethylbis (2-methyl- 4- (naphthalen- inden-1-yl) silane (7.76 g, 13.7 mmol, yield 70%).

(3) Catalyst synthesis

: 50 ml schlenk flask to Dimethylbis (2-methyl-4- ( naphthalen-1-yl) -1H-inden-1-yl) into the silane (0.5 g, 0.879 mmol) , put the Et ₂ O (10 ml) And dissolved at room temperature. The solution was cooled to -20 C and n- BuLi (2.5 M in hexane, 0.71 ml, 1.78 mmol) was slowly added dropwise and stirred at room temperature for 16 hours. The solution was cooled to -78 < 0 > C and then slowly added dropwise to a 50 ml Schlenk flask containing ZrCl4 _- THF (332 mg, 0.879 mmol). The solution was allowed to warm to room temperature and stirred for 16 hours, and the solvent was removed under reduced pressure. CH ₂ Cl ₂ (15 ml) was added thereto, and crystals were then precipitated at -20 ° C for 48 hours. The precipitated crystals were filtered under reduced pressure, washed with a small amount of CH ₂ Cl ₂ , and the separated crystals were dried under reduced pressure at room temperature for 8 hours to obtain racemic powdery catalyst compound (224 mg, 0.308 mmol, yield 35%) .

The results of NMR analysis for the catalyst compound are as follows.

^{1 H NMR (500 MHz, CDCl} 3): 7.0-8.0 (. M, 22H, arom H), 6.5 (s, 2H, HC (3)), 2.2 (s, 6H, CH 3), 1.3 (s, 6H, CH3 ' Si).

Example  1: Preparation of propylene homopolymer

900 ml of toluene and 3 ml of methylaluminoxane solution (10 wt% toluene) were added to a 2 L autoclave reactor, 150 g of liquid propylene was added thereto, and the temperature of the reactor was preheated to 60 ° C. Then, the transition metal compound (1 mM, 0.3 ml) according to the above synthesis example was placed in a reactor, and the polymerization reaction was allowed to proceed for 10 minutes. Then, excessive ethanol was added to the polymer solution to cool the solution to induce precipitation. The obtained polymer was dried in a vacuum oven at 70 占 폚 for 12 hours or longer to obtain polypropylene.

Example  2: Propylene / 1- Hexen  Preparation of Copolymer

Liquid propylene (150 g) and 1-hexene (10 g) were added to 900 ml of toluene and 3 ml of methylaluminoxane solution (10 wt% toluene) in a 2 L autoclave reactor. ≪ / RTI > Then, the catalyst compound (1 mM, 0.3 ml) according to Synthesis Example was added to the reactor, and the polymerization reaction was continued for 10 minutes. Then, excessive ethanol was added to the polymer solution to cool the solution to induce precipitation. The obtained polymer was dried in a vacuum oven at 70 캜 for 12 hours or longer to obtain a propylene / 1-hexene copolymer.

Example  3 and 4: Propylene / 1- Hexen  Preparation of Copolymer

Propene / 1-hexene copolymer was obtained in the same manner as in Example 2, except that the content of 1-hexene charged was adjusted to 20 g (Example 3) or 30 g (Example 4).

Comparative Example  1: Preparation of propylene homopolymer

[(Dimethylsilylene) bis (2-methyl-4-phenylindenyl) zirconium dichloride represented by the following formula instead of the transition metal compound according to the synthesis example; Polypropylene was obtained in the same manner as in Example 1 except that the polypropylene was used.

Comparative Example  2: Propylene / 1- Hexen  Preparation of Copolymer

Polypropylene was obtained in the same manner as in Example 2, except that (Dimethylsilylene) bis (2-methyl-4-phenylindenyl) zirconium dichloride (manufactured by S-PCI) was used instead of the transition metal compound according to Synthesis Example.

Test Example

The mass of the propylene polymer obtained from the above examples was measured, and the activity of the catalyst was calculated. From the samples, 10 mg of each sample was taken and subjected to GPC analysis to confirm the molecular weight and molecular weight distribution.

Comonomer
Input (g) Catalytic activity
(kg / mmol * hr) polymer
Tm
(° C) Mw
(g / mol) Mw / Mn LCB
(1-Hx mol%) Example 1 - 450 161 844,000 2.1 - Comparative Example 1 - 387 159 268,000 2.7 - Example 2 10 714 129 - - 7.5 Example 3 20 732 110 - - 13.1 Example 4 30 360 100 - - 16.5 Comparative Example 2 10 450 140 - - 6.1

As can be seen from the above Table 1, the high molecular weight polypropylene was obtained by the method of Example 1, and the propylene / alpha olefin copolymer produced with excellent copolymerization efficiency was obtained by the methods of Examples 2 to 4 there was.

Claims (6)

A process for producing a propylene-based polymer comprising the step of polymerizing propylene or propylene with an alpha-olefin having 4 or more carbon atoms in the presence of a catalyst composition comprising a transition metal compound represented by the following formula
[Chemical Formula 1]

In Formula 1,
M is a Group 4 transition metal;
Each X is independently halogen, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an alkylaryl group having 7 to 20 carbon atoms, or an arylalkyl group having 7 to 20 carbon atoms;
Each of R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁷ , R ⁸ , R ⁹ , R ¹⁰ and R ¹¹ is independently hydrogen, an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms , An aryl group having 6 to 20 carbon atoms, an alkylaryl group having 7 to 20 carbon atoms, or an arylalkyl group having 7 to 20 carbon atoms; Any one of R ³ and R ⁴ and any one of R ⁹ and R ¹⁰ is independently an aryl group having 10 to 20 carbon atoms which is substituted or unsubstituted with an alkyl group having 1 to 10 carbon atoms;
R ⁶ and R ¹² are each independently an alkyl group having 1 to 5 carbon atoms;
Q is carbon (C), silicon (Si), germanium (Ge), or tin (Sn);
R ¹³ and R ¹⁴ are each independently an alkyl group having 1 to 10 carbon atoms.
The method according to claim 1,
In Formula 1, M is titanium (Ti), zirconium (Zr), or hafnium (Hf); X is halogen; Any one of R ³ and R ⁴ and any one of R ⁹ and R ¹⁰ is independently a naphthyl group substituted or unsubstituted with an alkyl group having 1 to 10 carbon atoms; R ⁶ and R ¹² are each independently an alkyl group having 1 to 3 carbon atoms; And R ¹³ and R ¹⁴ are each independently an alkyl group having 1 to 10 carbon atoms.
The method according to claim 1,
Wherein the transition metal compound represented by Formula 1 is a compound represented by one of the following structural formulas:

,

,

,

.
The method according to claim 1,
The alpha-olefin may be selected from the group consisting of 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, Wherein the propylene-based polymer is at least one compound selected from the group consisting of ethylene and propylene.
The method according to claim 1,
Wherein the catalyst composition further comprises at least one promoter compound selected from the group consisting of compounds represented by the following formulas (2), (3), and (4)
(2)
R ¹⁵ - [Al (R ¹⁵ ) -O] _a --R ¹⁷
In Formula 2,
R ¹⁵ , R ¹⁶ and R ¹⁷ 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,
a is an integer of 2 or more;
(3)
D (R ¹⁸⁾ ₃
In Formula 3,
D is aluminum or boron;
R ¹⁸ is each independently halogen, a hydrocarbyl group having 1 to 20 carbon atoms, or a hydrocarbyl group having 1 to 20 carbon atoms substituted with halogen;
[Chemical Formula 4]
^{[LH] + [Z (A} ) 4] - or ^{[L] + [Z (A} ) 4] -
In Formula 4,
L is a neutral or cationic Lewis base;
[LH] + or [L] ⁺ is a Bronsted acid;
H is a hydrogen atom;
Z is a Group 13 element;
A is independently at each occurrence one or more hydrogen atoms independently selected from the group consisting of halogen, a hydrocarbyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms substituted with an alkoxy or phenoxy radical having 1 to 20 carbon atoms, or an alkyl group having 1 to 20 carbon atoms.
The method according to claim 1,
Wherein the propylene homopolymer having a weight average molecular weight of 200,000 to 2,000,000 g / mol is obtained through the polymerization reaction step.