KR20110053002A - Catalyst system for olefin polymerization comprising trioxasilocane and method for olefin polymerization using the same - Google Patents

Abstract

PURPOSE: A catalyst system for olefin polymerization is provided to improve melt-fluidity, tacticity and apparent density of a polymer and to easily control the molecular weight distribution of an olefin polymer by diversifying a molar ratio of a trioxasilocane compound and an organosilane compound. CONSTITUTION: A catalyst system for olefin polymerization includes (a) a transition metal oxide component including group 4, 5, or 6 elements in the periodic table as a solid main catalyst component, (b) an organometallic compound component including group 13 elements in the periodic table as a co-catalyst component, and (c) an organosilane compound represented by chemical formula 1 as an outside electron donor.

Description

Catalyst for olefin polymerization containing trioxacylocan and method for olefin polymerization using same TECHNICAL FIELD TECHNICAL FIELD

The present invention relates to a catalyst system for olefin polymerization and an olefin polymerization method using the same. More particularly, the present invention relates to a transition metal compound as a main catalyst component, an organometallic compound as a cocatalyst component, and an organic silane compound cyclized as an external electron donor component. The present invention relates to a Ziegler-Natta catalyst system for olefin polymerization containing trioxacylocan, and an olefin polymerization method using the same.

The present invention relates to a catalyst system for olefin polymerization and an olefin polymerization method using the same. More particularly, the present invention relates to a transition metal compound as a main catalyst component, an organometallic compound as a cocatalyst component, and an organic silane compound cyclized as an external electron donor component. The present invention relates to a Ziegler-Natta catalyst system for olefin polymerization containing trioxacylocan, and an olefin polymerization method using the same.

Polyolefins are obtained by polymerizing olefin monomers such as ethylene and propylene, and are generally known to be produced using a Ziegler-Natta catalyst system containing a transition metal halide as the main catalyst component.

Until now, various Ziegler-Natta catalyst systems have been known, and polyolefins prepared using various Ziegler-Natta catalyst systems have various properties in stereoregularity, molecular weight distribution, impact strength, melt flowability, rigidity, heat sealability, stereoregularity, and the like. Also indicates.

On the other hand, in the Ziegler-Natta catalyst system, the organosilane compound is used as an internal electron donor in the preparation of a solid main catalyst component comprising a halogen-containing titanium compound supported on an activated magnesium halide compound, or a solid main catalyst component and an aluminum-alkyl coarse. It has been used as an external electron donor introduced into the reactor during polymerization with a catalyst.

Typical organosilane compounds that have been used in Ziegler-Natta catalyst systems include Si-OR, Si-OCOR or Si-NR ₂ groups, where R is alkyl, alkenyl, aryl, arylalkyl or cycloalkyl having 1 to 20 carbon atoms. Have When such an organosilane compound is used as an internal electron donor, for example, U.S. Pat. No. 4,472,524, 4,522,930, 4,560,671, 4,581,342, 4,657,882 and European Patent Application Nos. 45976 and 45977 have.

In particular, U.S. Patent Nos. 4,784,983 and 4,861,847 disclose solid products based on (A) titanium, magnesium, halogen, polycarboxylic acid esters and organophosphorus compounds, (B) organoaluminum compounds and (C) organosilanes. It describes a catalyst system for olefin polymerization and copolymerization consisting of a compound; U.S. Patent Nos. 4,990,479 and 5,438,110 disclose (A) solid titanium catalyst components containing magnesium, titanium and halogens, (B) organoaluminum compounds and (C) cyclopentyl groups, cyclopentenyl groups, cyclopentadienyl groups Or a catalyst system for olefin polymerization composed of an organosilicon compound containing derivatives derived from these groups; US Pat. No. 4,829,038 discloses solid hydrocarbon-insoluble, magnesium-containing, titanium-containing, electron donor-containing components, alkyl aluminum compounds, and diisobutyldimethoxysilane, diisopropyldimethoxysilane, t-butyltrimeth A catalyst system for olefin polymerization comprising an organosilane compound selected from the group consisting of methoxysilane and di-t-butyldimethoxysilane and mixtures thereof is described.

In addition, Korean Patent Publication No. 10-2005-0013131 discloses the use of an organosilicon compound such as dicyclopentyldimethoxysilane, propyltriethoxysilane or methylcyclohexyldimethoxysilane as a selectivity control agent (SCA). Ziegler-Natta catalyst systems for olefin polymerization to improve polymer properties are described. WO 95/21203 recognizes the regulatory behavior of SCA when the molar ratio of SCA: transition metal is used at 33: 1 in a single reaction step.

Korean Patent Application No. 10-2006-0078834 discloses a catalyst system for olefin polymerization which improves melt flow by mixing organosilicon compounds such as dicyclopentyldimethoxysilane and trioxacylocan, in which case the catalyst activity is lowered. There is a disadvantage.

In the reaction of polymerizing olefin monomers having three or more carbon atoms, such as propylene, the inclusion of an organosilane compound as an electron donor in the Ziegler-Natta catalyst system promotes an increase in the stereoregularity of the resulting polymer. However, when organosilane compounds are used to promote increased stereoregularity of polyolefins in Ziegler-Natta polymerization, various other properties, including catalytic activity, tend to be lowered.

Korean Patent Laid-Open Publication No. 10-2008-0071298 discloses that Ziegler-Natta catalyst system for olefin polymerization, including trioxacylocan, an aliphatic group-substituted organosilane compound as an external electron donor component, has a polymerization activity, melt flowability, and stereoregularity. Disclosed is to provide an olefin polymer with improved various properties such as, and apparent density, but this catalyst system has difficulty in controlling molecular weight distribution.

Accordingly, there is a continuing need for a Ziegler-Natta catalyst system capable of controlling the molecular weight distribution of a polymer and an olefin polymerization method using the same while using an organic silane compound as an external electron donor while maintaining various properties in which the polymer is improved.

The present invention has been made to solve the problems of the prior art as described above, and an object of the present invention is that the polymer produced by the catalyst system having excellent polymerization activity exhibits improved melt flowability, stereoregularity, and apparent density. In addition, the olefin polymer may be prepared by mixing a trioxacyclocan compound having an cyclic structure substituted by an aromatic hydrocarbon and an organosilane compound as an external electron donor in the catalyst system, and changing the molar ratio of the trioxacyclocan compound and the organosilane compound. It is to provide an olefin polymerization catalyst system capable of easily controlling the molecular weight distribution.

The present invention provides (a) a transition metal compound component comprising an element belonging to Group 4, 5 or 6 of the periodic table as a solid main catalyst component; (b) an organometallic compound component comprising an element belonging to group 13 of the periodic table as a promoter component; And (c) provides a catalyst system for olefin polymerization comprising an organosilane compound represented by the following formula (1) as an external electron donor component.

In Chemical Formula 1,

R ₁ and R ₂ are each independently hydrogen, aromatic hydrocarbon having 6 to 10 carbon atoms;

R ₇ , R ₈ , R ₉ , and R ₁₀ are each independently hydrogen, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or a cycloalkyl group having 5 to 30 carbon atoms. ;

n and m are each independently an integer of 1-3.

According to the present invention, there is provided a catalyst system further comprising an organosilane compound represented by the following formula (2) as the external electron donor component (c).

In Formula 2, R ₃ , R ₄ , R ₅ and R ₆ are each independently hydrogen; An alkyl group having 1 to 20 carbon atoms; Alkenyl groups having 2 to 20 carbon atoms; An alkoxy group having 1 to 20 carbon atoms; Or a cycloalkyl group having 5 to 30 carbon atoms. "Alkyl group" in the formula (2) includes both linear or branched alkyl group.

“Aromatic hydrocarbons” in Formulas 1 and 2 have 6 to 10 carbon atoms. One or more hydrogen atoms included in such an aromatic hydrocarbon may be substituted with a hydroxy group, a halogen atom, a carboxyl group, a nitro group, an amine group or a cyan group.

In addition, in the general formulas (1) and (2), “alkenyl group” includes both linear or branched alkenyl groups, and has 2 to 20, preferably 2 to 10, more preferably 2 to 5 carbon atoms. Examples of such alkenyl groups include, but are not limited to, vinyl or propenyl groups, and one or more hydrogen atoms included in the alkenyl group may be substituted with a hydroxy group, a halogen atom, a carboxyl group, a nitro group, an amine group, or a cyan group. Can be.

In addition, "Alkoxy group" in the formula (2) is a substituent in which -O- is bonded to the end of the alkyl group, such as -O-alkyl group includes both straight or branched form, 1 to 20, preferably 1 To 10, more preferably 1 to 5 carbon atoms. Examples of such alkoxy groups include, but are not limited to, methoxy or ethoxy groups, and one or more hydrogen atoms included in the alkoxy group may be substituted with a hydroxy group, a halogen atom, a carboxyl group, a nitro group, an amine group, or a cyan group. have.

In addition, the "cycloalkyl group" in the formula (2) is a saturated cyclic alkyl group containing no double bond therein. Examples of such a cycloalkyl group include a cyclopentyl group or a cyclohexyl group, and at least one hydrogen atom contained in the cycloalkyl group may be substituted with a hydroxy group, a halogen atom, a carboxyl group, a nitro group, an amine group or a cyan group. Can be.

In the present specification, the cyclic organic silane compound represented by Chemical Formula 1 will be abbreviated as "trioxasilocane compound".

According to the present invention, R ₁ and R ₂ of the compound of Formula 1 are each independently provided a catalyst system for olefin polymerization, characterized in that the aromatic hydrocarbon having 6 to 10 carbon atoms.

According to the present invention, R ₃ and R ₄ in Chemical Formula 2 are each independently an alkoxy group having 1 to 20 carbon atoms, and R ₅ and R ₆ are each independently a cycloalkyl group having 5 to 30 carbon atoms. A catalyst system is provided.

According to the present invention, there is provided a catalyst system wherein the compound of Formula 1 is a compound represented by the following Formula 3.

According to the present invention, there is provided a catalyst system wherein the compound of Formula 2 is a compound represented by the following Formula 4.

According to the present invention, there is provided a catalyst system in which the molar ratio of the compound of formula 2 to the compound of formula 1 is 0.1 to 10, more preferably 1/3 to 3.

According to the present invention, there is provided a catalyst system for olefin polymerization, wherein the molecular weight distribution of the olefin polymer is controlled by changing the molar ratio of the organosilane compound represented by Formula 2 to the organosilane compound represented by Formula 1.

According to the present invention, there is provided a catalyst system for olefin polymerization in which the molar ratio of the organosilane compound represented by Formula 4 to the organosilane compound represented by Formula 3 is 0.1 to 10, more preferably 1/3 to 3.

According to the present invention, there is provided a catalyst system for olefin polymerization, wherein the molecular weight distribution of the olefin polymer is controlled by changing the molar ratio of the organosilane compound represented by Formula 4 to the organosilane compound represented by Formula 3.

According to the present invention there is provided a catalyst system wherein the transition metal compound component (a) is a solid titanium compound containing magnesium, titanium, a halogen element and an internal electron donor.

According to the present invention, there is provided a catalyst system wherein the internal electron donor contained in the transition metal compound component (a) is a diether compound, a phthalate compound or a mixture thereof.

According to the present invention, there is provided a catalyst system wherein the organometallic compound component (b) is an organoaluminum compound.

According to the present invention, the organometallic compound component (b) is a catalyst system selected from the group consisting of trialkylaluminum, dialkylaluminum halides, alkylaluminum dihalides, dialkylaluminum hydrides, alkylaluminum sesquihalides and mixtures thereof Is provided.

According to the present invention, the organometallic compound component (b) is Al (C ₂ H ₅ ) ₃ , Al (C ₂ H ₅ ) ₂ H, Al (C ₃ H ₇ ) ₃ , Al (C ₃ H ₇ ) ₂ H, Al (C ₄ H ₉ ) ₂ H, Al (iC ₄ H ₉ ) ₂ H, Al (iC ₄ H ₉ ) ₃ , Al (C ₈ H ₁₇ ) ₃ , Al (C ₁₂ H ₂₅ ) ₃ , Al (C ₂ H ₅ ) (C ₁₂ H ₂₅ ) ₂ , Al (iC ₄ H ₉ ) (C ₁₂ H ₂₅ ) ₂ , Al (C ₁₈ H ₃₇ ) ₂ (iC ₄ H ₉ ), (C ₂ H ₅ ) Provided is a catalyst system selected from the group consisting of ₂ AlCl, (iC ₃ H ₉ ) ₂ AlCl, Al (C ₁₆ H ₃₃ ) ₃ , (C ₂ H ₅ ) ₃ Al ₂ Cl _3, and mixtures thereof.

According to the invention, the organometallic compound component (b) is a mixture of Al (C ₂ H ₅ ) ₃ and Al (iC ₄ H ₉ ) ₃ ; A mixture of Al (C ₂ H ₅ ) ₃ and Al (C ₈ H ₁₇ ) ₃ ; A mixture of Al (C ₄ H ₉ ) ₂ H and Al (C ₈ H ₁₇ ) ₃ ; A mixture of Al (iC ₄ H ₉ ) ₃ and Al (C ₈ H ₁₇ ) ₃ ; A mixture of Al (C ₂ H ₅ ) ₃ and Al (C ₁₂ H ₂₅ ) ₃ ; A mixture of Al (iC ₄ H ₉ ) ₃ and Al (C ₁₂ H ₂₅ ) ₃ ; A mixture of Al (C ₂ H ₅ ) ₃ and Al (C ₁₆ H ₃₃ ) ₃ ; And a mixture of Al (C ₃ H ₇ ) ₃ and Al (C ₁₈ H ₃₇ ) ₂ (iC ₄ H ₉ ).

According to the present invention, there is provided a catalyst system having a molar ratio of the organometallic compound component (b) to the transition metal compound component (a) of 5 to 800.

According to the present invention, there is provided a catalyst system in which the molar ratio of the external electron donor component (c) to the transition metal compound component (a) is 1 to 150.

The present invention also provides a method for polymerizing olefins using the catalyst system for olefin polymerization.

According to the invention, there is provided a polymerization process wherein the olefin is an alpha-olefin.

According to the invention, there is provided a polymerization process wherein said alpha-olefin is selected from the group consisting of propylene, 1-butene, 1-pentene, 1-hexene or mixtures thereof.

According to the present invention, there is provided a polymerization process in which the rate of olefin introduction into the polymerization reactor is from 0.002 to 100 g / g of catalyst / hour for polymerization. In the present specification, the olefin injection rate into the polymerization reactor means the amount of olefin introduced into the polymerization reactor per unit time with respect to the polymerization unit g for polymerization present in the polymerization reactor.

According to the present invention, a polymerization process can be provided in which the rate of olefin introduction into the polymerization reactor is from 0.02 to 10 g olefin / g polymerization catalyst / hour.

According to the present invention, an olefin polymer prepared using the olefin polymerization method of the present invention is provided.

According to the present invention, a polymer prepared by a catalyst system having excellent polymerization activity exhibits excellent melt flowability, stereoregularity, and apparent density, and a trioxa having a ring structure in which an aromatic hydrocarbon is substituted as an external electron donor of the catalyst system. It is possible to provide an olefin polymerization catalyst system capable of controlling the molecular weight distribution of the olefin polymer by using a mixture of a silocan compound and an organic silane compound and by changing the molar ratio of the trioxacylocan compound and the organic silane compound.

Hereinafter, the present invention will be described in more detail.

The catalyst system for olefin polymerization according to the present invention uses a transition metal compound containing an element belonging to Group 4, 5 or 6 of the periodic table as a main catalyst component, and includes an element belonging to Group 13 of the periodic table as a cocatalyst component. An organometallic compound is used, and as an external electron donor component, an organic silane compound represented by the formula (1), or a mixture of the organic silane compound represented by the formula (1) and the organic silane compound represented by the formula (2) is used.

The organosilane compound of Chemical Formula 1 may function as an external electron donor in the catalyst system for olefin polymerization according to the present invention, and includes a central silicon atom and three oxygen atoms, of which two oxygen atoms are directly connected to the central silicon atom. It is characterized by having a ring structure in the form of bonding (hereinafter referred to as "trioxacylocan ring structure"). The ring structure is preferably a hexagonal ring structure or more.

In the organosilane compound represented by Formula 1, n and m are each independently 1 or 2, preferably in terms of stabilization of the trioxacylocan ring structure, and particularly preferably both n and m are 2.

Among the organosilane compounds represented by the general formula (1), compounds in which both R ₁ and R ₂ are aromatic hydrocarbons having 6 carbon atoms are preferable.

R ₃ and R ₄ in Chemical Formula 2 are each independently an alkoxy group having 1 to 20 carbon atoms, and R ₅ and R ₆ are each independently a cycloalkyl group having 5 to 30 carbon atoms.

A more preferable example is a compound represented by the above formula (2,2-diphenyl-1,3,6,2-trioxacylocan).

On the other hand, the organic silane compound of Formula 2 is a silane compound having four substituents around the Si, when used in the catalyst system for olefin polymerization according to the present invention serves as an external electron donor. All organic silane compounds generally used as external electron donors in the catalyst system for olefin polymerization can be used. Preferably, alkoxysilane compounds such as dicyclopentyldimethoxysilane, cyclohexylmethyldimethoxysilane or vinyltriethoxysilane are used. Used. Preferred examples of the organosilane compound represented by Formula 2 include a compound represented by Formula 4 (dicyclopentyldimethoxysilane).

In the catalyst system of the present invention, when the compound of Formula 1 and the compound of Formula 2 are used together as an external electron donor, the molecular weight distribution of the olefin polymer polymerized by changing the molar ratio of the compound of Formula 2 to the compound of Formula 1 It can be adjusted, the molar ratio is preferably 0.1 to 10, more preferably 1/3 to 3. When the molar ratio of the compound of formula 2 to the compound of formula 1 is less than 0.1, stereoregularity is lowered, and when it exceeds 10, hydrogen reactivity is lowered.

In addition, in the catalyst system of the present invention, when the compound of Formula 3 and the compound of Formula 4 are used together as an external electron donor, the olefin polymer is polymerized by changing the molar ratio of the compound of Formula 4 to the compound of Formula 3 The molecular weight distribution of can be controlled, the molar ratio of the compound of formula 4 to the compound of formula 3 is preferably 0.1 to 10, more preferably 1/3 to 3. When the molar ratio of the compound of formula 4 to the compound of formula 3 is less than 0.1, stereoregularity is lowered, and when it exceeds 10, hydrogen reactivity is lowered.

The catalyst system for olefin polymerization according to the present invention is a transition metal compound component, preferably magnesium, titanium, halogen elements and internal electrons, comprising as solid main catalyst component (a) an element belonging to group 4, 5 or 6 of the periodic table. Solid titanium compounds containing donors. As said titanium compound, a tetravalent titanium compound is preferable. Such a transition metal compound for olefin polymerization and a method for producing the same are known in the art, and any known transition metal compound can be used without limitation within the scope of achieving the object of the present invention.

In the catalyst system for olefin polymerization according to the present invention, as the internal electron donor contained in the transition metal compound component (a), an internal electron donor commonly used in the preparation of the solid main catalyst component for olefin polymerization can be used without particular limitation. Among them, it is preferable to use a diether compound, a phthalate compound or a mixture thereof. Examples of the diether-based compound include 2-n-propyl-2-cyclohexyl-1,3-dimethoxypropane and cyclopolyenic 1,3-diether. Examples of the phthalate-based compound include Diethyl phthalate, diisobutyl phthalate, di neopentyl phthalate, etc. are mentioned.

The catalyst system for olefin polymerization according to the present invention comprises, as cocatalyst component (b), an organometallic compound component comprising an element belonging to group 13 of the periodic table, preferably an organoaluminum compound. The organoaluminum compound is preferably selected from the group consisting of trialkylaluminum, dialkylaluminum halide, alkylaluminum dihalide, dialkylaluminum hydride, alkylaluminum sesquihalide and mixtures thereof, more preferably Al (C). ₂ H ₅ ) ₃ , Al (C ₂ H ₅ ) ₂ H, Al (C ₃ H ₇ ) ₃ , Al (C ₃ H ₇ ) ₂ H, Al (C ₄ H ₉ ) ₂ H, Al (iC ₄ H ₉ ) ₂ H, Al (C ₈ H ₁₇ ) ₃ , Al (C ₁₂ H ₂₅ ) ₃ , Al (C ₂ H ₅ ) (C ₁₂ H ₂₅ ) ₂ , Al (iC ₄ H ₉ ) (C ₁₂ H ₂₅ ) ₂ , Al (iC ₄ H ₉ ) ₂ H, Al (iC ₄ H ₉ ) ₃ , Al (C ₁₈ H ₃₇ ) ₂ (iC ₄ H ₉ ), (C ₂ H ₅ ) ₂ AlCl, (iC ₃ H ₉ ) ₂ AlCl, Al (C ₁₆ H ₃₃ ) ₃ , (C ₂ H ₅ ) ₃ Al ₂ Cl ₃ and mixtures thereof. In addition, a mixture of organoaluminum compounds may also be used as the promoter component (b), and in particular, mixtures of different organoaluminum compounds may be used, specifically, Al (C ₂ H ₅ ) ₃ and Al (iC ₄ H ₉ ) a mixture of ₃ ; A mixture of Al (C ₂ H ₅ ) ₃ and Al (C ₈ H ₁₇ ) ₃ ; A mixture of Al (C ₄ H ₉ ) ₂ H and Al (C ₈ H ₁₇ ) ₃ ; A mixture of Al (iC ₄ H ₉ ) ₃ and Al (C ₈ H ₁₇ ) ₃ ; A mixture of Al (C ₂ H ₅ ) ₃ and Al (C ₁₂ H ₂₅ ) ₃ ; A mixture of Al (iC ₄ H ₉ ) ₃ and Al (C ₁₂ H ₂₅ ) ₃ ; A mixture of Al (C ₂ H ₅ ) ₃ and Al (C ₁₆ H ₃₃ ) ₃ ; And a mixture of Al (C ₃ H ₇ ) ₃ and Al (C ₁₈ H ₃₇ ) ₂ (iC ₄ H ₉ ).

It is also preferable to use a chlorine-free organoaluminum compound as the promoter component (b). Suitable chlorine-free organoaluminum compounds are trialkylaluminum or dialkylaluminum hydrides having hydrocarbon groups of 1 to 16 carbon atoms, preferably Al (C ₂ H ₅ ) ₃ , Al (C ₂ H ₅ ) ₂ H, Al (C ₃ H ₇ ) ₃ , Al (C ₃ H ₇ ) ₂ H, Al (iC ₄ H ₉ ) ₃ , Al (iC ₄ H ₉ ) ₂ H, Al (C ₈ H ₁₇ ) ₃ , Al (C ₁₂ H ₂₅ ) ₃ , Al (C ₂ H ₅ ) (C ₁₂ H ₂₅ ) ₂ and Al (iC ₄ H ₉ ) (C ₁₂ H ₂₅ ) ₂ .

In the catalyst system for olefin polymerization according to the present invention, the molar ratio of the organometallic compound component (b) to the transition metal compound component (a) is preferably 5 to 800. If the molar ratio is less than 5, there is a problem in that the active point of the catalyst is not activated, and if it exceeds 800, there is a problem in that the activity is lowered due to the overreduction of titanium, which is not preferable.

In the catalyst system for olefin polymerization according to the present invention, the molar ratio of the external electron donor component (c) to the transition metal compound component (a) is preferably 1 to 150, more preferably 30 to 100. If the molar ratio is less than 1, there is a problem that the stereoregularity of the resulting polymer is lowered, and if it exceeds 150, there is a problem that the catalytic activity is lowered.

The catalyst system for olefin polymerization of the present invention as described above may be used in the polymerization of general olefins, and is particularly preferable for the polymerization of alpha-olefins. Examples of alpha-olefins include propylene, 1-butene, 1-pentene, 1-hexene or mixtures thereof, of which propylene is particularly preferred. The olefin polymerization method according to the present invention includes not only homopolymerization of alpha-olefins but also copolymerization of two or more kinds of olefins. Therefore, in the olefin polymerization method according to the present invention, for example, not only homopolymerization of propylene but also copolymerization of propylene with 1-butene or 1-hexene and the like can be performed.

The olefin polymerization using the catalyst system for olefin polymerization of the present invention may be performed according to a conventional polymerization process, and a polymerization process known in the art may be used without limitation.

In the polymerization process of the olefins using the catalyst system according to the present invention, the olefin injection rate into the polymerization reactor is preferably 0.002 to 100 g olefin / g polymerization catalyst / hour, 0.02 to 10 g olefin / g polymerization catalyst / hour More preferred. When the input rate of the olefin is less than 0.002g olefin / g polymerization catalyst / hour, there is a problem that the activity is lowered because the catalyst active point retention time is not reached, and when the catalyst exceeds 100g olefin / g polymerization / hour Since the exothermic reaction cannot be controlled, there is a problem that the active point of the catalyst is separated from the carrier, which is not preferable.

According to the olefin polymerization method of the present invention, by using a catalyst system comprising a mixture of the organic silane compound represented by the formula (1) and the organic silane compound represented by the formula (2) as an external electron donor component, melting while maintaining high catalytic activity Polyolefins with improved index and stereoregularity can be obtained.

Hereinafter, preferred examples are provided to aid the understanding of the present invention, but the following examples are merely for exemplifying the present invention, and it will be apparent to those skilled in the art that various changes and modifications can be made within the scope and spirit of the present invention. It is natural that such variations and modifications fall within the scope of the appended claims.

Properties of the polymer synthesized in the embodiment of the present invention was measured through the following experimental method.

(1) polymerization activity

The polymerization activity of the catalyst was calculated as the weight (kg) ratio of the resulting polymer per amount of catalyst used (g catalyst) (unit: kg PP / g catalyst).

(2) melt flow rate (MFR)

The melt flow index was measured using a weight of 2.16 kg at a temperature of 230 ° C. in accordance with ASTM D1238, expressed in weight (g) of polymer melted for 10 minutes (unit: g / 10 min).

(3) apparent density

IPT model 1132 was used to measure the weight of polymer in 100 ml containers in g / ml.

(4) Isotacticity

Stereoregularity of the polymer is the weight ratio of the polymer that is not extracted in boiling o -xylene for 1 hour (unit:%). The stereoregularity measurement of the polymer is described in detail as follows.

First, 200 ml xylene was prepared in a flask and then filtered through a 200 mm No. 4 extraction paper. The aluminum pan was dried in an oven at 150 ° C. for 30 minutes and then cooled in a desiccator and the mass was measured. Next, 100 ml of filtered o -xylene was collected by a pipette, transferred to an aluminum pan, and heated to 145 to 150 ° C to evaporate all o -xylene. The aluminum pan was then vacuum dried for 1 hour at a temperature of 100 ± 5 ° C. and a pressure of 13.3 kPa. After the aluminum pan was cooled in a desiccator, the above procedure was repeated twice, and the o -xylene-only blank test was completed within a weight error of 0.0002 g.

Next, the polymer obtained in the example was dried (70 ° C., 13.3 kPa, 60 minutes, vacuum oven), and then 2 ± 0.0001 g of the polymer sample cooled in the desiccator was placed in a 500 ml flask, and 200 ml of o − was added thereto. Xylene was added. The flask was connected with nitrogen and cooling water, and the flask was heated to reflux o -xylene for 1 hour. Thereafter, the flask was placed in air for 5 minutes, cooled to 100 ° C. or lower, and the flask was shaken and placed in a thermostat (25 ± 0.5 ° C.) for 30 minutes to precipitate insoluble matters. The resultant solution in which the precipitate was formed was filtered repeatedly until it was clean with 200 mm No. 4 extraction paper. After drying at 150 ° C. for 30 minutes, 100 ml of the filtered solution was added to a pre-weighed aluminum pan after cooling in a desiccator, and the aluminum pan was heated to 145 to 150 ° C. to evaporate o -xylene. The evaporated aluminum pan was vacuum dried for 1 hour at a temperature of 70 ± 5 ° C. and a pressure of 13.3 kPa, and the procedure of cooling in a desiccator was repeated twice, and the weight was measured within an error of 0.0002 g.

The weight ratio (XS) of the part dissolved in o- xylene in the polymer was obtained by the following formula, and the weight ratio (XI = 100-XS) of the polymer not extracted in o -xylene was obtained from It is shown in Table 1 as regularity.

XS =

[XS = o -xylene dissolved in polymer, wt%]

Vbo = volume of initial o -xylene, mL (= 200ml)

Vb1 = o -volume taken from polymer dissolved in xylene, mL (= 100 ml)

Vb2 = volume of o -xylene taken at ball measurement, mL (= 100 ml)

W2 = sum of the weight of polymer remaining in the aluminum pan after evaporating the aluminum pan and o -xylene, g

W1 = weight of aluminum pan, g

Wo = weight of initial polymer, g (= 2 g)

B = average value of the balance remaining in the aluminum pan when the ball is measured, g

Example  One

(1) solid for olefin polymerization Main catalyst  Synthesis of Ingredients

25.25 g of magnesium compound (MgCl ₂ ) and 150 ml of anhydrous heptane were added to a 500 ml glass reactor at 0 ° C. under a nitrogen atmosphere, followed by stirring. Then, 21.6 ml of 1M phthalate compound (diisobutylphthalate) was added dropwise and stirred for 10 minutes. Thereafter, 100 ml of 0 ° C TiCl ₄ was added thereto, and the mixture was reacted at room temperature for 1 hour. Further, 150 ml of TiCl ₄ was added dropwise, and the mixture was heated to 100 ° C for 2 hours. After the reaction, the TiCl ₄ was removed, washed six times with heptane at 80 ° C., and then dried under vacuum at 40 ° C. and stored. The obtained solid titanium main catalyst component contained 2.4% by weight of titanium atoms.

(2) 2,2- Diphenyl -1,3,6,2- Trioxailocan  Produce

An organosilane compound having a structure of Chemical Formula 3 (2,2-diphenyl-1,3,6,2-trioxacyclocan) was prepared as follows.

In a 500 ml round bottom flask, imidazole [1.65 g, 24 mmol, Aldrich] and dimethylformamide (25 ml, Aldrich) were added and stirred at room temperature for 5 minutes, followed by diethylene glycol (1.16 g, 12 mmol, Aldrich). Stirred for a minute. Dichlorodiphenylsilane (2.17ml, 10mmol, TCI) was slowly added thereto and stirred at room temperature for 24 hours to react.

After the reaction was completed, water (100 ml) was poured into the resulting mixture, the layers were separated, and the product was extracted three times with 100 ml of ethyl acetate per time. The combined organic fractions were dried over MgSO ₄ , filtered and the solvent removed via rotary evaporation. The resulting solvent was distilled off under reduced pressure to obtain 2,2-diphenyl-1,3,6,2-trioxacylocan (1.19 g, 4.07 mmol, 42% yield), which is the organosilane compound of Formula 3 It was. The prepared organosilane compound of Chemical Formula 3 was identified by nuclear magnetic resonance spectroscopy ( ¹ H-NMR).

¹ H-NMR: δ 7.71 to 7.70 (m, 4H), 7.40 to 7.37 (m, 6H), 4.05 to 4.03 (t, 4H), 3.80 to 3.78 (t, 4H)

(3) propylene polymerization

The reactor with a capacity of 2 L was vacuum dried for 1 hour and then purged sufficiently with nitrogen, 4.0 mmol of triethylaluminum at room temperature, 2,2-diphenyl-1,3,6, prepared in step (2), 0.4 mmol of 2-trioxacylocan (DPTOS), 10 mg of the solid main catalyst component (titanium content of 5.0 μmol) prepared in step (1) was added to 4 ml of purified hexane, and the slurry was mixed and injected into the reactor. Ratio of silane to titanium (Si / Ti) = 80]. Thereafter, 3,300 ppm of hydrogen per mol of propylene was added thereto, and then 1.5 L of liquid propylene was added thereto, and then the temperature was raised to 70 ° C. while stirring the mixture. After the completion of the polymerization reaction, the unreacted gas was discharged, the temperature was cooled to room temperature, and the reaction was terminated. The resulting polymer was separated and collected and dried in a vacuum oven at 70 ° C. for at least 1 hour to obtain a white polypropylene polymer. The polymerization experiment results are shown in Table 1 below.

Example  2

0.1 mmol of 2,2-diphenyl-1,3,6,2-trioxacylocan (DPTOS) and dicyclopentyldimethoxysilane prepared in step (2) of Example 1 as an external electron donor in the propylene polymerization step (DCPDMS, manufactured by Shinetsu Co., Ltd.) Polymerization was carried out in the same manner as in Example 1, except that 0.3 mmol was added to the reactor to obtain a white polymer. The polymerization experiment results are shown in Table 1 below.

Example  3

0.2 mmol of 2,2-diphenyl-1,3,6,2-trioxacylocan (DPTOS) and dicyclopentyldimethoxy silane prepared in step (2) of Example 1 as external electron donor in propylene polymerization step (DCPDMS, manufacturer: Shinetsu Co., Ltd.) A white polymer was obtained by polymerization in the same manner as in Example 1, except that 0.2 mmol was added to the reactor. The polymerization experiment results are shown in Table 1 below.

Example  4

0.3 mmol of 2,2-diphenyl-1,3,6,2-trioxacylocan (DPTOS) and dicyclopentyldimethoxysilane prepared in step (2) of Example 1 as an external electron donor in a propylene polymerization step (DCPDMS, manufacturer: Shinetsu Co., Ltd.) Polymerization was carried out in the same manner as in Example 1 except that 0.1 mmol was added to the reactor to obtain a white polymer. The polymerization experiment results are shown in Table 1 below.

Comparative example  One

A white polymer was obtained by polymerization in the same manner as in Example 1 except that no external electron donor was used in the propylene polymerization step. The polymerization experiment results are shown in Table 1 below.

Comparative example  2

A white polymer was obtained by polymerization in the same manner as in Example 1, except that 0.4 mmol of dicyclopentyldimethoxysilane (DCPDMS, manufactured by Shinetsu Co., Ltd.) was used as an external electron donor in the propylene polymerization step. The polymerization experiment results are shown in Table 1 below.

* Polymerization condition: hydrogen injection amount (hydrogen / propylene: 3,300ppm / mol), reaction time (1hr), reaction temperature (70 ℃)

 DPTOS: 2,2-diphenyl-1,3,6,2-trioxacylocan

 DCPDMS: Dicyclopentyldimethoxysilane (manufacturer: Shinetsu)

Looking at the results of Table 1, as in Example 1, excellent melt flow using 2,2-diphenyl-1,3,6,2-trioxacylocan (DPTOS) alone as an external electron donor during propylene polymerization It can be seen that the propylene polymer having excellent stereoregularity compared to Comparative Example 1 can be produced. In addition, 2,2-diphenyl-1,3,6,2-trioxacylocan (DPTOS) and dicyclopentyldimethoxysilane (DCPDMS) as an external electron donor during propylene polymerization as in Examples 3 and 4 When the mixture is used, it can be seen that when compared with Comparative Example 2, the melt flowability is improved and the molecular weight distribution is wider, thereby making it possible to prepare a polypropylene having improved process formability. In particular, 2,2-diphenyl-1,3,6,2-trioxacylocan (DPTOS) and dicyclopentyldimethoxysilane (DCPDMS) are 3: 1 as external electron donors during propylene polymerization as in Example 4. When used as a ratio, the molecular weight distribution was markedly improved and the melt flowability was also high. Thus, a polypropylene polymer having excellent workability can be produced.

Therefore, according to the present invention, the polymer produced by the olefin polymerization catalyst system of the present invention having excellent polymerization activity exhibits improved melt flowability, stereoregularity and apparent density, and as an external electron donor of the olefin polymerization catalyst system of the present invention. 2,2-diphenyl-1,3,6,2-trioxacyclocan (DPTOS), which is a trioxacyclocan compound having a ring structure substituted by an aromatic hydrocarbon, and dicyclopentyldimethoxysilane (DCPDMS), which is an organosilane compound ) Was mixed and the molar ratio of DPTOS and DCPDMS was changed to show that the molecular weight distribution of the olefin polymer can be easily controlled over a wide range.

Claims (20)

(a) a transition metal compound component comprising an element belonging to Group 4, 5 or 6 of the periodic table as a solid main catalyst component; (b) an organometallic compound component comprising an element belonging to group 13 of the periodic table as a promoter component; And (c) a catalyst system for olefin polymerization comprising an organosilane compound represented by the following formula (1) as an external electron donor component: [Formula 1]

In Chemical Formula 1, R ₁ and R ₂ are each independently hydrogen or an aromatic hydrocarbon having 6 to 10 carbon atoms; R ₇ , R ₈ , R ₉ , and R ₁₀ are each independently hydrogen, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or a cycloalkyl group having 5 to 30 carbon atoms. ; n and m are each independently an integer of 1-3. The catalyst system for olefin polymerization according to claim 1, further comprising an organosilane compound represented by the following Chemical Formula 2 as the external electron donor component (c): [Formula 2]

In Formula 2, R ₃ , R ₄ , R ₅ and R ₆ are each independently hydrogen, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or 5 to 30 carbon atoms Represents a cycloalkyl group. The catalyst system for olefin polymerization according to claim 1 or 2, wherein R ₁ and R ₂ of the organosilane compound represented by Chemical Formula 1 are each independently an aromatic hydrocarbon having 6 to 10 carbon atoms. The catalyst system for olefin polymerization according to claim 2, wherein the organic silane compound represented by Chemical Formula 1 is a compound represented by Chemical Formula 3. (3)

The olefin according to claim 2, wherein R ₃ and R ₄ in Formula 2 are each independently an alkoxy group having 1 to 20 carbon atoms, and R ₅ and R ₆ are each independently a cycloalkyl group having 5 to 30 carbon atoms. Catalyst system for polymerization. The catalyst system for olefin polymerization according to claim 4, wherein the organic silane compound represented by Chemical Formula 2 is an organic silane compound represented by the following Chemical Formula 4. [Formula 4]

The catalyst system for olefin polymerization according to claim 2, wherein the molar ratio of the organosilane compound represented by Formula 2 to the organosilane compound represented by Formula 1 is 0.1 to 10. The catalyst system for olefin polymerization according to claim 7, wherein the molar ratio of the organosilane compound represented by Formula 2 to the organosilane compound represented by Formula 1 is 1/3 to 3. The method for olefin polymerization according to claim 7 or 8, wherein the molecular weight distribution of the olefin polymer is controlled by changing the molar ratio of the organosilane compound represented by Formula 2 to the organosilane compound represented by Formula 1. Catalytic system. The catalyst system for olefin polymerization according to claim 6, wherein the molar ratio of the organosilane compound represented by Formula 4 to the organosilane compound represented by Formula 3 is 0.1 to 10. The catalyst system for olefin polymerization according to claim 10, wherein the molar ratio of the organosilane compound represented by Formula 4 to the organosilane compound represented by Formula 3 is 1/3 to 3. The method for olefin polymerization according to claim 10 or 11, wherein the molecular weight distribution of the olefin polymer is controlled by changing the molar ratio of the organosilane compound represented by Formula 4 to the organosilane compound represented by Formula 3. Catalytic system. The catalyst system for olefin polymerization according to claim 1 or 2, wherein the transition metal compound component (a) is a solid titanium compound containing magnesium, titanium, a halogen element and an internal electron donor. The catalyst system for olefin polymerization according to claim 13, wherein the internal electron donor is one selected from the group consisting of diether compounds, phthalate compounds, and mixtures thereof. The catalyst system for olefin polymerization according to claim 1 or 2, wherein the organometallic compound component (b) is an organoaluminum compound. The method of claim 15, wherein the organometallic compound component (b) is Al (C ₂ H ₅ ) ₃ , Al (C ₂ H ₅ ) ₂ H, Al (C ₃ H ₇ ) ₃ , Al (C ₃ H ₇ ) ₂ H, Al (C ₄ H ₉ ) ₂ H, Al (iC ₄ H ₉ ) ₂ H, Al (iC ₄ H ₉ ) ₃ , Al (C ₈ H ₁₇ ) ₃ , Al (C ₁₂ H ₂₅ ) ₃ , Al (C ₂ H ₅ ) (C ₁₂ H ₂₅ ) ₂ , Al (iC ₄ H ₉ ) (C ₁₂ H ₂₅ ) ₂ , Al (C ₁₈ H ₃₇ ) ₂ (iC ₄ H ₉ ), (C ₂ H ₅ ) ₂ AlCl, (iC ₃ H ₉ ) ₂ AlCl, Al (C ₁₆ H ₃₃ ) ₃ , (C ₂ H ₅ ) ₃ Al ₂ Cl ₃ , and olefin polymerization, characterized in that selected from the group consisting of Catalyst system. The catalyst system for olefin polymerization according to claim 1 or 2, wherein the molar ratio of the organometallic compound component (b) to the transition metal compound component (a) is 5 to 800. The catalyst system for olefin polymerization according to claim 1 or 2, wherein the molar ratio of the external electron donor component (c) to the transition metal compound component (a) is 1 to 150. An olefin polymerization method characterized by polymerizing olefins using the catalyst system for olefin polymerization according to claim 1. An olefin polymer prepared using the olefin polymerization method according to claim 19.