KR20220022851A - Olefin copolymer and method for preparing olefin copolymer - Google Patents

Abstract

According to the present invention, an olefin copolymer excellent in drop impact strength and transparency, and a method for manufacturing the same are provided. The present invention provides an olefin copolymer comprising ethylene, and 1-hexene (1-hexene) and 4-methyl-1-pentene as a comonomer, wherein a haze measured based on ASTM D1003 by molding into a film having a thickness of 0.05 mm is 3 to 10% or less, and a molecular weight distribution (MWD) is 2 to 5.

Description

Olefin copolymer and its manufacturing method

The present invention relates to an olefin copolymer and a method for preparing the same.

Olefin polymerization catalyst systems can be classified into Ziegler-Natta and metallocene catalyst systems, and these two highly active catalyst systems have been developed according to their respective characteristics. Among them, the metallocene catalyst consists of a combination of a main catalyst containing a transition metal compound as a main component and a cocatalyst containing an organometallic compound containing aluminum as a main component. Such a catalyst is a homogeneous complex catalyst and is a single site catalyst. , and has a narrow molecular weight distribution according to the single active point characteristic, and a polymer with a uniform composition distribution of comonomers is obtained.

However, the polymer polymerized using the metallocene catalyst has a narrow molecular weight distribution, and when applied to some products, there is a problem of lowering productivity due to the effect of extrusion load, etc. In order to solve this problem, a method of controlling the molecular weight distribution of a polymer by supporting two different types of metallocene catalyst precursors on a carrier together with an activator and polymerizing the polymer using the same has been proposed.

On the other hand, linear low density polyethylene (LLDPE) is prepared by copolymerizing ethylene and alpha olefin under a polymerization catalyst. Linear low-density polyethylene has the characteristics of general polyethylene, high breaking strength and elongation, and excellent tear strength and drop impact strength, so it is used for stretch films and overlap films. At this time, the important physical properties of the film, such as drop impact strength and transparency, are greatly influenced by alpha olefin as a comonomer.

However, there is a problem in that it is difficult to satisfy all physical properties due to the limitations of catalyst technology and process technology. Accordingly, there is a demand for the development of linear low-density polyethylene having improved transparency while maintaining strength and physical properties.

An object of the present invention is to provide an olefin copolymer having excellent drop impact strength and transparency. In addition, the present invention is to provide a method for producing the olefin copolymer.

The present invention is ethylene; And 1-hexene (1-hexene) and 4-methyl-1-pentene (4-methyl-1-pentene) as a comonomer, the haze measured based on ASTM D1003 by molding into a film having a thickness of 0.05 mm ( haze) is 3% or more and 10% or less, and a molecular weight distribution (MWD) of 2 or more and 5 or less.

In addition, the present invention is a first transition metal compound represented by the following formula (1); a second transition metal compound represented by the following formula (2); And in the presence of a hybrid supported catalyst comprising a carrier on which the first and second transition metal compounds are supported, ethylene and 1-hexene and 4-methyl-1-pentene as comonomers (4-methyl- 1-pentene), wherein the molar ratio of the first transition metal compound to the second transition metal compound is 1:0.3 to 1:3.5.

[Formula 1]

In Formula 1,

R ₁ and R ₂ are each independently hydrogen, halogen, C _1-20 alkyl, C _2-20 alkenyl, C _1-20 alkoxy or C _2-20 alkoxyalkyl,

X ₁ and X ₂ are each independently halogen or C _1-20 alkyl,

[Formula 2]

In Formula 2,

R ₃ and R ₄ are each independently hydrogen, halogen, C _1-20 alkyl, C _2-20 alkenyl, C _1-20 alkoxy or C _2-20 alkoxyalkyl,

X ₃ and X ₄ are each independently halogen or C _1-20 alkyl.

In addition, the present invention provides a film comprising the olefin copolymer.

According to the present invention, an olefin copolymer having excellent drop impact strength and transparency and a method for preparing the same can be provided.

The terminology used herein is used to describe exemplary embodiments only, and is not intended to limit the invention. The singular expression includes the plural expression unless the context clearly dictates otherwise. In this specification, terms such as "comprises", "comprising" or "have" are intended to designate the presence of an embodied feature, step, element, or a combination thereof, but one or more other features or steps; It should be understood that the possibility of the presence or addition of components, or combinations thereof, is not precluded in advance.

Since the invention can have various changes and can have various forms, specific embodiments are illustrated and described in detail below. However, this is not intended to limit the invention to the specific disclosed form, it should be understood to include all modifications, equivalents and substitutes included in the spirit and scope of the invention.

Hereinafter, the olefin copolymer of the present invention will be described in detail.

The olefin copolymer of the present invention has excellent drop impact strength and improved transparency (haze). The olefin copolymer includes 1-hexene and 4-methyl-1-pentene (4M1P) as comonomers in addition to ethylene. The inclusion of 4-methyl-1-pentene as a comonomer improves the transparency of the olefin copolymer and reduces haze. At this time, in order not to inhibit the reaction of 4-methyl-1-pentene, the highly reactive 1-hexene and 1-hexene are not added simultaneously, but are added alternately.

Meanwhile, the olefin copolymer of the present invention is prepared in the presence of a supported hybrid catalyst including a first metallocene compound and a second metallocene compound, which will be described later. The hybrid supported catalyst has a high comonomer incorporation, and by using it, the drop impact strength is maintained at an excellent level.

Preferably, the haze of the olefin copolymer may be 3% or more, 4% or more, 5% or more, 6% or more, or 7% or more, and 10% or less, 9.5% or less, or 9% or less. . When the haze of the olefin copolymer is excessively increased to more than 10%, it is difficult to achieve a sufficient level of transparency when the olefin copolymer is applied to the film, and it is difficult to satisfy the optical properties of the level required for the product to which the film is applied. . The haze is measured according to ASTM D1003 by molding into a film having a thickness of 0.05 mm.

Preferably, the molecular weight distribution (MWD; a value obtained by dividing a weight average molecular weight by a number average molecular weight; Mw/Mn) of the olefin copolymer may be 2 or more and 5 or less. More preferably, the molecular weight distribution of the olefin copolymer may be 2.2 or more, 2.4 or more, 2.5 or more, 2.6 or more, or 2.8 or more, and 4.5 or less, 4.0 or less, 3.5 or less, 3.2 or less, or 3.1 or less. When the molecular weight distribution of the olefin copolymer is less than 2, the processability of the olefin copolymer is reduced, and when the molecular weight distribution exceeds 5, there is a problem in that mechanical properties such as drop impact strength, haze and tensile strength are reduced.

Preferably, the drop impact strength of the olefin copolymer is 1000 g or more, 2000 g or less, 1900 g or less, 1800 g or less, 1700 g or less, 1600 g or less, 1500 g or less, or 1400 g or less. The drop impact strength is measured based on ASTM D1709A by molding into a film having a thickness of 0.05 mm.

Preferably, the density of the olefin copolymer is 0.910 g/cm ³ or more, 0.912 g/cm ³ or more, 0.913 g/cm ³ or more, 0.914 g/cm ³ or more, or 0.915 g/cm ³ or more, and 0.930 g /cm ³ or less, 0.928 g/cm ³ or less, 0.926 g/cm ³ or less, 0.924 g/cm ³ or less, 0.922 g/cm ³ or less, 0.920 g/cm ³ or less, or 0.918 g/cm ³ or less. The density is measured based on ASTM D 792.

Preferably, the weight average molecular weight of the olefin copolymer is about 50000 g/mol or more, about 60000 g/mol or more, about 70000 g/mol or more, about 80000 g/mol or more, about 90000 g/mol or more, about 100000 g/mol or more, or about 110000 g/mol or more, about 200000 g/mol or less, about 190000 g/mol or less, 180000 g/mol or less, 170000 g/mol or less, 160000 g/mol or less, 150000 g/mol or less, or 140000 g/mol or less.

The weight average molecular weight (Mw) and number average molecular weight (Mn) were measured by gel permeation chromatography (GPC, PL GPC220, Agilent Technologies). Specifically, as a gel permeation chromatography (GPC) apparatus, a Waters PL-GPC220 instrument may be used, and a Polymer Laboratories PLgel MIX-B 300 mm long column may be used. At this time, the measurement temperature is 160 °C, 1,2,4-trichlorobenzene (1,2,4-Trichlorobenzene) can be used as a solvent, and the flow rate can be applied at 1 mL/min. Each polyethylene sample was pretreated by dissolving it in trichlorobenzene (1,2,4-Trichlorobenzene) containing 0.0125% BHT at 160 °C for 10 hours using a GPC analysis device (PL-GP220), and the concentration of 10 mg/10mL After preparing it, it can be measured by supplying it in an amount of 200 μL. In addition, the values of Mw and Mn can be derived using a calibration curve formed using a polystyrene standard specimen. The weight average molecular weight of the polystyrene standard specimen is 2000 g/mol, 10000 g/mol, 30000 g/mol, 70000 g/mol, 200000 g/mol, 700000 g/mol, 2000000 g/mol, 400000 g/mol, 1000000 g Nine types of /mol can be used.

Therefore, in the olefin polymer of one embodiment, since the drop impact strength and transparency, which are important physical properties of the film to which the synthesized polymer is applied, can be improved to an equivalent level or more compared to the prior art, the film is manufactured, stored and transported or , stable durability can be realized through excellent mechanical strength in the process of product application, and at the same time, excellent optical properties can be realized in products to which the film is applied by securing transparency.

On the other hand, as described above, the olefin copolymer of one embodiment may be prepared by the method for preparing the olefin copolymer to be described later.

According to another embodiment of the invention, a first transition metal compound represented by the following formula (1); a second transition metal compound represented by the following formula (2); And in the presence of a hybrid supported catalyst comprising a carrier on which the first and second transition metal compounds are supported, 1-hexene and 4-methyl-1-pentene (4-methyl-1) as a comonomer with ethylene. -pentene), wherein the molar ratio of the first transition metal compound to the second transition metal compound is 1:0.3 to 1:3.5, a method for producing an olefin copolymer is provided.

[Formula 1]

In Formula 1,

R ₁ and R ₂ are each independently hydrogen, halogen, C _1-20 alkyl, C _2-20 alkenyl, C _1-20 alkoxy or C _2-20 alkoxyalkyl,

X ₁ and X ₂ are each independently halogen or C _1-20 alkyl,

[Formula 2]

In Formula 2,

R ₃ and R ₄ are each independently hydrogen, halogen, C _1-20 alkyl, C _2-20 alkenyl, C _1-20 alkoxy or C _2-20 alkoxyalkyl,

X ₃ and X ₄ are each independently halogen or C _1-20 alkyl.

According to the embodiment, by using a precursor comprising the first transition metal compound represented by Formula 1 and the second transition metal compound represented by Formula 2 in a specific ratio, copolymerizability and supporting performance are improved compared to the prior art. An improved hybrid supported catalyst can be provided.

Specifically, the hybrid supported catalyst having a molar ratio (A:B) of 1:0.3 to 1:3.5 of the first transition metal compound (A) and the second transition metal compound (B) has excellent supported performance, catalytic activity and high pore properties. Polymerization may be exhibited. In particular, when preparing an ultra-low-density olefin copolymer, that is, ultra-low-density polyethylene in a slurry process under such a hybrid supported catalyst, the conventional ultra-low-density polyethylene melts or swells (swell), thereby reducing productivity and preventing the occurrence of fouling. , process stability can be improved. In addition, by using the hybrid supported catalyst, it is possible to provide a polyolefin having excellent physical properties, for example, ultra-low density polyethylene.

On the other hand, when the molar ratio (A:B) of the first transition metal compound and the second transition metal compound is less than 1:0.3, there is a disadvantage in that it is difficult to produce ultra-low density polyethylene as copolymerization is lowered, and when it exceeds 1:3.5, the desired polymer There is a problem in that it is difficult to reproduce the molecular structure of

In the transition metal compound included in the hybrid supported catalyst according to the embodiment, the substituents of Chemical Formulas 1 and 2 will be described in more detail as follows.

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

C _1-20 alkyl may be straight chain, branched chain or cyclic alkyl. Specifically, C _1-20 alkyl is C _1-20 straight chain alkyl; C _1-10 straight chain alkyl; C _1-5 straight chain alkyl; C _3-20 branched or cyclic alkyl; C _3-15 branched or cyclic alkyl; or C _3-10 branched chain or cyclic alkyl. More specifically, C _1-20 alkyl may be methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, tert-butyl, n-pentyl, iso-pentyl or cyclohexyl, and the like.

C _2-20 Alkenyl can be straight-chain, branched-chain or cyclic alkenyl. Specifically, C _2-20 alkenyl is C _2-20 straight chain alkenyl, C _2-10 straight chain alkenyl, C _2-5 straight chain alkenyl, C _3-20 branched chain alkenyl, C _3-15 branched chain alkenyl kenyl, C _3-10 branched chain alkenyl, C _5-20 cyclic alkenyl or C _5-10 cyclic alkenyl. More specifically, C _2-20 alkenyl may be ethenyl, propenyl, butenyl, pentenyl or cyclohexenyl, and the like.

C _6-20 aryl may mean a monocyclic, bicyclic or tricyclic aromatic hydrocarbon. Specifically, C _6-20 aryl may be phenyl, naphthyl or anthracenyl, and the like.

C _7-20 Alkylaryl may mean a substituent in which one or more hydrogens of aryl are substituted with alkyl. Specifically, C _7-20 alkylaryl may be methylphenyl, ethylphenyl, n-propylphenyl, iso-propylphenyl, n-butylphenyl, iso-butylphenyl, tert-butylphenyl or cyclohexylphenyl.

C _7-20 Arylalkyl may mean a substituent in which one or more hydrogens of the alkyl are substituted by aryl. Specifically, C _7-20 Arylalkyl may be benzyl, phenylpropyl or phenylhexyl and the like.

C _1-20 Alkoxy may be straight-chain, branched-chain or cyclic alkoxy. Specifically, C _1-20 alkoxy may include, but is not limited to, methoxy, ethoxy, n-butoxy, tert-butoxy, phenyloxy, cyclohexyloxy, and the like.

C _2-20 alkoxyalkyl may mean a substituent in which one or more hydrogens of alkyl are substituted by alkoxy. Specifically, as C _2-20 alkoxyalkyl, methoxymethyl, ethoxymethyl, methoxyethyl, ethoxyethyl, butoxymethyl, butoxyethyl, butoxypropyl, butoxybutyl, butoxyheptyl, butoxy and hexyl, but is not limited thereto.

Preferably, R ₁ and R ₂ may each independently be C _4-20 alkyl or C _5-9 straight-chain alkyl substituted with tert-butoxy, more preferably, R ₁ and R ₂ are each independently n-hexyl substituted with n-butyl or tert-butoxy. In addition, the R ₁ and R ₂ may be substituted with the same substituent.

Preferably, X ₁ and X ₂ may each independently be chlorine or methyl, and more preferably, X ₁ and X ₂ may each independently be chlorine.

Specifically, the first transition metal compound represented by Formula 1 may be a compound represented by Formula 1a or Formula 1b, but is not limited thereto.

[Formula 1a]

[Formula 1b]

.

.

The first transition metal compound represented by the above structural formulas may be synthesized by applying known reactions, and more detailed synthesis methods may refer to Examples.

Preferably, R ₃ and R ₄ may each independently be C _1-3 alkyl, more preferably R ₃ and R ₄ may be n-propyl.

Preferably, X ₃ and X ₄ may each independently be chlorine or methyl.

Specifically, the second transition metal compound represented by Formula 2 may be a compound represented by Formula 2a or Formula 2b, but is not limited thereto.

[Formula 2a]

[Formula 2b]

.

.

The second transition metal compound represented by the above structural formulas may be synthesized by applying known reactions, and more detailed synthesis methods may refer to Examples.

In the supported hybrid catalyst according to the embodiment, the first transition metal compound represented by Formula 1 contributes to making a low molecular weight linear copolymer, and the second transition metal compound represented by Formula 2 is a high molecular weight linear copolymer. It can contribute to making a copolymer. The supported hybrid catalyst may exhibit excellent supported performance, catalytic activity and high copolymerizability by using a low-copolymerizable first transition metal compound and a high-copolymerizable second transition metal compound together as a hybrid catalyst. . In particular, when ultra-low-density polyethylene is manufactured in a slurry process under such a hybrid supported catalyst, process stability is improved, thereby preventing the fouling problem that has occurred in the past. In addition, by using the hybrid supported catalyst, it is possible to provide a polyolefin having excellent physical properties, for example, ultra-low density polyethylene.

Meanwhile, as the carrier, a carrier containing a hydroxyl group or a siloxane group on the surface may be used. Specifically, as the carrier, a carrier containing a hydroxyl group or a siloxane group having high reactivity by drying at a high temperature to remove moisture from the surface may be used. More specifically, the carrier may include any one or more mixtures selected from the group consisting of silica, alumina and magnesia. The carrier may be dried at a high temperature, and they typically include oxides, carbonates, sulfates, and nitrates such as Na ₂ O, K ₂ CO ₃ , BaSO ₄ and Mg(NO ₃ ) ₂ .

The drying temperature of the carrier is preferably 40 to 800 °C, more preferably 100 to 600 °C, and most preferably 100 to 300 °C. If the drying temperature of the carrier is less than 40 ℃, there is too much moisture, so that the surface moisture and the cocatalyst react. It disappears and only the siloxane remains, which is not preferable because the reaction site with the promoter decreases.

The amount of hydroxyl groups on the surface of the carrier is preferably 0.1 to 10 mmol/g, more preferably 0.5 to 5 mmol/g. The amount of hydroxyl groups on the surface of the carrier can be controlled by the method and conditions or drying conditions of the carrier, such as temperature, time, vacuum or spray drying, and the like.

If the amount of the hydroxyl group is less than 0.1 mmol/g, there are few reaction sites with the co-catalyst, and if it exceeds 10 mmol/g, it is not preferable because it may be caused by moisture other than the hydroxyl group present on the surface of the carrier particle. not.

The supported hybrid catalyst according to the embodiment may further include a co-catalyst to activate the transition metal compound, which is a catalyst precursor. The cocatalyst is not particularly limited as long as it is an organometallic compound containing a Group 13 metal, and can be used when polymerizing olefins under a general metallocene catalyst. Specifically, the cocatalyst may be at least one compound selected from the group consisting of compounds represented by the following Chemical Formulas 3 to 5.

[Formula 3]

R ₆ -[Al(R ₅ )-O] _n -R ₇

In Formula 3,

R ₅ , R ₆ and R ₇ are each independently hydrogen, halogen, a C _1-20 hydrocarbyl group, or a halogen-substituted C _1-20 hydrocarbyl group,

n is an integer greater than or equal to 2,

[Formula 4]

D(R ₈ ) ₃

In Formula 4,

D is aluminum or boron,

R ₈ is each independently a halogen, a C _1-20 hydrocarbyl group, a C _1-20 hydrocarbyloxy group, or a halogen-substituted C _1-20 hydrocarbyl group,

[Formula 5]

[LH] ⁺ [W(A) ₄ ] ^- or [L] ⁺ [W(A) ₄ ] ^-

In Formula 5,

L is a neutral or cationic Lewis base,

H is a hydrogen atom,

W is a group 13 element,

A is each independently a C _1-20 hydrocarbyl group; C _1-20 hydrocarbyloxy group; and one or more of the substituents in which one or more hydrogen atoms of these substituents are substituted with one or more substituents of halogen, a C _1-20 hydrocarbyloxy group and a C _1-20 hydrocarbyl (oxy)silyl group.

Unless otherwise limited herein, the following terms may be defined as follows.

The hydrocarbyl group is a monovalent functional group in which a hydrogen atom is removed from hydrocarbon, and is an alkyl group, an alkenyl group, an alkynyl group, an aryl group, an aralkyl group, an aralkenyl group, an aralkynyl group, an alkylaryl group, an alkenylaryl group, and an alkyl group. It may include a nylaryl group and the like. 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, an ethyl group, an n-propyl group, an iso-propyl group, an n-butyl group, an iso-butyl group, a tert-butyl group, an n-pentyl group, and a n-hexyl group. , a straight-chain, branched-chain or cyclic alkyl group such as n-heptyl group and cyclohexyl group; Or it may be an aryl group such as a phenyl group, a naphthyl group, or an anthracenyl group.

The hydrocarbyloxy group is a functional group in which a 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 is a methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, iso-butoxy group, tert-butoxy group, n-pentoxy group , a straight-chain, branched-chain or cyclic alkoxy group such as n-hexoxy group, n-heptoxy group, cyclohexoxy group; Alternatively, 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 to 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, the hydrocarbyl (oxy)silyl group having 1 to 20 carbon atoms is an alkyl group such as a methylsilyl group, a dimethylsilyl group, a trimethylsilyl group, a dimethylethylsilyl group, a diethylmethylsilyl group, and a dimethylpropylsilyl group. silyl group; alkoxysilyl groups such as a methoxysilyl group, a dimethoxysilyl group, a trimethoxysilyl group and a dimethoxyethoxysilyl group; It may be an alkoxyalkylsilyl group such as a methoxydimethylsilyl group, a diethoxymethylsilyl group, and a dimethoxypropylsilyl group.

Non-limiting examples of the compound represented by Formula 3 may include methylaluminoxane, ethylaluminoxane, isobutylaluminoxane, or tert-butylaluminoxane. And, non-limiting examples of the compound represented by Formula 4 include trimethylaluminum, triethylaluminum, triisobutylaluminum, tripropylaluminum, tributylaluminum, dimethylchloroaluminum, triisopropylaluminum, tri-sec-butylaluminum, Tricyclopentyl aluminum, tripentyl aluminum, triisopentyl aluminum, trihexyl aluminum, trioctyl aluminum, ethyl dimethyl aluminum, methyldiethyl aluminum, triphenyl aluminum, tri-p-tolyl aluminum, dimethyl aluminum methoxide or dimethyl aluminum Toxide etc. are mentioned. Finally, non-limiting examples of the compound represented by Formula 5 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-tetrafluorophenyl)borate, N,N-dimethylanilinium tetrakis(2,3,4,6-tetrafluorophenyl) ) borate, hexadecyldimethylammonium tetrakis(pentafluorophenyl)borate, N-methyl-N-dodecylanilinium tetrakis(pentafluorophenyl)borate or methyldi(dodecyl)ammonium tetrakis(pentafluoro phenyl) borate and the like.

The amount of the co-catalyst used may be appropriately adjusted according to the physical properties or effects of the desired hybrid supported catalyst.

The hybrid supported catalyst according to the embodiment may include, for example, supporting a cocatalyst on the support; and supporting the first and second transition metal compounds, which are catalyst precursors, on a promoter supported carrier.

Specifically, in the step of supporting the cocatalyst on the carrier, the cocatalyst may be added to the carrier dried at a high temperature, and stirred at a temperature of about 20 to 120° C. to prepare a carrier supported on the cocatalyst.

And, in the step of supporting the catalyst precursor on the support supporting the promoter, the first and second transition metal compounds are added to the support supporting the promoter obtained in the step of supporting the promoter on the support, and then again at about 20 to 120 ° C. A supported catalyst can be prepared by stirring at a temperature of

In the step of supporting the catalyst precursor on the promoter supported carrier, the first and second transition metal compounds are added and stirred to the promoter supported carrier, and then a supported catalyst may be further added to prepare a supported catalyst.

The content of the carrier, the cocatalyst, the cocatalyst supported carrier and the transition metal compound used in the hybrid supported catalyst according to the embodiment may be appropriately adjusted according to the desired physical properties or effects of the supported catalyst.

Specifically, in the hybrid supported catalyst, the molar ratio of the first transition metal compound to the second transition metal compound is It may be 1:0.3 to 1:3.5. By including the first and second transition metal compounds in the above-described mixing molar ratio, excellent supporting performance, catalytic activity, and high copolymerizability may be exhibited. In particular, when ultra-low-density polyethylene is manufactured in a slurry process under such a hybrid supported catalyst, process stability is improved, thereby preventing the fouling problem that has occurred in the past. In addition, by using the hybrid supported catalyst, it is possible to provide a polyolefin having excellent physical properties, for example, ultra-low density polyethylene.

On the other hand, if the molar ratio (A:B) of the first transition metal compound and the second transition metal compound is less than 1:0.3, there is a disadvantage in that it is difficult to produce ultra-low density polyethylene as copolymerization is lowered, and when it exceeds 1:3.5, the There is a problem in that it is difficult to reproduce the molecular structure of the desired polymer.

In this case, the amount of the metallocene compound supported on the silica carrier by the above step may be 0.01 to 1 mmol/g based on 1 g of the carrier. That is, it is preferable to control so as to fall within the above-described supported amount range in consideration of the contribution effect of the catalyst by the metallocene compound.

In preparing the hybrid supported catalyst, the reaction solvent includes a hydrocarbon solvent such as pentane, hexane, heptane, and the like; Alternatively, an aromatic solvent such as benzene or toluene may be used.

For a specific method of preparing the supported catalyst, reference may be made to Examples to be described later. However, the preparation method of the supported catalyst is not limited to the contents described herein, and the preparation method may additionally employ a step commonly employed in the technical field to which the present invention belongs, and the steps of the preparation method ( ) may be modified by means of a routinely changeable step(s).

Examples of the monomer of the olefin copolymer of the present invention include ethylene, alpha-olefin, and cyclic olefin, and a diene olefin monomer or a triene olefin monomer having two or more double bonds may also be polymerized. Specific examples of the monomer include ethylene, propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dode cene, 1-tetradecene, 1-hexadecene, 1-aitocene, norbornene, norbornadiene, ethylidenenorbornene, phenylnorbornene, vinylnorbornene, dicyclopentadiene, 1,4-butadiene, 1, 5-pentadiene, 1,6-hexadiene, styrene, alpha-methylstyrene, divinylbenzene, 3-chloromethylstyrene, etc. are available, and two or more of these monomers may be mixed and copolymerized. When the olefin copolymer is a copolymer of ethylene and other comonomers, the comonomer is at least one comonomer selected from the group consisting of propylene, 1-butene, 1-hexene, 4-methyl-1-pentene and 1-octene. It is preferable to be More preferably, ethylene, 1-hexene and 4-methyl-1-pentene are included.

At this time, the input amount of 1-hexene is 6 wt% or more, 7 wt% or more, 8 wt% or more, or 8.5 wt% or more, and 15 wt% or less, 13 wt% or less, 11 wt% or less, based on the total weight of the ethylene input , or 10% by weight or less. If it is less than the above range, there may be a problem that the drop impact strength of the olefin copolymer is lowered. If it exceeds the above range, the degree of copolymerization of 1-hexene is too high, and the degree of copolymerization of 4-methyl-1-pentene is low. There is a problem to lose.

On the other hand, the input amount of 4-methyl-1-pentene is 6 wt% or more, 8 wt% or more, 9 wt% or more, or 10 wt% or more, 15 wt% or less, 13 wt% or less, based on the total weight of the input ethylene; or 11% by weight or less. If it is less than the above range, an appropriate degree of copolymerization for each comonomer may not be achieved, which may cause problems in that the haze value is increased and the transparency is lowered.

The 1-hexene and 4-methyl-1-pentene may be added in a weight ratio of 2:5 to 5:2, more preferably, 3:5 to 5:3, or 4:5 to 5:4. It can be added by weight. When the weight ratio of 1-hexene to 4-methyl-1-pentene is out of 2:5 to 5:2, the effect is biased to one side, and there is a problem that the haze and the drop impact strength range cannot be simultaneously satisfied.

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, an emulsion polymerization process, a gas phase polymerization process, can be employed. .

The polymerization of the olefin monomer may be performed by reacting at a temperature of about 25 to about 500 °C and a reaction pressure of about 1 to about 100 kgf/cm ² for about 1 to about 24 hours. Specifically, the polymerization of the olefinic monomer may be carried out at a temperature of about 25 to about 500 °C, preferably about 25 to about 200 °C, more preferably about 50 to about 100 °C. In addition, the reaction pressure may be from about 1 to about 100 kgf/cm ² , preferably from about 1 to about 60 kgf/cm ² , more preferably from about 5 to about 45 kgf/cm ² .

In addition, in the polymerization reaction, the supported hybrid catalyst 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. In this case, by treating the solvent with a small amount of alkylaluminum or the like, a small amount of water or air that may adversely affect the catalyst may be removed in advance.

In addition, if necessary, the slurry polymerization may be performed under hydrogenation or non-hydrogenation conditions.

On the other hand, the step of polymerizing ethylene and 1-hexene and 4-methyl-1-pentene as comonomers is 1-hexene and 4-methyl- It includes the step of alternately inputting 1-pentene. Since 1-hexene has a higher reactivity than 4-methyl-1-pentene, when both comonomers are simultaneously added, the reaction of 4-methyl-1-pentene is inhibited by 1-hexene. In order to prevent this, 1-hexene and 4-methyl-1-pentene are preferably added alternately. In this case, 4-methyl-1-pentene may be added after 1-hexene is added, or 1-hexene may be added after 4-methyl-1-pentene is added. The number of times of alternating input is not particularly limited as long as it is one or more times, and may be appropriately adjusted according to the desired physical properties or effects of the olefin copolymer.

Meanwhile, according to another embodiment of the present invention, a film including the olefin copolymer of the embodiment may be provided. The film can be manufactured by applying various molding methods, conditions, and devices known in the field of polymer molding without limitation.

In the film of the other embodiment, the olefin copolymer may include all of the contents described above in the one embodiment.

In addition, the film is molded into a film having a thickness of 0.05 mm and has a drop impact strength of 1000 g or more, or 1100 g or more, measured based on ASTM D1709A, 2000 g or less, 1900 g or less, 1800 g or less, 1700 g or less, 1600 g or less, 1500 g or less, or 1400 g or less.

In addition, the film is molded into a film having a thickness of 0.05 mm and has a haze measured based on ASTM D1003 of 3% or more, 4% or more, 5% or more, 6% or more, or 7% or more, and 10% or less, 9.5% or less, or 9% or less.

The content on the drop impact strength and haze may also include all of the content described above in the embodiment.

The olefin copolymer prepared by the above preparation method may be used for various purposes requiring such physical properties, and there is no particular limitation on the use. For example, it can be used for agricultural/industrial use and packaging that require high drop impact strength, and it can also be used for stretch films that are difficult to apply to conventional low-density polyethylene or high-density polyethylene.

Hereinafter, it will be described in more detail to help the understanding of the present invention. However, the following examples only illustrate the present invention, and the content of the present invention is not limited by the following examples.

Preparation Example 1: Preparation of hybrid supported catalyst

Silica (SP952 manufactured by Grace Davison) was dehydrated and dried under vacuum at a temperature of 200° C. for 12 hours.

In a 20L sus high pressure reactor, 3.0 kg of toluene solution was put, and 1000 g of dried silica (SP952 manufactured by Grace Davison) was added, followed by stirring while raising the temperature of the reactor to 40 °C. After the silica was sufficiently dispersed for 60 minutes, 8 kg of a 10 wt% methylaluminoxane (MAO)/toluene solution was added, followed by stirring at 200 rpm for 12 hours. After raising the reactor temperature to 60 °C, 0.1 mmol of the compound represented by Formula 1b was dissolved in a solution state, added, and after 2 hours reaction, 0.05 mmol of the compound represented by Formula 2b was dissolved in a solution state, added, and reacted for 2 hours was added After stopping the stirring and settling for 30 minutes, the reaction solution was decantation. 3.0 kg of hexane was put into the reactor, the hexane slurry was transferred to filter dry, and the hexane solution was filtered. A supported catalyst was prepared by drying at 50° C. under reduced pressure for 4 hours.

Examples 1 to 3: Preparation of Olefin Copolymer and Film

Ethylene, 1-hexene and 4-methyl-1-pentene were polymerized in the presence of the supported catalyst prepared in Preparation Example 1 under the conditions shown in Table 1 below.

In this case, the polymerization reactor is an isobutane slurry loop process continuous polymerizer or a fluidized bed process continuous polymerizer.

The polymerization reactor polymerized by the slurry process was an isobutane slurry loop process continuous polymerizer, the reactor volume was 140 L, and the reaction flow rate was about 7 m/s. Gases (ethylene, hydrogen) required for polymerization were constantly and continuously added, and the comonomers 1-hexene and 4-methyl-1-pentene were also continuously added at regular intervals according to the input conditions in Table 1 below. became Individual flow rates were adjusted to suit the target product. Concentrations of all gases and comonomers 1-hexene and 4-methyl-1-pentene were confirmed by on-line gas chromatograph. The supported catalyst was introduced into the isobutane slurry, the reactor pressure was maintained at about 40 bar, and the polymerization temperature was carried out at about 80 °C.

The polymerization reactor polymerized in the gas phase reaction process is a fluidized bed process continuous polymerization reactor, in which gas streams (ethylene, hydrogen) necessary for polymerization are continuously input and circulated through the fluidized bed, and 1-hexene and comonomer 4-Methyl-1-pentene was also continuously and alternately added at regular time intervals according to the input conditions shown in Table 1 and circulated through the fluidized bed. The individual flow rate was adjusted according to the target product, and when appropriate reaction conditions were provided in the dispersed fluidized bed, a catalytic reaction took place and polymerization proceeded. Concentrations of all gases and comonomers 1-hexene and 4-methyl-1-pentene were confirmed by on-line gas chromatograph. The reactor pressure was maintained at about 20 bar, and the polymerization temperature was carried out at about 80 °C.

The composition containing the prepared olefin copolymer was molded by blown film extrusion under the following molding conditions to prepare films of BUR 2.5 and thickness of 50 μm, respectively.

[Molding conditions]

Molding machine: Single-Layer Blown film extruder with a die diameter of 120 mm

Screw: standard single

Die set temperature: 170 ℃

Die gap: 2 mm

Extrusion rate: 390 g/min

Comparative Examples 1 to 4: Preparation of Olefin Copolymer and Film

Ethylene and 1-hexene and/or 4-methyl-1-pentene were polymerized in the presence of the supported catalyst prepared in Preparation Example 1 under the conditions shown in Table 1 below. Descriptions of the slurry process and the gas phase reaction process are the same as in Examples 1 to 3 above.

The composition containing the prepared olefin copolymer was molded by blown film extrusion under the following molding conditions to prepare films of BUR 2.5 and thickness of 50 μm, respectively.

[Molding conditions]

Molding machine: Single-Layer Blown film extruder with a die diameter of 120 mm

Screw: standard single

Die set temperature: 170 ℃

Die gap: 2 mm

Extrusion rate: 390 g/min

fair Comonomer input conditions ethylene
(kg/h) 1-Hx/C2
(weight%) 4M1P/C2
(weight%) ethylene
(mol%) C6/C2
(molar ratio) Example 3 slurry 1-Hx after 2 hours input
Repeat 4M1P input for 1 hour 25.1 9.5 11 5.9 0.25 Comparative Example 1 slurry 1-Hx 25.0 12.0 - 6.0 0.26 fair Comonomer input conditions Ethylene (kg/h) 1-Hx/C2
(weight%) 4M1P/C2
(weight%) C2 PP
(kg/cm ² A) Example 1 weather 1-Hx 3 hours after input
4M1P 2 hours input repetition 18.0 9.0 10.2 14.0 Example 2 weather 1-Hx After 1 hour input
4M1P 2 hours input repetition 20.5 8.8 10.5 14.1 Comparative Example 2 weather 1-Hx 19.5 8.5 - 14.1 Comparative Example 3 weather 4M1P 20.0 - 11 13.8 Comparative Example 4 weather 1-Hx, 4M1P mix 20.5 6.0 5.0 14.0

- Ethylene: Ethylene input per hour- 1-Hx/C2: Weight ratio (percentage) of 1-hexene to the total weight of ethylene input

- 4M1P/C2: Weight ratio (percentage) of 4-methyl-1-pentene to the total weight of ethylene input

- C6/C2: molar ratio of 1-hexene and 4-methyl-1-pentene to ethylene in the slurry reactor

- C2 PP: partial pressure of ethylene in the gas phase reactor

Experimental example

The catalytic activity of Examples 1 to 3 and Comparative Examples 1 to 4 and the physical properties of the olefin copolymer or film thereof were measured by the following method, and the results are shown in Table 2 below.

(1) Catalytic activity (kg PE/g Cat/hr): Calculated as the ratio of the weight of the polymer produced (kg PE) per the catalyst content (g Cat) used per unit time (hr) (kg PE).

(2) Density (g/cm ³ ) Density was measured according to ASTM D 792.

(3) Haze (%): It was measured based on ASTM D 1003 for the olefin copolymer film. At this time, each specimen was measured 10 times and the average value was taken.

(4) Drop impact strength (g): For the olefin copolymer film, the drop impact strength was measured according to the conditions of ASTM D1709A. The drop impact strength was determined by measuring at least 20 times per film sample.

(5) Weight average molecular weight (Mw, g/mol): The weight average molecular weight was measured by gel permeation chromatography (GPC, PL GPC220, Agilent Technologies). Specific measurement conditions are as follows.

A Waters PL-GPC220 instrument was used as a gel permeation chromatography (GPC) apparatus, and a Polymer Laboratories PLgel MIX-B 300 mm long column was used. At this time, the measurement temperature was 160 °C, 1,2,4-trichlorobenzene (1,2,4-Trichlorobenzene) was used as a solvent, and the flow rate was applied at 1 mL/min. Each polyethylene sample was pretreated by dissolving it in trichlorobenzene (1,2,4-Trichlorobenzene) containing 0.0125% of BHT at 160 °C for 10 hours, prepared to a concentration of 10 mg/10mL, and supplied in an amount of 200 μL. measured. In addition, the values of Mw and Mn were derived using a calibration curve formed using a polystyrene standard specimen. The weight average molecular weight of the polystyrene standard specimen is 2000 g/mol, 10000 g/mol, 30000 g/mol, 70000 g/mol, 200000 g/mol, 700000 g/mol, 2000000 g/mol, 4000000 g/mol, 1000000 g Nine species of /mol were used.

catalytic activity
(kgPE/gCat/hr) density
(g/cm ³ ) haze
(%) Drop impact strength (g) Mw (g/mol) MWD Example 1 4.5 0.9175 6.1 1150 129,000 2.9 Example 2 4.3 0.9173 7 1100 124,000 3.1 Example 3 4.2 0.9153 8 1180 114,000 2.8 Comparative Example 1 4 0.9169 21 1100 126,000 2.8 Comparative Example 2 4 0.9180 20 1000 134,000 2.6 Comparative Example 3 4.1 0.9184 4.5 600 125,000 3.0 Comparative Example 4 4.2 0.9182 20 900 144,000 2.7

In Table 2, it was confirmed that the haze and drop impact strength of an embodiment of the present invention using 1-hexene and 4-methyl-1-pentene as comonomers were excellent. In particular, it was confirmed that the physical properties of the example of the present invention in which the two types of comonomers were added together were superior to those of Comparative Example 4 in which the two types of comonomers were added together.

Claims (15)

ethylene; and 1-hexene and 4-methyl-1-pentene as comonomers,
It is molded into a film with a thickness of 0.05 mm and has a haze of 3% or more and 10% or less, measured based on ASTM D1003,
Molecular weight distribution (MWD) of 2 or more and 5 or less,
Olefin copolymers.
According to claim 1,
Molded into a film with a thickness of 0.05 mm and having a drop impact strength of 1000 g or more and 2000 g or less, measured based on ASTM D1709A,
Olefin copolymers.
The method of claim 1,
Density measured based on ASTM D 792 is 0.910 g/cm ³ or more and 0.930 g/cm ³ or less,
Olefin copolymers.
According to claim 1,
A weight average molecular weight of 50,000 g/mol or more and 200,000 g/mol or less,
Olefin copolymers.
A first transition metal compound represented by the following formula (1); a second transition metal compound represented by the following formula (2); And in the presence of a hybrid supported catalyst comprising a carrier on which the first and second transition metal compounds are supported, ethylene and 1-hexene and 4-methyl-1-pentene as comonomers (4-methyl- 1-pentene) comprising the step of polymerizing,
The molar ratio of the first transition metal compound to the second transition metal compound is 1:0.3 to 1:3.5,
The method for preparing the olefin copolymer of claim 1 :
[Formula 1]

In Formula 1,
R ₁ and R ₂ are each independently hydrogen, halogen, C _1-20 alkyl, C _2-20 alkenyl, C _1-20 alkoxy or C _2-20 alkoxyalkyl,
X ₁ and X ₂ are each independently halogen or C _1-20 alkyl,
[Formula 2]

In Formula 2,
R ₃ and R ₄ are each independently hydrogen, halogen, C _1-20 alkyl, C _2-20 alkenyl, C _1-20 alkoxy or C _2-20 alkoxyalkyl,
X ₃ and X ₄ are each independently halogen or C _1-20 alkyl.
6. The method of claim 5,
R ₁ and R ₂ are each independently C _4-20 alkyl or C _5-9 straight chain alkyl substituted with tert-butoxy;
A method for producing an olefin copolymer.
6. The method of claim 5,
The first transition metal compound represented by Formula 1 is a compound represented by Formula 1a or Formula 1b,
Method for preparing olefin copolymer:
[Formula 1a]

[Formula 1b]

.
6. The method of claim 5,
R ₃ and R ₄ are each independently C _1-3 alkyl;
A method for producing an olefin copolymer.
6. The method of claim 5,
The second transition metal compound represented by Formula 2 is a compound represented by Formula 2a or Formula 2b,
Method for preparing olefin copolymer:
[Formula 2a]

[Formula 2b]

.
6. The method of claim 5,
The carrier comprises a mixture of any one or more selected from the group consisting of silica, alumina and magnesia,
A method for producing an olefin copolymer.
6. The method of claim 5,
The supported hybrid catalyst further comprises at least one cocatalyst selected from the group consisting of compounds represented by the following Chemical Formulas 3 to 5,
Method for preparing olefin copolymer:
[Formula 3]
R ₆ -[Al(R ₅ )-O] _n -R ₇
In Formula 3,
R ₅ , R ₆ and R ₇ are each independently hydrogen, halogen, a C _1-20 hydrocarbyl group, or a halogen-substituted C _1-20 hydrocarbyl group,
n is an integer greater than or equal to 2,
[Formula 4]
D(R ₈ ) ₃
In Formula 4,
D is aluminum or boron,
R ₈ is each independently a halogen, a C _1-20 hydrocarbyl group, a C _1-20 hydrocarbyloxy group, or a halogen-substituted C _1-20 hydrocarbyl group,
[Formula 5]
[LH] ⁺ [W(A) ₄ ] ^- or [L] ⁺ [W(A) ₄ ] ^-
In Formula 5,
L is a neutral or cationic Lewis base,
H is a hydrogen atom,
W is a group 13 element,
A is each independently a C _1-20 hydrocarbyl group; C _1-20 hydrocarbyloxy group; and one or more of the substituents in which one or more hydrogen atoms of these substituents are substituted with one or more substituents of halogen, a C _1-20 hydrocarbyloxy group and a C _1-20 hydrocarbyl (oxy)silyl group.
6. The method of claim 5,
The input amount of the 1-hexene (1-hexene) is 6% by weight or more and 15% by weight or less based on the total weight of the input ethylene,
A method for producing an olefin copolymer.
6. The method of claim 5,
The input amount of the 4-methyl-1-pentene (4-methyl-1-pentene) is 6 wt% or more and 15 wt% or less, based on the total weight of the input ethylene;
A method for producing an olefin copolymer.
6. The method of claim 5,
The step of polymerizing ethylene with 1-hexene and 4-methyl-1-pentene as a comonomer alternates between 1-hexene and 4-methyl-1-pentene. comprising the step of putting
A method for producing an olefin copolymer.
Comprising the olefin copolymer of claim 1,
film.