KR20210038328A - Film comprising olefin copolymer - Google Patents

Abstract

The present invention relates to a film comprising terpolymers. An olefin copolymer included in the film of the present invention has an optimized range of density, melt index, and molecular weight distribution, and by controlling a content ratio between comonomers to a certain range, it is possible to provide a polymer having excellent physical properties. Therefore, the film produced by using the same has excellent sealing properties, cling properties and mechanical properties, and thus can be used effectively for a multi-purpose film.

Description

Film comprising olefin copolymer {Film comprising olefin copolymer}

The present invention relates to a film comprising an olefin copolymer. More specifically, it relates to a film including an olefin copolymer, which is suitable for a film for various purposes such as food packaging because of excellent properties such as sealing properties and mechanical properties.

In general, a polymer film refers to a non-fibrous flat plastic molded product having a thickness of 0.25 mm (1/100 inch) or less. Polymers are lightweight, have good barrier properties, are excellent in transparency, and are relatively inexpensive, so they are used in almost all fields such as packaging, household goods, automobiles, electronic devices, and aircraft, and are easy to process and make into films. Synthetic polymers such as polyethylene, polypropylene, polyvinyl chloride, and polyethylene terephthalate have been developed at home and abroad and are widely used as polymer films. Currently, many synthetic polymers are used alone or blended as a film material.

In particular, polyethylene (PE) is classified into low-density polyethylene, high-density polyethylene, and linear low-density polyethylene according to density, copolymerization, and branch type, and various polyethylene products are also emerging in the recently commercialized metallocene catalyst system.

Low-density polyethylene is one of the general-purpose resins that were successfully synthesized by ICI in 1933, and then used as an insulating material for military radars due to their outstanding electrical properties, and expanded to various packaging materials. Its main uses include general packaging, agriculture, shrink film, paper coating, etc. Especially, it has a long chain branch and has excellent melt tension, making it suitable for coating applications.

Linear low-density polyethylene is a resin prepared by copolymerizing ethylene and alpha olefin at low pressure using a polymerization catalyst, and has a narrow molecular weight distribution, short chain branches of a certain length, and no long chain branches. Linear low-density polyethylene film has high breaking strength and elongation in addition to the properties of general polyethylene, and has excellent tear strength and drop impact strength, so it is increasingly used for stretch films, overlap films, etc., where it is difficult to apply existing low-density polyethylene or high-density polyethylene. I'm doing it.

In such linear low-density polyethylene, the breaking strength, tear strength, and fall impact strength, which are important properties of the film, are greatly influenced by the alpha olefin used as a comonomer, and the alpha olefins used include 1-butene and 1-hexene. , 1-octene, etc.

In general, the physical properties of linear low-density polyethylene films are known to be excellent when 1-octene is used, but 1-octene comonomers are expensive and are disadvantageous in terms of economics. On the other hand, in the case of a stretch film requiring adhesive strength, it is required to use polyethylene having a fairly low density. Meanwhile, in the slurry loop process, which is one of the general polyethylene polymerization processes, it is known that the use of 1-butene as a comonomer is most advantageous in obtaining a low density polyethylene. However, in the case of 1-butene, the physical properties of 1-butene are lower than that of other comonomers, and it is a technology that requires a lot of industrial demand to manufacture a low-density linear polyethylene product with a low density by using other comonomers other than 1-butene.

In Korean Patent Laid-Open No. 2016-0010351, a comonomer distribution satisfies a CI index of 0.5 to 5, a melt flow index (MI) of 2.0 to 5.0 g/10 minutes, and a weight ratio of 1-hexene to 1-butene. Ethylene-1-hexene-1-butene terpolymer of 1 to 5 and a stretch film including the same were disclosed. However, the ternary copolymer and the stretch film including the same have a problem in that the use is limited due to poor processability.

Therefore, in this background, there is a constant demand for the manufacture of better products in which a balance between various physical properties and economics is achieved, and further improvement is required.

The present invention is to solve the problems of the prior art as described above, and to provide a film including an olefin copolymer having excellent properties such as sealing properties and mechanical properties.

One aspect of the present invention for achieving the above object,

Including an olefin copolymer satisfying the following (1) to (4),

A film having a sealing initation temperature of 99° C. or less is provided:

(1) According to ASTM D1238, the melt index (MI) measured at 190° C. under a load condition of 2.16 kg is 0.1 to 100 g/10 min;

(2) the density is 0.910 to 0.940 g/cm ³ ;

(3) molecular weight distribution (weight average molecular weight/number average molecular weight) is 2.0-10.0; And

(4) Based on the weight of the total olefin copolymer, 82.0 to 99.0 wt% of ethylene, 0.05 to 3.0 wt% of the first comonomer, and 0.05 to 15.0 wt% of the second comonomer are included.

The olefin copolymer included in the film of the present invention has an optimized range of density, melt index, and molecular weight distribution, and by controlling the content ratio between comonomers within a certain range, it is possible to provide a polymer having excellent physical properties.

Therefore, the film manufactured using this has excellent sealing properties, cling properties And it has mechanical properties, it can be usefully used to be suitable for a multi-purpose film such as a food packaging film or a stretch film.

The present invention will be described in detail below and exemplify specific embodiments, as various modifications can be made and various forms can be obtained. However, this is not intended to limit the present invention to a specific form disclosed, it should be understood to include all changes, equivalents, and substitutes included in the spirit and scope of the present invention.

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

One aspect of the present invention provides a film comprising an olefin copolymer satisfying the following (1) to (4) and having a sealing initation temperature of 99° C. or less:

(1) According to ASTM D1238, the melt index (MI) measured at 190° C. under a load condition of 2.16 kg is 0.1 to 100 g/10 min;

(2) the density is 0.910 to 0.940 g/cm ³ ;

(3) molecular weight distribution (weight average molecular weight/number average molecular weight) is 2.0-10.0; And

(4) 82.0 to 99.0 wt% of ethylene, 0.05 to 3.0 wt% of the first comonomer, and 0.05 to 15.0 wt% of the second comonomer, based on the total weight of the olefin copolymer.

In general, the density of the olefin copolymer is affected by the amount of alpha olefin comonomer used. That is, when the amount of the alpha olefin comonomer used is large, the density decreases, and when the amount of the alpha olefin comonomer used is small, the density increases. However, it is not easy to implement special properties such as density, sealing properties suitable for food packaging films and stretch films, and cling properties only with the amount of a single comonomer used.

Thus, the olefin copolymer of the present invention has an optimized range of density, melt index, and molecular weight distribution, and a terpolymer containing different first and second comonomers as alpha olefin comonomers in predetermined amounts. It characterized in that it comprises a. Accordingly, while having a low density and excellent processability, the hot-tack sealing strength and adhesive properties measured by the sealing initiation temperature are excellent, and physical properties suitable for a multipurpose film, especially a food packaging film and a stretch film, can be implemented.

The copolymer according to an embodiment of the present invention contains 82.0 to 99.0 wt% of ethylene, 0.05 to 3.0 wt% of the first comonomer, and 0.05 to 15.0 wt% of the second comonomer, based on the weight of the total olefin copolymer. Include as.

The first and second comonomers are alpha olefin compounds that can be copolymerized with ethylene to form a copolymer, and the first and second comonomers each mean different compounds. Although not limited thereto, the first and second comonomers are different from each other and may be propylene, 1-butene, 1-hexene, or 1-octene, respectively.

According to an embodiment of the present invention, based on the weight of the total copolymer, the copolymer is 82.0 to 99.0 wt% of ethylene, 0.05 to 3.0 wt% of propylene as the first comonomer, and as the second comonomer. It may contain 1-butene in an amount of 0.05 to 15.0 wt%.

Alternatively, the copolymer is 82.0 to 99.0 wt% of ethylene, 0.05 to 3.0 wt% of propylene as the first comonomer, and 0.05 to 15.0 of 1-hexene as the second comonomer, based on the weight of the total copolymer. It may be included in wt%.

Alternatively, the copolymer is 82.0 to 99.0 wt% of ethylene, 0.05 to 3.0 wt% of propylene as the first comonomer, and 0.05 to 15.0 1-octene as the second comonomer, based on the weight of the entire copolymer. It may be included in wt%.

Alternatively, the copolymer is based on the weight of the total copolymer, 82.0 to 99.0 wt% of ethylene, 0.05 to 3.0 wt% of 1-butene as the first comonomer, and 0.05 to 1-hexene as the second comonomer It may be included in to 15.0wt%.

Alternatively, the copolymer includes 82.0 to 99.0 wt% of ethylene, 0.05 to 3.0 wt% of 1-butene as the first comonomer, and 0.05 to 3.0 wt% of 1-octene as the second comonomer, based on the weight of the entire copolymer. It may be included in to 15.0wt%.

Alternatively, the copolymer includes 82.0 to 99.0 wt% of ethylene, 0.05 to 3.0 wt% of 1-hexene as the first comonomer, and 0.05 to 3.0 wt% of 1-octene as the second comonomer, based on the weight of the entire copolymer. It may be included in to 15.0wt%.

The olefin copolymer according to the present invention has a density in the range of about 0.910 to about 0.940 g/cm ^{3 as} measured according to ASTM D792. More specifically, the density of the olefin copolymer is 0.910 g / cm ³ or more, or 0.914 g / cm ³ or more, or 0.915 g / cm ³ or more, or 0.916 g / cm ³ or more, or 0.917 g / cm ³ or more, Or 0.918 g/cm ³ or more, 0.940 g/cm ³ or less, or 0.935 g/cm ³ or less, or 0.930 g/cm ³ or less, or 0.925 g/cm ³ or less. When the density of the olefin copolymer is within the above range, excellent adhesion and fall impact strength may be exhibited.

The olefin copolymer according to the present invention has a melt index (MI) of 0.1 to 100 g/10 min, measured at 190° C. and 2.16 kg load condition according to ASTM D1238. More specifically, the melt index (MI) of the olefin copolymer is 0.1 g/10min or more, or 0.5 g/10min or more, or 1.2 g/10min or more, or 1.4 g/10min or more, or 1.5 g/10min or more, 100 g/10min or less, or 90 g/10min or less, or 80 g/10min or less, or 50 g/10min or less, or 20 g/10min or less, or 12 g/10min or less, or 10 g/10min or less, or 5 g/10min or less, or 4 g/10min or less, or 3 g/10min or less, or 2.5 g/10min or less, or 2.0 g/10min or less, or 1.9 g/10min or less. As the melt index of the olefin copolymer has the above range, both excellent molding processability and mechanical properties may be satisfied.

The olefin copolymer according to the present invention has a molecular weight distribution (weight average molecular weight/number average molecular weight) of 2.0 to 10.0. More specifically, the molecular weight distribution of the olefin copolymer is 2.0 or more, or 2.2 or more, or 2.4 or more, or 2.5 or more, or 2.6 or more, or 3.0 or more, or 4.0 or more, while 10.0 or less, or 9.0 or less, or 8.0 or less , Or 7.0 or less, or 6.0 or less, or 5.0 or less, or 4.0 or less, or 3.0 or less. When the molecular weight distribution is within the above range, both excellent molding processability and mechanical properties can be satisfied.

In addition, according to an embodiment of the present invention, the weight average molecular weight (Mw) of the olefin copolymer may be 50,000 to 150,000 g/mol. More specifically, the weight average molecular weight of the olefin copolymer is about 50,000 g/mol or more, or 60,000 g/mol or more, or 50,000 g/mol or more and 150,000 g/mol or less, or 130,000 g/mol or less, or 120,000 g /mol or less, or 100,000 g/mol or less, but is not limited thereto.

In the present invention, the number average molecular weight (Mn), weight average molecular weight (Mw), and molecular weight distribution are determined by using gel permeation chromatography (GPC) to determine the weight average molecular weight (Mw) and number average molecular weight (Mn) of the olefin copolymer. Each was measured, and the ratio (Mw/Mn) of the weight average molecular weight to the number average molecular weight was calculated as a molecular weight distribution.

Specifically, a sample of the olefin copolymer was evaluated using a Waters PL-GPC220 instrument using a Polymer Laboratories PLgel MIX-B 300 mm length column. The evaluation temperature was 160°C, 1,2,4-trichlorobenzene was used as a solvent, and the flow rate was measured at a rate of 1 mL/min. The sample was prepared at a concentration of 10 mg/10 mL, and then supplied in an amount of 200 μL. The values of Mw and Mn were measured using a calibration curve formed using polystyrene standards. The molecular weight of the polystyrene standard was 2,000 / 10,000 / 30,000 / 70,000 / 200,000 / 700,000 / 2,000,000 / 4,000,000 / 10,000,000.

The film of the present invention comprising the above-described olefin copolymer satisfies a hot tack sealing strength of more than 2N when measured under hot-tack conditions according to ASTM F 1921. More specifically, using a J&B hot tack tester, the sealing time was 0.5 seconds, the sealing pressure was 0.3 MPa, the delay time was 0.1 seconds, the tensile speed was 200 mm/second, and the measurements were taken at each temperature at 5°C intervals between 95°C and 120°C. When the hot-tack sealing strength measured as the highest value is more than 2N, for example, it has a characteristic of 2.1N or more, or 2.2N or more, or 2.3N or more. The higher the hot-tack sealing strength, the better the sealing strength, so the upper limit thereof is not particularly limited, but may be, for example, 4.0N or less, 3.8N or less, or 3.7N or less.

In addition, the film of the present invention satisfies a sealing start temperature of 99° C. or less when measured under hot-tack conditions according to ASTM F 1921. More specifically, the sealing (heat sealing) start temperature when it reaches 2N when measured under the conditions of a sealing time of 0.5 sec, a sealing pressure of 0.3 MPa, a delay time of 0.1 sec, and a tensile speed of 200 mm/sec is 99°C or less, for example. For example, it has a characteristic of 98°C or less, or 96°C or less. The lower the sealing start temperature is, the better the low-temperature sealing property and the sealing strength, so the lower limit thereof is not particularly limited, but may be, for example, 80° C. or more, 85° C. or more, or 88° C. or more.

As described above, the film of the present invention has excellent sealing properties.

In addition, the film of the present invention has excellent fall impact strength and adhesion.

According to an embodiment of the present invention, the film of the present invention has a fall impact strength measured based on ASTM D 1709 [Method A] of 500 g or more, for example, about 500 to about 1,500 g, preferably about 600 To about 1,200 g.

The olefin copolymer according to the present invention, as described above, is suitable for film applications such as low density, excellent processability, adhesive strength, and fall impact strength, and can be particularly usefully used to produce a stretch film.

The film according to the present invention may be manufactured according to a method of inflation molding so that the olefin copolymer pellets satisfying the above-described predetermined conditions are put into a single screw extruder to have a certain thickness, but the present invention is not limited thereto. It can be prepared according to the method commonly used in the.

The olefin copolymer according to the present invention may be prepared according to the manufacturing method described below, for example, but is not limited thereto.

More specifically, the olefin copolymer of the present invention is not limited thereto, but in the presence of a catalyst composition comprising a first transition metal compound represented by the following formula (1) and a second transition metal compound represented by the following formula (2), an olefin monomer It can be prepared by polymerizing.

[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 Chemical Formula 2,

R ₃ and R ₄ are each 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 an embodiment of the present invention, the catalyst composition having a molar ratio (A:B) of 1:0.3 to 1:3.5 of the first transition metal compound and the second transition metal compound has excellent support performance, catalytic activity, and high air weight. Can represent synthesis. In particular, in the case of preparing polyethylene under such a catalyst composition, the conventional low density polyethylene melts or swells, thereby reducing productivity and preventing fouling from occurring, thereby improving process stability. In addition, polyethylene having excellent physical properties may be provided by using the catalyst composition.

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 low-density polyethylene as the copolymerization is lowered, and if it exceeds 1:3.5, the desired polymer There is a problem that it is difficult to reproduce the molecular structure.

In the transition metal compound included in the catalyst composition according to the embodiment, the substituents of 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 can 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 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.

C _2-20 Alkenyl can be straight chain, branched chain or cyclic alkenyl. Specifically, C _2-20 alkenyl is C _2-20 straight alkenyl, C _2-10 straight alkenyl, C _2-5 straight alkenyl, C _3-20 branched alkenyl, C _3-15 branched 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.

C _6-20 aryl can mean monocyclic, bicyclic or tricyclic aromatic hydrocarbons. Specifically, C _6-20 aryl may be phenyl, naphthyl or anthracenyl.

C _7-20 Alkylaryl may mean a substituent in which at least one hydrogen of an aryl is substituted by alkyl. Specifically, the 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 alkyl are substituted by aryl. Specifically, C _7-20 The arylalkyl may be benzyl, phenylpropyl or phenylhexyl, and the like.

C _1-20 Alkoxy can be straight chain, branched chain or cyclic alkoxy. Specifically, examples of C _1-20 alkoxy include, but are not limited to, methoxy, ethoxy, n-butoxy, tert-butoxy, phenyloxy, and cyclohexyloxy.

C _2-20 alkoxyalkyl may mean a substituent in which at least one hydrogen of alkyl is substituted by alkoxy. Specifically, as C _2-20 alkoxyalkyl, methoxymethyl, ethoxymethyl, methoxyethyl, ethoxyethyl, butoxymethyl, butoxyethyl, butoxypropyl, butoxybutyl, butoxyheptyl, butoxy Hexyl and the like may be mentioned, but the present invention is not limited thereto.

In the catalyst composition according to the embodiment, R ₁ and R ₂ in Formula 1 may each independently be C _{4-20 alkyl or C 5-9} straight-chain alkyl substituted with tert-butoxy, and more preferably, R ₁ and R ₂ may each independently be n-hexyl substituted with n-butyl or tert-butoxy. In addition, in Formula 1, R ₁ and R ₂ may be substituted with the same substituent.

In Formula 1, X ₁ and X ₂ may each independently be chlorine or methyl, but more preferably, it may be methyl.

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 a more detailed synthesis method may be referred to Examples.

In the catalyst composition according to the embodiment, in Formula 1, R ₃ and R ₄ may each independently be C _1-3 alkyl, and more preferably R ₃ and R ₄ may be n-propyl.

In Formula 2, X ₃ and X ₄ may each independently be chlorine or methyl. In addition, X ₃ and X ₄ may be substituted with the same substituent.

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 a more detailed synthesis method may be referred to Examples.

In the catalyst composition 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 the formation of coalitions. The catalyst composition may exhibit excellent support performance, catalytic activity, and high co-polymerization by using the first transition metal compound of low co-polymerization and the second transition metal compound of high co-polymerization together as a hybrid catalyst. In particular, in the case of manufacturing polyethylene under such a catalyst composition, process stability is improved, and thus fouling problems that have occurred in the prior art can be prevented. In addition, polyethylene having excellent physical properties may be provided by using the catalyst composition.

Meanwhile, the catalyst composition according to the embodiment may further include a carrier supporting the first transition metal compound and the second transition metal compound.

As the carrier, a carrier containing a hydroxy group or a siloxane group on the surface may be used. Specifically, as the carrier, a carrier containing a highly reactive hydroxyl group or a siloxane group may be used by drying at a high temperature to remove moisture from the surface. More specifically, as the carrier, silica, alumina, magnesia, or a mixture thereof may be used. The carrier may be dried at high temperature, and these may include oxides, carbonates, sulfates, and nitrate components 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. When the drying temperature of the carrier is less than 40°C, there is too much moisture so that the moisture on the surface and the cocatalyst react, and when it exceeds 800°C, the pores on the surface of the carrier are combined and the surface area decreases, and there are no many hydroxy groups on the surface. It is not preferable because only the high siloxane group remains and the reaction site with the cocatalyst decreases.

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

If the amount of the hydroxy group is less than 0.1 mmol/g, the reaction site with the cocatalyst is small, and if it exceeds 10 mmol/g, it is not preferable because it may be due to moisture other than the hydroxy group present on the surface of the carrier particle. not.

The catalyst composition according to the embodiment may further include a cocatalyst to activate the transition metal compound as a catalyst precursor. The cocatalyst is an organometallic compound containing a group 13 metal, and is not particularly limited as long as it can be used when polymerizing olefins under a general metallocene catalyst. Specifically, the cocatalyst may be one or more compounds 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 Chemical Formula 3,

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

n is an integer of 2 or more,

[Formula 4]

D(R ₈ ) ₃

In Chemical Formula 4,

D is aluminum or boron,

R ₈ are each independently halogen, C _1-20 hydro-car invoking, C _1-20 hydro-car bilok group, or substituted C _1-20 hydro-car invoking by halogen,

[Formula 5]

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

In Chemical Formula 5,

L is a neutral or cationic Lewis base,

H is a hydrogen atom,

W is a group 13 element,

Each A is independently a C _1-20 hydrocarbyl group; C _1-20 hydrocarbyloxy group; And at least one hydrogen atom of these substituents is any one of a substituent substituted with at least one of _{halogen, a C 1-20} hydrocarbyloxy group, and a C _{1-20 hydrocarbyl (oxy) silyl group.}

In the present specification, the following terms may be defined as follows unless there is a specific limitation.

Hydrocarbyl group is a monovalent functional group in the form of removing a hydrogen atom from a hydrocarbon, and is an alkyl group, alkenyl group, alkynyl group, aryl group, aralkyl group, aralkenyl group, aralkynyl group, alkylaryl group, alkenylaryl group, and alkynyl group. It may include a nilaryl group and the like. In addition, the hydrocarbyl group having 1 to 20 carbon atoms may be a hydrocarbyl group having 1 to 15 carbon atoms or 1 to 10 carbon atoms. Specifically, the hydrocarbyl group having 1 to 20 carbon atoms is a methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, tert-butyl group, n-pentyl group, n-hexyl group , a linear, branched or cyclic alkyl group such as an n-heptyl group and a cyclohexyl group; Or it may be an aryl group such as a phenyl group, a naphthyl group, or an anthracenyl group.

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 linear, branched or cyclic alkoxy group such as an n-hectoxy group, an n-heptoxy group, and a cyclohectoxy group; Or, it may be an aryloxy group such as a phenoxy group or a naphthalenoxy group.

The hydrocarbyl (oxy)silyl group _{is a functional group in which 1 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 dimethylmethylsilyl group, and a dimethylpropylsilyl group. Silyl group; Alkoxysilyl groups such as methoxysilyl group, dimethoxysilyl group, trimethoxysilyl group, and dimethoxyethoxysilyl group; Alkoxyalkylsilyl groups such as a methoxydimethylsilyl group, a diethoxymethylsilyl group, and a dimethoxypropylsilyl group.

Non-limiting examples of the compound represented by Formula 3 above include methylaluminoxane, ethylaluminoxane, isobutylaluminoxane, tert-butylaluminoxane, and the like. And, non-limiting examples of the compound represented by Formula 4 include trimethyl aluminum, triethyl aluminum, triisobutyl aluminum, tripropyl aluminum, tributyl aluminum, dimethyl chloro aluminum, triisopropyl aluminum, tri-sec-butyl aluminum, Tricyclopentyl aluminum, tripentyl aluminum, triisopentyl aluminum, trihexyl aluminum, trioctyl aluminum, ethyl dimethyl aluminum, methyl diethyl aluminum, triphenyl aluminum, tri-p-tolyl aluminum, dimethyl aluminum methoxide or dimethyl aluminum 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 content of the cocatalyst used may be appropriately adjusted according to the properties or effects of the desired catalyst composition.

The catalyst composition according to the embodiment may be prepared through, for example, supporting a cocatalyst on the support, and supporting the first and second transition metal compounds, which are catalyst precursors, on the cocatalyst supporting support. I can.

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

And, in the step of supporting the catalyst precursor on the cocatalyst-carrying support, the first and second transition metal compounds are added to the co-catalyst-carrying support obtained in the step of supporting the co-catalyst on the support. It can be stirred at a temperature of to prepare a supported catalyst.

In the step of supporting the catalyst precursor on the cocatalyst-carrying carrier, the first and second transition metal compounds are added to the co-catalyst-carrying carrier, followed by stirring, and then a co-catalyst may be additionally 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 catalyst composition according to the above embodiment may be appropriately adjusted according to the properties or effects of the desired supported catalyst.

Specifically, in the catalyst composition, the molar ratio of the first transition metal compound and 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 mixing molar ratio described above, excellent support performance, catalytic activity, and high copolymerization may be exhibited. In particular, in the case of manufacturing polyethylene under such a catalyst composition, process stability is improved, and thus fouling problems that have occurred in the prior art can be prevented. In addition, polyethylene having excellent physical properties may be provided by using the catalyst composition.

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 that it is difficult to produce polyethylene as the copolymerization is lowered, and if it exceeds 1:3.5, the desired There is a problem in that it is difficult to reproduce the molecular structure of a 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 the metallocene compound so that it falls within the above-described supported amount range in consideration of the contribution effect of the catalyst.

When preparing the hybrid supported catalyst, the reaction solvent may include a hydrocarbon solvent such as pentane, hexane, and heptane; 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 manufacturing method of the supported catalyst is not limited to the content described in the present specification, and the manufacturing method may additionally employ a step commonly employed in the technical field to which the present invention belongs, and the step of the manufacturing method ( S) can be changed by step(s) which are usually changeable.

The catalyst composition described above may exhibit excellent support performance, catalytic activity, and high co-polymerization, and even if a low-density polyethylene is prepared under such a catalyst composition, it is possible to prevent problems related to conventional productivity degradation and fouling, and improve process stability.

The method for preparing the olefin copolymer may copolymerize ethylene and a comonomer using a continuous slurry polymerization reactor, a loop slurry reactor, or the like, but is not limited thereto.

The polymerization reaction may be carried out using one continuous slurry polymerization reactor, a loop slurry reactor, a gas phase reactor, or a solution reactor.

The polymerization of the olefin-based monomer may be performed by reacting for about 1 to about 24 hours at a temperature of about 25 to about 500° C. and ^{a reaction pressure of about 1 to about 100 kgf/cm 2.} Specifically, the polymerization of the olefinic monomer may be performed 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 performed at about 1 to about 100 kgf/cm ² , preferably about 1 to about 60 kgf/cm ² , more preferably about 5 to about 45 kgf/cm ² .

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

In addition, if necessary, the polymerization may be carried out under hydrogenated or non-added conditions.

In addition, during the polymerization reaction, an organic aluminum compound for removing moisture in the reactor is further added, so that the polymerization reaction may proceed in the presence of the organic aluminum compound. Specific examples of such an organoaluminum compound include trialkyl aluminum, dialkyl aluminum halide, alkyl aluminum dihalide, aluminum dialkyl hydride, or alkyl aluminum sesqui halide, and more specific examples thereof include 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 ) 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 , (C ₂ H ₅ ) ₂ AlCl, (iC ₃ H ₉ ) ₂ AlCl or (C ₂ H ₅ ) ₃ Al ₂ Cl ₃ . These organoaluminum compounds may be continuously introduced into the reactor, and may be added in a ratio of about 0.1 to 10 moles per 1 kg of the reaction medium introduced into the reactor for proper moisture removal.

In addition, when a transition metal compound is used in the form supported on a carrier, the transition metal compound is an aliphatic hydrocarbon solvent having 5 to 12 carbon atoms, such as pentane, hexane, heptane, nonane, decane, and isomers thereof, and toluene, benzene. It may be dissolved or diluted in an aromatic hydrocarbon solvent such as, dichloromethane, or a hydrocarbon solvent substituted with a chlorine atom such as chlorobenzene. The solvent used here is preferably used after removing a small amount of water or air acting as a catalyst poison by treating a small amount of alkyl aluminum, and it is possible to further use a cocatalyst.

Hereinafter, preferred embodiments are presented to aid the understanding of the present invention. However, the following examples are only for illustrating the present invention, and the present invention is not limited thereto.

<Example>

Preparation example of supported catalyst

Preparation Example 1: Preparation of hybrid supported catalyst

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

3.0 kg of a toluene solution was added to a 20L sus high-pressure reactor, 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 sufficiently dispersing silica 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℃, dissolve 0.01mmol of the compound represented by Formula 1b in a solution state, and then react for 2 hours. After dissolving 0.01mmol of the compound represented by Formula 2a in a solution state, add and react for 2 hours. Was added. After stopping the stirring and settling for 30 minutes, the reaction solution was decanted. 3.0 kg of hexane was added to the reactor, the hexane slurry was transferred to filter dry, and the hexane solution was filtered. It was dried under reduced pressure at 50° C. for 4 hours to prepare a supported catalyst.

[Formula 1b]

[Formula 2a]

Olefin Polymerization Example

Example 1

In the presence of the hybrid supported catalyst prepared in Preparation Example 1, a terpolymer of ethylene/1-butene/1-hexene was slurry-polymerized.

At this time, the polymerization reactor was a continuous polymerization reactor that is an isobutane slurry loop process, the reactor volume was 140L, and the reaction flow rate was operated at about 7m/s. Gases (ethylene, hydrogen) required for polymerization and 1-butene and 1-hexene, which are comonomers, are constantly and continuously injected, and individual flow rates are adjusted according to the target product. The concentrations of all gases and comonomers 1-butene and 1-hexene were confirmed by on-line gas chromatograph. The supported catalyst was introduced as an isobutane slurry, the reactor pressure was maintained at about 40 bar, and the polymerization temperature was carried out at about 85°C.

Examples 2 to 3

Linear low-density polyethylene was prepared in the same manner as in Example 1, except that the contents of the comonomers 1-butene and 1-hexene were different.

Comparative Example 1

Commercially obtained ethylene/1-hexene copolymer (MI=1.0 g/10min, density=0.918 g/cm ³ ) was used as Comparative Example 1.

Comparative Example 2

Commercially obtained ethylene/1-hexene copolymer (MI=3.5 g/10min, density=0.918 g/cm ³ ) was used as Comparative Example 2.

<Experimental Example>

Physical property measurement

The olefin copolymer obtained in Examples and Comparative Examples is 180 to 210°C using a twin screw extruder (W&P Twin Screw Extruder, 75 pie, L/D=36) after prescribing an antioxidant (Iganox 1010 + Igafos 168, CIBA). Granulated at the extrusion temperature. Film molding was performed using a single screw extruder (Shinhwa Industries Single Screw Extruder, Blown Film M/C, 50 pie, L/D=20) and inflation molding to a thickness of 0.05 mm at an extrusion temperature of 165 to 200°C. At this time, the die gap (Die Gap) was set to 2.0 mm, and the expansion ratio (Blown-Up Ratio) was set to 2.3.

Physical properties and film properties of the olefin copolymer were measured according to the following evaluation method, and the results are shown in Table 1 below.

1) Density: ASTM 1505

2) Melt Index (MI, 2.16 kg/10 min): ASTM D1238, 2.16 kg, 190 ℃

3) Weight average molecular weight and molecular weight distribution: The number average molecular weight, the weight average molecular weight, and the Z average molecular weight were measured using a measurement temperature of 160°C and gel permeation chromatography-FTIR (GPC-FTIR). The molecular weight distribution was expressed by the ratio of the weight average molecular weight and the number average molecular weight.

4) Fall impact strength: Fall weight impact strength was obtained by measuring 20 or more times per film sample based on ASTM D 1709 [Method A].

5) Sealing (heat sealing) start temperature: In accordance with ASTM F 1921, when measured under the conditions of sealing time of 0.5 seconds, sealing pressure of 0.3 MPa, delay time of 0.1 seconds, and tensile speed of 200 mm/s using a J&B hot tack tester The temperature upon reaching was measured.

6) Hot-tack sealing strength: In accordance with ASTM F 1921, using a J&B hot tack tester, sealing time 0.5 seconds, sealing pressure 0.3 MPa, delay time 0.1 seconds, tensile speed 200 mm/second, and 5 ℃ between 95 ℃ and 120 ℃ The highest strength measured at each temperature at intervals was taken as the hot-tack sealing strength.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comonomer 1-butene (% by weight) 0.8 1.0 1.5 - - 1-hexene (% by weight) 8.5 8.2 7.6 8.8 9.0 Melt index
(2.16kg, 190℃, g/cm ³ ) 1.5 1.6 1.8 1.0 3.5 Density (g/cm ³ ) 0.918 0.917 0.917 0.918 0.918 Weight average molecular weight
(*10 ⁴ g/mol) 10.6 10.5 10.0 11.8 8.5 Molecular weight distribution 2.7 2.7 2.8 2.5 2.3 Drop impact strength (g) 1,200 800 500 1,050 300 Sealing start temperature (℃) 95 93 91 102 100 Hot-tack sealing strength (N/25.4mm)* 95℃ 2.81 2.35 2.05 0.68 0.49 100℃ 3.21 2.62 2.19 1.43 1.09 105℃ 3.55 2.72 2.33 2.32 1.61 110℃ 3.27 2.55 2.41 3.48 2.37 115℃ 3.19 2.45 2.22 3.10 2.61 120℃ 3.04 2.43 2.15 3.58 2.75

*N/A: When measuring the strength, if it is less than 0.5 N/25.4mm, it is indicated as side-bulk (N/A).

Referring to Table 1, Examples 1 to 3 of the present invention contain 1-hexene and 1-butene as comonomers at a constant weight, and have a melt index and density satisfying a predetermined range, while having a low sealing start temperature and a low temperature. It showed excellent hot-tack sealing strength from to high temperature. Therefore, it is expected to be useful in multipurpose films such as food packaging films or stretch films, as it has excellent sealing properties, cling properties, and mechanical properties.

Claims (10)

Including an olefin copolymer satisfying the following (1) to (4),
A film having a sealing initation temperature of 99° C. or less:
(1) According to ASTM D1238, the melt index (MI) measured at 190° C. under a load condition of 2.16 kg is 0.1 to 100 g/10 min;
(2) the density is 0.910 to 0.940 g/cm ³ ;
(3) molecular weight distribution (weight average molecular weight/number average molecular weight) is 2.0-10.0; And
(4) 82.0 to 99.0 wt% of ethylene, 0.05 to 3.0 wt% of the first comonomer, and 0.05 to 15.0 wt% of the second comonomer, based on the total weight of the olefin copolymer.
The method of claim 1,
The olefin copolymer is 82.0 to 99.0 wt% of ethylene, 0.05 to 3.0 wt% of propylene as the first comonomer, and 0.05 to 15.0 of 1-butene as the second comonomer, based on the weight of the total olefin copolymer. The film, which is a terpolymer comprising in wt%.
The method of claim 1,
The olefin copolymer is 82.0 to 99.0 wt% of ethylene, 0.05 to 3.0 wt% of propylene as the first comonomer, and 0.05 to 15.0 of 1-hexene as the second comonomer, based on the weight of the total olefin copolymer. The film, which is a terpolymer comprising in wt%.
The method of claim 1,
The olefin copolymer includes 82.0 to 99.0 wt% of ethylene, 0.05 to 3.0 wt% of propylene as the first comonomer, and 0.05 to 15.0 1-octene as the second comonomer, based on the weight of the total olefin copolymer. The film, which is a terpolymer comprising in wt%.
The method of claim 1,
The olefin copolymer is 82.0 to 99.0 wt% of ethylene, 0.05 to 3.0 wt% of 1-butene as the first comonomer, and 0.05 to 1-hexene as the second comonomer, based on the weight of the total olefin copolymer. The film is a terpolymer containing to 15.0wt%.
The method of claim 1,
The olefin copolymer includes 82.0 to 99.0 wt% of ethylene, 0.05 to 3.0 wt% of 1-butene as the first comonomer, and 0.05 to 3.0 wt% of 1-octene as the second comonomer, based on the weight of the total olefin copolymer. The film is a terpolymer containing to 15.0wt%.
The method of claim 1,
The olefin copolymer contains 82.0 to 99.0 wt% of ethylene, 0.05 to 3.0 wt% of 1-hexene as the first comonomer, and 0.05 to 3.0 wt% of 1-octene as the second comonomer, based on the weight of the total olefin copolymer. The film is a terpolymer containing to 15.0wt%.
The method of claim 1,
The olefin copolymer has a weight average molecular weight (Mw) of 50,000 to 150,000 g/mol.
The method of claim 1,
A film having a hot-tack sealing strength of greater than 2N at 95°C to 120°C.
The method of claim 1,
The olefin copolymer is prepared by polymerizing an olefin monomer in the presence of a catalyst composition including a first transition metal compound represented by the following Formula 1 and a second transition metal compound represented by the following Formula 2, a film:
[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 Chemical 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.