KR102601121B1 - Polyethylene - Google Patents

Abstract

The present invention relates to polyethylene. More specifically, it relates to polyethylene, which has excellent abrasion resistance and is suitable for manufacturing fibers.

Description

Polyethylene {POLYETHYLENE}

The present invention relates to polyethylene. More specifically, it relates to polyethylene, which has excellent abrasion resistance and is suitable for manufacturing fibers.

Olefin polymerization catalyst systems can be classified into Ziegler-Natta and metallocene catalyst systems, and these two highly active catalyst systems have been developed to suit their respective characteristics. The Ziegler-Natta catalyst has been widely applied to existing commercial processes since its invention in the 1950s. However, because it is a multisite catalyst with multiple active sites, it is characterized by a wide molecular weight distribution of the polymer and the composition of the comonomer. There is a problem that there is a limit to securing the desired physical properties because the distribution is not uniform.

On the other hand, metallocene catalysts are composed of a combination of a main catalyst mainly composed of transition metal compounds and a cocatalyst which is an organometallic compound mainly composed of aluminum. Such catalysts are homogeneous complex catalysts and are called single site catalysts. It has a narrow molecular weight distribution due to the single active point characteristics, and has the characteristic of obtaining a polymer with a uniform composition distribution of the comonomer.

Meanwhile, polypropylene resin used as a non-woven material has excellent chemical resistance and tensile strength and has been mainly used as a surface material for sanitary products such as diapers and sanitary napkins. However, homopolypropylene resin generally has a low content of low molecular weight copolymer and Due to low solubility of ren, there is a disadvantage in producing a rough surface when manufacturing non-woven fabrics.

In order to improve the surface feel, polypropylene resin was mixed with polyethylene resin to produce a bicomponent fiber using polypropylene resin on the inside and polyethylene resin on the outside, and was used as a non-woven material to improve touch and softness. . In addition, in order to provide convenience to users by improving the feel and ductility of non-woven fabrics, there is a trend to reduce the thickness of the spun yarn used.

Accordingly, when manufacturing polyethylene used in the bi-component fiber, there is a greater need for the development of polyethylene with a narrow molecular weight distribution and reduced dust generation to ensure excellent tensile strength and ductility.

In order to solve the problems of the prior art, the present invention has a narrow molecular weight distribution and low crystallinity within a similar melt index (MI) range, thereby increasing the molecular entanglement contribution (Effective Number of Physical Cross-link) and fluffing during stretching processing. Alternatively, it is intended to provide polyethylene with improved abrasion resistance by reducing the level of dust generation.

In order to solve the above problems, the present invention,

Provided is polyethylene that satisfies the following conditions 1) to 4):

1) a melt index (MI) of 0.5 to 40 g/10 min as measured according to ASTM D1238 at 190°C and a load of 2.16 kg;

2) molecular weight distribution (MWD) is 2.3 to 2.6;

3) Crystallinity measured using DSC (Differential Scanning Calorimeter) according to ASTM F2625 is 63 to 71%; and

4) Crystal relaxation temperature (T _cr , Crystal Relaxation Temperature) measured using DMA (Dynamic mechanical analysis) is 42 to 50°C.

According to the present invention, compared to conventional polyethylene having a similar melt index (MI), the molecular weight distribution is narrow and the degree of crystallinity is low, so the contribution of molecular entanglement (Effective Number of Physical Cross-link) is increased, and the abrasion resistance is thereby improved. can be provided.

In addition, the polyethylene according to the present invention reduces the level of fluff or dust generation during stretching processing, and this can also improve abrasion resistance.

Accordingly, the polyethylene according to the present invention can be usefully applied to the manufacture of textile products such as diapers, masks, various sanitary materials, medical fibers, and other general consumer goods.

In the present invention, terms such as first, second, etc. are used to describe various components, and the terms are used only for the purpose of distinguishing one component from other components.

Additionally, the terminology used herein is only used to describe exemplary embodiments and is not intended to limit the invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as “comprise,” “comprise,” or “have” are intended to designate the presence of implemented features, numbers, steps, components, or a combination thereof, and are intended to indicate the presence of one or more other features or It should be understood that this does not exclude in advance the possibility of the presence or addition of numbers, steps, components, or combinations thereof.

Since the present invention can be subject to various changes and can take various forms, specific embodiments will be illustrated and described in detail below. However, this is not intended to limit the present invention to a specific disclosed form, and should be understood to include all changes, equivalents, and substitutes included in the spirit and technical scope of the present invention.

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

Polyethylene according to one embodiment of the present invention is characterized by satisfying the following conditions 1) to 4): 1) Melt index (MI) measured according to ASTM D1238 at 190°C and under a load of 2.16 kg is 0.5 to 40 g/10 min; 2) molecular weight distribution (MWD) is 2.3 to 2.6; 3) Crystallinity measured using DSC (Differential Scanning Calorimeter) according to ASTM F2625 is 63 to 71%; and 4) the crystal relaxation temperature (T _cr , Crystal Relaxation Temperature) measured using DMA (Dynamic mechanical analysis) is 42 to 50°C.

When manufacturing polyethylene used in bi-component fibers using polypropylene resin on the inside and polyethylene resin on the outside, polyethylene with narrow molecular weight distribution and reduced dust generation is used to ensure excellent tensile strength and ductility. Development is required.

Meanwhile, when manufacturing polyethylene fibers, as the low molecular weight component in polyethylene decreases, polymer chain entanglement occurs more effectively and abrasion resistance tends to increase. Therefore, the fewer low molecular weight components and the narrower the relative molecular weight distribution, the better the wear resistance can be achieved. However, if the low molecular weight component is too small, the processability during fiber spinning is reduced, single yarns and knots occur, and the surface uniformity of the fiber is reduced.

The lower the crystal relaxation temperature, which shows the strength and uniformity of the crystal structure of polyethylene, the lower the brittleness, which reduces the generation of fluff or dust during the fiber stretching process and increases the abrasion resistance of the final fiber product. Therefore, even among polyethylene having a similar molecular weight distribution, there may be a significant difference in wear resistance depending on the crystal relaxation temperature.

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

1) Melt index (MI)

Polyethylene according to one embodiment of the present invention has a melt index (MI) of 0.5 to 40 g/10 min measured according to ASTM D1238 at 190°C and under a load of 2.16 kg.

More specifically, the melt index (MI) of the polyethylene of the present invention according to one embodiment is 0.5 g/10min or more, or 1.0 g/10min or more, or 5 g/10min or more, or 10 g/10min or more, or 15 g. /10min or more, or 18 g/10min or more, and 40 g/10min or less, or 35 g/10min or less, or 30 g/10min or less, or 25 g/10min or less, or 20 g/10min or less.

By having the above melt index, the molecular weight and viscosity of polyethylene can be optimized and spinnability can be improved during fiber production.

2) Molecular weight distribution (MWD)

Polyethylene according to one embodiment of the present invention has a molecular weight distribution (MWD, Mw/Mn) of 2.3 to 2.6.

More specifically, the molecular weight distribution of the polyethylene of the present invention according to one embodiment may be 2.3 or more, or 2.35 or more, or 2.4 or more, and 2.6 or less, or 2.55 or less, or 2.5 or less, or 2.45 or less.

Since the polyethylene of the present invention has a relatively narrow molecular weight distribution as described above compared to its high melt index, polymer chain entanglement can occur more effectively and abrasion resistance can be improved.

In the present invention, the number average molecular weight (Mn), weight average molecular weight (Mw), and molecular weight distribution are measured by measuring the weight average molecular weight (Mw) and number average molecular weight (Mn) of polyethylene using gel permeation chromatography (GPC), respectively. And the ratio of weight average molecular weight to number average molecular weight (Mw/Mn) was calculated as the molecular weight distribution.

Specifically, samples of polyethylene were evaluated using a Waters PL-GPC220 instrument using a Polymer Laboratories PLgel MIX-B 300 mm long column. The evaluation temperature was 160°C, 1,2,4-trichlorobenzene was used as a solvent, and the flow rate was measured at 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. Nine types of molecular weights of polystyrene standards were used: 2,000 / 10,000 / 30,000 / 70,000 / 200,000 / 700,000 / 2,000,000 / 4,000,000 / 10,000,000.

3) Crystallinity

Polyethylene according to one embodiment of the present invention has a crystallinity of 63 to 71% as measured using DSC (Differential Scanning Calorimeter) according to ASTM F2625.

More specifically, the crystallinity of the polyethylene of the present invention according to one embodiment may be 63% or more, or 65% or more, or 68% or more, and 71% or less, or 70% or less, or 69% or less.

Crystallinity is an indicator of the thermal properties of polyethylene. Since the polyethylene of the present invention has a low crystallinity compared to the high melt index as described above, the contribution of molecular entanglement (Effective Number of Physical Cross-link) increases, resulting in better wear resistance. It can indicate intensity.

The method for measuring the crystallinity can refer to ASTM F2625, and will be explained in more detail in the examples below.

4) Crystal relaxation temperature (T _cr , Crystal Relaxation Temperature)

Polyethylene according to one embodiment of the present invention has a crystal relaxation temperature (T _cr , Crystal Relaxation Temperature) of 42 to 50° C. measured using dynamic mechanical analysis (DMA).

More specifically, the crystal relaxation temperature (T _cr ) of the polyethylene of the present invention according to one embodiment is 42°C or higher, or 43°C or higher, or 44°C or higher, and 50°C or lower, or 49°C or lower, or 48°C or lower. , or may be below 47°C.

Crystal relaxation temperature is an indicator that can predict the strength and uniformity of the crystal structure of polyethylene. Since the polyethylene of the present invention has a low crystal relaxation temperature compared to the high melt index as described above, brittleness is reduced during the stretching process. This can reduce the generation of fluff or dust. Accordingly, the fiber containing polyethylene of the present invention can exhibit excellent abrasion resistance.

The crystal relaxation temperature is measured using a dynamic mechanical analysis (DMA), and will be described in more detail in the examples described later.

The method for measuring the crystal relaxation temperature will be described in more detail in the examples described later.

5) Abrasion Resistance

The polyethylene of the present invention as described above has an abrasion resistance measured with reference to ASTM D5264 of 0.2 mg/cm ³ or less.

More specifically, the abrasion resistance of the polyethylene of the present invention according to one embodiment is 0.1 mg/cm ³ or more, or 0.11 mg/cm ³ or more, or 0.12 mg/cm ³ or more, and 0.2 mg/cm ³ or less, or It may be 0.18 mg/cm ³ or less, or 0.16 mg/cm ³ or less, or 0.14 mg/cm ³ or less.

The polyethylene of the present invention has excellent abrasion resistance as described above and can be usefully applied to the manufacture of textile products such as diapers, masks, various sanitary materials, medical fibers, and other general consumer goods.

The method of measuring the abrasion resistance will be explained in more detail in the examples described later.

6) Other physical properties

Polyethylene according to one embodiment of the present invention has a melt flow rate ratio (MFRR) of MI ₅ /MI _2.16 , preferably 2 to 3.

The MFRR is the melt index (MI ₅ ) measured at 190°C and 5 kg load for the polyethylene divided by the melt index (MI _2.16 ) measured at 190°C and 2.16 kg load according to ASTM D1238.

More specifically, the melt flow rate ratio (MFRR) of the polyethylene measured according to ASTM D1238 at 190°C is 2.2 or more, or 2.3 or more, or 2.4 or more, or 2.5 or more, and is 2.90 or less, or 2.85 or less, or 2.7 or less, or has less than or equal to 2.56.

By having the above narrow melt flow rate range, the polyethylene of the present invention can achieve excellent filterability and improved process yield.

In addition, the polyethylene may be high density polyethylene (HDPE) that satisfies a density (ASTM D1505, 23°C) of 0.945 g/cm ³ to 0.965 g/cm ³ .

More specifically, the density of the polyethylene is 0.948 g/cm ³ or more, or 0.949 g/cm ³ or more, or 0.950 g/cm ³ or more, and 0.960 g/cm ³ or less, or 0.958 g/cm ³ or less, or 0.955 g/cm 3 or more. It may be g/cm ³ or less, or 0.953 g/cm ³ or less.

According to one embodiment of the present invention, the polyethylene may be, for example, a copolymer of ethylene and alpha olefin. At this time, the alpha olefin is propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-eicocene, norbornene, norbonadiene, ethylidene nobodene, phenylnobodene, vinylnobodene, dicyclopentadiene, 1,4-butadiene, 1,5- It may include pentadiene, 1,6-hexadiene, styrene, alpha-methylstyrene, divinylbenzene, and 3-chloromethylstyrene. Preferably, the polyethylene may be a copolymer of ethylene and 1-butene, a copolymer of ethylene and 1-hexene, or a copolymer of ethylene and 1-octene.

Meanwhile, polyethylene according to an embodiment of the invention having the above physical properties is manufactured by a production method comprising polymerizing an olefin monomer in the presence of a catalyst composition containing a metallocene compound as a catalytically active ingredient. It can be.

More specifically, the polyethylene of the present invention is not limited thereto, but may be produced by copolymerizing ethylene and alpha-olefin in the presence of a catalyst composition containing a metallocene compound represented by the following formula (1).

[Formula 1]

In Formula 1,

B is boron,

M is a group 4 transition metal,

R ₁ to R ₄ are each independently hydrogen, C _1-20 alkyl, C _3-20 cycloalkyl, or C _6-20 aryl, or R ₁ and R ₂ or R ₃ and R ₄ are bonded to each other and substituted or Forming an unsubstituted C _6-60 aromatic ring,

R ₅ and R ₆ are each independently C _1-20 alkyl, C _3-20 cycloalkyl, or C _6-20 aryl, or R ₅ and R ₆ are combined to form a C _3-60 aliphatic ring, or C _{6 -60} forms an aromatic ring,

X ₁ and X ₂ are each independently C _1-20 alkyl or -O(CO)R', where R' is C _1-20 alkyl,

Q is a C _2-60 heterocycle containing at least one selected from the group consisting of substituted or unsubstituted N, O and S,

Y and Y' are elements constituting Q,

Y is N, O, or S,

Y' is an element of Q adjacent to Y, and is either N or C.

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

The halogen may be fluoro (F), chloro (Cl), bromo (Br), or iodo (I).

The alkyl may be straight chain or branched chain alkyl. Specifically, the 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 chain alkyl; C _3-15 branched chain alkyl; Or it may be C _3-10 branched chain alkyl. More specifically, C _1-20 alkyl is a methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, tert-butyl group, n-pentyl group, or iso-pentyl group, etc. However, it is not limited to this. Meanwhile, in this specification, “iPr” refers to an iso-propyl group.

The cycloalkyl may be cyclic alkyl. Specifically, the C _3-20 cycloalkyl is C _3-20 cyclic alkyl; C _3-15 cyclic alkyl; Or it may be C _3-10 cyclic alkyl. More specifically, cyclopropyl, cyclobutyl, cyclopentyl, 3-methylcyclopentyl, 2,3-dimethylcyclopentyl, cyclohexyl, 3-methylcyclohexyl, 4-methylcyclohexyl, 2,3-dimethylcyclohexyl, Examples include, but are not limited to, 3,4,5-trimethylcyclohexyl, 4-tert-butylcyclohexyl, cycloheptyl, and cyclooctyl. Meanwhile, in this specification, “Cy” refers to cycloalkyl having 3 to 6 carbon atoms.

The alkenyl may be straight chain, branched chain, or cyclic alkenyl. Specifically, the 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. It may be alkenyl, 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.

The alkoxy group may be a straight chain, branched chain, or cyclic alkoxy group. Specifically, the C _1-20 alkoxy is a C _1-20 straight chain alkoxy group; C _1-10 straight chain alkoxy; C _1-5 straight chain alkoxy group; C _3-20 branched or cyclic alkoxy; C _3-15 branched or cyclic alkoxy; Or it may be C _3-10 branched or cyclic alkoxy. More specifically, C _1-20 alkoxy is methoxy group, ethoxy group, n-propoxy group, iso-propoxy group, n-butoxy group, iso-butoxy group, tert-butoxy group, n-pentoxy group, iso- A pentoxy group, a neo-pentoxy group, or a cyclohexoxy group may be included, but are not limited thereto.

The alkoxyalkyl has a structure including -Ra-O-Rb and may be a substituent in which one or more hydrogens of alkyl (-Ra) are replaced with alkoxy (-O-Rb). Specifically, the C _2-20 alkoxyalkyl is methoxymethyl group, methoxyethyl group, ethoxymethyl group, iso-propoxymethyl group, iso-propoxyethyl group, iso-propoxyhexyl group, tert-butoxymethyl group, tert- There is a butoxyethyl group or a tert-butoxyhexyl group, but it is not limited thereto.

The aryl includes monocyclic, bicyclic or tricyclic aromatic hydrocarbons. According to one embodiment of the present invention, the aryl group may have 6 to 60 carbon atoms or 6 to 20 carbon atoms, and specifically includes phenyl, naphthyl, anthracenyl, dimethylanilinyl, anisolyl, etc., but is not limited thereto.

The heteroaryl is a heteroaryl containing at least one of O, N, and S as a heterogeneous element, and the number of carbon atoms is not particularly limited, but may have 2 to 60 carbon atoms or 2 to 20 carbon atoms. Examples of heteroaryl include xanthene, thioxanthen, thiophene group, furan group, pyrrole group, imidazole group, thiazole group, oxazole group, oxadiazole group, triazole group, pyridyl group, bipyridyl group, Pyridinyl group, pyrimidyl group, triazine group, acridyl group, pyridazine group, pyrazinyl group, quinolinyl group, quinazoline group, quinoxalinyl group, phthalazinyl group, pyrido pyrimidinyl group, pyrido pyrazinyl group, pyrazino pyrazinyl group, isoquinoline group, indole group, carbazole group, benzoxazole group, benzoimidazole group, benzothiazole group, benzocarbazole group, benzothiophene group, dibenzothiophene group, benzofuranyl group, Examples include phenanthroline group, isoxazolyl group, thiadiazolyl group, phenothiazinyl group, and dibenzofuranyl group, but are not limited to these.

The hydrocarbyl group refers to a monovalent hydrocarbon compound, and includes an alkyl group, alkenyl group, alkynyl group, aryl group, aralkyl group, aralkenyl group, aralkynyl group, alkylaryl group, and alkenyl aryl group. group and alkynylaryl group. In one example, the hydrocarbyl group can be straight chain, branched chain, or cyclic alkyl. More specifically, the hydrocarbyl group having 1 to 30 carbon atoms is methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, tert-butyl group, n-pentyl group, n-hexyl group. Straight-chain, branched-chain, or cyclic alkyl groups such as actual group, n-heptyl group, and cyclohexyl group; Alternatively, it may be an aryl group such as phenyl, biphenyl, naphthyl, anthracenyl, phenanthrenyl, or fluorenyl. Additionally, it may be alkylaryl such as methylphenyl, ethylphenyl, methylbiphenyl, and methylnaphthyl, and may also be arylalkyl such as phenylmethyl, phenylethyl, biphenylmethyl, and naphthylmethyl. Additionally, it may be alkenyl such as allyl, allyl, ethenyl, propenyl, butenyl, and pentenyl.

The heterocycle includes both an aliphatic ring containing one or more elements selected from the group consisting of N, O, and S, and an aromatic ring containing one or more elements selected from the group consisting of N, O, and S.

And, the Group 4 transition metal may be titanium (Ti), zirconium (Zr), hafnium (Hf), or rutherphodium (Rf), and specifically, titanium (Ti), zirconium (Zr), or hafnium (Hf). It may be, and more specifically, it may be zirconium (Zr) or hafnium (Hf), but it is not limited thereto.

The above-mentioned substituents are optionally hydroxy groups within the range of achieving the same or similar effects as the desired effect; halogen; alkyl or alkenyl, aryl, alkoxy; Alkyl or alkenyl, aryl, alkoxy containing one or more heteroatoms from groups 14 to 16; Amino; Silyl; Alkylsilyl or alkoxysilyl; Phosphine group; phosphide group; Sulfonate group; and may be substituted with one or more substituents selected from the group consisting of a sulfone group.

The metallocene compound represented by Formula 1 adopts a bridge structure containing boron anions, unlike the commonly used CGC type precursor. Conventional CGC-type precursors contain a neutral bridge structure containing silicon, so that the ligand units have a negative charge. This causes structural limitations, making it difficult to develop various physical properties when manufacturing olefin polymers.

On the other hand, the metallocene compound has a negatively charged bridge structure and may have a neutral ligand unit. The ligand unit of the present invention is a heterocyclic ring Q of the above formula (1), where Y, an element of Q, coordinates with a metal, and Y', an element of Q adjacent to Y, is connected to a bridge. Accordingly, in the present invention, a catalyst having higher activity and higher copolymerization than existing CGC precursors can be manufactured by employing various neutral ligand units satisfying the above structure.

In addition, metallocene compounds include alkyl or carboxylate as a metal substituent, which acts as a good leaving group and promotes reaction with cocatalysts such as MAO, thereby increasing activity.

Therefore, using the metallocene compound can maintain the high melt index of polyethylene, reduce the low molecular weight component, narrow the molecular weight distribution, and increase the SCB content to increase the molecular entanglement contribution (Effective Number of Physical Cross-link). Therefore, polyethylene with excellent abrasion resistance can be manufactured.

In Formula 1, preferably, M may be zirconium (Zr).

Preferably, R ₁ to R ₄ are each independently hydrogen, C _1-10 alkyl, or C _6-20 aryl, or R ₁ and R ₂ or R ₃ and R ₄ are bonded to each other to form substituted or unsubstituted C Can form _6-20 aromatic rings,

More preferably, R ₁ to R ₄ are each independently hydrogen or methyl, or R ₁ and R ₂ or R ₃ and R ₄ are bonded to each other to form a benzene ring, or 1,2,3,4-tetrahydro. Can form a naphthalene ring, wherein the benzene ring or 1,2,3,4-tetrahydronaphthalene ring is unsubstituted or one or more selected from the group consisting of methyl, tertbutyl, and 4-tertbutyl phenyl. It may be substituted with 4 substituents.

Preferably, R ₅ and R ₆ are each independently C _1-10 alkyl, or C _6-20 aryl, or R ₅ and R ₆ are combined to form a C _3-20 aliphatic ring, or C _6-20 aromatic ring. can form a ring,

More preferably, R ₅ and R ₆ are each independently methyl or phenyl, or R ₅ and R ₆ may be combined with each other to form a cyclooctane ring.

Most preferably, R ₅ and R ₆ may each be phenyl.

Preferably, X ₁ and X ₂ may each independently be methyl or acetate.

Preferably, R' may be methyl.

Preferably, X ₁ and X ₂ may be identical to each other.

Preferably, Q may be a C _2-20 heterocycle containing at least one selected from the group consisting of substituted or unsubstituted N, O, and S,

More preferably, Q may be a pyridine ring, a quinoline ring, a 4,5-dihydroxazole ring, a pyrazole ring, or a benzoxazole ring, wherein Q is unsubstituted or methyl, isopropyl, and diphenyl. It may be substituted with 1 to 4 substituents selected from the group consisting of amino.

More preferably, Q may be a pyridine ring, 4,5-dihydroxazole ring, pyrazole ring, or benzoxazole ring, wherein Q is unsubstituted or consists of methyl, isopropyl and diphenylamino. It may be substituted with 1 to 4 substituents selected from the group.

Y is a hetero atom that coordinates with metal M, preferably, Y may be N.

Meanwhile, specific examples of the metallocene compound represented by Formula 1 include compounds represented by the following structural formulas, but the present invention is not limited thereto:

.

.

If X _{1 and} It can be manufactured according to the manufacturing method. The manufacturing method may be further detailed in the manufacturing examples described later.

[Scheme 1]

In Scheme 1, B, M, R ₁ to R ₆ , X ₁ , X ₂ , Q, Y and Y' are as defined in Formula 1 above.

The catalyst composition according to one embodiment of the invention may include the metallocene compound of Formula 1 above as a single catalyst.

At this time, the catalyst composition may include the metallocene compound as a single component, or may be in the form of a supported metallocene catalyst including the metallocene compound and a carrier. When a supported metallocene catalyst is used, the morphology and physical properties of the produced polyethylene are excellent, and it can be suitably used in conventional slurry polymerization, bulk polymerization, and gas phase polymerization processes.

Specifically, the carrier may be a carrier having a highly reactive hydroxyl group, silanol group, or siloxane group on the surface. For this purpose, the carrier is surface modified by calcination or has moisture removed from the surface by drying. can be used For example, silica prepared by calcining silica gel, silica dried at high temperature, silica-alumina, and silica-magnesia can be used, and these are typically Na ₂ O, K ₂ CO ₃ , BaSO ₄ , and Mg(NO ₃ ) ₂ It may contain oxides, carbonates, sulfates, and nitrates.

The temperature during calcination or drying of the carrier may be about 200°C to about 600°C, or about 250°C to about 600°C. If the calcination or drying temperature for the carrier is low, there is a risk that the moisture remaining on the carrier may react with the cocatalyst because there is too much moisture remaining on the carrier, and the cocatalyst support rate is relatively low due to the excessive presence of hydroxyl groups. It can be higher, but this results in a large amount of cocatalyst being required. In addition, if the drying or calcining temperature is too high, the pores on the surface of the carrier merge and the surface area decreases, many hydroxy groups or silanol groups disappear from the surface, and only siloxane remains, which raises the risk of reducing the reaction site with the cocatalyst. there is.

The amount of hydroxyl groups on the surface of the carrier is preferably 0.1 mmol/g to 10 mmol/g, and more preferably 0.5 mmol/g to 5 mmol/g. The amount of hydroxy groups on the surface of the carrier can be adjusted by the preparation method and conditions of 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, there are few reaction sites with the cocatalyst, and if it exceeds 10 mmol/g, it is not preferable because it may be caused by moisture other than the hydroxy group present on the surface of the carrier particle. not.

For example, the amount of hydroxy groups on the surface of the carrier may be 0.1 mmol/g to 10 mmol/g or 0.5 mmol/g to 5 mmol/g. The amount of hydroxy groups on the surface of the carrier can be adjusted by the preparation method and conditions of the carrier or drying conditions such as temperature, time, vacuum or spray drying. If the amount of the hydroxy group is too low, there are few reaction sites with the cocatalyst, and if it is too large, it may be caused by moisture other than the hydroxy group present on the surface of the carrier particle.

Among the above-mentioned carriers, silica, especially silica manufactured by calcining silica gel, is supported by chemically bonding the functional group of the silica carrier and the compound of formula 1, so that almost no catalyst is released from the surface of the carrier during the propylene polymerization process. As a result, fouling that occurs on the reactor wall or between polymer particles can be minimized when producing polyethylene through slurry or vapor phase polymerization.

In addition, when supported on a carrier, the compound of Formula 1 is present in an amount of about 10 μmol or more, or about 30 μmol or more, and about 100 μmol or less, or about 80 μmol or less per weight of the carrier, for example, based on about 1 g of silica. It can be supported within a content range. When supported in the above content range, it exhibits appropriate supported catalyst activity, which can be advantageous in terms of maintaining the activity of the catalyst and economic efficiency.

In addition, the catalyst composition may further include one or more cocatalysts along with the metallocene compound and carrier described above.

The cocatalyst may be any cocatalyst used when polymerizing olefins under a general metallocene catalyst. This cocatalyst causes a bond to be created between the hydroxyl group in the carrier and the Group 13 transition metal. In addition, since the cocatalyst exists only on the surface of the carrier, it can contribute to securing the unique characteristics of the specific hybrid catalyst composition without fouling phenomenon in which polymer particles stick to the reactor wall or each other.

In addition, the catalyst composition according to the present invention may include, in addition to the metallocene compound, one or more cocatalyst compounds selected from the group consisting of compounds represented by Formulas 2 to 4 below.

[Formula 2]

-[Al(R ₁₀ )-O]a-

In Formula 2,

R ₁₀ is halogen; or C _1-20 hydrocarbyl substituted or unsubstituted with halogen;

a is an integer greater than or equal to 2,

[Formula 3]

D( _R11 ) ₃

In Formula 3 above,

D is aluminum or boron;

R ₁₁ is halogen; or C _1-20 hydrocarbyl substituted or unsubstituted with halogen,

[Formula 4]

[LH] ⁺ [ZA ₄ ] ^- or [L] ⁺ [ZA ₄ ] ^-

In Formula 4 above,

L is a neutral or cationic Lewis base;

H is a hydrogen atom;

Z is a group 13 element;

A is each independently C 6-20 aryl or C _1-20 alkyl in _which one or more hydrogen atoms are substituted with halogen, C _1-20 hydrocarbyl, C _1-20 alkoxy, or phenoxy.

The compound represented by Formula 2 may serve as an alkylating agent and an activator, the compound represented by Formula 3 may serve as an alkylating agent, and the compound represented by Formula 4 may serve as an activator. there is.

The compound represented by Formula 2 is not particularly limited as long as it is an alkylaluminoxane, but for example, it may be methylaluminoxane, ethyl aluminoxane, isobutyl aluminoxane, butylaluminoxane, etc., and preferably may be methylaluminoxane. .

The compound represented by Formula 3 is not particularly limited as long as it is an alkyl metal compound, but for example, trimethyl aluminum, triethyl aluminum, triisobutyl aluminum, tripropyl aluminum, tributyl aluminum, dimethyl chloroaluminum, triisopropyl aluminum, Tri-s-butyl aluminum, tricyclopentyl aluminum, tripentyl aluminum, triisopentyl aluminum, trihexyl aluminum, trioctyl aluminum, ethyldimethyl aluminum, methyldiethyl aluminum, triphenyl aluminum, tri-p-tolyl aluminum, dimethyl It may be aluminum methoxide, dimethyl aluminum ethoxide, trimethyl boron, triethyl boron, triisobutyl boron, tripropyl boron, tributyl boron, etc., and is preferably selected from trimethyl aluminum, triethyl aluminum, and triisobutyl aluminum. You can.

Examples of compounds represented by Formula 4 include triethylammonium tetraphenylboron, tributylammonium tetraphenylboron, trimethylammonium tetraphenylboron, tripropylammonium tetraphenylboron, and trimethylammonium tetra(p-tolyl). Boron, trimethylammonium tetra(o,p-dimethylphenyl)boron, tributylammonium tetra(p-trifluoromethylphenyl)boron, trimethylammonium tetra(p-trifluoromethylphenyl)boron, tributylammonium tetra Pentafluorophenylboron, N,N-diethylanilinium tetraphenylboron, N,N-diethylanilinium tetrapentafluorophenylboron, diethylammonium tetrapentafluorophenylboron, triphenylphosphonium Tetraphenylboron, trimethylphosphonium tetraphenylboron, triethylammonium tetraphenylaluminum, tributylammonium tetraphenylaluminum, trimethylammonium tetraphenylaluminum, tripropylammoniumtetraphenylaluminum, trimethylammonium tetra(p-tolyl) ) Aluminum, tripropylammonium tetra(p-tolyl) aluminum, triethylammonium tetra(o,p-dimethylphenyl) aluminum, tributylammonium tetra(p-trifluoromethylphenyl) aluminum, trimethylammonium tetra( p-trifluoromethylphenyl) aluminum, tributylammonium tetrapentafluorophenyl aluminum, N, N-diethylanilinium tetraphenylaluminum, N,N-diethylanilinium tetrapentafluorophenyl aluminum, di Ethylammonium tetrapentatetetraphenyl aluminum, triphenylphosphonium tetraphenylaluminum, trimethylphosphonium tetraphenylaluminum, tripropylammonium tetra(p-tolyl)boron, triethylammonium tetra(o,p-dimethylphenyl)boron , tributylammonium tetra(p-trifluoromethylphenyl)boron, triphenylcarbonium tetra(p-trifluoromethylphenyl)boron, triphenylcarboniumtetrapentafluorophenylboron, etc., preferably Alumoxane can be used, and more preferably, methylaluminoxane (MAO), which is an alkylaluminoxane, can be used.

Additionally, the catalyst composition may include the cocatalyst and the metallocene compound of Formula 1 at a molar ratio of about 1:1 to about 1:10000, preferably about 1:1 to about 1:1000. It may be included in a molar ratio of, and more preferably, it may be included in a molar ratio of about 1:10 to about 1:100. At this time, if the molar ratio is less than about 1, the metal content of the cocatalyst is too small and catalytic active species are not formed well, which may lower activity. If the molar ratio exceeds about 10,000, there is a risk that the metal in the cocatalyst may act as a catalyst poison. there is.

The amount of the cocatalyst supported may be about 3 mmol to about 25 mmol, or about 5 mmol to about 20 mmol, based on 1 g of carrier.

Meanwhile, the catalyst composition includes the steps of supporting a cocatalyst on a carrier; Supporting a metallocene compound on a carrier carrying the cocatalyst; and a carrier on which the cocatalyst and the metallocene compound are supported.

In the above method, the loading conditions are not particularly limited and can be performed within a range well known to those skilled in the art. For example, high-temperature loading and low-temperature loading can be appropriately used. For example, the loading temperature may range from about -30 ^o C to about 150 ^o C, and preferably from about 50 ^o C to about 98 o C. ^o C, or about 55 ^o C to about 95 ^o C. The loading time can be appropriately adjusted depending on the amount of the first metallocene compound to be loaded. The reacted supported catalyst can be used as is by removing the reaction solvent by filtration or distillation under reduced pressure. If necessary, it can be used after Soxhlet filtering with an aromatic hydrocarbon such as toluene.

In addition, the preparation of the supported catalyst may be performed under a solvent or without a solvent. If a solvent is used, acceptable solvents include aliphatic hydrocarbon solvents such as hexane or pentane, aromatic hydrocarbon solvents such as toluene or benzene, hydrocarbon solvents substituted with a chlorine atom such as dichloromethane, diethyl ether or tetrahydrofuran (THF). ), ether-based solvents such as acetone, and most organic solvents such as ethyl acetate, and hexane, heptane, toluene, or dichloromethane are preferable.

Meanwhile, polyethylene according to one embodiment of the present invention may be produced by a method for producing polyethylene including the step of polymerizing polyethylene in the presence of a catalyst composition containing the metallocene compound.

The method for producing polyethylene can be carried out by slurry polymerization using ethylene and alpha-olefin as raw materials in the presence of the above-described catalyst composition by applying conventional equipment and contact technology.

The method for producing polyethylene may copolymerize ethylene and alpha-olefin using a continuous slurry polymerization reactor, a loop slurry reactor, etc., but is not limited thereto.

Specifically, in the copolymerization step, about 0.45 mol or less, or about 0.1 mol to about 0.45 mol, or about 0.4 mol or less, or about 0.2 mol to about 0.4 mol, or about 0.35 mol or less, is added based on 1 mol of ethylene. It can be achieved by reacting at about 0.25 mole to about 0.35 mole.

The method for producing polyethylene does not require increasing the comonomer content to lower the product density, so the process is stable and the high drop impact strength of the product is reproducible.

In addition, the alpha-olefin is 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, It may be one or more selected from the group consisting of 1-octadecene, 1-eicocene, and mixtures thereof.

Specifically, in the method for producing polyethylene, for example, 1-hexene can be used as the alpha-olefin. Accordingly, in the slurry polymerization, the ethylene and 1-hexene can be polymerized to produce an ultra-low density polyethylene copolymer.

And, the polymerization temperature is about 25 ^o C to about 500 ^o C, or about 25 ^o C to about 300 ^o C, or about 30 ^o C to about 200 ^o C, or about 50 ^o C to about 150 ^o C, or It may be about 60 ^o C to about 120 ^o C. In addition, the polymerization pressure is about 1 kgf/cm2 to about 100 kgf/cm2, or about 1 kgf/cm2 to about 50 kgf/cm2, or about 5 kgf/cm2 to about 45 kgf/cm2, or about 10 kgf/cm2 to It may be about 40 kgf/cm2, or about 15 kgf/cm2 to about 35 kgf/cm2.

The catalyst composition containing the metallocene compound of Formula 1 according to the present invention is an aliphatic hydrocarbon solvent having 5 to 12 carbon atoms, such as pentane, hexane, heptane, nonane, decane, and isomers thereof, and aromatic hydrocarbons such as toluene and benzene. It can be injected by dissolving or diluting it in a solvent, such as dichloromethane or chlorobenzene, in a hydrocarbon solvent substituted with a chlorine atom. The solvent used here is preferably treated with a small amount of alkyl aluminum to remove a small amount of water or air, which acts as a catalyst poison, and it is also possible to use a co-catalyst.

In one example, the polymerization step is performed by using hydrogen gas at about 800 ppm or less, or about 0 to about 800 ppm, or about 300 ppm or less, or about 10 ppm to about 300 ppm, or about 100 ppm or less, or about 15 ppm or less, based on the ethylene content. It can be performed by adding about 100 ppm.

In this ethylene copolymerization process, the catalyst composition containing the metallocene compound of the present invention can exhibit high catalytic activity. For example, the catalyst activity during ethylene copolymerization is about 4.0 kg PE/g·cat when calculated as the ratio of the weight of polyethylene (kg PE) produced per mass (g) of the catalyst composition used based on unit time (hr). ㆍhr or more or about 4.0 kg PE/g·cat·hr to about 50 kg PE/g·cat·hr. Specifically, the activity of the catalyst composition is about 4.2 kg PE /g·cat·hr or more, or about 4.3 kg PE/g·cat·hr or more, or about 4.5 kg PE/g·cat·hr or more, or about 40 It may be less than or equal to kg PE/g·cat·hr, or less than or equal to about 30 kg PE/g·cat·hr, or less than or equal to about 15 kg PE/g·cat·hr.

According to the present invention, polyethylene can be produced by copolymerizing ethylene and alpha-olefin using a catalyst composition containing the metallocene compound of Chemical Formula 1 described above.

At this time, the polyethylene produced may be an ethylene 1-hexene copolymer.

The method for producing polyethylene is performed by slurry polymerization in the presence of the catalyst composition described above, and thus polyethylene with excellent physical properties can be provided.

In particular, the catalyst composition containing the metallocene compound of Formula 1 according to the present invention exhibits high activity as described above during the copolymerization of ethylene and alpha-olefin, without excessively increasing the content of alpha-olefin as a comonomer. Along with the high molecular weight, the short chain branch (SCB) content within the molecule can be increased.

The polyethylene of the present invention manufactured by the manufacturing method of one embodiment described above has a narrow molecular weight distribution and low crystallinity within a similar melt index (MI) range, resulting in increased molecular entanglement contribution (Effective Number of Physical Cross-link) and stretching. The level of fluff or dust generated during processing is reduced, and the abrasion resistance is improved, making it suitable for use in textile products.

Below, preferred embodiments are presented to aid understanding of the present invention. However, the following examples are provided only to make the present invention easier to understand, and the content of the present invention is not limited thereto.

<Example>

Synthesis Example 1

2-Bromopyridine (1 eq.) was dissolved in tetrahydrofuran (0.1 M), and then n -butyllithium (1 eq.) was slowly added dropwise at -90°C and stirred at the same temperature for 1 hour. Afterwards, chlorodiphenylborane (1 eq.) was dissolved in toluene (0.3 M), and then slowly added dropwise to the first reactant at -78°C and stirred for 1 hour. After stirring at room temperature for 12 hours, the solvent was vacuum dried, toluene was added, solids were removed through a filter, etc., and the remaining liquid was vacuum dried to obtain diphenyl(pyridin-2-yl)borane.

After dissolving the diphenyl(pyridin-2-yl)borane (1 eq.) in tetrahydrofuran (0.1 M), a solution of lithium tetramethylcyclopentadienide (Li(CpMe ₄ ), 1 eq.) in tetrahydrofuran (0.1 M) was cooled at 0°C. It was slowly added dropwise and stirred at room temperature overnight. After vacuum drying the solvent, toluene/diethyl ether (volume ratio 3/1, 0.3 M) was added and dissolved, and MCl ₄ (1 eq.) was mixed with toluene (0.2 M) and added at -78°C and stirred at room temperature overnight. did. After completion of the reaction, the solvent is dried under vacuum, dichloromethane is added, salts are removed through a filter, etc., and the filtrate is vacuum dried and recrystallized by adding dichloromethane/hexane. The produced solid was filtered, vacuum dried, and dichloro{diphenyl(pyridin-2-yl-κ N )(η ⁵ -2,3,4,5-tetramethylcyclopenta-2,4-dien-1-ylidene)borate}zirconium( IV) was obtained.

Dichloro{diphenyl(pyridin-2-yl-κ N )(η ⁵ -2,3,4,5-tetramethylcyclopenta-2,4-dien-1-ylidene)borate}zirconium(IV) (1 eq.) to toluene /diethyl ether (volume ratio 3/1, 0.3 M), a solution of methyl lithium (2 eq.) dissolved in hexane or diethyl ether was slowly added dropwise at -78°C and stirred at room temperature for 12 hours. After completion of the reaction, the solvent is dried under vacuum, dichloromethane is added, salts are removed through a filter, etc., and the filtrate is vacuum dried and recrystallized by adding dichloromethane/hexane. The resulting solid was filtered and vacuum dried to obtain a precursor compound.

1H NMR (500 MHz, CDCl ₃ , ppm)=δ 8.32(d, 1H), 8.05(d, 4H), 7.70(t, 1H), 7.42(t, 1H), 7.40(t, 4H), 7.23( d, 1H), 7.17(t, 2H), 2.08(s, 6H), 1.93(s, 6H) 0.95(s, 6H)

Synthesis Example 2

2-Bromopyridine (1 eq.) was dissolved in tetrahydrofuran (0.1 M), and then n -butyllithium (1 eq.) was slowly added dropwise at -90°C and stirred at the same temperature for 1 hour. Afterwards, chlorodiphenylborane (1 eq.) was dissolved in toluene (0.3 M), and then slowly added dropwise to the first reactant at -78°C and stirred for 1 hour. After stirring at room temperature for 12 hours, the solvent was vacuum dried, toluene was added, solids were removed through a filter, etc., and the remaining liquid was vacuum dried to obtain diphenyl(pyridin-2-yl)borane.

After dissolving the diphenyl(pyridin-2-yl)borane (1 eq.) in tetrahydrofuran (0.1 M), a solution of lithium tetramethylcyclopentadienide (Li(CpMe ₄ ), 1 eq.) in tetrahydrofuran (0.1 M) was cooled at 0°C. It was slowly added dropwise and stirred at room temperature overnight. After vacuum drying the solvent, toluene/diethyl ether (volume ratio 3/1, 0.3 M) was added and dissolved, and MCl ₄ (1 eq.) was mixed with toluene (0.2 M) and added at -78°C and stirred at room temperature overnight. did. After completion of the reaction, the solvent is dried under vacuum, dichloromethane is added, salts are removed through a filter, etc., and the filtrate is vacuum dried and recrystallized by adding dichloromethane/hexane. The produced solid was filtered, vacuum dried, and dichloro{diphenyl(pyridin-2-yl-κ N )(η ⁵ -2,3,4,5-tetramethylcyclopenta-2,4-dien-1-ylidene)borate}zirconium( IV) was obtained.

Dichloro{diphenyl(pyridin-2-yl-κ N )(η ⁵ -2,3,4,5-tetramethylcyclopenta-2,4-dien-1-ylidene)borate}zirconium(IV) (1 eq.) to toluene /diethyl ether (volume ratio 3/1, 0.3 M), a solution of sodium acetate (2 eq.) dissolved in hexane or diethyl ether was slowly added dropwise at -78°C, and stirred at room temperature for 12 hours. After completion of the reaction, the solvent is dried under vacuum, dichloromethane is added, salts are removed through a filter, etc., and the filtrate is vacuum dried and recrystallized by adding dichloromethane/hexane. The resulting solid was filtered and vacuum dried to obtain a precursor compound.

1H NMR (500 MHz, CDCl ₃ , ppm)=δ 8.35(d, 1H), 8.04(d, 4H), 7.72(t, 1H), 7.45(t, 1H), 7.35(t, 4H), 7.20( d, 1H), 7.11(t, 2H), 2.12(s, 6H), 2.01(s, 6H), 1.88(s, 6H)

Synthesis Example 3

Dimethyl{diphenyl(pyridin-2-yl-κ N ) was synthesized in the same manner as in Synthesis Example 1, except that lithium 2-methyl-4-(4-tertbutylphenyl)-inenide was used instead of lithium tetramethylcyclopentadienide (Li(CpMe ₄ )). (η ⁵ -2-methyl-4-(4-tertbutylphenyl))borate}zirconium(IV) precursor compound was obtained.

1H NMR (500 MHz, CDCl ₃ , ppm)=δ 8.34(d, 1H), 8.13(d, 4H), 8.05(d, 1H), 7.79-74(m, 2H), 7.47(t, 1H), 7.41-7.39(m, 6H), 7.35(m, 3H), 7.23(d, 1H), 7.20(t, 2H), 6.66(s, 1H), 2.09(s, 3H), 1.49(s, 9H) , 0.94(s, 6H) ppm.

Synthesis Example 4

Dimethyl{diphenyl(pyridin-2-yl) was prepared in the same manner as in Synthesis Example 1, except that lithium 2,7-di-tert-butyl-9H-fluorene-9-ylidenide was used instead of lithium tetramethylcyclopentadienide (Li(CpMe ₄ )). -κ N )(η ⁵ -2,7-di-tert-butyl-9H-fluorene-9-ylidene)borate}zirconium(IV) precursor compound was obtained.

1H NMR (500 MHz, CDCl ₃ , ppm)=δ 8.40(d, 1H), 8.12(d, 4H), 8.09(d, 2H), 7.73-7.70(m, 3H), 7.50(t, 1H), 7.40-7.36(m, 6H), 7.19(d, 1H), 7.14(t, 2H), 1.44(s, 18H), 0.90(s, 6H) ppm

Synthesis Example 5

In Synthesis Example 1, instead of lithium tetramethylcyclopentadienide (Li(CpMe ₄ )), lithium 1, 2, 3, 4, 7, 8, 9, 10- octahydro- 1, 1, 4, 4, 7, 7, 10, 10- Dimethyl{diphenyl(pyridin-2-yl-κ N )(η ⁵ -1, 2, 3, 4, 7) using the same method except that octamethyl-12H - dibenzo[ b, h ] fluoren-12-ylidenide was used. , 8, 9, 10- octahydro- 1, 1, 4, 4, 7, 7, 10, 10- octamethyl- 12 H - dibenzo[ b, h ] fluoren- 12-ylidene)borate}zirconium(IV) precursor compound was obtained.

1H NMR (500 MHz, CDCl ₃ , ppm)=δ 8.42(d, 1H), 8.13(d, 4H), 8.07(s, 2H), 7.74(t, 1H), 7.53(s, 2H), 7.44( t, 1H), 7.42(t, 4H), 7.26(d, 1H), 7.10(t, 2H) 1.66(m, 4H), 1.46(m, 4H), 1.30-0.99(m, 24H), 0.94( s, 6H) ppm.

Synthesis Example 6

Dimethyl{(cyclooctan-1,5-diyl)(pyridin-2- yl-κN)(η5-2,3,4,5-tetramethylcyclopenta-2,4-dien-1-ylidene)borate}zirconium(IV) precursor compound was obtained.

1H NMR (500 MHz, CDCl ₃ , ppm)=δ 8.49(d, 1H), 7.70(t, 1H), 7.41(t, 1H), 7.21(d, 1H), 2.16(s, 6H), 2.05- 1.85(m, 12H), 1.69-1.60(m, 4H), 1.52(br m, 2H), 1.02(br m, 2H), 0.93(s, 6H) ppm.

<Manufacture example of supported catalyst>

Manufacturing Example 1

After adding 50 mL toluene to a pico reactor, 7 g of silica gel (SYLOPOL 952X, calcinated under 250 ℃) was added under Ar, and 10 mmol of methylaluminoxane (MAO) was slowly injected at room temperature and reacted at 95 ℃. The reaction was stirred for 24 hours. After completion of the reaction, cool to room temperature, leave for 15 minutes, and decant the solvent using a cannula. Toluene (400 mL) was added, stirred for 1 minute, left for 15 minutes, and the solvent was decanted using a cannula.

60 μmol of the metallocene compound of Synthesis Example 1 was dissolved in 30 mL of toluene and then transferred to the reactor using a cannula. The reaction was stirred at 80°C for 2 hours. After the reaction was completed and precipitation was completed, it was cooled to room temperature, left for 15 minutes, and the solvent was decanted using a cannula. The upper layer solution was removed, and the remaining reaction product was washed with toluene. After washing again with hexane, N,N-Bis(2-hydroxyethyl)pentadeylamine (Atmer 163) was added as an antistatic agent under hexane based on the silica weight (g). 2 wt% was dissolved in 3 mL of hexane and stirred at room temperature for 10 minutes. After the reaction was completed and precipitation was completed, the upper layer was removed and transferred to a glass filter to remove the solvent.

A silica-supported metallocene catalyst in the form of solid particles was obtained by first drying under vacuum at room temperature for 5 hours and secondly drying under vacuum at 45°C for 4 hours.

Preparation Example 2 to Preparation Example 6

A silica-supported metallocene catalyst was prepared in the same manner as Preparation Example 1, except that the metallocene compounds of Synthesis Examples 2 to 6 were used instead of the metallocene compound of Synthesis Example 1.

Comparative Manufacturing Example 1

A silica-supported metallocene catalyst was prepared in the same manner as Preparation Example 1, except that [tBu-O-(CH ₂ ) ₆ -C ₅ H ₄ ] ₂ ZrCl ₂ was used instead of the metallocene compound of Synthesis Example 1. was manufactured.

<Polyethylene polymerization example>

Example 1

Polyethylene (ethylene-1-hexene copolymer) was prepared in the presence of the supported catalyst obtained in Preparation Example 1, and the specific method is as follows.

A 600 mL stainless steel reactor was vacuum dried at 120°C and cooled, and 1 g of trimethyl aluminum (TMA) was added to 250 g of hexane at room temperature and stirred for 10 minutes. After removing all of the reacted hexane, 250 g of hexane and 0.5 g of triisobutylaluminum (TIBAL) were added and stirred for 5 minutes. Then, 7 mg of the supported catalyst obtained in Preparation Example 1 was added, and the temperature was raised to 80° C. and stirred. After stopping stirring at 80°C, 10 mL of 1-hexene (C6), a comonomer, was added, and ethylene (C2) was filled to 15 bar and stirring was started. After polymerization for 30 minutes, unreacted C2 was vented.

Examples 2 to 6

Polyethylene was prepared in the same manner as Example 1, except that the supported catalysts of Preparation Examples 2 to 6 were used instead of the supported catalyst of Preparation Example 1.

Comparative Example 1

ASPUN™ 6835A Fiber Resin (Dow) was used as polyethylene in Comparative Example 1.

Comparative Example 2

SK MK910 (SK General Chemicals) was used as polyethylene in Comparative Example 2.

Comparative Example 3

ASPUN™ 6850A Fiber Resin (Dow) was used as polyethylene in Comparative Example 3.

Comparative Example 4

SK MM810 (SK General Chemicals) was used as polyethylene in Comparative Example 4.

Comparative Example 5

Polyethylene was prepared in the same manner as Example 1, except that the supported catalyst of Comparative Preparation Example 1 was used instead of the supported catalyst of Preparation Example 1.

<Experimental example>

The physical properties of the polyethylene prepared in Examples and Comparative Examples were measured as follows, and the results are shown in Table 1 below.

(1) Melt Index (MI, g/10min)

It was measured with a load of 2.16 kg at 190°C according to ASTM D1238, and expressed as the weight (g) of the polymer melted for 10 minutes.

(2) Molecular weight distribution (MWD, Mw/Mn)

The weight average molecular weight (Mw) and number average molecular weight (Mn) of polyethylene were measured using gel permeation chromatography (GPC, manufactured by Water), and the weight average molecular weight was divided by the number average molecular weight to obtain molecular weight distribution (MWD). , Mw/Mn) was calculated.

Specifically, a Waters PL-GPC220 instrument was used as a gel permeation chromatography (GPC) device, and a 300 mm long column from Polymer Laboratories PLgel MIX-B was used. At this time, the measurement temperature was 160°C, 1,2,4-trichlorobenzene was used as a solvent, and the flow rate was 1 mL/min. The polymer samples according to Examples and Comparative Examples were pretreated by melting them in 1,2,4-Trichlorobenzene (1,2,4-Trichlorobenzene) containing 0.0125% BHT at 160°C for 10 hours using a GPC analysis device (PL-GP220). , prepared at a concentration of 10 mg/10mL and then supplied in an amount of 200 μL. The values of Mw and Mn were derived using a calibration curve formed using a polystyrene standard specimen. The weight average molecular weight of polystyrene standard specimens 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, 10000000 g. Nine types of /mol were used.

(3) Crystallinity

Crystallinity was measured using Differential Scanning Calorimeter (DSC) with reference to ASTM F2625.

Specifically, using a differential scanning calorimeter (DSC), DSC2500 (TA Instruments), the polyethylene copolymer was heated to 200°C, maintained for 3 minutes, lowered to 0°C, and then increased again. At this time, the temperature increase rate and cooling rate were each 10°C/min, and Tm was measured in the second temperature rising section. At this time, the crystallinity was calculated using the following equation 1. Theoretically, △H (at 100%) of PE is known to be 293 J/g.

[Equation 1]

Crystallinity (%) = △H (heat of fusion, endothermic enthalpy measured during melting transition, area of melting peak) / △H (at 100%) is endothermic enthalpy when 100% crystalline material (100%)) = △ H (heat of fusion, endothermic enthalpy measured during melting transition, area of melting peak) / 293 J/g

(4) T _cr (Crystal Relaxation Temperature)

Using a dynamic mechanical analysis (DMA), the rheological properties of the injection specimens according to temperature were evaluated and T _cr was determined.

More specifically, the polyethylene samples of Examples and Comparative Examples were pressed at 190°C to create rectangular specimens with a thickness of 0.5 mm, a width of 6 mm, and a length of 30 mm. The polyethylene specimen was mounted on TA Instruments' Q800 DMA, and the storage modulus E' and loss modulus E'' were measured by periodically deforming the specimen while increasing the temperature from -80℃ to 140℃ at a rate of 5℃ per minute. When tan(delta), which is the loss modulus at each temperature divided by the storage modulus, is calculated, the temperature at which tan(delta) is maximum is the crystal relaxation temperature.

(5) Abrasion Resistance

Regarding the polyethylene of the above Examples and Comparative Examples, see Report No. 4364 of the Naval Research Laboratories, published May 25, 1954 entitled "Manufacture of Superfine Organic Fibers" by Wente, Van. A. Boone, C. D., and Fluharty, E. L.], a non-woven fabric was manufactured by extruding masterbatch pellets into a microfiber web.

Specifically, the polyethylene resin of Examples and Comparative Examples was mixed with IF168 additive (1000 ppm) to prepare a masterbatch, and then pelletized using a 25 mm twin-screw extruder. Subsequently, using a 31 mm Brabender conical twin screw extruder, the molten masterbatch composition and LG H7550 Polypropylene were supplied to the melt pump (65 rpm) at a weight fraction ratio of 1:1, and then through the discharge port (10 discharge ports/cm) and 381 It was fed into a 25 cm wide melt blowing die with an outlet diameter of μm. The melt temperature was 210 °C, the screw speed was 120 rpm, the die was maintained at 210 °C, the primary air temperature and pressure were 270 °C and 54 kPa (7.8 psi), respectively, and the polymer throughput rate was 5.2 kg/hr. , the collector/die distance was 15.0 cm. While the ultrafine fibers spun from the discharge port fell into the collector, they were cooled with cooling air using two pumps, and the ultrafine fibers collected from the collector were manufactured into non-woven fabric through a calender process using upper and lower rolls. At this time, the temperature of the cooling wind was 16 ℃, and the temperatures of the upper and lower rolls during the calender process were 160 ℃/155 ℃, respectively.

Refer to ASTM D5264 for the nonwoven fibers manufactured in this way. Abrasion resistance was measured using Sutherland Ink Rub Tester 2000.

More specifically, the fibers to which the samples of Examples and Comparative Examples were applied were each manufactured into cloth specimens measuring 11.0 cm x 4.0 cm and sanded (20 cycles, 42 cycles/min) with 320 grit sandpaper (Sutherland Ink Rub Tester 2000). The amount of fiber dust coming off per unit area was measured.

That is, wear resistance (mg/cm ³ ) = Total weight of loose fiber / surface area, and it was determined that the smaller the amount of fiber dust coming off per unit area, the higher the abrasion resistance.

MI _2.16
(g/10min) MWD Crystallinity
(%) T _cr
(℃) MFRR (MI ₅ /MI _2.16 ) density
(g/ ^cm3 ) Abrasion resistance
(mg/cm ³ ) Example 1 19.2 2.45 63 43.3 2.54 0.952 0.1 Example 2 19.5 2.46 68 46 2.52 0.953 0.12 Example 3 18.9 2.39 70 48 2.53 0.954 0.14 Example 4 20 2.38 65 44 2.50 0.951 0.11 Example 5 24.4 2.45 71 46.2 2.66 0.955 0.12 Example 6 29.7 2.35 69 46.8 2.54 0.951 0.13 Comparative Example 1 19.4 2.79 65 42.9 2.71 0.950 0.22 Comparative Example 2 19.6 2.71 71 49.1 2.71 0.955 0.3 Comparative Example 3 28.1 2.64 66 45.5 2.70 0.954 0.25 Comparative Example 4 30.8 2.61 70 45.7 2.69 0.954 0.26 Comparative Example 5 18.3 2.47 74 51.5 2.58 0.954 0.33

Referring to Table 1, the polyethylene of Examples 1 to 6 of the present invention showed excellent abrasion resistance of 0.2 mg/cm ³ or less compared to Comparative Examples 1 to 5 having similar melt indices.

Claims (10)

The conditions 1) to 4) below are satisfied,
Polyethylene produced by copolymerizing ethylene and alpha-olefin in the presence of a catalyst composition containing a metallocene compound represented by the following formula (1):
1) a melt index (MI) of 0.5 to 40 g/10 min as measured according to ASTM D1238 at 190°C and a load of 2.16 kg;
2) molecular weight distribution (MWD) is 2.3 to 2.6;
3) Crystallinity measured using DSC (Differential Scanning Calorimeter) according to ASTM F2625 is 63 to 71%; and
4) Crystal relaxation temperature (T _cr , Crystal Relaxation Temperature) measured using DMA (Dynamic mechanical analysis) is 42 to 50°C,
[Formula 1]

In Formula 1,
B is boron,
M is a group 4 transition metal,
R ₁ to R ₄ are each independently hydrogen, C _1-20 alkyl, C _3-20 cycloalkyl, or C _6-20 aryl, or R ₁ and R ₂ or R ₃ and R ₄ are bonded to each other and substituted or Forming an unsubstituted C _6-60 aromatic ring,
R ₅ and R ₆ are each independently C _1-20 alkyl, C _3-20 cycloalkyl, or C _6-20 aryl, or R ₅ and R ₆ are combined to form a C _3-60 aliphatic ring, or C _{6 -60} forms an aromatic ring,
X ₁ and X ₂ are each independently C _1-20 alkyl or -O(CO)R', where R' is C _1-20 alkyl,
Q is a C _2-60 heterocycle containing at least one selected from the group consisting of substituted or unsubstituted N, O and S,
Y and Y' are elements constituting Q,
Y is N, O, or S,
Y' is an element of Q adjacent to Y, and is either N or C.
According to paragraph 1,
Polyethylene having a melt index (MI) of 18 to 40 g/10 min, measured according to ASTM D1238 at 190°C and under a load of 2.16 kg.
According to paragraph 1,
Polyethylene having an abrasion resistance of 0.2 mg/cm ³ or less, measured with reference to ASTM D5264.
According to paragraph 1,
The polyethylene is a copolymer of ethylene and alpha olefin.
According to paragraph 4,
The alpha olefin is propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1 -Tetradecene, 1-hexadecene, 1-eicocene, norbornene, norbonadiene, ethylidene nobodene, phenylnobodene, vinylnobodene, dicyclopentadiene, 1,4-butadiene, 1,5-penta Polyethylene containing at least one member selected from the group consisting of diene, 1,6-hexadiene, styrene, alpha-methylstyrene, divinylbenzene, and 3-chloromethylstyrene.
delete According to paragraph 1,
R ₁ to R ₄ are each independently hydrogen or methyl, or R ₁ and R ₂ or R ₃ and R ₄ are combined with each other to form a benzene ring or a 1,2,3,4-tetrahydronaphthalene ring; ,
wherein the benzene ring or 1,2,3,4-tetrahydronaphthalene ring is unsubstituted or substituted with 1 to 4 substituents selected from the group consisting of methyl, tertbutyl and 4-tertbutyl phenyl, polyethylene .
According to paragraph 1,
R ₅ and R ₆ are each independently methyl or phenyl, or R ₅ and R ₆ are combined with each other to form a cyclooctane ring in polyethylene.
According to paragraph 1,
The compound represented by Formula 1 is polyethylene, which is any one of the compounds represented by the following structural formula:

.
According to paragraph 1,
The catalyst composition further includes at least one cocatalyst compound selected from the group consisting of compounds represented by the following formulas 2 to 4:
[Formula 2]
-[Al(R ₁₀ )-O]a-
In Formula 2,
R ₁₀ is halogen; or C _1-20 hydrocarbyl substituted or unsubstituted with halogen;
a is an integer greater than or equal to 2,
[Formula 3]
D( _R11 ) ₃
In Formula 3 above,
D is aluminum or boron;
R ₁₁ is halogen; or C _1-20 hydrocarbyl substituted or unsubstituted with halogen,
[Formula 4]
[LH] ⁺ [ZA ₄ ] ^- or [L] ⁺ [ZA ₄ ] ^-
In Formula 4 above,
L is a neutral or cationic Lewis base;
H is a hydrogen atom;
Z is a group 13 element;
A is each independently C 6-20 aryl or C _1-20 alkyl in _which one or more hydrogen atoms are substituted with halogen, C _1-20 hydrocarbyl, C _1-20 alkoxy, or phenoxy.