Propylene-ethylene random copolymer

Abstract

The present invention relates to a propylene-ethylene random copolymer that can simultaneously achieve excellent fiber strength by maximizing the ethylene content to provide sufficient softness during fiber processing and being suitable for high-speed spinning.

Description

Technology Field

[0001] The present invention relates to a propylene-ethylene random copolymer. Background Technology

[0003] Polypropylene is a general-purpose resin with a very wide range of applications. It is easy to process and offers excellent physical properties relative to its cost, allowing it to replace traditional materials such as glass, wood, paper, and metal, and expanding its scope of application to other plastics and even engineering plastics.

[0005] These catalysts for polypropylene polymerization can be broadly classified into Ziegler-Natta catalysts and metallocene catalysts. Ziegler-Natta catalysts are multi-site catalysts with multiple active sites, which is characterized by a wide molecular weight distribution of the polymer. However, there is a problem in that the compositional distribution of the comonomer is not uniform, which limits the ability to secure desired physical properties. In particular, when performing random copolymerization with ethylene to ensure transparency in the presence of a Ziegler-Natta catalyst (Z / N), the high polymerization of ethylene results in the formation of a heterogeneous polymer rather than a uniform copolymer; that is, a polymer in which ethylene polymers are formed as blocks between propylene polymers rather than a repeating structure. This not only significantly degrades physical properties but also leads to high volatile organic compound (VOC) emissions.

[0007] In contrast, metallocene catalysts consist of a combination of a main catalyst, primarily composed of transition metal compounds, and a co-catalyst, primarily composed of aluminum and an organometallic compound. These catalysts are homogeneous complex catalysts and single-site catalysts; due to their single-site characteristics, they enable the production of polymers with a narrow molecular weight distribution and a uniform comonomer composition. Furthermore, the stereoregularity, copolymerization characteristics, molecular weight, and crystallinity of the polymer can be altered by modifying the catalyst's ligand structure and changing polymerization conditions. Additionally, polypropylene produced using metallocene catalysts exhibits extremely low volatile organic compound (VOC) content, aligning with growing environmental concerns; consequently, the transition to polypropylene resin products utilizing metallocene catalysts is accelerating.

[0009] The narrow molecular weight distribution characteristic of polypropylene treated with such metallocene catalysts makes it highly suitable for processing into fibers. In the case of polypropylene resins treated with Ziegler-Natta catalysts, a cracking process involving the addition of peroxides and extrusion is required to achieve a molecular weight distribution suitable for fiber processing. However, this process generates byproducts such as VOCs and causes resin contamination due to additive formulations. Therefore, it can be said that polypropylene treated with metallocene catalysts possesses characteristics specialized for fiber applications.

[0011] However, fibers manufactured from polypropylene using conventional metallocene catalysts exhibit excellent stiffness and low toxicity to the human body, but they possess stiffness resulting from the resin's physical properties. Recently, market trends for synthetic fibers have been shifting toward enhancing softness, and accordingly, efforts are being made to apply copolymers using ethylene as a comonomer to secure softness in polypropylene resins. These ethylene copolymers exhibit lower melting points and crystallinity depending on the ethylene content, resulting in improved softness during fiber processing compared to propylene homopolymers. However, when manufacturing polypropylene using known metallocene catalysts, the inherently low melting point limits the ability to increase the comonomer content within the copolymer. In other words, increasing the comonomer content to lower the melting point leads to process instability. Consequently, the fibers currently in high demand for softness are insufficient, and efforts are underway to address this issue.

[0013] Therefore, there is a need to develop a method for manufacturing polypropylene that uses a metallocene catalyst to produce high-rigidity products with excellent polymer uniformity through high-speed spinning, as well as to secure soft fiber characteristics by maximizing the ethylene content. The problem to be solved

[0015] The present specification aims to provide a propylene-ethylene random copolymer that exhibits sufficient softness characteristics during fiber processing and is suitable for high-speed spinning, thereby simultaneously ensuring excellent fiber strength. means of solving the problem

[0017] The present invention provides a propylene-ethylene random copolymer having a weight-average molecular weight (Mw) of 165,000 g / mol to 400,000 g / mol, a molecular weight distribution (Mw / Mn) of 2.4 or less, a melting point (Tm) of 133 °C or higher, and an ethylene content of 2 weight% or more.

[0019] For example, the propylene-ethylene random copolymer may have a melting point (Tm) of 133 °C to 150 °C, an ethylene content of 2.0 wt% to 5.5 wt%, and a molecular weight distribution (Mw / Mn) of 2.0 to 2.4.

[0021] In addition, for the above propylene-ethylene random copolymer, the integral value of the region where the Log MW value is 6.0 or higher on the GPC curve graph where the x-axis is log MW and the y-axis is dw / dlogMw may be 0.8% or less of the total integral value.

[0023] In addition, the above propylene-ethylene random copolymer may have a residual stress ratio of 0.1% or less.

[0025] Meanwhile, the above propylene-ethylene random copolymer may be prepared by copolymerizing a propylene monomer and an ethylene comonomer in the presence of a catalyst composition comprising a metallocene compound of the following chemical formula 1.

[0026] [Chemical Formula 1]

[0027]

[0028] In the above chemical formula 1,

[0029] M is a group 4 transition metal, and

[0030] X 1 and X 2 They are identical or different from each other, and each is independently a halogen element, and

[0031] R 1 and R 2 are identical or different from each other, and each independently C 1-20 Alkyl, C 2-20 Alkenyl, C 2-20 Alkoxyalkyl, C 6-20 Aril, C 7-40 Alkylaryl, C 7-40 It is an arylalkyl, and

[0032] R 3 to R 6are identical or different from each other, and each independently C 1-20 It is alkyl, and

[0033] R 7 is substituted or unsubstituted C 6-20 Arilgo,

[0034] R 8 is C 1-20 It is an alkyl.

[0036] At this time, in the above Chemical Formula 1, R 1 and R 2 are respectively C 1-8 Straight-chain or branched-chain alkyl, or C 2-12 It may be a straight-chain or branched-chain alkoxyalkyl, and specifically may be methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, hexyl, or t-butoxyhexyl.

[0038] And, in the above chemical formula 1, R 3 to R 6 are respectively C 1-6 Straight-chain or branched-chain alkyl or C 1-3 It may be a straight-chain or branched-chain alkyl, specifically methyl, ethyl, propyl, or isopropyl, isopropyl, and preferably methyl.

[0040] Also, in the above chemical formula 1, it may be preferable that M is zirconium (Zr) or hafnium (Hf).

[0042] And, in the above chemical formula 1, R 7 phenyl, C 1-6 Phenyl, naphthyl, or C substituted with straight-chain or branched-chain alkyl groups 1-6 It may be a naphthyl substituted with a straight-chain or branched-chain alkyl group, specifically, the phenyl or naphthyl may each have one or more of the hydrogen substituents C 1-6 It may be substituted with a straight-chain or branched-chain alkyl group. For example, the phenyl or naphthyl may be substituted with one or more of the hydrogen substituents, respectively, with methyl, ethyl, propyl, isopropyl, butyl, isobutyl, or t-butyl.

[0044] And, in the above chemical formula 1, R 8 C 1-6 Straight-chain or branched-chain alkyl or C 1-3 It may be a straight-chain or branched-chain alkyl, specifically methyl, ethyl, or propyl, and preferably methyl.

[0046] And, the metallocene compound represented by the above chemical formula 1 may specifically be represented by, for example, the following chemical formula 1-1.

[0047] [Chemical Formula 1-1]

[0048]

[0049] In the above chemical formula 1-1, M, X 1 , X 2 , R 1 , R 2 , R 7 It is as defined in Chemical Formula 1.

[0051] In addition, the metallocene compound represented by Chemical Formula 1 above may specifically be any one of the compounds represented by the following structural formulas, for example. The following structural formulas are merely examples for explaining the present invention, and the present invention is not limited thereto.

[0052]

[0053]

[0054]

[0055]

[0056]

[0058] In addition, the step of copolymerizing the propylene monomer and the ethylene monomer in the presence of the catalyst composition may be carried out by reacting the propylene and ethylene in a weight ratio of about 99.9:0.1 to about 90:10, and by introducing hydrogen gas at about 750 ppm or less based on the total molar content of the monomer for forming the propylene-ethylene copolymer.

[0060] In addition, the present invention provides a fiber for multifilament or spunbond prepared from the propylene-ethylene copolymer described above.

[0062] The terms used in this specification are used merely to describe exemplary embodiments and are not intended to limit the invention.

[0064] A singular expression includes a plural expression unless the context clearly indicates otherwise.

[0066] In this specification, terms such as “comprising,” “comprising,” or “having” are used to describe features, numbers, steps, components, or combinations thereof that are implemented, and do not exclude one or more other features, numbers, steps, components, combinations thereof, or the possibility of addition.

[0068] Additionally, in this specification, where each layer or element is referred to as being formed "on" or "above" each layer or element, it means that each layer or element is formed directly on each layer or element, or that another layer or element may be additionally formed between each layer, on an object, or on a substrate.

[0070] The present invention is capable of various modifications and may take various forms, and specific embodiments are illustrated and described in detail below. However, this is not intended to limit the invention to the specific disclosed forms, and it should be understood that the invention includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention.

[0072] The present invention will be described in detail below.

[0074] A propylene-ethylene random copolymer according to one embodiment of the present invention is characterized by satisfying the conditions that the weight-average molecular weight (Mw) is 165,000 g / mol to 400,000 g / mol, the molecular weight distribution (Mw / Mn) is 2.4 or less, the melting point (Tm) is 133 °C or higher, and the ethylene content is 2 weight% or higher.

[0076] Propylene (co)polymers produced using Ziegler-Natta catalysts have a problem in that their stiffness is significantly reduced due to a decrease in crystal properties. In addition, even when using conventional metallocene catalysts, the low melting point causes fouling during the polymerization process and limits the increase in the content of the comonomer ethylene. Therefore, it is necessary to improve the process so that sufficient softness characteristics can be achieved during fiber processing and high strength suitable for high-speed spinning can be secured by increasing the ethylene content.

[0078] Accordingly, according to the present invention, a propylene-ethylene random copolymer can be provided that exhibits sufficient softness characteristics during fiber processing and is suitable for high-speed spinning, thereby simultaneously securing excellent fiber strength.

[0080] In particular, the present invention provides a propylene-ethylene random copolymer comprising ethylene as a comonomer among randomly copolymerized polypropylene, which can secure softer properties under the same melting point conditions than a resin using butene as a comonomer. Butene is a comonomer that forms branches capable of maintaining tacticity within the polymer structure, but since ethylene does not have such properties, it can be said to be more suitable for securing soft properties.

[0082] A propylene-ethylene random copolymer according to one embodiment of the present invention is characterized by having an ethylene content of 2 weight% or more at a high melting point (Tm) of 133°C or higher. In particular, the propylene-ethylene random copolymer can secure a very high melting point in a homopolypropylene resin and achieve high copolymerization with ethylene by using a metallocene catalyst of a novel structure as described below, thereby maintaining a high melting point even at such a high ethylene content.

[0084] Specifically, the propylene-ethylene random copolymer according to one embodiment of the present invention may have a melting point (Tm) of 133 °C or higher or 133 °C to 150 °C. By having such a high melting point, not only is fouling not observed during the polymerization process, but excellent fiber strength can also be achieved by being suitable for high-speed spinning. More specifically, the propylene-ethylene random copolymer may have a melting point (Tm) of about 134 °C or higher or about 134 °C to about 150 °C, or about 135 °C or higher or about 135 °C to about 150 °C.

[0086] In the present invention, the melting point (Tm) can be measured using a Differential Scanning Calorimeter (DSC, device name: DSC 2920, manufacturer: TA instrument). Specifically, the temperature is raised to heat a polypropylene polymer to 200 ℃, maintained at that temperature for 5 minutes, then lowered to 30 ℃, and then raised again so that the temperature corresponding to the peak of the DSC (Differential Scanning Calorimeter, manufactured by TA) curve is set as the melting point (Tm). At this time, the rate of temperature increase and decrease is 10 ℃ / min, and the melting point (Tm) is the result measured during the second temperature increase and decrease interval.

[0088] In addition, the propylene-ethylene random copolymer according to one embodiment of the present invention may have an ethylene content of about 2 wt% or more, or about 2 wt% to about 5.5 wt%, at a melting point (Tm) of 133 °C or higher, as described above. By increasing the ethylene content while maintaining such a high melting point, sufficient softness characteristics can be achieved during fiber processing. More specifically, the propylene-ethylene random copolymer may have an ethylene content of about 2.05 wt% or more, or about 2.1 wt% or more, and may also have an ethylene content of about 5 wt% or less, or about 3.5 wt% or less, or about 3 wt% or less, or about 2.8 wt% or less.

[0090] In the case of manufacturing a propylene-ethylene random copolymer using conventional comonomers, the inclusion of heterogeneous comonomers between the main chains deforms the lamellar structure of the resin, resulting in a lowered melting point (Tm) and problems such as failure to maintain excellent stiffness or difficulty in securing process stability. In contrast, the present invention utilizes a metallocene catalyst with a novel structure as described below to secure a very high melting point in the homopolypropylene resin and achieve high copolymerization with ethylene, thereby enabling improved physical properties that maintain a high melting point of 133°C or higher even with such high ethylene content.

[0092] In the present invention, the content of ethylene, which is a comonomer in the propylene-ethylene random copolymer, is determined according to ASTM D 5576 by fixing a film or film-shaped specimen of the propylene-ethylene random copolymer to the magnetic holder of an FT-IR instrument, and then using the IR absorption spectrum at 4800–3500 cm⁻¹, which reflects the specimen thickness. -1 710–760 cm, where the peak height and ethylene component appear -1 Measure the area of ​​each, and use the measured values ​​for the Standard sample's 710–760 cm² -1 Peak area 4800–3500 cm -1 The comonomer content can be calculated by substituting the value obtained by plotting the value divided by the peak height into the calibration formula.

[0094] Meanwhile, the propylene-ethylene random copolymer according to one embodiment of the present invention may have a weight-average molecular weight (Mw) of about 165,000 g / mol to about 400,000 g / mol to be suitable for processing into multifilament fibers or spunbond fibers. Specifically, the weight-average molecular weight (Mw) of the propylene-ethylene random copolymer may be about 220,000 g / mol to about 400,000 g / mol, or about 260,000 g / mol to about 400,000 g / mol, when processed for multifilament fibers. In addition, when processed for spunbond fibers, the weight-average molecular weight (Mw) of the propylene-ethylene random copolymer may be about 165,000 g / mol to about 250,000 g / mol, or about 165,000 g / mol or more, or about 165,000 g / mol to about 175,000 g / mol.

[0096] In addition, the above-described propylene-ethylene random copolymer is characterized by maximizing the high melting point and ethylene content as described above, while maintaining a low molecular weight distribution (MWD, Mw / Mn) of 2.4 or less without increasing. By having such a narrow molecular weight distribution, a high-rigidity product can be obtained through high-speed spinning with excellent uniformity during fiber processing. More specifically, the molecular weight distribution of the above-described propylene-ethylene random copolymer may be about 2.4 or less, or about 2.0 to about 2.4, or about 2.1 to about 2.4, or about 2.2 to about 2.4.

[0098] In the present invention, the molecular weight distribution can be obtained by measuring the weight-average molecular weight (Mw) and number-average molecular weight (Mn) of the propylene-ethylene random copolymer using gel permeation chromatography (GPC), respectively, and calculating the ratio of the weight-average molecular weight to the number-average molecular weight (Mw / Mn) as the molecular weight distribution.

[0100] Specifically, a Waters PL-GPC220 instrument can be used as the gel permeation chromatography (GPC) device, and a Polymer Laboratories PLgel MIX-B 300 mm long column can be used. The measurement temperature is 160 ℃, 1,2,4-trichlorobenzene can be used as the solvent, and a flow rate of 1 mL / min can be applied. Polypropylene samples can be pretreated by dissolving them in trichlorobenzene containing 0.0125% BHT at 160 ℃ for 10 hours using the GPC analyzer (PL-GP220), prepared to a concentration of 10 mg / 10 mL, and then supplied in a volume of 200 μL for measurement. Additionally, the values ​​of Mw and Mn can be derived using a calibration curve formed using a polystyrene standard specimen. Nine types of polystyrene standard specimens with weight-average molecular weights can be used: 2000 g / mol, 10000 g / mol, 30000 g / mol, 70000 g / mol, 200000 g / mol, 700000 g / mol, 2000000 g / mol, 4000000 g / mol, and 10000000 g / mol.

[0102] In addition, the propylene-ethylene random copolymer may have an integral value in the region where the Log MW value is 6.0 or higher on the GPC curve graph, which is a log graph of the weight-average molecular weight (Mw) measured as described above, i.e., where the x-axis is log MW and the y-axis is dw / dlogMw, that is, 0.8% or less or 0.4% to 0.8% of the total integral value. Thus, a high-rigidity product can be obtained through high-speed spinning with excellent uniformity during fiber processing. More specifically, the propylene-ethylene random copolymer may have an integral value in the region where the Log MW value is 6.0 or higher on the GPC curve graph that is 0.75% or less or 0.5% to 0.75% of the total Log MW value, or 0.7% or less or 0.6% to 0.7%.

[0104] Meanwhile, the propylene-ethylene random copolymer according to one embodiment of the present invention may have a residual stress ratio of 0.1% or less or 0.01% to 0.1%, and specifically, 0.08% or less or 0.02% to 0.08%, or 0.07% or less or 0.03% to 0.7%.

[0106] In particular, the residual stress ratio (Y) of the above-mentioned propylene-ethylene random copolymer can be verified through rheological property tests under conditions similar to those during fiber manufacturing, and is a value measured according to the following formula 1 by performing a stress relaxation test by applying a large strain to the polymer.

[0107] [Formula 1]

[0108] Residual stress ratio (Y) = (RS1 / RS0)*100

[0110] In the above formula 1, RS0 is the residual stress at 0.02 seconds (t0) after applying 200% strain to the polymer sample at 235°C, and RS1 is the residual stress at 1.00 seconds (t1) after applying 200% strain to the polymer sample at 235°C.

[0112] For example, the residual stress ratio (Y) of the above-described propylene-ethylene random copolymer is the ratio of residual stress values ​​measured at time t0 and t1 in a stress relaxation test as described in Formula 1 above as a percentage [(RS1 / RS0)*100] value, and the residual stress ratio (Y) may be about 0.1% or less, or about 0.01% to about 0.1%, or about 0.08% or less, or about 0.02% to about 0.08%, or about 0.07% or less, or about 0.03% to about 0.7%. That is, according to one example of the invention, if the ratio of residual stress according to Formula 1 above exceeds about 0.1%, the possibility of single yarn may increase when processing fibers using the said polymer as a raw material.

[0114] In the above formula 1, RS0 represents the residual stress immediately after applying a 200% deformation to a propylene-ethylene random copolymer at 235°C [e.g., less than 0.05 seconds or at any point in time (t0) between 0.001 and 0.049 seconds]. And, in the above formula 1, RS1 represents the residual stress within about 1.5 seconds after t0 [e.g., at any point in time (t1) between 0.05 and 2.00 seconds] under the same conditions as RS0.

[0116] Specifically, in the above calculation formula 1, t0 can be selected from 0.01 seconds, or 0.015 seconds, or 0.02 seconds, or 0.025 seconds, or 0.03 seconds, or 0.035 seconds, or 0.04 seconds, or 0.045 seconds. And, in the above calculation formula 1, t1 can be selected from 0.05 seconds, or 0.10 seconds, or 0.20 seconds, or 0.30 seconds, or 0.40 seconds, or 0.50 seconds, or 0.60 seconds, or 0.70 seconds, or 0.80 seconds, or 0.90 seconds, or 1.00 seconds, or 1.10 seconds, or 1.20 seconds, or 1.30 seconds, or 1.40 seconds, or 1.50 seconds, or 1.60 seconds, or 1.70 seconds, or 1.80 seconds, or 1.90 seconds, or 2.00 seconds.

[0118] Preferably, in order to easily obtain valid data when measuring residual stress, it may be advantageous for t0 to be 0.02 seconds and t1 to be 1.00 seconds in the above calculation formula 1.

[0120] In addition, the residual stress ratio (Y) of the above propylene-ethylene random copolymer is measured under conditions similar to processing conditions when manufacturing multifilament fibers or spunbond fibers (e.g., 235°C). The temperature of 235°C corresponds to a temperature suitable for completely melting the propylene-ethylene random copolymer to perform melt-spun.

[0122] Meanwhile, the propylene-ethylene random copolymer may have a total volatile organic compound (TVOC) emission of about 70 ppm or less, or about 65 ppm or less, or about 60 ppm or less, or about 50 ppm or less, or about 30 ppm or less, as measured according to the VDA 277 method. By having such low total volatile organic compound (TVOC) emissions, eco-friendliness can be ensured in the fiber product itself or in the fiber processing process.

[0124] As described above, the propylene-ethylene random copolymer of the present invention can secure excellent fiber strength by maximizing the ethylene content along with superior process stability compared to conventional Ziegler-Natta catalyst-applied polypropylene or conventional metallocene catalyst-applied polypropylene, while exhibiting sufficient softness characteristics during fiber processing and being suitable for high-speed spinning.

[0126] A propylene random copolymer according to one embodiment of the invention having the physical properties and compositional characteristics as described above can be manufactured by a manufacturing method comprising the step of randomly copolymerizing a propylene monomer and an ethylene comonomer in the presence of a catalyst composition comprising a metallocene compound of Chemical Formula 1 as a catalytic active component.

[0127] [Chemical Formula 1]

[0128]

[0129] In the above chemical formula 1,

[0130] M is a group 4 transition metal, and

[0131] X 1 and X 2 They are identical or different from each other, and each is independently a halogen element, and

[0132] R 1 and R 2 are identical or different from each other, and each independently C 1-20 Alkyl, C 2-20 Alkenyl, C 2-20 Alkoxyalkyl, C6-20 Aril, C 7-40 Alkylaryl, C 7-40 It is an arylalkyl, and

[0133] R 3 to R 6 are identical or different from each other, and each independently C 1-20 It is alkyl, and

[0134] R 7 is substituted or unsubstituted C 6-20 Arilgo,

[0135] R 8 is C 1-20 It is an alkyl.

[0137] Meanwhile, unless otherwise specifically limited in this specification, the following terms may be defined as follows.

[0139] Halogens can be fluorine (F), chlorine (Cl), bromine (Br), or iodine (I).

[0141] Number of carbon atoms 1 to 20 (C 1-20 The alkyl of ) may be a straight-chain, branched-chain, or cyclic alkyl. Specifically, the alkyl having 1 to 20 carbon atoms may be a straight-chain alkyl having 1 to 20 carbon atoms; a straight-chain alkyl having 1 to 15 carbon atoms; a straight-chain alkyl having 1 to 5 carbon atoms; a branched-chain or cyclic alkyl having 3 to 20 carbon atoms; a branched-chain or cyclic alkyl having 3 to 15 carbon atoms; or a branched-chain or cyclic alkyl having 3 to 10 carbon atoms. For example, the above alkyl having 1 to 20 carbon atoms (C 1-20 The alkyl groups of ) include methyl, ethyl, propyl, isopropyl, n-butyl, tert-butyl, pentyl, hexyl, heptyl, octyl, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, etc., but are not limited to these.

[0143] Number of carbon atoms 2 to 20 (C 2-20Alkenyls of ) include straight-chain or branched-chain alkenyls, specifically allyl, allyl, ethenyl, propenyl, butenyl, fentenyl, etc., but are not limited to these.

[0145] Number of carbon atoms 1 to 20 (C 1-20 Examples of alkoxy groups include methoxy, ethoxy, isopropoxy, n-butoxy, tert-butoxy, phenyloxy, cyclohexyloxy, etc., but are not limited to these.

[0147] Number of carbon atoms 2 to 20 (C 2-20 The alkoxyalkyl group of the above-described alkyl is a functional group in which one or more hydrogens are substituted with an alkoxy, and specifically, examples include alkoxyalkyls such as methoxymethyl, methoxyethyl, ethoxymethyl, iso-propoxymethyl, iso-propoxyethyl, iso-propoxypropyl, iso-propoxyhexyl, tert-butoxymethyl, tert-butoxyethyl, tert-butoxypropyl, tert-butoxyhexyl; or aryloxyalkyls such as phenoxyhexyl, but are not limited thereto.

[0149] Number of carbon atoms 1 to 20 (C 1-20 ) alkylsilyl or carbon atoms 1 to 20 (C 1-20 The alkoxysilyl group of ) is a functional group in which 1 to 3 hydrogens of -SiH3 are substituted with 1 to 3 alkyl or alkoxy groups as described above, and specifically, examples include alkylsilyls such as methylsilyl, dimethylsilyl, trimethylsilyl, dimethylethylsilyl, diethylmethylsilyl, or dimethylpropylsilyl; alkoxysilyls such as methoxysilyl, dimethoxysilyl, trimethoxysilyl, or dimethoxyethoxysilyl; and alkoxyalkylsilyls such as methoxydimethylsilyl, diethoxymethylsilyl, or dimethoxypropylsilyl, but are not limited thereto.

[0151] Number of carbon atoms 1 to 20 (C 1-20The silylalkyl group of ) is a functional group in which one or more hydrogens of the alkyl group described above are substituted with silyl, and specifically, examples include -CH2-SiH3, methylsilylmethyl or dimethylethoxysilylpropyl, but are not limited thereto.

[0153] In addition, carbon atoms numbering 1 to 20 (C 1-20 The alkylenes of ) are the same as the alkyls described above except that they are divalent substituents, specifically methylene, ethylene, propylene, butylene, pentylene, hexylene, heptylene, octylene, cyclopropylene, cyclobutylene, cyclopentylene, cyclohexylene, cycloheptylene, cyclooctylene, etc., but are not limited to these.

[0155] 6 to 20 carbon atoms (C 6-20 The aryl of ) may be a monocyclic, bicyclic, or tricyclic aromatic hydrocarbon. For example, the above 6 to 20 carbon atoms (C 6-20 Examples of aryls of ) include phenyl, biphenyl, naphthyl, anthracenyl, phenanthrenyl, fluorenyl, etc., but are not limited to these.

[0157] 7 to 20 carbon atoms (C 7-20 The alkylaryl of ) may refer to a substituent in which one or more hydrogens of the aromatic ring are substituted by the aforementioned alkyl group. For example, the above 7 to 20 carbon atoms (C 7-20 Examples of alkylaryls include methylphenyl, ethylphenyl, methylbiphenyl, methylnaphthyl, etc., but are not limited to these.

[0159] The above carbon atoms numbering 7 to 20 (C 7-20 The arylalkyl of ) may refer to a substituent in which one or more hydrogens of the above-described alkyl are substituted by the above-described aryl. For example, the above 7 to 20 carbon atoms (C 7-20 Examples of arylalkyls of ) include phenylmethyl, phenylethyl, biphenylmethyl, naphthylmethyl, etc., but are not limited to these.

[0161] In addition, 6 to 20 carbon atoms (C 6-20 The arylenes of ) are identical to the aryls described above except that they are divalent substituents, specifically phenylene, biphenylene, naphthylene, anthracenylene, phenanthrenylene, fluorenylene, etc., but are not limited to these.

[0163] And, the group 4 transition metal may be titanium (Ti), zirconium (Zr), hafnium (Hf), or rutherfordium (Rf), specifically titanium (Ti), zirconium (Zr), or hafnium (Hf), more specifically zirconium (Zr) or hafnium (Hf), but is not limited thereto.

[0165] In addition, the Group 13 elements may be boron (B), aluminum (Al), gallium (Ga), indium (In), or thallium (Tl), and specifically may be boron (B) or aluminum (Al), but are not limited thereto.

[0167] The substituents described above may be optionally substituted with one or more substituents selected from the group consisting of hydroxyl groups; halogens; alkyl or alkenyl, aryl, alkoxy; alkyl or alkenyl, aryl, alkoxy comprising one or more heteroatoms of groups 14 to 16; silyl; alkylsilyl or alkoxysilyl; phosphine groups; phosphide groups; sulfonate groups; and sulfone groups, within the range of producing the same or similar effects as the desired effect.

[0169] A catalyst composition used for manufacturing a propylene-ethylene random copolymer according to one embodiment of the present invention includes the compound of Formula 1 as a single metallocene catalyst. Accordingly, compared to the case where two or more conventional catalysts are mixed and used, the molecular weight distribution of the propylene copolymer produced can be significantly narrowed, and it can be confirmed that the stiffness of the propylene-ethylene random copolymer is improved.

[0171] The metallocene compound represented by the above chemical formula 1 has an asymmetric structure in which cyclopentadienyl series groups, which are different from each other above and below as ligands, are connected by a bridge.

[0173] Specifically, in the above chemical formula 1, the upper part of the ligand is connected to a bridge by a cyclopentadienyl group substituted with an alkyl group, and in the above chemical formula 1, the lower part of the ligand is connected to a bridge by an indacenyl structure having a specific substituent.

[0175] Due to the unique structure described above, it is possible to possess various characteristics of two different cyclopentadienyls or take on selective advantages, thereby exhibiting superior catalytic activity.

[0177] Specifically, the above cyclopentadienyl structure can maintain a certain steric spatial arrangement when forming polypropylene, thereby securing isotacticity and maintaining high activity. In the case of cyclopentadienyl (Cp) substituted only with hydrogen, since there is no bulky portion, the catalyst faces the insertion of propylene in a completely open state, causing the tacticity to collapse and forming atactic polypropylene (atactic PP).

[0179] In addition, when propylene (C3) and H2 react together, a competitive reaction occurs. If a bulky structure is substituted at position 2 of the indacenyl structure among the ligands of Chemical Formula 1, for example, R 8 Ga C 1-20 When substituted with an alkyl group, a specific steric spatial arrangement is imparted to the metal center, improving the reactivity of the H2 group, which is smaller in size relative to the C3 group. Therefore, at the 2nd position of the indacenyl structure, R in the form of methyl, etc. 8 Ga C 1-20When an alkyl-substituted structure is incorporated, hydrogen reactivity can be increased during the polymerization process.

[0181] In addition, an aryl substituent capable of donating electrons at position 4 of the indacenyl structure, such as R 7 This substituted or unsubstituted C 6-20 By including an aryl substituent, electrons are enriched to the metal atoms included in the bridge structure of Chemical Formula 1, thereby enabling higher catalytic activity.

[0183] In particular, among the metallocene compounds represented by Chemical Formula 1 above, the indacenyl structure can achieve a very excellent effect in the active part when combined with cyclopentadienyl compared to the general indenyl structure. This appears to be because, regarding the steric effect of cyclopentadienyl, the indacenyl structure can secure a flat structure facing each other compared to indenyl, thereby exerting a certain influence on the active site and acting very favorably for the activation of the propylene monomer. This result can be confirmed by the increase in the tacticity of the polymerized polypropylene.

[0185] As described above, the metallocene compound represented by Chemical Formula 1 can have high structural stability and can exhibit high polymerization activity even when supported on a carrier, because it supplies electrons to a transition metal in a form where two ligands are connected by a bridge group.

[0187] At this time, in the above chemical formula 1, it may be preferable that M is zirconium (Zr) or hafnium (Hf).

[0189] And, in the above chemical formula 1, R 1 and R 2 are respectively C 1-8 Straight-chain or branched-chain alkyl, or C 2-12It may be a straight-chain or branched-chain alkoxyalkyl, and specifically may be methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, hexyl, or t-butoxyhexyl.

[0191] And, in the above chemical formula 1, R 3 to R 6 are respectively C 1-6 Straight-chain or branched-chain alkyl or C 1-3 It may be a straight-chain or branched-chain alkyl, specifically methyl, ethyl, propyl, or isopropyl, isopropyl, and preferably methyl.

[0193] And, in the above chemical formula 1, R 7 phenyl, C 1-6 Phenyl, naphthyl, or C substituted with straight-chain or branched-chain alkyl groups 1-6 It may be a naphthyl substituted with a straight-chain or branched-chain alkyl group, specifically, the phenyl or naphthyl may each have one or more of the hydrogen substituents C 1-6 It may be substituted with a straight-chain or branched-chain alkyl group. For example, the phenyl or naphthyl may be substituted with one or more of the hydrogen substituents, respectively, with methyl, ethyl, propyl, isopropyl, butyl, isobutyl, or t-butyl.

[0195] Substituents at each position of these aromatic groups can supply sufficient electrons to the aromatic groups through an inductive effect, and by increasing the overall size of the metallocene compound and increasing the available angle, they facilitate the approach of monomers, thereby exhibiting superior catalytic activity.

[0197] And, in the above chemical formula 1, R 8 C 1-6 Straight-chain or branched-chain alkyl or C 1-3 It may be a straight-chain or branched-chain alkyl, specifically methyl, ethyl, or propyl, and preferably methyl.

[0199] And, the metallocene compound represented by the above chemical formula 1 may specifically be represented by, for example, the following chemical formula 1-1.

[0200] [Chemical Formula 1-1]

[0201]

[0202] In the above chemical formula 1-1, M, X 1 , X 2 , R 1 , R 2 , R 7 It is as defined in Chemical Formula 1.

[0204] In addition, the compound represented by the above chemical formula 1 may be, specifically, any one of the compounds represented by the following structural formulas, for example.

[0206]

[0207]

[0208]

[0209]

[0210]

[0212] The metallocene compound represented by the above chemical formula 1 can be prepared by a known synthesis method of organic compounds, and is described in more detail in the examples described below.

[0214] In the method for preparing a metallocene compound or catalyst composition of the present invention, the equivalent (eq) means molar equivalent (eq / mol).

[0216] Meanwhile, in the catalyst composition of the present invention, the metallocene compound of Formula 1 may be used in the form of a supported catalyst supported on a carrier or in the form of an unsupported catalyst. For example, it may be used in the form of a supported catalyst when performing a bulk-slurry polymerization process, and in the form of an unsupported catalyst when performing a solution polymerization process. In particular, it is preferable to use it in the form of a supported catalyst to ensure the stability of the polymerization process using the catalyst composition and the uniformity of physical property control.

[0218] As the above carrier, a carrier having highly reactive hydroxyl groups or siloxane groups on its surface may be used, and preferably, a carrier having highly reactive hydroxyl groups and siloxane groups that has been dried to remove moisture from its surface may be used.

[0220] For example, silica dried at high temperatures, silica-alumina, and silica-magnesia may be used, and these may typically contain oxide, carbonate, sulfate, and nitrate components such as Na2O, K2CO3, BaSO4, and Mg(NO3)2.

[0222] The drying temperature of the above carrier is preferably about 200°C to about 800°C, more preferably about 300°C to about 600°C, and most preferably about 300°C to about 400°C. If the drying temperature of the above carrier is less than about 200°C, there is too much moisture, causing the moisture on the surface to react with the co-catalyst, etc. If it exceeds about 800°C, the pores on the surface of the carrier merge, reducing the surface area, and also many hydroxyl groups on the surface are lost, leaving only siloxane groups, which reduces the reaction sites with the co-catalyst, etc., so it is not desirable.

[0224] For example, the amount of hydroxyl groups on the surface of the carrier is preferably about 0.1 mmol / g to about 10 mmol / g, and more preferably about 0.5 mmol / g to about 5 mmol / g. The amount of hydroxyl groups on the surface of the carrier can be controlled by the manufacturing method and conditions of the carrier or drying conditions, such as temperature, time, vacuum, or spray drying. If the amount of hydroxyl groups is less than about 0.1 mmol / g, there are few reaction sites with the co-catalyst, etc., and if it exceeds about 10 mmol / g, it is undesirable because there is a possibility that it is caused by moisture in addition to the hydroxyl groups present on the surface of the carrier particles.

[0226] When the metallocene compound of Formula 1 is supported on a carrier, the weight ratio of the total transition metal to the carrier included in the metallocene compound represented by Formula 1 may be about 1:1 to about 1:1000. When the carrier and the metallocene compound are included in the above weight ratio, appropriate supported catalyst activity is exhibited, which may be advantageous in terms of maintaining catalyst activity and economic efficiency. More specifically, the weight ratio of the compound of Formula 1 to the carrier may be about 1:10 to about 1:30, and even more specifically, about 1:15 to about 1:20.

[0228] In addition, the catalyst composition may further include a co-catalyst in addition to the metallocene compound of Formula 1 and the support to improve high activity and process stability. Such a co-catalyst 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.

[0230] Specifically, the above co-catalyst may include one or more of the compounds represented by the following chemical formula 2.

[0231] [Chemical Formula 2]

[0232] -[Al(R 21 )-O] m -

[0233] In the above chemical formula 2,

[0234] R 21 are identical or different from each other, and each independently halogen, C 1-20 alkyl or C 1-20 It is a haloalkyl;

[0235] m is an integer greater than or equal to 2.

[0237] Examples of compounds represented by the above chemical formula 2 may be alkylaluminoxan compounds in which repeating units are connected in a linear, circular, or network form, and specifically, aluminoxan compounds such as methylaluminoxan, ethylaluminoxan, isobutylaluminoxan, or butylaluminoxan may be used, and any one or more of these may be used.

[0239] In addition, the above co-catalyst may include one or more of the compounds represented by the following chemical formula 3.

[0240] [Chemical Formula 3]

[0241] J(R 31 )3

[0242] In the above chemical formula 3,

[0243] R 31 They are identical or different from each other, and each independently halogen, C 1-20 alkyl or C 1-20 It is a haloalkyl;

[0244] J is aluminum or boron.

[0246] Examples of compounds represented by the above chemical formula 3 include trimethylaluminum, triethylaluminum, triisobutylaluminum, tripropylaluminum, tributylaluminum, dimethylchloroaluminum, triisopropylaluminum, tri-s-butylaluminum, tricyclopentylaluminum, tripentylaluminum, triisopentylaluminum, trihexylaluminum, trioctylaluminum, ethyldimethylaluminum, methyldiethylaluminum, triphenylaluminum, tri-p-tolylaluminum, dimethylaluminum methoxide, dimethylaluminum ethoxide, trimethylboron, triethylboron, triisobutylboron, tripropylboron, tributylboron, etc., and more specifically, may be selected from trimethylaluminum, triethylaluminum, and triisobutylaluminum.

[0248] In addition, the above co-catalyst may include one or more of the compounds represented by the following chemical formula 4.

[0249] [Chemical Formula 4]

[0250] [EH] + [ZQ4] -

[0251] In the above chemical formula 4,

[0252] E is a neutral or cationic Lewis base;

[0253] H is a hydrogen atom;

[0254] Z is a Group 13 element;

[0255] Q are identical or different from each other, and each independently C 6-20 Aryl or C 1-20 It is an alkyl, and here, the above C 6-20 Aryl or C 1-20 The alkyl group is unsubstituted or a halogen, C 1-20 Alkyl, C 1-20 Alkoxy and C 6-20 It is substituted with one or more substituents selected from the group consisting of phenoxy.

[0257] Examples of compounds represented by the above chemical formula 4 include triethylammonium tetraphenylboron, tributylammonium tetraphenylboron, trimethylammonium tetraphenylboron, tripropylammonium tetraphenylboron, trimethylammonium tetra(p-tolyl)boron, trimethylammonium tetra(o,p-dimethylphenyl)boron, tributylammonium tetra(p-trifluoromethylphenyl)boron, trimethylammonium tetra(p-trifluoromethylphenyl)boron, tributylammonium tetrapentafluorophenylboron, N,N-diethylanilinium tetraphenylboron, N,N-diethylanilinium tetrapentafluorophenylboron, diethylammonium tetrapentafluorophenylboron, triphenylphosphonium tetraphenylboron, trimethylphosphonium tetraphenylboron, triethylammonium tetraphenylalumin, tributylammonium tetraphenylalumin, trimethylammonium tetraphenylalumin, triethylammonium tetraphenylalumin, tributylammonium tetraphenylalumin, trimethylammonium tetraphenylalumin. Tripropylammonium tetraphenylaluminum, 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 tetrapentafluorophenylaluminum, N,N-Diethylanilinium tetraphenylaluminum, N,N-Diethylanilinium tetrapentafluorophenylaluminum, Diethylammonium tetrapentatetraphenylaluminum, Triphenylphosphonium tetraphenylaluminum, Trimethylphosphonium tetraphenylaluminum, Tripropylammonium tetra(p-tolyl)boron, Triethylammonium tetra(o,p-dimethylphenyl)boron, Examples include tributylammonium tetra(p-trifluoromethylphenyl)boron, triphenylcarbonium tetra(p-trifluoromethylphenyl)boron, or triphenylcarbonium tetrapentafluorophenylboron, and any one or more of these may be used.

[0259] When the above-mentioned co-catalyst is further included, the weight ratio of the metallocene compound of Formula 1 to the co-catalyst may be about 1:10 to about 1:1000. When the co-catalyst and the metallocene compound are included in the above weight ratio, appropriate supported catalyst activity is exhibited, which may be advantageous in terms of maintaining catalyst activity and economic efficiency. More specifically, the weight ratio of the compound of Formula 1 to the co-catalyst may be about 1:50 to about 1:500, or about 1:100 to about 1:300.

[0261] The above co-catalyst may be supported at a content of about 3 mmol or more or about 5 mmol or more per weight of the carrier, for example, based on 1 g of silica, and may also be supported at a content of about 20 mmol or less or about 15 mmol or less. When included within the above content ranges, the effect of improving catalyst activity due to the use of the co-catalyst may be exhibited.

[0263] When the catalyst composition comprises both the carrier and the co-catalyst described above, the catalyst composition may be prepared by a manufacturing method comprising the steps of supporting a co-catalyst compound on a carrier and supporting a compound represented by Formula 1 on the carrier, wherein the order of supporting the co-catalyst and the metallocene compound of Formula 1 may be changed as necessary.

[0265] At this time, hydrocarbon solvents such as pentane, hexane, heptane, etc., or aromatic solvents such as benzene, toluene, etc., may be used as reaction solvents when preparing the catalyst composition.

[0267] Meanwhile, a propylene-ethylene random copolymer according to one embodiment of the present invention can be prepared by copolymerizing a propylene monomer and an ethylene comonomer in the presence of a catalyst composition comprising a metallocene compound represented by Formula 1.

[0269] At this time, the propylene monomer and the ethylene comonomer may be used in a weight ratio of about 99.9:0.1 to about 90:10, or about 99.7:0.3 to about 93:7, or about 99.5:0.5 to about 96:4, or about 99.1:0.9 to about 95:5, or about 99:1 to about 97.7:2.3. For example, the ethylene comonomer may be reacted in an amount of about 0.1% to about 10% by weight, or about 0.3% to about 7% by weight, or about 0.5% to about 4% by weight, or about 0.9% to about 5% by weight, or about 1% to about 2.3% by weight, based on the total weight of the propylene and ethylene input into the copolymerization process. In the above polymerization process, the weight ratio of ethylene can be about 99.9:0.1 or higher in terms of achieving sufficient physical properties, and about 90:10 or lower in terms of the limit of production by bulk polymerization process.

[0271] The method for manufacturing the above-described propylene-ethylene random copolymer can be carried out using a monomer mixture containing propylene and ethylene as a raw material in the presence of the catalyst composition described above, by applying conventional apparatus and contact techniques.

[0273] The above polymerization process can be carried out as a continuous polymerization process, and various polymerization processes known as polymerization reactions of olefin monomers, such as a continuous solution polymerization process, a bulk polymerization process, a suspension polymerization process, a slurry polymerization process, or an emulsion polymerization process, may be employed. In addition, the polymerization reaction can be carried out by copolymerizing propylene monomers and comonomers by contacting them using one or two continuous slurry polymerization reactors, loop slurry reactors, gas phase reactors, or solution reactors. In particular, a continuous bulk-slurry polymerization process may be preferred in terms of obtaining a uniform molecular weight distribution and commercial production of the product.

[0275] In addition, the polymerization temperature may be about 25 ℃ to about 200 ℃, preferably about 40 ℃ to about 150 ℃, more preferably about 60 ℃ to about 100 ℃. Furthermore, the polymerization pressure may be about 1 kgf / ㎠ to about 100 kgf / ㎠, preferably about 5 kgf / ㎠ to about 80 kgf / ㎠, more preferably about 10 kgf / ㎠ to about 50 kgf / ㎠.

[0277] For example, the above catalyst composition, i.e., the metallocene catalyst, can be dissolved or diluted and injected in an aliphatic hydrocarbon solvent having 5 to 12 carbon atoms, such as pentane, hexane, heptane, nonane, decane, and their isomers, an aromatic hydrocarbon solvent such as toluene and benzene, or a hydrocarbon solvent substituted with chlorine atoms such as dichloromethane and chlorobenzene. It is preferable to use a solvent that has been treated with a small amount of alkyl aluminum to remove small amounts of water or air, which act as catalyst poisons, and it is also possible to carry out the process using additional co-catalysts.

[0279] If necessary, the polymerization process may be carried out under conditions of hydrogenation or non-hydrogenation.

[0281] For example, in the polymerization process described above, when the catalyst composition comprising the compound represented by Chemical Formula 1 is contacted with a propylene monomer and an ethylene comonomer under hydrogen gas, the hydrogen gas may be introduced at a concentration of about 750 ppm or less or about 100 ppm to about 750 ppm with respect to the total molar content of the monomer for forming the propylene-ethylene random copolymer.

[0283] By controlling the amount of hydrogen gas used, the molecular weight distribution and fluidity of the propylene-ethylene random copolymer produced can be controlled within a desired range while exhibiting sufficient catalytic activity, and accordingly, a propylene-ethylene random copolymer with appropriate physical properties can be produced according to the application. For example, if the amount of hydrogen gas input exceeds about 750 ppm, the stiffness of the propylene-ethylene random copolymer may decrease when processed into a fiber for multifilament or a fiber for spunbond. On the other hand, if the amount of hydrogen gas input is less than about 100 ppm, the processability and elongation of the propylene-ethylene random copolymer produced may decrease, and yarn breakage or partial yarn breakage may occur during the actual spinning process. More specifically, the hydrogen gas may be introduced in an amount of about 600 ppm or less, about 400 ppm or less, about 340 ppm or less, or about 300 ppm or less, or about 250 ppm or less, with respect to the total molar content of the monomer for forming the propylene-ethylene random copolymer, and may also be introduced in an amount of about 120 ppm or more, or about 150 ppm or more, or about 180 ppm or more, or about 200 ppm or more.

[0285] As such, the propylene-ethylene random copolymer according to the present invention can be prepared by copolymerizing propylene and ethylene using the supported metallocene catalyst described above. As a result, the propylene-ethylene random copolymer maintains a high melting point even with increased ethylene content and has an optimized weight-average molecular weight along with a narrow molecular weight distribution, thereby maximizing the ethylene content to exhibit sufficient softness characteristics during fiber processing and achieving excellent fiber strength suitable for high-speed spinning. Accordingly, the propylene-ethylene random copolymer according to the present invention may be particularly useful for manufacturing multifilament or spunbond fibers that require high rigidity and excellent softness.

[0287] Meanwhile, according to another embodiment of the invention, a resin composition for manufacturing fibers for multifilament or spunbond comprising the propylene-ethylene random copolymer is provided, and fibers, fabrics, woven fabrics, and nonwoven fabrics for multifilament or spunbond manufactured using the same are provided.

[0289] As the above-mentioned propylene-ethylene random copolymer has been explained in detail previously, a detailed explanation is omitted here.

[0291] For example, a resin composition for manufacturing multifilament or spunbond fibers comprising the above-mentioned propylene-ethylene random copolymer has a tensile strength of approximately 200 kgf / cm² as measured according to the ASTM D 638 method. 2 Above or about 200 kgf / cm² 2 Up to about 1000 kgf / cm² 2 And, the flexural modulus measured according to the ASTM D 790 method is approximately 13,900 kgf / cm 2 Less than or about 8000 kgf / cm² 2 Up to about 13,900 kgf / cm² 2 It may be. The resin composition of the above-mentioned propylene-ethylene random copolymer has a tensile strength of approximately 200 kgf / cm² in terms of securing processability and elongation with high stiffness when manufacturing fibers for multifilament or spunbond fibers. 2 It can be above this level, and in terms of achieving excellent softness along with such high stiffness, the flexural modulus is approximately 13,900 kgf / cm² 2 It can be less than

[0293] Specifically, the tensile strength of the resin composition of the propylene-ethylene random copolymer is approximately 240 kgf / cm² 2 Above, or about 255 kgf / cm² 2 Above, or approximately 265 kgf / cm²2 Above, or approximately 270 kgf / cm² 2 It may be higher, and in some cases, about 800 kgf / cm² 2 Less than, or about 700 kgf / cm² 2 Less than, or about 600 kgf / cm² 2 Less than, or approximately 450 kgf / cm² 2 It may be less than or equal to. In addition, the flexural modulus of the resin composition of the propylene-ethylene random copolymer is approximately 13,500 kgf / cm². 2 Less than, or approximately 13,100 kgf / cm² 2 Less than, or approximately 12,800 kgf / cm² 2 Less than, or approximately 12,800 kgf / cm² 2 It may be less than, and in some cases, approximately 9000 kgf / cm² 2 Above, or about 10,000 kgf / cm² 2 Above, or approximately 11,000 kgf / cm² 2 Above, or about 12,000 kgf / cm² 2 It could be more than that.

[0295] In addition, the flexural strength of the resin composition of the above-mentioned propylene-ethylene random copolymer, measured according to the American Society for Testing Materials standard ASTM D 790 method, is approximately 415 kgf / cm 2 Less than or about 100 kgf / cm² 2 Up to 415 kgf / cm² 2 It can be, specifically about 410 kgf / cm² 2 Less than, or about 400 kgf / cm² 2 Less than, or approximately 395 kgf / cm² 2 Less than, or approximately 390 kgf / cm² 2 It may be less than, and in some cases, about 100 kgf / cm² 2 Above, or about 200 kgf / cm² 2 Above, or about 300 kgf / cm² 2 Above, or approximately 375 kgf / cm²2 It could be more than that.

[0297] For example, the tensile strength, flexural modulus, and flexural strength values ​​of the resin composition of the above-mentioned propylene-ethylene random copolymer are obtained by formulating additives such as a neutralizing agent (Calcium stearate) at 500 ppm, a primary antioxidant (Irganox 1010, manufactured by BASF) at 500 ppm, a secondary antioxidant (Irganox 168, manufactured by BASF) at 1000 ppm, a slip agent (Erucamide, manufactured by ALDRICH) at 1000 ppm, and an anti-blocking agent (SiO2, manufactured by SIPERNAT) at 100 ppm to 10 kg of propylene-ethylene random copolymer, drawing a strand at 5 to 15 kg / h at 180 to 220 ℃, manufacturing pellets from this strand using a pelletizer at approximately 500 to 900 rpm, and using an injection molding machine The physical property values ​​are measured from the injection-molded product, and the method for measuring the tensile strength, flexural modulus, and flexural strength can be referenced to the method described in Test Example 2 below.

[0299] A fiber for multifilament or spunbond prepared using a resin composition comprising a propylene-ethylene random copolymer of the present invention can simultaneously achieve high stiffness along with significantly improved softness compared to fibers comprising propylene polymers prepared using conventional Ziegler-Natta catalysts or metallocene catalysts. Effects of the invention

[0301] The propylene-ethylene random copolymer according to the present invention can maintain a high melting point and secure excellent physical properties such as stiffness and process stability without fouling, and can also secure sufficient softness characteristics when processing fibers with a high content of ethylene, which is a comonomer, making it advantageous for manufacturing high-strength multifilament fibers or spunbond fibers. Specific details for implementing the invention

[0303] The operation and effects of the invention will be described in more detail below through specific embodiments. However, these embodiments are merely examples of the invention and do not define the scope of the invention.

[0305] <Example>

[0306] Preparation of Metallocene Compounds

[0307] Synthesis Example 1

[0308]

[0310] Preparation of the ligand compound (2-Methyl-4-(3',5'-ditertbutylphenyl)Indacenyl) dimethyl (2,3,4,5-tetramethyl cyclopentadienyl) silane

[0311] After dissolving 2,3,4,5-tetramethylcyclopentadiene (TMCP) in tetrahydrofuran (THF), n-butyllithium (n-BuLi, 1.05 eq) was slowly added dropwise at -25 ℃, and the mixture was stirred at room temperature for 3 hours. Then, dichlorodimethylsilane (1.05 eq) was added at -10 ℃, and the mixture was stirred overnight at room temperature. In another reactor, 2-methyl-4-(3',5'-di(tert-butyl)phenyl) indacene (1 eq)) was dissolved in a mixed solvent of toluene / tetrahydrofuran (Toluene / THF) (volume ratio 3 / 2, 0.5 M), and then n-BuLi (1.05 eq) was slowly added dropwise at -25 °C, followed by stirring at room temperature for 3 hours. Subsequently, CuCN (2 mol%) was added and stirred for 30 minutes, after which the first reaction product, the mono-Si solution, was added. The mixture was then stirred overnight at room temperature, worked up with water, and dried to obtain the ligand.

[0313]

[0315] Preparation of the transition metal compound Dimethylsilanediyl(2-Methyl-4-(3',5'-ditertbutylphenyl)Indacenyl)(2,3,4,5-tetramethyl cyclopentadienyl) zirconium dichloride

[0316] The ligand prepared above was dissolved in Toluene / Ether (volume ratio 2 / 1, 0.53 M), n-BuLi (2.05 eq) was added at -25 °C, and the mixture was stirred at room temperature for 5 hours. A slurry was prepared in a separate flask by mixing ZrCl4 (1 eq) with toluene (0.17 M), added to the ligand solution, and stirred overnight at room temperature. Upon completion of the reaction, the solvent was vacuum dried, dichloromethane was reintroduced to remove LiCl using a filter, the filtrate was vacuum dried, and dichloromethane / hexane was added to recrystallize at room temperature. The resulting solid was then filtered and vacuum dried to obtain the metallocene compound of the title.

[0318] For the transition metal compound obtained in this way, Bruker AVANCE III HD 500 MHz NMR / PABBO(1H / 19F / Broad band) probe: 1 NMR data was measured using H, solvent: CDCl3.

[0320] 1 H-NMR (500 MHz, CDCl3): 7.73 (s, 2H), 7.56 (s, 1H), 7.42 (s, 1H), 6.36 (s, 1H), 2.85-2.80 (m, 4H), 2.12 (s, 6H), 1.95 (m, 2H), 1.79 (s, 9H), 1.31 (s, 18H), 1.00 (s, 6H) ppm

[0322] Synthesis Example 2

[0323]

[0325] Preparation of the ligand compound (2-Methyl-4-phenylIndacenyl) dimethyl (2,3,4,5-tetramethyl cyclopentadienyl) silane

[0326] After dissolving 2,3,4,5-tetramethylcyclopentadiene (TMCP) in tetrahydrofuran (THF), n-butyllithium (n-BuLi, 1.05 eq) was slowly added dropwise at -25 ℃, and the mixture was stirred at room temperature for 3 hours. Then, dichlorodimethylsilane (1.05 eq) was added at -10 ℃, and the mixture was stirred overnight at room temperature. In another reactor, 2-methyl-4-phenyl indacene (1 eq) was dissolved in a mixed solvent of toluene / tetrahydrofuran (Toluene / THF) (volume ratio 3 / 2, 0.5 M), and then n-BuLi (1.05 eq) was slowly added dropwise at -25 °C, followed by stirring at room temperature for 3 hours. Subsequently, CuCN (2 mol%) was added and stirred for 30 minutes, after which the first reaction product, the mono-Si solution, was added. The mixture was then stirred overnight at room temperature, worked up with water, and dried to obtain the ligand.

[0328]

[0330] Preparation of the transition metal compound Dimethylsilanediyl(2-Methyl-4-phenylIndacenyl)(2,3,4,5-tetramethyl cyclopentadienyl) zirconium dichloride

[0331] The ligand prepared above was dissolved in Toluene / Ether (volume ratio 2 / 1, 0.53 M), n-BuLi (2.05 eq) was added at -25 °C, and the mixture was stirred at room temperature for 5 hours. A slurry was prepared in a separate flask by mixing ZrCl4 (1 eq) with toluene (0.17 M), added to the ligand solution, and stirred overnight at room temperature. Upon completion of the reaction, the solvent was vacuum dried, dichloromethane was reintroduced to remove LiCl using a filter, the filtrate was vacuum dried, and dichloromethane / hexane was added to recrystallize at room temperature. The resulting solid was then filtered and vacuum dried to obtain the metallocene compound of the title.

[0333] 1 H-NMR (500 MHz, CDCl3): 7.54-7.38 (m, 6H), 6.37 (s, 1H), 2.85-2.80 (m, 4H), 2.12 (s, 6H), 1.95 (m, 2H), 1.79 (s, 9H), 0.99 (s, 6H) ppm

[0335] Synthesis Example 3

[0336]

[0338] Preparation of the ligand compound (2-Methyl-4-(2'-naphthylene)Indacenyl) dimethyl (2,3,4,5-tetramethyl cyclopentadienyl) silane

[0339] After dissolving 2,3,4,5-tetramethylcyclopentadiene (TMCP) in tetrahydrofuran (THF), n-butyllithium (n-BuLi, 1.05 eq) was slowly added dropwise at -25 ℃, and the mixture was stirred at room temperature for 3 hours. Then, dichlorodimethylsilane (1.05 eq) was added at -10 ℃, and the mixture was stirred overnight at room temperature. In another reactor, 2-methyl-4-(2'-naphthylene) indacene (1 eq) was dissolved in a mixed solvent of toluene / tetrahydrofuran (Toluene / THF) (volume ratio 3 / 2, 0.5 M), and then n-BuLi (1.05 eq) was slowly added dropwise at -25 °C, followed by stirring at room temperature for 3 hours. Subsequently, CuCN (2 mol%) was added and stirred for 30 minutes, after which the first reaction product, the mono-Si solution, was added. The mixture was then stirred overnight at room temperature, worked up with water, and dried to obtain the ligand.

[0341]

[0343] Preparation of the transition metal compound Dimethylsilanediyl(2-Methyl-4-(2'-naphthylene)Indacenyl)(2,3,4,5-tetramethyl cyclopentadienyl) zirconium dichloride

[0344] The ligand prepared above was dissolved in Toluene / Ether (volume ratio 2 / 1, 0.53 M), n-BuLi (2.05 eq) was added at -25 ℃, and the mixture was stirred at room temperature for 5 hours. A slurry was prepared in a separate flask by mixing ZrCl4 (1 eq) with toluene (0.17 M), added to the ligand solution, and stirred overnight at room temperature. Upon completion of the reaction, the solvent was vacuum dried, dichloromethane was reintroduced to remove LiCl using a filter, the filtrate was vacuum dried, and dichloromethane / hexane was added to recrystallize at room temperature. The resulting solid was then filtered and vacuum dried to obtain the metallocene compound of the title.

[0346] 1 H-NMR (500 MHz, CDCl3): 8.80 (d, 1H), 8.50 (d, 1H), 8.2-8.05 (m, 2H), 7.75 (t, 1H), 7.55-7.36 (m, 3H), 6.36 (s, 1H), 2.85-2.81 (m, 4H), 2.13 (s, 6H), 1.95 (m, 2H), 1.8 (s, 6H), 1.78 (s, 3H), 1.01 (s, 6H) ppm

[0348] Synthesis Example 4

[0349]

[0351] Preparation of the ligand compound (2-Methyl-4-(3',5'-ditertbutylphenyl)Indacenyl) diethyl (2,3,4,5-tetramethyl cyclopentadienyl) silane

[0352] After dissolving 2,3,4,5-tetramethylcyclopentadiene (TMCP) in tetrahydrofuran (THF), n-butyllithium (n-BuLi, 1.05 eq) was slowly added dropwise at -25 ℃, and the mixture was stirred at room temperature for 3 hours. Then, dichlorodiethylsilane (1.05 eq) was added at -10 ℃, and the mixture was stirred overnight at room temperature. In another reactor, 2-methyl-4-(3',5'-di(tert-butyl)phenyl) indacene (1 eq)) was dissolved in a mixed solvent of toluene / tetrahydrofuran (Toluene / THF) (volume ratio 3 / 2, 0.5 M), and then n-BuLi (1.05 eq) was slowly added dropwise at -25 °C, followed by stirring at room temperature for 3 hours. Subsequently, CuCN (2 mol%) was added and stirred for 30 minutes, after which the first reaction product, the mono-Si solution, was added. The mixture was then stirred overnight at room temperature, worked up with water, and dried to obtain the ligand.

[0354]

[0356] Preparation of the transition metal compound Diethylsilanediyl(2-Methyl-4-(3',5'-ditertbutylphenyl)Indacenyl)(2,3,4,5-tetramethyl cyclopentadienyl) zirconium dichloride

[0357] The ligand prepared above was dissolved in Toluene / Ether (volume ratio 2 / 1, 0.53 M), n-BuLi (2.05 eq) was added at -25 ℃, and the mixture was stirred at room temperature for 5 hours. A slurry was prepared in a separate flask by mixing ZrCl4 (1 eq) with toluene (0.17 M), added to the ligand solution, and stirred overnight at room temperature. Upon completion of the reaction, the solvent was vacuum dried, dichloromethane was reintroduced to remove LiCl using a filter, the filtrate was vacuum dried, and dichloromethane / hexane was added to recrystallize at room temperature. The resulting solid was then filtered and vacuum dried to obtain the metallocene compound of the title.

[0359] 1 H-NMR (500 MHz, CDCl3): 7.73 (s, 2H), 7.55 (s, 1H), 7.41 (s, 1H), 6.38 (s, 1H), 2.86-2.80 (m, 4H), 2.12 (s, 6H), 1.95 (m, 2H), 1.79 (s, 9H), 1.28 (t, 6H), 0.94 (m, 4H) ppm

[0361] Synthesis Example 5

[0362]

[0364] Preparation of the ligand compound (2-Methyl-4-(3',5'-ditertbutylphenyl)Indacenyl) methylphenyl (2,3,4,5-tetramethyl cyclopentadienyl) silane

[0365] After dissolving 2,3,4,5-tetramethylcyclopentadiene (TMCP) in tetrahydrofuran (THF), n-butyllithium (n-BuLi, 1.05 eq) was slowly added dropwise at -25 ℃, and the mixture was stirred at room temperature for 3 hours. Then, dichloromethylphenylsilane (1.05 eq) was added at -10 ℃, and the mixture was stirred overnight at room temperature. In another reactor, 2-methyl-4-(3',5'-di(tert-butyl)phenyl) indacene (1 eq)) was dissolved in a mixed solvent of toluene / tetrahydrofuran (Toluene / THF) (volume ratio 3 / 2, 0.5 M), and then n-BuLi (1.05 eq) was slowly added dropwise at -25 °C, followed by stirring at room temperature for 3 hours. Subsequently, CuCN (2 mol%) was added and stirred for 30 minutes, after which the first reaction product, the mono-Si solution, was added. The mixture was then stirred overnight at room temperature, worked up with water, and dried to obtain the ligand.

[0367]

[0369] Preparation of the transition metal compound Methylphenylsilanediyl(2-Methyl-4-(3',5'-ditertbutylphenyl)Indacenyl)(2,3,4,5-tetramethyl cyclopentadienyl) zirconium dichloride

[0370] The ligand prepared above was dissolved in Toluene / Ether (volume ratio 2 / 1, 0.53 M), n-BuLi (2.05 eq) was added at -25 ℃, and the mixture was stirred at room temperature for 5 hours. A slurry was prepared in a separate flask by mixing ZrCl4 (1 eq) with toluene (0.17 M), added to the ligand solution, and stirred overnight at room temperature. Upon completion of the reaction, the solvent was vacuum dried, dichloromethane was reintroduced to remove LiCl using a filter, the filtrate was vacuum dried, and dichloromethane / hexane was added to recrystallize at room temperature. The resulting solid was then filtered and vacuum dried to obtain the metallocene compound of the title.

[0372] 1 H-NMR (500 MHz, CDCl3): 7.73 (s, 2H), 7.56 (s, 1H), 7.42-7.28 (m, 6H), 6.38 (s, 1H), 2.88-2.82 (m, 4H), 2.12 (s, 6H), 1.95 (m, 2H), 1.79 (s, 9H), 1.31 (s, 18H), 0.98 (s, 3H) ppm

[0374] Comparative Synthesis Example 1

[0375]

[0377] Preparation of the ligand compound bis(2-Methyl-4-(4'-tertbutylphenyl)Inden-1yl) silane

[0378] 2-Methyl-4-(4'-tertbutylphenyl)Indene (1 equiv) was dissolved in Toluene / THF (10:1 0.3 M), and n-BuLi (2.1 eq) was slowly added dropwise at -25 ℃, followed by stirring at room temperature for 3 hours. Subsequently, CuCN (2 mol%) was added and stirred for 30 minutes, followed by the addition of dichlorodimethylsilane (0.53 eq) at -10 ℃, and the mixture was stirred overnight at room temperature. After stirring overnight at room temperature and working up with water, the mixture was dried to obtain the ligand.

[0380]

[0382] Preparation of the transition metal compound Dimethylsilanediylbis(2-Methyl-4-(4'-tertbutylphenyl)Inden-1yl) zirconium dichloride

[0383] The ligand prepared above was dissolved in Toluene / Ether (volume ratio 10 / 1, 0.1 M), n-BuLi (2.05 eq) was added at -25 ℃, and the mixture was stirred at room temperature for 5 hours. A slurry was prepared in a separate flask by mixing ZrCl4 (1 eq) with toluene (0.17 M), added to the ligand solution, and stirred overnight at room temperature. Upon completion of the reaction, the solvent was vacuum dried, dichloromethane was reintroduced to remove LiCl using a filter, the filtrate was vacuum dried, and dichloromethane / hexane was added to recrystallize at room temperature. The resulting solid was then filtered and vacuum dried to obtain the metallocene compound of the title.

[0385] Comparative Synthesis Example 2

[0386]

[0388] Preparation of the ligand compound (2-Methyl-4-(4'-tertbutylphenyl)Inden-1yl)dimethyl(2,3,4,5-tetramethyl cyclopentadienyl) silane

[0389] (2,3,4,5-tetramethyl) cyclopentadiene (1 equiv) was dissolved in THF (0.3 M), and n-BuLi (1.05 eq) was slowly added dropwise at -25 ℃, followed by stirring at room temperature for 3 hours. Then, dichloro dimethyl silane (1.05 eq) was added at -10 ℃, followed by stirring overnight at room temperature. In another reactor, 2-Methyl-4-(4'-tertbutylphenyl)indene (1 eq) was dissolved in Toluene / THF (3 / 2, 0.5 M), and n-BuLi (1.05 eq) was slowly added dropwise at -25 ℃, followed by stirring at room temperature for 3 hours. Afterward, CuCN (2 mol%) was added and stirred for 30 minutes, followed by the addition of the first reaction product, the mono-Si solution. Afterward, the ligand was obtained by stirring overnight at room temperature, working up with water, and drying.

[0391]

[0393] Preparation of the transition metal compound Dimethylsilanediyl(2-Methyl-4-(4'-tertbutylphenyl)Inden-1-yl)(2,3,4,5-tetramethyl cyclopentadienyl) zirconium dichloride

[0394] The ligand prepared above was dissolved in Toluene / Ether (volume ratio 2 / 1, 0.53 M), n-BuLi (2.05 eq) was added at -25 ℃, and the mixture was stirred at room temperature for 5 hours. A slurry was prepared in a separate flask by mixing ZrCl4 (1 eq) with toluene (1.2 M), added to the ligand solution, and stirred overnight at room temperature. Upon completion of the reaction, the solvent was vacuum dried, dichloromethane was reintroduced to remove LiCl using a filter, the filtrate was vacuum dried, and dichloromethane / hexane was added to recrystallize at room temperature. The resulting solid was then filtered and vacuum dried to obtain the metallocene compound of the title.

[0396] Preparation of Supported Catalysts

[0397] Preparation Example 1

[0398] 100 g of silica gel (Silica gel, SYLOPOL 952X, calcined under 250 ℃) was placed in a 2 L reactor under Ar, and 766 mL of MAO was slowly injected at room temperature and stirred at 90 ℃ for 15 hours. After the reaction was complete, the mixture was cooled to room temperature and left to stand for 15 minutes, after which the solvent was decanted using a cannula. 400 mL of toluene was added and stirred for 1 minute, after which the mixture was left to stand for 15 minutes, after which the solvent was decanted using a cannula.

[0400] 700 μmol of the metallocene compound from Synthesis Example 1 was dissolved in 400 mL of toluene and transferred to a reactor using a cannula. After stirring at 50 °C for 5 hours, the mixture was cooled to room temperature and left to stand for 15 minutes, after which the solvent was decanted using a cannula. This process of adding 400 mL of toluene, stirring for 1 minute, and leaving for 15 minutes to decant the solvent using a cannula was repeated twice. In the same manner, 400 mL of hexane was added, stirred for 1 minute, and left to stand for 15 minutes to decant the solvent using a cannula. Then, an antistatic agent (Atmer 163, 3 g) was dissolved in 400 mL of hexane and transferred to a reactor using a cannula. The mixture was stirred at room temperature for 20 minutes and transferred to a glass filter to remove the solvent.

[0402] A supported catalyst was obtained by first drying at room temperature under vacuum for 5 hours and second drying at 45°C under vacuum for 4 hours.

[0404] Preparation Examples 2 to 5

[0405] A silica-supported metallocene catalyst was prepared in the same manner as in Preparation Example 1, except that the metallocene compounds of Synthesis Examples 2 to 5 were used instead of the metallocene compound of Synthesis Example 1.

[0407] Comparative Manufacturing Examples 1 to 2

[0408] A silica-supported metallocene catalyst was prepared in the same manner as in Preparation Example 1, except that the metallocene compounds of Comparative Synthesis Examples 1 and 2 were used instead of the metallocene compound of Synthesis Example 1.

[0410] <Preparation of Propylene-Ethylene Random Copolymer>

[0411] Example 1

[0412] Bulk-slurry polymerization of propylene and ethylene was carried out using two continuous loop reactors (continuous pilot plant) in the presence of the silica-supported metallocene catalyst prepared in Preparation Example 1.

[0414] At this time, for bulk-slurry polymerization, the supported catalyst prepared according to Preparation Example 1 was used in the form of a mud catalyst mixed with oil and grease at a concentration of 16 wt%. The catalyst mixture thus prepared was fed into a pre-polymerization reactor along with approximately 20 kg / hr of propylene, and after a residence time of at least 8 minutes, it was continuously fed into a loop reactor. At this time, hydrogen was introduced into the loop reactor along with the propylene flowing in, the reactor temperature was maintained at approximately 70 ℃, and the reactor pressure was approximately 35 kg / cm². 2 The amount of hydrogen was maintained at (retention time 2 hours). At this time, the amount of hydrogen input was about 230 ppm based on the total molar content of the propylene input in a continuous manner and the ethylene input directly into the loop reactor (mol ppm). In addition, ethylene (C2) was input directly into the loop reactor to be 2.0 wt% based on the total weight of the propylene and ethylene input into the copolymerization process, and a bulk-slurry polymerization process was performed.

[0416] Examples 2 to 5

[0417] As shown in Table 1 below, the silica-supported catalysts prepared in Preparation Examples 2 to 5, respectively, were used as metallocene catalysts, and bulk-slurry polymerization of propylene and ethylene was performed in the same manner as in Example 1, except that the amount of hydrogen input and the amount of ethylene input were different.

[0419] Comparative Examples 1 to 2

[0420] As shown in Table 1 below, the silica-supported catalysts prepared in Comparative Examples 1 and 2 were used as metallocene catalysts, respectively, and bulk-slurry polymerization of propylene and ethylene was performed in the same manner as in Example 1, except that the hydrogen input amount (ppm) and the ethylene input amount (C2 Feed) were different.

[0422] The specific polymerization process conditions regarding the bulk-slurry polymerization of propylene and ethylene according to the examples and comparative examples are as shown in Table 1 below. In addition, the activity of the catalyst in the polymerization process was measured by the following method, and the results are as shown in Table 1 below.

[0424] Catalytic activity (Activity, kg PP / g·cat·hr)

[0425] It was calculated as the ratio of the weight (kg PP) of the propylene-ethylene random copolymer produced per unit time (h) of the mass (g) of the supported catalyst used.

[0427] Types of catalysts Hydrogen input amount (ppm) C2 input amount (wt%) Catalytic activity (kg / g·cat·hr) Example 1 Preparation Example 1 230 2 27 Example 2 Preparation Example 2 210 1.8 21 Example 3 Preparation Example 3 230 2.2 20 Example 4 Preparation Example 4 240 2 29 Example 5 Preparation Example 5 230 2.3 40 Comparative Example 1 Comparative Manufacturing Example 1 460 1.5 20 Comparative Example 2 Comparative Manufacturing Example 2 200 1.9 7

[0429] In Table 1 above, the amount of hydrogen input is the amount (mol ppm) based on the total molar content of the monomer for forming the propylene-ethylene copolymer, and the amount of ethylene (C2) input is the amount (weight%) based on the total weight of the propylene and ethylene input into the polymerization process.

[0431] <Test Example 1>

[0432] Evaluation of physical properties of propylene-ethylene random copolymer

[0433] The physical properties of the propylene-ethylene random copolymers prepared in the above examples and comparative examples were evaluated by the following method.

[0435] Comonomer content (C2, wt%)

[0436] In accordance with ASTM D 5576, after fixing a film or film-type specimen of propylene-ethylene random copolymer to the magnetic holder of the FT-IR instrument, at 4800–3500 cm⁻¹, which reflects the specimen thickness in the IR absorption spectrum -1 710–760 m where the ethylene component of the peak appears -1 The peak area was measured for each, and the measured values ​​were compared to the 710–760 cm² of the Standard sample. -1 Peak area 4800–3500 cm -1 The comonomer content was calculated by substituting the value obtained by plotting the value divided by the peak height into the calibration equation.

[0438] Melting point (Tm)

[0439] The melting point (Tm) of a propylene polymer was measured using a Differential Scanning Calorimeter (DSC, device name: DSC 2920, manufacturer: TA instrument). Specifically, the polymer was heated to 200 °C and maintained at that temperature for 5 minutes, then lowered to 30 °C, and then the temperature was raised again to measure the peak of the DSC curve as the melting point (Tm). At this time, the rate of temperature increase and decrease was 10 °C / min, and the melting point (Tm) was the result measured during the second temperature increase and decrease interval.

[0441] Weight-average molecular weight (Mw, g / mol) and molecular weight distribution (MWD, polydispersity index), Log MW ratio (0.6 or higher)

[0442] The weight-average molecular weight (Mw) and number-average molecular weight (Mn) of the polymer were measured using gel permeation chromatography (GPC, manufactured by Water), and the molecular weight distribution (MWD) was calculated by dividing the weight-average molecular weight by the number-average molecular weight.

[0444] Specifically, a Waters PL-GPC220 instrument was used for gel permeation chromatography (GPC), and a Polymer Laboratories PLgel MIX-B 300 mm long column was used. The measurement temperature was 160 °C, 1,2,4-trichlorobenzene was used as the solvent, and the flow rate was set to 1 mL / min. Polymer samples according to the examples and comparative examples were each pretreated by dissolving them in trichlorobenzene containing 0.0125% BHT at 160 °C for 10 hours using a GPC analyzer (PL-GP220), prepared to a concentration of 10 mg / 10 mL, and supplied in a volume of 200 μL. The values ​​of Mw and Mn were derived using a calibration curve formed using a polystyrene standard specimen. Nine types of polystyrene standard specimens with weight-average molecular weights of 2000 g / mol, 10000 g / mol, 30000 g / mol, 70000 g / mol, 200000 g / mol, 700000 g / mol, 2000000 g / mol, 4000000 g / mol, and 10000000 g / mol were used.

[0446] In addition, the ratio (%) of the integral value of the region where the Log MW value is 6.0 or higher to the total integral value was calculated and shown in Table 2 below, based on the log (log) graph of the weight-average molecular weight (Mw) of the propylene-ethylene random copolymer measured in this way, i.e., the GPC curve graph where the x-axis is log MW and the y-axis is dw / dlogMw.

[0448] Measurement of residual stress ratio

[0449] For the propylene-ethylene random copolymers prepared in the above examples and comparative examples, a sample was taken and a strain of 200% was applied at 235°C, and the change in residual stress was measured for 10 minutes.

[0451] For the measurement of the above residual stress, a Discovery Hybrid Rheometer (DHR) from TA Instruments was used, and the sample was sufficiently loaded between upper and lower plates with a diameter of 25 mm, melted at 235 ℃, and then measured with the gap fixed at 1 mm.

[0453] Based on the measured residual stress data, the ratio of residual stress (RS%) was calculated according to the following formula 1 and is shown in Table 2 below.

[0455] [Formula 1]

[0456] Residual stress ratio (Y) = (RS1 / RS0)*100

[0458] In the above formula 1, RS0 is the residual stress at 0.02 seconds (t0) after applying 200% strain to the polymer sample at 235°C, and RS1 is the residual stress at 1.00 seconds (t1) after applying 200% strain to the polymer sample at 235°C.

[0460] The results of the physical property evaluation of the propylene-ethylene random copolymer measured by the method described above are shown in Table 2 below.

[0462] C2 content (wt%) Tm(℃) Mw MWD Log MW (6.0 or higher, %) Residual stress ratio (%) Example 1 2.6 135 171,000 2.3 0.62 0.06 Example 2 2.1 137 170,000 2.4 0.63 0.05 Example 3 2.8 135 167,000 2.3 0.61 0.05 Example 4 2.6 135 172,000 2.3 0.7 0.05 Example 5 2.8 135 173,000 2.4 0.68 0.07 Comparative Example 1 1.5 135 172,000 2.6 0.91 0.13 Comparative Example 2 1.3 136 169,000 2.5 0.85 0.11

[0464] As shown in Table 2 above, it was confirmed that the propylene-ethylene random copolymers of Examples 1 to 6 according to the present invention can secure a high melting point (Tm) of 135 °C to 137 °C, maintain high strength properties suitable for high-speed spinning with a weight-average molecular weight (Mw) of 166,000 g / mol to 173,000 g / mol and a narrow molecular weight distribution (MWD) of 2.0 to 2.4, while simultaneously increasing the ethylene (C2) content to 2.1 wt% to 2.8 wt%. In addition, in the case of Examples 1 to 6, it can be seen that the integral value in the region where the Log MW value is 6.0 or higher is significantly low at 0.61% to 0.7% of the total integral value, and the residual stress ratio can also be reduced to 0.03% to 0.07%.

[0466] <Test Example 2>

[0467] Evaluation of physical properties of resin composition of propylene-ethylene random copolymer

[0468] To 10 kg of the propylene-ethylene random copolymer prepared in the above examples and comparative examples, additives of 500 ppm of a neutralizing agent (Calcium stearate), 500 ppm of a primary antioxidant (Irganox 1010, manufactured by BASF), 1000 ppm of a secondary antioxidant (Irganox 168, manufactured by BASF), 1000 ppm of a slip agent (Erucamide, manufactured by ALDRICH), and 1000 ppm of an anti-blocking agent (SiO2, manufactured by SIPERNAT) were added, and a strand was drawn at 180 ℃ to 220 ℃ at a rate of 5 kg / h to 15 kg / h, and the strand was made into pellets using a pelletizer at approximately 500 rpm to 900 rpm, and an injection-molded product was produced by injecting the strands using an injection molding machine. The injection-molded product manufactured in this way was used as a specimen of a resin composition containing a propylene-ethylene random copolymer, and its physical properties were evaluated in the following manner.

[0470] Tensile strength measurement (kg / ㎠)

[0471] The tensile strength at yield of the above injection molded specimen was measured using an Instron Universal Testing Machine (UTM) in accordance with ASTM D 638.

[0473] Measurement of flexural strength (kg / cm²) and flexural modulus (kg / cm²)

[0474] The flexural strength and flexural modulus of the above injection-molded specimens were measured using an Instron Universal Testing Machine (UTM) in accordance with the American Society for Testing Materials standard ASTM D 790 (1997). In accordance with ASTM D 790 (1997), the flexural strength and flexural modulus were measured using a 3-point bending test jig (indenter 10 mm, point 10 mm), with a supports span set to 100 mm and a crosshead speed of 5.3 mm / min. The above injection-molded specimens were placed in a constant temperature and humidity chamber adjusted to a temperature of 23 ℃ and a relative humidity of 50% for 24 hours before being subjected to the above material property evaluation test.

[0476] Tensile strength (kg / cm²) Flexural strength (kg / ㎠) Flexural modulus (kg / cm²) Example 1 272 383 12112 Example 2 280 390 12300 Example 3 267 379 12055 Example 4 270 380 12320 Example 5 271 378 12112 Comparative Example 1 300 430 14200 Comparative Example 2 295 420 13920

[0478] As shown in Table 3 above, when a resin composition is prepared through an injection molding process using the propylene-ethylene random copolymers of Examples 1 to 6 according to the present invention, the tensile strength is 270 kgf / cm² 2 Exhibits high stiffness as described above, while having a flexural strength of 390 kgf / cm² 2 It is less than or equal to, and the flexural modulus is 12320 kgf / cm² 2 It can be confirmed that the softness characteristics of the resin composition are improved along with high strength as it decreases below this level.

Claims

Claim 1 A propylene-ethylene random copolymer satisfying (a) to (f) below, having a tensile strength of 240 kgf / cm² as measured according to the ASTM D 638 method. 2 That is all, and the flexural modulus measured according to the ASTM D 790 method is 13,500 kgf / cm 2 Polypropylene composition having the following: (a) a melting point (Tm) of 133 °C to 137 °C, (b) an ethylene content of 2 wt% to 2.8 wt%, (c) a weight-average molecular weight (Mw) of 165,000 g / mol to 400,000 g / mol, (d) a molecular weight distribution (Mw / Mn) of 2.2 to 2.4, (e) an integral value of the region where the Log MW value is 6.0 or higher on a GPC curve graph where the x-axis is log MW and the y-axis is dw / dlogMw is 0.8% or less of the total integral value, and (f) a residual stress ratio of 0.1% or less. Claim 2 In claim 1, the propylene-ethylene random copolymer is a polypropylene composition having (a) a melting point (Tm) of 135 ℃ to 137 ℃. Claim 3 In claim 1, the propylene-ethylene random copolymer is a polypropylene composition having a content of (b) ethylene of 2.1% to 2.8% by weight. Claim 4 In claim 1, the propylene-ethylene random copolymer is a polypropylene composition having (c) a weight-average molecular weight (Mw) of 167,000 g / mol to 400,000 g / mol. Claim 5 In claim 1, the propylene-ethylene random copolymer is a polypropylene composition having a molecular weight distribution (Mw / Mn) of 2.3 to 2.

4. Claim 6 The polypropylene composition according to claim 1, wherein the propylene-ethylene random copolymer is such that the integral value of the region where the Log MW value is 6.0 or higher in the (e) GPC curve graph where the x-axis is log MW and the y-axis is dw / dlogMw is 0.4% to 0.8% of the total integral value. Claim 7 In claim 1, the propylene-ethylene random copolymer is a polypropylene composition having a (f) residual stress ratio of 0.01% to 0.1%. Claim 8 In claim 1, the polypropylene composition has a tensile strength of 200 kgf / cm² as measured according to the ASTM D 638 method. 2 Up to 1000 kgf / cm² 2 Phosphorus, polypropylene composition. Claim 9 In claim 1, the polypropylene composition has a flexural modulus of 8,000 kgf / cm² as measured according to the American Society for Testing Materials (ASTM) D 790 method. 2 Up to 13,900 kgf / cm² 2 Phosphorus, polypropylene composition. Claim 10 In claim 1, the polypropylene composition has a flexural strength of 415 kgf / cm² as measured according to the ASTM D 790 method. 2 Polypropylene composition. Claim 11 The polypropylene composition of claim 1, wherein the propylene-ethylene random copolymer is prepared by copolymerizing a propylene monomer and an ethylene comonomer in the presence of a catalyst composition comprising a metallocene compound of the following formula 1: [Formula 1] In the above Chemical Formula 1, M is a Group 4 transition metal, and X 1 and X 2 are identical or different from each other, and each is independently a halogen element, and R 1 and R 2 are identical or different from each other, and each independently C 1-20 Alkyl, C 2-20 Alkenyl, C 2-20 Alkoxyalkyl, C 6-20 Aril, C 7-40 Alkylaryl, C 7-40 It is an arylalkyl, and R 3 to R 6 are identical or different from each other, and each independently C 1-20 It is alkyl, and R 7 is substituted or unsubstituted C 6-20 Arilgo, R 8 is C 1-20 It is an alkyl. Claim 12 In Paragraph 11, R 1 and R 2 are respectively C 1-8 Straight-chain or branched-chain alkyl, or C 2-12 It is a straight-chain or branched-chain alkoxyalkyl; R 3 to R 6 are respectively C 1-6 It is a straight-chain or branched-chain alkyl; M is zirconium (Zr) or hafnium (Hf); and R 7 phenyl, C 1-6 Phenyl, naphthyl, or C substituted with straight-chain or branched-chain alkyl groups 1-6 It is a naphthyl substituted with a straight-chain or branched-chain alkyl; R 8 C 1-6 Polypropylene composition, which is a straight-chain or branched-chain alkyl. Claim 13 In claim 11, the polypropylene composition wherein the metallocene compound is represented by the following chemical formula 1-1: [Chemical Formula 1-1] In the above chemical formula 1-1, M, X 1 , X 2 , R 1 , R 2 , R 7 ...is as defined in Paragraph 11. Claim 14 In claim 11, the above-mentioned metallocene compound is any one of the compounds represented by the following structural formulas, in a polypropylene composition: . Claim 15 A polypropylene composition according to claim 11, wherein the copolymerization step is performed by reacting propylene and ethylene in a weight ratio of 99.9:0.1 to 90:

10. Claim 16 A polypropylene composition according to claim 11, wherein the copolymerization step is performed by introducing hydrogen gas at a level of 750 ppm or less based on the total molar content of the monomer for forming a propylene-ethylene random copolymer. Claim 17 A polypropylene composition according to claim 11, wherein the copolymerization step comprises copolymerizing a monomer for forming a propylene-ethylene random copolymer and an ethylene comonomer in a bulk-slurry polymerization process. Claim 18 A polypropylene composition according to claim 11, wherein the copolymerization step comprises reacting the ethylene comonomer in an amount of 1% to 2.3% by weight based on the total weight of propylene and ethylene introduced into the polymerization process. Claim 19 A polypropylene composition according to claim 1, wherein the copolymerization step is performed under conditions of a temperature of 70 ℃ to 100 ℃ and a pressure of 10 kgf / ㎠ to 100 kgf / ㎠. Claim 20 A fiber for multifilament or spunbond, manufactured from a polypropylene resin composition according to any one of claims 1 to 10.

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