Ziegler-Natta catalyst for ethylene polymerization and method for producing the same

Abstract

The Ziegler-Natta catalyst for ethylene polymerization not only contains a Ziegler-Natta Pro-catalyst containing internal electron donors satisfying a specific formula, but also includes at least one additional external electron donor satisfying a specific formula, thereby increasing the number of active sites of the titanium compound. In the case of polyethylene produced from the Ziegler-Natta catalyst for ethylene polymerization, the high MFR ratio results in excellent processability and improved productivity of polyethylene resin.

Description

[Technical Field]

[0001] This invention relates to a Ziegler-Natta pro-catalyst for ethylene polymerization, a Ziegler-Natta catalyst for ethylene polymerization containing the same, methods for producing each of these, and polyethylene with excellent processability prepared using the Ziegler-Natta catalyst for ethylene polymerization. [Background technology]

[0002] Polyolefins are a type of polymer derived from simple olefins. Known methods for producing polyolefins include the use of Ziegler-Natta polymerization catalysts. Such catalysts use transition metal halides to polymerize vinyl monomers, providing polymers with a highly isotactic stereochemical configuration.

[0003] In particular, polyethylene, a type of polyolefin, has seen a diversification of applications in recent years, creating a need for catalysts and manufacturing methods to produce polyethylene resins with excellent processability in order to improve the productivity of the resin.

[0004] (Patent Document 1) KR10-2423660B [Overview of the project] [Problems that the invention aims to solve]

[0005] The objective is to provide a Ziegler-Natta Pro-catalyst for ethylene polymerization containing an internal electron donor satisfying a specific formula; a Ziegler-Natta Pro-catalyst for ethylene polymerization further containing at least one external electron donor satisfying a specific formula in a specific proportion; and polyethylene with excellent processability prepared using the Ziegler-Natta Pro-catalyst for ethylene polymerization. [Means for Solving the Problems]

[0006] The Ziegler-Natta procatalyst for ethylene polymerization on one side contains a titanium compound represented by the following formula 1, a magnesium compound represented by the following formula 2, and an internal electron donor represented by the following formula 3: (Formula 1) TiX , 4 , 3 , 20 , (OR 1 ) 4-n (In the above formula 1, R 1 is a substituted or unsubstituted C1-C 20 alkyl group, the substituents in the above substituted or unsubstituted are independently one or more selected from the group consisting of a halogen group, a cyano group, a nitro group, and a C1-C8 alkyl group, X is a halogen atom, and n is an integer from 0 to 4) (Formula 2) MgX2 (In the above formula 2, X is a halogen atom) (Formula 3)

[0007] [Chemical]

[0008] (In the above formula 3, R 2 and R 5 are independently a substituted or unsubstituted C1-C 20 alkyl group, R 3 and R 4 are independently a substituted or unsubstituted C1-C 20 alkyl group or are linked to each other to form a substituted or unsubstituted alicyclic ring, The substituents in the substituted or unsubstituted configurations are independently one or more selected from the group consisting of halogen groups, cyano groups, nitro groups, and C1-C8 alkyl groups, and (where a is an integer between 0 and 5).

[0009] The internal electron donor may be a compound represented by the following formula 3-1: (Formula 3-1)

[0010] [ka]

[0011] (In the above formula 3-1, R 6 and R 7 These are independently of substitution or non-substitution of C1-C 10 It is an alkyl group, R 8 and R 9 These are, independently, hydrogen; or substituted or unsubstituted C1-C 10 Alkyl group; or linked together as substituted or unsubstituted C5-C 12 Forms an alicyclic ring; and The substituents in the substituted or unsubstituted configurations are independently one or more selected from the group consisting of halogen groups, cyano groups, nitro groups, and C1-C8 alkyl groups.

[0012] The internal electron donor may be one or more selected from the group consisting of diethyl-2,2-diisopropylsuccinate, diethyl cyclohexane-1,2-dicarboxylate, and diisopropyl succinate.

[0013] Another aspect of the Ziegler-Natta catalyst for ethylene polymerization includes a Ziegler-Natta pro-catalyst for ethylene polymerization containing an internal electron donor represented by formula 3 below; an organoaluminum compound represented by formula 4 below; and an external electron donor represented by formula 5 below.

[0014] (Formula 3)

[0015] [ka]

[0016] (In the above formula 3, R 2 and R 5 These are independently of substitution or non-substitution of C1-C 20 It is an alkyl group, R 3 and R 4 These are independently of substitution or non-substitution of C1-C 20 They are alkyl groups, or linked together to form substituted or unsubstituted alicyclic rings. The substituents in the substituted or unsubstituted configurations are independently one or more selected from the group consisting of halogen groups, cyano groups, nitro groups, and C1-C8 alkyl groups, and (a is an integer between 0 and 5.)

[0017] (Formula 4) AlR 10 n X 3-n (In the above formula 4, R 10 C1-C is either substituted or non-substituted. 20 It is an alkyl group, The substituents in the substituted or unsubstituted configurations are independently one or more selected from the group consisting of halogen groups, cyano groups, nitro groups, and C1-C8 alkyl groups. X is a halogen atom, and n is an integer between 0 and 3.

[0018] (Formula 5) R 11 m Si(OR 12 ) 4-m (In formula 5 above, R 11 and R 12 These are independently of substitution or non-substitution of C1-C 20 Alkyl, substituted or unsubstituted C5-C 20 A cycloalkyl group, or a substituted or unsubstituted amine group, The substituents in the substituted or unsubstituted configurations are independently one or more selected from the group consisting of halogen groups, cyano groups, nitro groups, and C1-C8 alkyl groups, and m is an integer between 0 and 4.

[0019] The internal electron donor may be a compound represented by the following formula 3-1.

[0020] (Formula 3-1)

[0021] [ka]

[0022] (In the above formula 3-1, R 6 and R 7 These are independently of substitution or non-substitution of C1-C 10 It is an alkyl group, R 8 and R 9 These are, independently, hydrogen; or substituted or unsubstituted C1-C 10 Alkyl group; or linked together as substituted or unsubstituted C5-C 12 Forms an alicyclic ring; and The substituents in the substituted or unsubstituted configurations are independently one or more selected from the group consisting of halogen groups, cyano groups, nitro groups, and C1-C8 alkyl groups.

[0023] The internal electron donor may be one or more selected from the group consisting of diethyl-2,2-diisopropylsuccinate, diethyl cyclohexane-1,2-dicarboxylate, and diisopropyl succinate.

[0024] The external electron donor may be at least one compound represented by the following formulas 5-1 and 5-2.

[0025] (Formula 5-1)

[0026] [ka]

[0027] (In the above formula 5-1, R 13 ~R 16 These are independently of substitution or non-substitution of C1-C 20 Alkyl groups, or substituted or unsubstituted C5-C 20 It is a cycloalkyl group, and The substituents in the substituted or unsubstituted configurations are independently one or more selected from the group consisting of halogen groups, cyano groups, nitro groups, and C1-C8 alkyl groups.

[0028] (Formula 5-2)

[0029] [ka]

[0030] (In the above formula 5-2, R 17 ~R 20 These are independently of substitution or non-substitution of C1-C 20 Alkyl groups, or substituted or unsubstituted C5-C 20 It is a cycloalkyl group, and The substituents in the substituted or unsubstituted configurations are independently one or more selected from the group consisting of halogen groups, cyano groups, nitro groups, and C1-C8 alkyl groups.

[0031] The external electron donor may be at least one compound represented by formulas 5-1a to 5-1d and 5-2a below.

[0032] (Formula 5-1a)

[0033] [ka]

[0034] (Formula 5-1b)

[0035] [ka]

[0036] (Formula 5-1c)

[0037] [ka]

[0038] (Formula 5-1d)

[0039] [ka]

[0040] (Formula 5-2a)

[0041] [ka]

[0042] In one specific example, the external electron donor may include two compounds from the compounds represented by formulas 5-1a to 5-1d and formula 5-2a. In one specific example, the external electron donor includes a first compound selected from the compounds represented by formulas 5-1a to 5-1d and formula 5-2a, and a second compound selected from the compounds represented by formulas 5-1a to 5-1d and formula 5-2a, wherein the first and second compounds are not the same, and the molar ratio of the first compound to the second compound may be about 1:0.5 to 1.5. In one specific example, the molar ratio of the first compound to the second compound may be about 1:0.6 to 1.4, for example, about 1:0.8, 1:1, or 1:1.2.

[0043] The molar ratio of the titanium compound to the external electron donor in the Ziegler-Natta main catalyst for ethylene polymerization may be approximately 1:3 to 7. In specific examples, the molar ratio of the titanium compound to the external electron donor in the Ziegler-Natta main catalyst for ethylene polymerization may be approximately 1:3.1 to 6.8, for example, approximately 1:3.5, 1:4.0, 1:4.5, 1:5.0, 1:5.5, 1:6.0, and 1:6.5.

[0044] Another aspect of the method for producing polyolefins includes the step of polymerizing an olefin having the following formula 6 in the presence of the Ziegler-Natta catalyst for ethylene polymerization;

[0045] (Formula 6) CH2=CHR 21 In the above formula, R 21 is hydrogen or a C1-C6 alkyl or aryl group. The polymerization described above can be carried out under conditions of a hydrogen gas atmosphere, a pressure of approximately 6 bar to 8 bar, and a temperature of approximately 80°C to 90°C.

[0046] Polyethylene relating to another aspect is produced by the method for producing polyolefins, and the MFR ratio (MFR 21.6 / MFR 2.16 ) is characterized by being approximately 30 to 40. In a specific example, the MFR ratio (MFR21.6 / MFR 2.16 ) could be approximately 30.2 to 39.8, for example, 30.6, 31.1, 31.2, 31.7, 32.4, 32.8, 36.4, 37.6, 36.7, or 39.8. [Effects of the Invention]

[0047] The Ziegler-Natta Pro-catalyst for ethylene polymerization not only increases the number of active sites of the titanium compound by containing internal electron donors that satisfy a specific formula, but also further increases the number of active sites of the titanium compound by containing at least one external electron donor that satisfies a specific formula in a specific proportion. This allows for the production of polyethylene with excellent processability. [Modes for carrying out the invention]

[0048] The above objectives, other objectives, features, and advantages will be readily apparent through the attached drawings and the following preferred embodiments. However, the embodiments described herein are not limited to those described herein and can be embodied in other forms. Rather, the embodiments presented herein are provided to ensure that the disclosed content is thorough and complete, and that the technical ideas are fully communicated to the average person in the art.

[0049] In this specification, terms such as “includes” or “have” indicate the presence of features, figures, stages, actions, components, parts, or combinations thereof described in the specification, and should be understood not to preclude the possibility of the presence or addition of one or more other features, figures, stages, actions, components, parts, or combinations thereof.

[0050] Unless otherwise explicitly stated, all numbers, values, and / or expressions used herein to describe the quantities of components, reaction conditions, polymer compositions, and formulations should be understood to be approximate in all cases, as they reflect the various uncertainties of measurement that arise when obtaining such values ​​among essentially different numbers. Furthermore, where numerical ranges are disclosed herein, such ranges are continuous and, unless otherwise noted, include all values ​​from the minimum to the maximum value within such range. Additionally, where such ranges refer to integers, unless otherwise noted, include all integers from the minimum to the maximum value within such range.

[0051] In this specification, when a range is given for a variable, it can be understood that the variable includes all values ​​within the given range, including the end point of the given range. For example, the range "5 to 10" can be understood to include not only the values ​​5, 6, 7, 8, 9, and 10, but also any sub-ranges such as 6 to 10, 7 to 10, 6 to 9, 7 to 9, etc., and any values ​​between integers that are within the range of the given range, such as 5.5, 6.5, 7.5, 5.5 to 8.5, and 6.5 to 9. Similarly, the range "10% to 30%" can be understood to include not only all integers up to 30% and values ​​such as 10%, 11%, 12%, 13%, etc., but also any sub-ranges such as 10% to 15%, 12% to 18%, 20% to 30%, etc., and any values ​​between integers that are within the range of the given range, such as 10.5%, 15.5%, 25.5%, etc.

[0052] In recent years, as polyethylene has become more diverse in its applications, there has been a need for catalysts and manufacturing methods to produce polyethylene resins with excellent processability in order to improve the productivity of the resin.

[0053] In response to this problem, the inventors diligently conducted research and, as a result, discovered that when polyethylene is produced using a Ziegler-Natta Pro-catalyst for ethylene polymerization containing an internal electron donor satisfying a specific formula, and a Ziegler-Natta catalyst for ethylene polymerization further containing at least one external electron donor satisfying a specific formula in a specific proportion, the internal and external electron donors increase the active sites of the titanium compound, thereby enabling the production of polyethylene with excellent processability. The inventors have now completed this process.

[0054] Unless otherwise specified herein, "C1-C n "Alkyl group" refers to primary alkyl groups, secondary alkyl groups (n≧3), and tertiary alkyl groups (n≧4) having 1 to n carbon atoms. Examples include functional groups such as methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, tert-butyl, and n-hexyl.

[0055] Unless otherwise specified herein, "C1-C 10 "Alkoxy" means an -OR group, where R is "C1-C 10 It includes "alkyl," "aryl," "heteroaryl," or "benzyl." Preferred alkoxy groups include, for example, methoxy, ethoxy, phenoxy, benzyloxy, etc.

[0056] Unless otherwise specified herein, the aryl group means a monocyclic or polycyclic compound having 2 to 30 carbon atoms containing one or more benzene rings, and a chemical group obtained by removing one hydrogen atom from a derivative thereof. For example, the monocyclic or polycyclic compound containing a benzene ring includes a benzene ring, toluene or xylene with an alkyl side chain attached to a benzene ring, biphenyl in which two or more benzene rings are linked by a single bond, fluorene, xanthene or anthraquinone in which a benzene ring is condensed with a cycloalkyl group or heterocycloalkyl group, and naphthalene or anthracene in which two or more benzene rings are condensed.

[0057] Unless otherwise specified herein, the prefix hetero means that one to three heteroatoms selected from the group consisting of -N-, -O-, -S-, and -P- substitute for a carbon atom. For example, these could be pyridine, pyrrole, or carbazole containing a nitrogen atom as the heteroatom; furan or dibenzofuran containing an oxygen atom as the heteroatom; or dibenzothiophene, diphenylamine, etc.

[0058] Unless otherwise specified herein, a halogen group means a Group 17 element, which may be, for example, a fluoro group, a chloro group, a bromo group, or an iodine group.

[0059] In this specification, substitution or unsubstituted means whether or not a substituent is substituted, where the substituent may be one or more selected from the group consisting of halogen groups, cyano groups, nitro groups, and C1-C8 alkyl groups.

[0060] A Ziegler-Natta pro-catalyst for ethylene polymerization according to one embodiment comprises a titanium compound represented by the following formula 1; a magnesium compound represented by the following formula 2; and an internal electron donor represented by the following formula 3.

[0061] (Formula 1) TiX n (OR 1 ) 4-n In the above formula 1, R 1 This includes halogen groups, nitrile groups, nitro groups, amine groups, and substituted or unsubstituted C1-C groups. 10 Alkoxy groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, or substituted or unsubstituted C1-C 20 It can be an alkyl group, preferably a substituted or unsubstituted C1-C 20It may be an alkyl group. In this case, the substituents in the substituted or unsubstituted groups may independently be one or more selected from the group consisting of halogen groups, cyano groups, nitro groups, and C1-C8 alkyl groups. Also, X may be a halogen atom, and n may be an integer from 0 to 4.

[0062] (Formula 2) MgX2 In equation 2 above, X can be a halogen atom.

[0063] (Formula 3)

[0064] [ka]

[0065] In the above equation 3, R 2 and R 5 These are, independently, halogen groups, nitrile groups, nitro groups, amine groups, and substituted or unsubstituted C1-C groups. 10 Alkoxy groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, or substituted or unsubstituted C1-C 20 It can be an alkyl group, preferably independently substituted or unsubstituted C1-C 20 It can be an alkyl group. Also, R 3 and R 4 This includes halogen groups, nitrile groups, nitro groups, amine groups, and substituted or unsubstituted C1-C groups. 10 Alkoxy groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, or substituted or unsubstituted C1-C 20 It can be an alkyl group, preferably independently substituted or unsubstituted C1-C 20 It can be an alkyl group. Also, R 3 and R 4 These elements can be linked together to form substituted or unsubstituted alicyclic rings. In this case, the substituents in the substituted or unsubstituted rings can independently be one or more selected from the group consisting of halogen groups, cyano groups, nitro groups, and C1-C8 alkyl groups. Also, a can be an integer from 0 to 5.

[0066] According to an embodiment, the titanium compound is a catalytic active site and plays a role in the growth of polyethylene. Specifically, it can be one or more selected from the group consisting of tetravalent titanium halides and titanium alkoxides. For example, it can be titanium tetrachloride (TiCl4), titanium trichloride (TiCl3), etc.

[0067] According to an embodiment, the magnesium compound serves as a carrier of the catalyst to stabilize the catalytic active site. Specifically, it can be magnesium chloride (MgCl2), magnesium oxide (MgO), magnesium sulfate (MgSO4), etc.

[0068] According to an embodiment, the internal electron donor can be a compound represented by the following formula 3-1.

[0069] (Formula 3-1)

[0070] [Chemical formula]

[0071] In formula 3-1, R 6 and R 7 are independently a halogen group, a nitrile group, a nitro group, an amine group, a substituted or unsubstituted C1-C 10 alkoxy group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted C1-C 20 alkyl group, and preferably a substituted or unsubstituted C!-C 20 alkyl group. Also, R 8 and R 9 are independently hydrogen, a halogen group, a nitrile group, a nitro group, an amine group, a substituted or unsubstituted C1-C 10 alkoxy group, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, or a substituted or unsubstituted C1-C 20 alkyl group, and preferably are independently hydrogen; or a substituted or unsubstituted C1-C 10It can be an alkyl group. Also, R 8 and R 9 These are C5-C that are linked together and substituted or non-substituted. 12 An alicyclic ring can be formed. In this case, the substituents in the substituted or unsubstituted rings may independently be one or more selected from the group consisting of halogen groups, cyano groups, nitro groups, and C1-C8 alkyl groups.

[0072] According to one example, the Ziegler-Natta Pro-catalyst for ethylene polymerization may contain one or more compounds selected from the group consisting of Diethyl-2,2-diisopropylsuccinate, Diethyl cyclohexane-1,2-dicarboxylate, and Diisopropyl succinate as internal electron donors, satisfying formula 3-1. Preferably, it may contain Diethyl-2,2-diisopropylsuccinate, which has functional groups of appropriate size and can generate diverse bonding modes on the magnesium chloride crystal surface. In other words, the Ziegler-Natta Pro-catalyst for ethylene polymerization contains a compound satisfying formula 3-1 as an internal electron donor. By increasing the number of active sites of titanium compounds during the process of generating bond modes [(110)bridge,(100)bridge] on the magnesium chloride crystal surface, it improves the molecular weight distribution of polyethylene, thereby increasing the processability of polyethylene produced by ethylene polymerization.

[0073] Another Ziegler-Natta catalyst for ethylene polymerization according to an aspect includes a Ziegler-Natta pro-catalyst for ethylene polymerization, an organoaluminum compound represented by Formula 4, and an external electron donor represented by Formula 5. At this time, among the contents related to the Ziegler-Natta catalyst for ethylene polymerization, the contents overlapping with the Ziegler-Natta pro-catalyst for ethylene polymerization may be omitted from the description.

[0074] (Formula 4) AlR 10 n X 3-n In Formula 4 above, R 10 is a halogen group, nitrile group, nitro group, amine group, substituted or unsubstituted C1-C 10 alkoxy group, substituted or unsubstituted aryl group, substituted or unsubstituted heteroaryl group, or substituted or unsubstituted C1-C 20 alkyl group, preferably a substituted or unsubstituted C1-C 20 alkyl group. At this time, the substituents in the substituted or unsubstituted may independently be one or more selected from the group consisting of a halogen group, cyano group, nitro group, and C1-C8 alkyl group. Also, X is a halogen atom, and n may be an integer from 0 to 3.

[0075] (Formula 5) R 11 m Si (OR 12 ) 4-m In Formula 5 above, R 11 and R 12 are independently a halogen group, nitrile group, nitro group, amine group, substituted or unsubstituted C1-C 10 alkoxy group, substituted or unsubstituted aryl group, substituted or unsubstituted heteroaryl group, substituted or unsubstituted C1-C 20 alkyl group, substituted or unsubstituted C5-C 20It may be a cycloalkyl group, or a substituted or unsubstituted amine group, preferably a substituted or unsubstituted C1-C 20 Alkyl, substituted or unsubstituted C5-C 20 It may be a cycloalkyl group, or a substituted or unsubstituted amine group. In this case, the substituent in the substituted or unsubstituted group may be one or more selected from the group consisting of halogen groups, cyano groups, nitro groups, and C1-C8 alkyl groups. Also, m may be an integer from 0 to 4.

[0076] According to one example, organoaluminum compounds play a role in increasing polymerization activity, and may include trialkylaluminum, with specific examples being triethylaluminum, trimethylaluminum, or diethylaluminum chloride.

[0077] According to one example, the external electron donor may be at least one of the compounds represented by the following formulas 5-1 and 5-2.

[0078] (Formula 5-1)

[0079] [ka]

[0080] In the above formula 5-1, R 13 ~R 16 These are, independently, halogen groups, nitrile groups, nitro groups, amine groups, and substituted or unsubstituted C1-C groups. 10 Alkoxy groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted C1-C 20 Alkyl groups, or substituted or unsubstituted C5-C 20 It can be a cycloalkyl group, preferably a substituted or unsubstituted C1-C 20 Alkyl groups, or substituted or unsubstituted C5-C 20It may be a cycloalkyl group. In this case, the substituent, whether substituted or unsubstituted, may independently be one or more selected from the group consisting of halogen groups, cyano groups, nitro groups, and C1-C8 alkyl groups.

[0081] (Formula 5-2)

[0082] [ka]

[0083] In the above equation 5-2, R 17 ~R 20 These are, independently, halogen groups, nitrile groups, nitro groups, amine groups, and substituted or unsubstituted C1-C groups. 10 Alkoxy groups, substituted or unsubstituted aryl groups, substituted or unsubstituted heteroaryl groups, substituted or unsubstituted C1-C 20 Alkyl groups, or substituted or unsubstituted C5-C 20 It can be a cycloalkyl group, preferably a substituted or unsubstituted C1-C 20 Alkyl groups, or substituted or unsubstituted C5-C 20 It may be a cycloalkyl group. In this case, the substituent, whether substituted or unsubstituted, may independently be one or more selected from the group consisting of halogen groups, cyano groups, nitro groups, and C1-C8 alkyl groups.

[0084] Preferably, the external electron donor may be at least one compound represented by formulas 5-1a to 5-1d and formula 5-2a below.

[0085] (Formula 5-1a)

[0086] [ka]

[0087] (Formula 5-1b)

[0088] [ka]

[0089] (Formula 5-1c)

[0090] [ka]

[0091] (Formula 5-1d)

[0092] [ka]

[0093] (Formula 5-2a)

[0094] [ka]

[0095] According to one embodiment, the external electron donor may contain one of the compounds represented by formulas 5-1a to 5-1d and formula 5-2a, or two compounds selected from the group consisting of the compounds represented by formulas 5-1a to 5-1d and formula 5-2a. Preferably, if two types are included, polymerization activity will increase due to the stabilization of the catalytic active site, so the external electron donor may contain two types. For example, if the external electron donor contains two types, it may contain the compound represented by formula 5-1a and one of the compounds represented by formulas 5-1b to 5-1d and formula 5-2a, or the compound represented by formula 5-1b and one of the compounds represented by formulas 5-1c to 5-1d and formula 5-2a, or the compound represented by formula 5-1c and one of the compounds represented by formulas 5-1d and 5-2a, or the compound represented by formula 5-1d and the compound represented by formula 5-2a.

[0096] In one embodiment, if the external electron donor contains two compounds, the molar ratio of the first compound selected from the compounds represented by formulas 5-1a to 5-1d and formula 5-2a to the second compound selected from the compounds represented by formulas 5-1a to 5-1d and formula 5-2a may be about 1:0.5 to 1.5. In this case, the first and second compounds may be different from each other. For example, the compound represented by formula 5-1a contained in the external electron donor can be the first compound, and any one of the compounds represented by formulas 5-1b to 5-1d and formula 5-2a can be the second compound. In this case, the molar ratio of the first compound to the second compound may be about 1:0.5 to 1.5, preferably 1:0.8 to 1.2. In a specific example, the molar ratio of the first compound to the second compound may be about 1:0.6 to 1.4, for example, about 1:0.8, 1:1, or 1:1.2.

[0097] Within the aforementioned molar ratio, the catalytic active sites remain stable, preventing a decrease in activity due to poisoning of the catalytic active sites.

[0098] According to one embodiment, the Ziegler-Natta catalyst for ethylene polymerization contains an internal electron donor that satisfies a specific formula of the Ziegler-Natta Pro-catalyst for ethylene polymerization, and at least one external electron donor that satisfies formulas 5-1 and 5-2, preferably formulas 5-1a to 5-1d and 5-2a. This further increases the number of active sites of titanium compounds in the process of stabilizing the catalytic active sites and generating additional bonding modes [(110)bridge, (100)bridge, (110)chelate] on the crystal plane of magnesium chloride, thereby improving the molecular weight distribution of polyethylene and further increasing the processability of polyethylene produced through ethylene polymerization.

[0099] Another embodiment of the method for producing a Ziegler-Natta pro-catalyst for ethylene polymerization includes the steps of: mixing a titanium compound represented by formula 1 and a magnesium compound represented by formula 2 and performing a first stirring; adding an internal electron donor represented by formula 3 to the result of the first stirring and performing a second stirring; and vacuum drying the result of the second stirring. In this case, any content of the method for producing a Ziegler-Natta pro-catalyst for ethylene polymerization that overlaps with the Ziegler-Natta pro-catalyst for ethylene polymerization may be omitted.

[0100] According to one example, the first stirring step involves adding the titanium compound represented by formula 1 and the magnesium compound represented by formula 2 to an organic solvent, and then stirring at a heating rate of approximately 0.5°C / min to 1.5°C / min from room temperature to a first temperature.

[0101] According to one embodiment, the organic solvent may be toluene, ether, acetone, alcohol, etc., and preferably toluene.

[0102] According to one embodiment, the first temperature can be approximately 70°C to 90°C, preferably 75°C to 85°C. If the first temperature is too low, the internal electron donor will not dissolve in the solvent, which is a disadvantage. If the first temperature is too high, side reactions of the internal electron donor will occur, which is a disadvantage.

[0103] According to one example, the second stirring step involves adding the internal electron donor represented by Equation 3 to the first stirring result, raising the temperature to a second temperature, and stirring for approximately 1.8 to 2.2 hours.

[0104] In one embodiment, the second temperature can be approximately 100°C to 120°C, preferably 105°C to 115°C. If the second temperature is outside this range and is too low, the titanium tetrachloride will not be supported on the carrier, and if the second temperature is too high, the solvent toluene will evaporate.

[0105] According to one embodiment, a third stirring step may be added after the second stirring step. A specific example is the step of removing the organic solvent and titanium tetrachloride (TiCl4), adding a new organic solvent and titanium tetrachloride (TiCl4), raising the temperature from room temperature to the third temperature, and stirring for approximately 1.8 to 2.2 hours. After stirring, the step of washing the result of the third stirring through an organic solvent or the like may be further included.

[0106] According to one embodiment, the third temperature can be approximately 100°C to 120°C, preferably 105°C to 115°C.

[0107] According to one embodiment, the vacuum drying step involves drying the second or third stirring result under vacuum to obtain a Ziegler-Natta main catalyst for ethylene polymerization supported in powder form. This step may further include washing the second or third stirring result with an organic solvent or the like before vacuum drying.

[0108] Another embodiment of the method for producing a Ziegler-Natta catalyst for ethylene polymerization includes the step of adding a Ziegler-Natta main catalyst for ethylene polymerization, an organoaluminum compound represented by formula 4, and an external electron donor represented by formula 5 to an organic solvent and then stirring. In this case, any content related to the method for producing a Ziegler-Natta catalyst for ethylene polymerization (Pro-catalyst) that overlaps with the Ziegler-Natta catalyst for ethylene polymerization may be omitted.

[0109] According to one embodiment, the organic solvent may be hexane, toluene, ether, acetone, alcohol, etc., and is preferably hexane.

[0110] In one embodiment, the stirring speed may be approximately 280 rpm to approximately 320 rpm, preferably approximately 290 rpm to approximately 310 rpm. In a specific example, the stirring speed may be approximately 285 rpm to 315 rpm, for example, approximately 290, 295, 300, 305, or 310 rpm.

[0111] According to one embodiment, stirring can be performed in a hydrogen gas atmosphere at a pressure of approximately 6 bar to approximately 8 bar. In a specific example, the pressure may be approximately 6.2 bar to 7.8 bar, for example, 6.4, 6.6, 6.8, 7, 7.2, 7.4, or 7.6 bar. This is to match the pressure of the ethylene monomer introduced during the production of polyethylene.

[0112] According to one embodiment, the titanium compound and external electron donor of the Ziegler-Natta main catalyst for ethylene polymerization can be added in a molar ratio of about 1:3 to 7, preferably 1:4 to 6. In a specific example, the molar ratio of the titanium compound and external electron donor of the Ziegler-Natta main catalyst for ethylene polymerization may be about 1:3.1 to 6.8, for example, about 1:3.5, 1:4.0, 1:4.5, 1:5.0, 1:5.5, 1:6.0, or 1:6.5. Within this molar ratio, the stability of the catalytic active site is excellent, and the reduction in activity due to poisoning of the catalytic active site can be prevented.

[0113] Another embodiment of the method for producing polyethylene includes the step of polymerizing an olefin having the following formula 6 in the presence of a Ziegler-Natta catalyst for ethylene polymerization; preferably, it may include the step of adding an ethylene monomer and polymerizing it.

[0114] (Formula 6) CH2=CHR 21 In the above equation 6, R 21 is hydrogen or a C1-C6 alkyl or aryl group.

[0115] According to one example, a method for producing polyethylene may include the step of polymerizing ethylene monomers in the presence of a Ziegler-Natta catalyst for ethylene polymerization, which can be carried out under conditions of a hydrogen gas atmosphere, a pressure of approximately 6 bar to 8 bar, and a temperature of approximately 80°C to 90°C. If the temperature is too low, the catalyst activity decreases and polymerization does not occur, while if the temperature is too high, the catalyst overreacts and its activity rapidly decreases.

[0116] According to one embodiment, the polymerization time may be about 0.5 hours to 1.5 hours, preferably 0.8 hours to 1.2 hours.

[0117] On the other hand, some of the information regarding polyethylene manufacturing methods may be omitted if it overlaps with the information on the Ziegler-Natta catalyst for ethylene polymerization.

[0118] In another embodiment, polyethylene produced according to a method for producing polyethylene from a Ziegler-Natta catalyst for ethylene polymerization has an MFR ratio (MFR 21.6 / MFR 2.16 ) can be approximately 30-40.

[0119] According to one example, polyethylene produced by a method for producing polyethylene from a Ziegler-Natta catalyst for ethylene polymerization exhibited the following MFR at a temperature of 190°C and a load of 21.6 kg. 21.6 The amount is approximately 30g / 10min to 46g / 10min, preferably MFR 21.6 The MFR was 30.6g / 10min to 45.1g / 10min at a temperature of 190°C and a load of 2.16kg. 2.16 The ratio is approximately 0.8g / 10min to 1.4g / 10min, preferably MFR. 2.16 This can range from 0.9g / 10min to 1.3g / 10min, which in turn affects the MFR ratio (MFR 21.6 / MFR 2.16 ) can be approximately 30-40. In a specific example, the MFR ratio (MFR21.6 / MFR 2.16 ) could be approximately 30.2 to 39.8, for example, 30.6, 31.1, 31.2, 31.7, 32.4, 32.8, 36.4, 37.6, 36.7, or 39.8.

[0120] In other words, polyethylene produced according to the method for producing polyethylene from the Ziegler-Natta catalyst for ethylene polymerization of the present invention has the advantage of improving the molecular weight distribution of polyethylene by including an internal electron donor that satisfies a specific formula, thereby increasing the active sites of the titanium compound in the process of generating the bonding mode [(110)bridge,(100)bridge] on the magnesium chloride crystal surface. Furthermore, by including an external electron donor that satisfies a specific formula in a certain proportion, the catalytic active sites are stabilized and additional bonding modes [(110)bridge,(100)bridge,(110)chelate] on the magnesium chloride crystal surface are further increased, thereby improving the molecular weight distribution of polyethylene and increasing the MFR ratio. As a result, processability is improved and the productivity of polyethylene resin can be increased.

[0121] The present invention will be described in more detail below with reference to examples. However, these examples are for illustrative purposes only, and the scope of the present invention is not limited to these examples.

[0122] Example 1: Production of polyethylene using Ziegler-Natta catalyst for ethylene polymerization Manufacturing Example 1: Production of Ziegler-Natta Pro-catalyst for Ethylene Polymerization 4 g of magnesium compound MgCl2 support and 8 ml of titanium compound TiCl4 were placed in 12 ml of organic solvent toluene, and the mixture was heated from room temperature to 80°C (1°C / min) and stirred for the first time. After the reaction temperature reached 80°C, diethyl-2,2-diisopropyl succinate (A) (4.5 mmol), an internal electron donor, was added to the mixture after the first stirring, and the mixture was heated to 110°C and stirred for 2 hours for the second time. Then, the TiCl4 + Toluene solution was removed, and a fresh mixture of TiCl4 (10 ml) + toluene (30 ml) was added, and the mixture was heated from room temperature to 110°C and stirred for 2 hours for the third time. The supported catalyst, which was the result of the third stirring, was washed twice with 100 ml of toluene and twice with 100 ml of hexane, and dried under vacuum to obtain the Ziegler-Natta main catalyst (supported catalyst) for ethylene polymerization in powder form.

[0123] Manufacturing Example 2: Production of Ziegler-Natta catalyst for ethylene polymerization and polyethylene A 2-liter high-pressure reactor was dried in an oven, assembled while still hot, and the reactor was subjected to a nitrogen atmosphere by alternating nitrogen and vacuum three times. Then, 1000 ml of hexane, an organic solvent, was added to the reactor, followed by 15 mg of Ziegler-Natta main catalyst for ethylene polymerization (Preparation Example 1), 0.18 ml of external electron donor [Formula 5-1a, cyclohexylmethyldimethoxysilane], and 2 ml of triethylaluminum, an organoaluminum compound. Subsequently, 7 bar of hydrogen was injected, and the Ziegler-Natta catalyst for ethylene polymerization was prepared while stirring at 300 rpm. The reactor temperature was then raised to 85°C, and polyethylene polymerization was carried out for 1 hour while adding ethylene at a pressure of 7 bar. After that, the reactor temperature was lowered to room temperature, and the resulting polymer was separated, collected, and dried to obtain a white powder polyethylene polymer.

[0124] Example 2: Production of polyethylene by changing the external electron donor Compared to Example 1, in Production Example 2, a polyethylene polymer was obtained in the same manner as in Example 1, except that dicyclopentyldimethoxysilane (Formula 5-1b) was used as the external electron donor.

[0125] Example 3: Production of polyethylene by changing the external electron donor Compared to Example 1, in Production Example 2, a polyethylene polymer was obtained in the same manner as in Example 1, except that diethylaminotriethoxysilane (Formula 5-2a) was used as the external electron donor.

[0126] Example 4: Production of polyethylene by changing the external electron donor Compared to Example 1, in Production Example 2, a polyethylene polymer was obtained in the same manner as in Example 1, except that dimethoxy(dibutyl)silane (formula 5-1c) was used as the external electron donor.

[0127] Example 5: Production of polyethylene by changing the external electron donor Compared to Example 1, in Production Example 2, a polyethylene polymer was obtained in the same manner as in Example 1, except that dimethoxy(dimethyl)silane (formula 5-1d) was used as the external electron donor.

[0128] Example 6: Production of polyethylene by changing the external electron donor In comparison with Example 1, the polyethylene polymer was obtained in the same manner as in Example 1, except that in Production Example 2, cyclohexylmethyldimethoxysilane (Formula 5-1a) and dicyclopentyldimethoxysilane (Formula 5-1b) were used as external electron donors in a 1:1 molar ratio.

[0129] Example 7: Production of polyethylene by changing the external electron donor In comparison with Example 1, the polyethylene polymer was obtained in the same manner as in Example 1, except that in Production Example 2, cyclohexylmethyldimethoxysilane (Formula 5-1a) and diethylaminotriethoxysilane (Formula 5-2a) were used as external electron donors in a 1:1 molar ratio.

[0130] Example 8: Production of polyethylene by changing the external electron donor In comparison with Example 1, the polyethylene polymer was obtained in the same manner as in Example 1, except that in Production Example 2, cyclohexylmethyldimethoxysilane (Formula 5-1a) and dimethoxy(dibutyl)silane (Formula 5-1c) were used as external electron donors in a 1:1 molar ratio.

[0131] Example 9: Production of polyethylene by changing the external electron donor In comparison with Example 1, the polyethylene polymer was obtained in the same manner as in Example 1, except that in Production Example 2, cyclohexylmethyldimethoxysilane (Formula 5-1a) and dimethoxy(dimethyl)silane (Formula 5-1d) were used as external electron donors in a 1:1 molar ratio.

[0132] Example 10: Production of polyethylene by changing the external electron donor Compared to Example 1, the polyethylene polymer was obtained in the same manner as in Example 1, except that cyclohexylmethyldimethoxysilane (Formula 5-1a) and dicyclopentyldimethoxysilane (Formula 5-1b) were used as external electron donors in a molar ratio of 1:0.6.

[0133] Example 11: Production of polyethylene by changing the external electron donor In comparison with Example 1, the polyethylene polymer was obtained in the same manner as in Example 1, except that cyclohexylmethyldimethoxysilane (Formula 5-1a) and dicyclopentyldimethoxysilane (Formula 5-1b) were used as external electron donors in a molar ratio of 1:1.4.

[0134] Comparative Example 1: Production of polyethylene using other catalysts In comparison with Example 1, the polyethylene polymer was obtained in the same manner as in Example 1, except that in Production Example 1, diisobutylphthalate (B) (4.5 mmol) was used as the internal electron donor instead of diethyl-2,2-diisopropyl succinate (A).

[0135] Comparative Example 2: Polyethylene production using a different external electron donor In comparison with Comparative Example 1, the polyethylene polymer was obtained by the same method as in Comparative Example 1, except that cyclohexylmethyldimethoxysilane (Formula 5-1a) and dicyclopentyldimethoxysilane (Formula 5-1b) were used as external electron donors in a 1:1 molar ratio.

[0136] Comparative Example 3: Polyethylene production using a different external electron donor In comparison with Comparative Example 1, the polyethylene polymer was obtained by the same method as in Comparative Example 1, except that cyclohexylmethyldimethoxysilane (Formula 5-1a) and dimethoxy(dibutyl)silane (Formula 5-1c) were used as external electron donors in a 1:1 molar ratio.

[0137] Comparative Example 4: Polyethylene production using a different external electron donor In comparison with Comparative Example 1, the polyethylene polymer was obtained by the same method as in Comparative Example 1, except that cyclohexylmethyldimethoxysilane (Formula 5-1a) and dimethoxy(dimethyl)silane (Formula 5-1d) were used as external electron donors in a 1:1 molar ratio.

[0138] Comparative Example 5: Polyethylene production using a different external electron donor In comparison with Example 1, the polyethylene polymer was obtained in the same manner as in Example 1, except that cyclohexylmethyldimethoxysilane (Formula 5-1a) and dicyclopentyldimethoxysilane (Formula 5-1b) were used as external electron donors in a molar ratio of 1:0.2.

[0139] Comparative Example 6: Polyethylene production using a different external electron donor In comparison with Example 1, the polyethylene polymer was obtained by the same method as in Example 1, except that cyclohexylmethyldimethoxysilane (Formula 5-1a) and dicyclopentyldimethoxysilane (Formula 5-1b) were used as external electron donors in a molar ratio of 1:1.8.

[0140] Comparative Example 7: Polyethylene production using a different external electron donor In comparison with Example 1, the polyethylene polymer was obtained by the same method as in Example 1, except that cyclohexylmethyldimethoxysilane (Formula 5-1a) and diethylaminotriethoxysilane (Formula 5-2a) were used as external electron donors in a molar ratio of 1:0.2.

[0141] Comparative Example 8: Polyethylene production using a different external electron donor In comparison with Example 1, the polyethylene polymer was obtained by the same method as in Example 1, except that cyclohexylmethyldimethoxysilane (Formula 5-1a) and diethylaminotriethoxysilane (Formula 5-2b) were used as external electron donors in a molar ratio of 1:1.8.

[0142] Method for evaluating the physical properties of polyethylene -Activity (G PE / G cat Measurement: Weight of resin obtained (g) / Weight of catalyst (g) -MFR 2.16 (g / 10min) measurement: ASTM D1238 (190℃) -MFR 21.6 (g / 10min) measurement: ASTM D1238 (190℃) -Density (kg / cm 3 Measurement: ASTM D792 Results of physical property evaluation of polyethylene

[0143] [Table 1]

[0144] *A=diethyl-2,2-diisopropyl succinate,B=diisobutylphthalate Referring to Table 1, in the case of polyethylene in Examples 1 to 11, even if other physical properties are similar, the MFR ratio (MFR) is higher compared to the polyethylene in Comparative Examples 1 to 4. 21.6 / MFR 2.16It was confirmed that the value was 30-40 and higher. This confirmed that, in the case of polyethylene produced by the polyethylene production method from the Ziegler-Natta catalyst for ethylene polymerization of the present invention, by including an internal electron donor that satisfies a specific formula, the active sites of the titanium compound are increased in the process of generating the bonding modes [(110)bridge,(100)bridge] on the magnesium chloride crystal surface, thereby improving the molecular weight distribution of polyethylene. Furthermore, by including an external electron donor that satisfies a specific formula in a certain proportion, the catalytic active sites are stabilized and additional bonding modes [(110)bridge,(100)bridge,(110)chelate] on the magnesium chloride crystal surface are further increased, improving the molecular weight distribution of polyethylene and increasing the MFR ratio value. As a result, it was confirmed that processability is improved and the productivity of polyethylene resin is increased.

[0145] In particular, in the case of polyethylene according to Examples 6 to 11, it was confirmed that the MFR ratio was relatively higher than that of polyethylene according to Examples 1 to 5. This confirmed that when two types of external electron donors satisfying the specific formula of the present invention are included, the catalytic active sites are further increased due to the effect of the two types of external electron donors with different bonding strengths being supported on the magnesium chloride carrier, resulting in an improved MFR ratio and thus improved processability, thereby improving the productivity of polyethylene resin.

[0146] For example, when the external electron donor contains two types of compounds, comparing the polyethylene according to Example 6 with the polyethylene according to Comparative Examples 5 and 6; or the polyethylene according to Example 7 with the polyethylene according to Comparative Examples 7 and 8; it was confirmed that if the molar ratio of the compound represented by formula 5-1a to any one of the compounds represented by formulas 5-1b to 5-1d and formula 5-2a in the external electron donor does not satisfy 1:0.5 to 1.5, the MFR ratio cannot be satisfied. In other words, even when the Ziegler-Natta catalyst for ethylene polymerization according to the present invention contains two types of external electron donors, the MFR ratio is only superior when the above molar ratio is satisfied, thus improving processability and increasing the productivity of polyethylene resin.

[0147] In other words, in the case of polyethylene produced by the method for producing polyethylene from the Ziegler-Natta catalyst for ethylene polymerization, the MFR ratio and activity (g PE / g cat Because of its high ) value, it has the advantage of excellent processability and can improve the productivity of polyethylene resin.

[0148] Simple modifications or alterations of the present invention can be readily carried out by a person with ordinary skill in the art, and all such modifications or alterations can be considered to fall within the scope of the present invention. [Industrial applicability]

[0149] The Ziegler-Natta Pro-catalyst for ethylene polymerization not only contains internal electron donors that satisfy a specific formula, thereby increasing the number of active sites in the titanium compound, but also further increases the number of active sites in the titanium compound by containing at least one external electron donor that satisfies a specific formula in a specific proportion, thus enabling the production of polyethylene with excellent processability.

Claims

1. Titanium compounds represented by the following formula 1; Magnesium compounds represented by the following formula 2; and The internal electron donor represented by the following equation 3; (Formula 1) TiX ｎ (OR １ ) ４－ｎ (In the above formula 1, R １ C is either substituted or non-substituted. １ -C ２０ It is an alkyl group, The substituents in the substituted or unsubstituted configurations are, independently, halogen groups, cyano groups, nitro groups, and C １ -C ８ One or more alkyl groups selected from the group consisting of alkyl groups, X is a halogen atom, and n is an integer between 0 and 4. (Formula 2) MẽX ２ (In the above formula 2, X is a halogen atom.) (Formula 3) 【Chemistry 1】 (In the above formula 3, R ２ and R ５ Independently, C is either substituted or non-substituted. １ -C ２０ It is an alkyl group, R ３ and R ４ Independently, C is either substituted or non-substituted. １ -C ２０ They are alkyl groups, or linked together to form substituted or unsubstituted alicyclic rings. The substituents in the substituted or unsubstituted configurations are, independently, halogen groups, cyano groups, nitro groups, and C １ -C ８ One or more selected from the group consisting of alkyl groups, and (a is an integer between 0 and 5) A Ziegler-natta procatalyst for ethylene polymerization, including the above.

2. The internal electron donor is given by the following formula 3-1 (Formula 3-1) 【Chemistry 2】 (In the above formula 3-1, R ６ and R ７ Independently, C is either substituted or non-substituted. １ -C １０ With an alkyl group, R ８ and R ９ These are, independently, hydrogen; or substituted or unsubstituted C １ -C １０ Alkyl alkyl groups; or linked together as substituted or unsubstituted C ５ -C １２ The alicyclic ring of; and In the aforementioned substituted or unsubstituted configurations, the substituents are independently halogen groups, cyano groups, nitro groups, and C １ -C ８ (One or more alkyl groups selected from the group consisting of alkyl groups.) The Ziegler-Natta main catalyst for ethylene polymerization according to claim 1, which is a compound represented by [formula].

3. The Ziegler-Natta main catalyst for ethylene polymerization according to claim 1, wherein the internal electron donor is one or more selected from the group consisting of diethyl-2,2-diisopropylsuccinate, diethylcyclohexane-1,2-dicarboxylate, and diisopropylsuccinate.

4. A Ziegler-Natta pro-catalyst for ethylene polymerization containing an internal electron donor represented by the following formula 3; Organic aluminum compounds represented by the following formula 4; and External electron donor represented by the following equation 5; (Formula 3) 【Transformation 3】 (In the above formula 3, R ２ and R ５ Independently, C is either substituted or non-substituted. １ -C ２０ It is an alkyl group, R ３ and R ４ Independently, C is either substituted or non-substituted. １ -C ２０ They are alkyl groups, or linked together to form substituted or unsubstituted alicyclic rings. The substituents in the substituted or unsubstituted configurations are, independently, halogen groups, cyano groups, nitro groups, and C １ -C ８ One or more alkyl groups selected from the group, and (a is an integer between 0 and 5) (Formula 4) AlR １０ ｎ X ３－ｎ (In the above formula 4, R １０ C is either substituted or non-substituted. １ -C ２０ With an alkyl group, The substituents in the substituted or unsubstituted configurations are, independently, halogen groups, cyano groups, nitro groups, and C １ -C ８ One or more alkyl groups selected from the group consisting of alkyl groups, X is a halogen atom, and n is an integer between 0 and 3. (Formula 5) R １１ ｍ Si(OR １２ ) ４－ｍ (In the above formula 5, R １１ and R １２ Independently, C is either substituted or non-substituted. １ -C ２０ Alkyl, substituted or unsubstituted C ５ -C ２０ A cycloalkyl group, or a substituted or unsubstituted amine group, The substituents in the substituted or unsubstituted configurations are, independently, halogen groups, cyano groups, nitro groups, and C １ -C ８ One or more selected from the group consisting of alkyl groups, and (m is an integer between 0 and 4) A Ziegler-Natta catalyst for ethylene polymerization, including the above.

5. The internal electron donor is a compound represented by the following formula 3-1. (Formula 3-1) 【Chemistry 4】 (In the above formula 3-1, R ６ and R ７ Independently, C is either substituted or non-substituted. １ -C １０ It is an alkyl group, R ８ and R ９ These are, independently, hydrogen; or substituted or unsubstituted C １ -C １０ Alkyl alkyl groups; or linked together as substituted or unsubstituted C ５ -C １２ The alicyclic ring of; and The substituents in the substituted or unsubstituted configurations are, independently, halogen groups, cyano groups, nitro groups, and C １ -C ８ (One or more alkyl groups selected from the group consisting of alkyl groups.) The Ziegler-Natta catalyst for ethylene polymerization according to claim 4.

6. The Ziegler-Natta catalyst for ethylene polymerization according to claim 4, wherein the internal electron donor is one or more selected from the group consisting of diethyl-2,2-diisopropylsuccinate diethylcyclohexane dicarboxylate and diisopropylsuccinate.

7. The aforementioned external electron donor is defined in the following equations 5-1 and 5-2 (Formula 5-1) 【Transformation 5】 (In the above formula 5-1, R １３ ~R １６ Independently, C is either substituted or non-substituted. １ -C ２０ Alkyl alkyl groups, or substituted or unsubstituted C ５ -C ２０ It is a cycloalkyl group, and The substituents in the substituted or unsubstituted configurations are, independently, halogen groups, cyano groups, nitro groups, and C １ -C ８ (One or more alkyl groups selected from the group consisting of alkyl groups.) (Formula 5-2) 【Transformation 6】 (In the above formula 5-2, R １７ ~R ２０ Independently, C is either substituted or non-substituted. １ -C ２０ Alkyl alkyl groups, or substituted or unsubstituted C ５ -C ２０ It is a cycloalkyl group, and The substituents in the substituted or unsubstituted configurations are, independently, halogen groups, cyano groups, nitro groups, and C １ -C ８ (One or more alkyl groups selected from the group consisting of alkyl groups.) The Ziegler-Natta catalyst for ethylene polymerization according to claim 4, comprising at least one compound represented by .

8. The external electron donor is represented by the following formulas 5-1a to 5-1d and 5-2a. (Formula 5-1a) 【Transformation 7】 (Formula 5-1b) 【Transformation 8】 (Formula 5-1c) 【Chemistry 9】 (Formula 5-1d) 【Chemistry 10】 (Formula 5-2a) 【Chemistry 11】 The Ziegler-Natta catalyst for ethylene polymerization according to claim 4, comprising at least one compound represented by .

9. The Ziegler-Natta catalyst for ethylene polymerization according to claim 8, wherein the molar ratio of a first compound selected from the compounds represented by formulas 5-1a to 5-1d and formula 5-2a to a second compound selected from the compounds represented by formulas 5-1a to 5-1d and formula 5-2a is 1:0.5 to 1.

5.

10. The Ziegler-natta catalyst for ethylene polymerization according to claim 4, wherein the molar ratio of the titanium compound to the external electron donor in the Ziegler-natta main catalyst for ethylene polymerization is 1:3 to 7.

11. In the presence of the Ziegler-Natta catalyst for ethylene polymerization according to any one of claims 4 to 10, the following formula 6 (Formula 6) CH ２ =CHR ２１ In the above formula 6, R ２１ is hydrogen or C １ -C ６ Alkyl or aryl group A method for producing a polyolefin, comprising the step of polymerizing an olefin having the following characteristics.

12. The method for producing polyethylene according to claim 11, wherein the polymerization is carried out under the conditions of a hydrogen gas atmosphere at a pressure of 6 bar to 8 bar and a temperature of 80°C to 90°C.

13. Manufactured by the method of claim 11, with an MFR ratio (MFR ２１．６ / MFR ２．１６ A polyethylene resin characterized in that the ratio is 30 to 40.

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