Ziegler-natta catalyst for olefin polymerization, method for preparing polyolefin, and polyolefin resin

Abstract

A Ziegler-Natta catalyst for olefin polymerization, a process for preparing a polyolefin, and a polyolefin resin are provided. A Ziegler-Natta catalyst includes: (i) a Ziegler-Natta procatalyst for olefin polymerization including a titanium compound represented by Formula 1, a magnesium compound represented by Formula 2, and an internal electron donor; (ii) an organo-aluminum compound represented by formula 7; and (iii) an external electron donor represented by Formula 3 wherein the internal electron donor comprises a mixture of a first internal electron donor represented by Formula 4, a second internal electron donor represented by Formula 5, and a third internal electron donor represented by Formula 6, a molar ratio of the external electron donor to the mixture being 115 to 130.

Description

Technical Field

[0001] This invention relates to Ziegler-Natta catalysts for olefin polymerization, methods for preparing polyolefins with good processability using the catalyst, and polyolefin resins. Background Technology

[0002] Polyolefins are a class of polymers derived from simple olefins. Known methods for preparing polyolefins utilize Ziegler-Natta catalysts for polymerization. Ziegler-Natta catalysts provide polymers with a highly isotactic stereochemical arrangement by polymerizing alkenyl monomers using transition metal halides.

[0003] In particular, in recent years, as polyethylene (a polyolefin) has been used in various applications, there is a need to prepare polyethylene resins with good processability to improve resin productivity.

[0004] [Existing Literature] [Patent Literature] Korean Patent Registration Publication No. 10-2423660 Summary of the Invention Technical issues One aspect of the present invention is to provide a catalyst for preparing polyolefins with good processability and a method for preparing polyolefins with good processability by satisfying the density, melt index and melt flow ratio described herein.

[0005] Technical solution According to one aspect of the invention, a Ziegler-Natta catalyst for olefin polymerization is provided.

[0006] According to one embodiment of the present invention, a Ziegler-Natta catalyst for olefin polymerization comprises: (i) a Ziegler-Natta pro-catalyst for olefin polymerization, comprising a titanium compound represented by Formula 1, a magnesium compound represented by Formula 2, and an internal electron donor; (ii) an organoaluminum compound represented by Formula 7; and (iii) an external electron donor represented by Formula 3; wherein the internal electron donor comprises a mixture of a first internal electron donor represented by Formula 4, a second internal electron donor represented by Formula 5, and a third internal electron donor represented by Formula 6; and wherein the molar ratio of the external electron donor to the mixture is about 115 to about 130. In some embodiments, the molar ratio of the external electron donor to the mixture may be in the range of about 117 to about 128, for example, about 117 to about 120, about 120 to about 125, or about 125 to about 128.

[0007] [Formula 1] TiX n(OR 1 ) 4-n (In Equation 1, R 1 Choose either freely substituted or unsubstituted C1-C. 20 Alkyl, substituted or unsubstituted C3-C 20 Cycloalkyl and substituted or unsubstituted C3-C 20 One of the groups composed of aryl groups. X is a halogen atom. n is an integer from 0 to 4, and The substituent in "substituted or unsubstituted" is independently at least one selected from the group consisting of halogen groups, cyano groups, nitro groups, and C1-C8 alkyl groups. [Equation 2] Mg(OR 2 ) k X 2-k (In Equation 2, R 2 Choose either freely substituted or unsubstituted C1-C. 20 Alkyl, substituted or unsubstituted C3-C 20 Cycloalkyl and substituted or unsubstituted C3-C 20 One of the groups composed of aryl groups. X is a halogen atom. k is an integer from 0 to 2, and The substituent in "substituted or unsubstituted" is independently at least one selected from the group consisting of halogen groups, cyano groups, nitro groups, and C1-C8 alkyl groups. [Formula 3]

[0008] (In Equation 3, L1 and L2 are independently substituted or unsubstituted C1-C. 20 Alkyl, wherein the substituent in "substituted or unsubstituted" is independently at least one selected from the group consisting of halogen groups, cyano, nitro and C1-C8 alkyl groups, and L3 and L4 are each independently selected from either substituted or unsubstituted C1-C. 20 Alkyl and substituted or unsubstituted C3-C 20 One of the groups consisting of cycloalkyl groups. The substituent in "substituted or unsubstituted" is independently at least one selected from the group consisting of halogen groups, cyano groups, nitro groups, and C1-C8 alkyl groups. [Formula 4]

[0009] (In Equation 4, R 3 Choose either freely substituted or unsubstituted C1-C. 20 Alkyl, substituted or unsubstituted C3-C 20 Cycloalkyl and substituted or unsubstituted C3-C 20 It is one of the groups consisting of aryl groups, wherein the substituent in "substituted or unsubstituted" is independently selected from at least one of the groups consisting of halogen groups, cyano groups, nitro groups, and C1-C8 alkyl groups. R 4 and R 5 Each is an independent branch C1-C 20 Alkyl groups, and m is an integer from 0 to 4. [Formula 5]

[0010] (In Equation 5, R 6 Independently, C1-C is either freely substituted or unsubstituted. 20 Alkyl, substituted or unsubstituted C3-C 20 Cycloalkyl and substituted or unsubstituted C3-C 20 It is one of the groups consisting of aryl groups, wherein the substituent in "substituted or unsubstituted" is independently selected from at least one of the groups consisting of halogen groups, cyano groups, nitro groups, and C1-C8 alkyl groups. R 7 It is a straight-chain C1-C 20 alkyl, R 8 It is a branch C1-C 20 Alkyl groups, and n is an integer between 0 and 4. [Formula 6]

[0011] (In Equation 6, R 9 Each can be independently selected as either substituted or unsubstituted C1-C. 20 Alkyl, substituted or unsubstituted C3-C 20 Cycloalkyl and substituted or unsubstituted C3-C 20 It is one of the groups consisting of aryl groups, wherein the substituent in "substituted or unsubstituted" is independently selected from at least one of the groups consisting of halogen groups, cyano groups, nitro groups, and C1-C8 alkyl groups. R 10 and R 11 Each is an independent linear C1-C chain. 20 Alkyl groups; and p is an integer from 0 to 4. [Formula 7] Al(R 13 ) p X 3-p (In Equation 7, R 13 It is selected from hydrogen atoms, substituted or unsubstituted C1-C. 20 Alkyl, substituted or unsubstituted C3-C 20 Cycloalkyl and substituted or unsubstituted C3-C 20 One of the groups composed of aryl groups. X is a halogen atom. p is an integer from 0 to 3; and The substituent in "substituted or unsubstituted" is independently at least one selected from the group consisting of halogen groups, cyano groups, nitro groups, and C1-C8 alkyl groups. According to another aspect of the present invention, a method for preparing polyolefins is provided.

[0012] According to one embodiment, a method for preparing polyolefins includes polymerizing olefin monomers in the presence of a Ziegler-Natta catalyst for olefin polymerization.

[0013] According to another aspect of the invention, a polyolefin resin is provided.

[0014] According to one embodiment, the polyolefin resin is prepared by a polyolefin preparation method and has a melt flow ratio (MFR) of about 20 to about 25. 21.6 / MFR 2.16 In some embodiments, the polyolefin resin may have a melt flow ratio (MFR) of about 20.2 to about 24.9, for example, about 20.2 to about 21.5, about 21.5 to about 22.5, about 22.5 to about 23.5, or about 23.5 to about 24.8. 21.6 / MFR 2.16 ).

[0015] Beneficial effects By satisfying the density, melt index, and melt flow ratio described herein, Ziegler-Natta catalysts for olefin polymerization produce polyolefins with good processability. Detailed Implementation

[0016] These and other objects, features, and advantages will become apparent from the embodiments described below with reference to the accompanying drawings. However, the invention is not limited to the embodiments described herein and may be practiced in other forms. Rather, the following embodiments are given by way of example to provide a thorough and complete understanding of the invention, thereby fully conveying the technical ideas to those skilled in the art.

[0017] In the description of the accompanying drawings, the same reference numerals denote the same elements. In the drawings, the dimensions of various elements, layers, etc., are enlarged for clarity. It should be understood that although the terms first, second, etc., may be used herein to describe various elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms are used to distinguish one element, component, region, layer, or segment from another element, component, region, layer, or segment. For example, without departing from the teachings of the exemplary embodiments, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment.

[0018] In this document, the singular forms “a”, “an”, and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0019] In this document, it should be understood that the terms “comprise,” “include,” “have,” etc., are intended to indicate the presence of the described features, quantities, steps, operations, components, parts, or combinations thereof, and are not intended to exclude the presence or addition of one or more other features, quantities, steps, operations, components, parts, or combinations thereof.

[0020] In this document, unless otherwise stated, all figures, values, and / or expressions used to express the amounts of components, reaction conditions, polymer compositions / compositions, and formulations should be understood to be limited in all cases by the term "about," as such figures are inherently approximate and reflect the various uncertainties encountered in the measurement process when obtaining such values. Furthermore, unless otherwise stated, when numerical ranges are disclosed herein, such ranges are continuous and include all values ​​from the minimum to the maximum of the range, and include the maximum value of the range. Additionally, unless otherwise stated, when such ranges refer to integers, the range includes all integers from the minimum to the maximum of the range, and includes the maximum value of the range.

[0021] In this document, when describing a specific range of a variable, the variable will be understood to include all values ​​within the range, including the endpoints of the range being described. For example, the range “5 to 10” will be understood to include not only values ​​such as 5, 6, 7, 8, 9, and 10, but also any subranges thereof, such as 6 to 10, 7 to 10, 6 to 9, 7 to 9, and any values ​​between integers falling within the 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%” will be understood to include not only values ​​such as 10%, 11%, 12%, and 13%, and all integers up to and including 30%, but also any subranges thereof, such as 10% to 15%, 12% to 18%, 20% to 30%, and any values ​​between any integers within the range, such as 10.5%, 15.5%, 25.5%, etc.

[0022] In recent years, as polyethylene has been used in various applications, there is a need for catalysts and preparation methods for polyethylene resins with good processability in order to improve resin productivity.

[0023] To address this problem, the inventors have developed a Ziegler-Natta catalyst for olefin polymerization and a method for preparing polyolefins. This method involves mixing at least three specific internal electron donors in the main catalyst with specific external electron donors, and then adjusting the molar ratio between the external and internal electron donors to prepare polyethylene with good processability. In this document, "good processability" can refer to the resin having an appropriate melt flow ratio to facilitate product manufacturing.

[0024] As used herein, "polyethylene with good processability" can be a polyolefin that satisfies the following properties: (i) Density: 0.950 g / cm³ 3 Up to 0.965 g / cm 3 ; (ii) Melt index: 0.1 g / 10 min to 2.0 g / 10 min; and (iii) Melt flow ratio: 20 to 25.

[0025] Density is measured according to ASTM D1505.

[0026] Melt flow index refers to the value under a load of 2.16 kg, and is measured at 190°C and a load of 2.16 kg according to ASTM D1238.

[0027] Melt flow ratio (MFR) is calculated as follows: The melt flow index (MI) is measured according to ASTM D1238 at 190°C and a load of 2.16 kg. 2.16) and according to ASTM D1238, the melt flow index (MI) was measured at 190°C and a load of 21.6 kg. 21.6 Then calculate the ratio between them (MI). 21.6 / MI 2.16 ).

[0028] A melt flow ratio greater than 25 indicates that, although the polyolefin resin prepared by polymerization has good processability, it has poor mechanical properties, such as tensile strength (break point), resulting in poor final properties of the polymerized resin. A melt flow ratio less than 20 indicates that the polyolefin resin prepared by polymerization has poor processability. Preferably, the melt flow ratio is from about 21 to about 25. In some embodiments, the melt flow ratio can be in the range of from about 20.2 to about 24.9, for example, from about 20.2 to about 21.5, from about 21.5 to about 22.5, from about 22.5 to about 23.5, or from about 23.5 to about 24.8.

[0029] In this document, unless otherwise stated, "C1-C" n "Alkyl" refers to primary alkyl, secondary alkyl (n≥3), and tertiary alkyl (n≥4) having 1 to n carbon atoms. For example, C1-C n Alkyl groups can be functional groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-hexyl, etc.

[0030] Unless otherwise stated, “straight chain” in the context of alkyl means that the carbon atom chain constituting the alkyl is a straight chain without branches.

[0031] Unless otherwise stated, “branched” in the context of an alkyl group means that at least a portion of the carbon atom chain constituting the alkyl group is branched.

[0032] Unless otherwise stated, aryl refers to a monocyclic or polycyclic aromatic hydrocarbon derived from a carbonyl group containing at least one benzene ring. 30 Chemical groups and their derivatives obtained by removing a hydrogen atom from a compound, including monocyclic or polycyclic compounds containing a benzene ring, such as toluene, xylene, etc., wherein the benzene ring or alkyl side chain is connected to the benzene ring; biphenyl, etc., wherein two or more benzene rings are connected to each other by a single bond; fluorene, xanthones, anthraquinone, etc., wherein the benzene ring is fused with a cycloalkyl or heterocyclic alkyl group; naphthalene, anthracene, etc., wherein two or more benzene rings are fused, etc.

[0033] In this document, unless otherwise stated, the prefix "heterogeneous" refers to the substitution of a carbon atom with one to three heteroatoms selected from the group consisting of -N-, -O-, -S-, and -P-. For example, heteroatoms may include pyridine, pyrrole, or carbazole containing a nitrogen atom, furan or dibenzofuran containing an oxygen atom, dibenzothiophene, diphenylamine, etc.

[0034] In this document, unless otherwise stated, halogen groups refer to elements of Group XVII, such as fluorine groups, chlorine groups, bromine groups, iodine groups, etc.

[0035] According to one embodiment, a Ziegler-Natta catalyst for olefin polymerization comprises: (i) a main catalyst comprising a titanium compound, a magnesium compound and an internal electron donor; (ii) an organoaluminum compound; and (iii) an external electron donor, wherein the internal donor is provided by a mixture of the three internal electron donors and the external electron donor and the mixture are present in a specific molar ratio.

[0036] Specifically, the Ziegler-Natta catalyst for olefin polymerization comprises an external electron donor represented by Formula 3, and a mixture of a first internal electron donor represented by Formula 4, a second internal electron donor represented by Formula 5, and a third internal electron donor represented by Formula 6, wherein the molar ratio of the external electron donor to the mixture is about 115 to about 130. In some embodiments, the molar ratio of the external electron donor to the mixture may be in the range of about 117 to about 128, for example, about 117 to about 120, about 120 to about 125, or about 125 to about 128. Hereinafter, "molar ratio" means (number of moles of external electron donor) / (number of moles of mixture).

[0037] [External electron donor] External electron donors are used to stabilize the catalytically active sites of titanium compounds in the master catalyst. The siloxane-based external electron donor represented in Formula 3, when applied to the internal electron donors described below, can promote the preparation of polyolefins with good processability.

[0038] An external electron donor can be represented by Equation 3: [Formula 3]

[0039] (In Equation 3, L1 and L2 are independently substituted or unsubstituted C1-C. 20 Alkyl, wherein the substituent in "substituted or unsubstituted" is independently at least one selected from the group consisting of halogen groups, cyano, nitro and C1-C8 alkyl groups; and L3 and L4 are each independently selected from either substituted or unsubstituted C1-C. 20 Alkyl and substituted or unsubstituted C3-C 20 (A group consisting of cycloalkyl groups, wherein the substituent in "substituted or unsubstituted" is independently at least one selected from the group consisting of halogen groups, cyano groups, nitro groups, and C1-C8 alkyl groups.) In one embodiment, at least one of L3 and L4 may be substituted or unsubstituted C3-C. 20Cycloalkyl groups. In this case, the Ziegler-Natta catalyst, when applied to a mixture of internal electron donors as described below, can promote the preparation of polyolefins with good processability.

[0040] For example, the external electron donor can be the first external electron donor, where either L3 or L4 in Formula 3 is a substituted or unsubstituted C3-C. 20 Cycloalkyl, such as substituted or unsubstituted C3-C 10 Cycloalkyl or substituted or unsubstituted C5-C6 cycloalkyl.

[0041] For example, the external electron donor can be a second external electron donor, where L3 and L4 in Formula 3 are both substituted or unsubstituted C3-C. 20 Cycloalkyl, such as substituted or unsubstituted C3-C 10 Cycloalkyl, or substituted or unsubstituted C5-C6 cycloalkyl.

[0042] The external electron donor may include at least one of a first external electron donor and a second external electron donor.

[0043] Preferably, the external electron donor is a second external electron donor. Since the second external electron donor can bind more strongly to the crystal facet (110) of the magnesium compound than the first external electron donor, it can reduce the number of final active sites, thereby lowering the melt flow ratio, whereby the melt flow ratio can easily reach a value of about 20 to about 25. In some embodiments, the melt flow ratio can be in the range of about 20.2 to about 24.9, for example, about 20.2 to about 21.5, about 21.5 to about 22.5, about 22.5 to about 23.5, or about 23.5 to about 24.8.

[0044] According to one embodiment, the catalyst may include an external electron donor represented by Formula 3, namely a single first external electron donor or a single second external electron donor.

[0045] According to one embodiment, the catalyst may be a mixture of two external electron donors represented by Formula 3. In one embodiment, the catalyst may be a mixture of a first external electron donor and a second external electron donor. For example, in a 10-molar mixture, the first external electron donor and the second external electron donor may be present in a molar ratio of 3:7 to 7:3, 4:6 to 6:4, or 5:5.

[0046] In one implementation, L1 and L2 can each be independently substituted or unsubstituted C1-C. 10 Alkyl, such as substituted or unsubstituted C1-C5 alkyl.

[0047] In one embodiment, the first external electron donor can be represented by Equation 3-1, and the second external electron donor can be represented by Equation 3-2: [Equation 3-1]

[0048] [Equation 3-2] .

[0049] According to one embodiment, based on 100 wt% of total Ziegler-Natta catalyst for olefin polymerization, an external electron donor may be present in an amount of about 30 wt% to about 50 wt%. Within this range, the catalytic active sites can exhibit high stability, and there is no problem of activity degradation due to poisoning of the catalytic active sites.

[0050] According to one embodiment, based on 100 wt% of the total external electron donor in a Ziegler-Natta catalyst for olefin polymerization, the external electron donor represented by Formula 3 may be present in an amount of about 95 wt% or higher, preferably about 99 wt% to about 100 wt%, more preferably about 100 wt%. Within this range, the effects of the present invention can be readily achieved. As used herein, "total external electron donor" may refer to a compound that is included independently of the main catalyst in a Ziegler-Natta catalyst for olefin preparation and that is known to those skilled in the art to function at the catalytically active sites of stabilizing titanium compounds.

[0051] [Internal electron donor] When external electron donors are included in Ziegler-Natta catalysts for olefin polymerization, internal electron donors are selected to prepare polyolefins with good processability, i.e., polyolefins that meet specific ranges of density, melt index, and melt index ratio. When used with external electron donors, internal electron donors provide a variety of active sites, thereby enabling the preparation of polyolefin resins with good processability.

[0052] According to the present invention, a mixture of a first internal electron donor represented by Formula 4, a second internal electron donor represented by Formula 5, and a third internal electron donor represented by Formula 6 is applied to an external electron donor such that the molar ratio of the external electron donor to the mixture is about 115 to about 130. In some embodiments, the molar ratio of the external electron donor to the mixture may be in the range of about 117 to about 128, for example, about 117 to about 120, about 120 to about 125, or about 125 to about 128.

[0053] [Formula 4]

[0054] (In Equation 4, R 3 Choose either freely substituted or unsubstituted C1-C. 20 Alkyl, substituted or unsubstituted C3-C 20Cycloalkyl and substituted or unsubstituted C3-C 20 One of the groups consisting of aryl groups, wherein the substituent in "substituted or unsubstituted" is independently selected from at least one of the groups consisting of halogen groups, cyano groups, nitro groups and C1-C8 alkyl groups; R 4 and R 5 Independently, it is a branch C1-C 20 Alkyl groups; and m is an integer between 0 and 4. [Formula 5]

[0055] (In Equation 5, R 6 Independently, C1-C is either freely substituted or unsubstituted. 20 Alkyl, substituted or unsubstituted C3-C 20 Cycloalkyl and substituted or unsubstituted C3-C 20 One of the groups consisting of aryl groups, wherein the substituent in "substituted or unsubstituted" is independently selected from at least one of the groups consisting of halogen groups, cyano groups, nitro groups and C1-C8 alkyl groups; R 7 It is a straight-chain C1-C 20 alkyl; R 8 It is a branch C1-C 20 Alkyl groups; and n is an integer between 0 and 4. [Formula 6]

[0056] (In Equation 6, R 9 Each can be independently selected as either substituted or unsubstituted C1-C. 20 Alkyl, substituted or unsubstituted C3-C 20 Cycloalkyl and substituted or unsubstituted C3-C 20 One of the groups consisting of aryl groups, wherein the substituent in "substituted or unsubstituted" is independently selected from at least one of the groups consisting of halogen groups, cyano groups, nitro groups and C1-C8 alkyl groups; R 10 and R 11 Each is an independent linear C1-C chain. 20 Alkyl groups; and P is an integer from 0 to 4. The mixture includes a first internal electron donor, a second internal electron donor, and a third internal electron donor.

[0057] For Ziegler-Natta catalysts for olefin polymerization, including those with a single first internal electron donor, a single second internal electron donor, or a single third internal electron donor, it may be difficult to prepare all polyolefins that satisfy the density, melt index, and melt flow ratio described above. In particular, such Ziegler-Natta catalysts may exhibit poor processability due to the difficulty in satisfying the aforementioned melt flow ratio. For Ziegler-Natta catalysts used in olefin polymerization with an external electron donor to internal electron donor molar ratio of less than 115 or greater than 130, it may be difficult to prepare all polyolefins that meet the density, melt index, and melt flow ratio described above, even when considering mixtures including internal electron donors relative to external electron donors. In particular, such Ziegler-Natta catalysts for olefin polymerization exhibit poor processability due to the difficulty in meeting the aforementioned melt flow ratios.

[0058] In one embodiment, the molar ratio of the external electron donor to the mixture can be in the range of 115 to 125.

[0059] In one embodiment, the mixture may include at least one type of first internal electron donor.

[0060] In one embodiment, the mixture may include at least one type of second internal electron donor.

[0061] In one embodiment, the mixture may include at least two types of third internal electron donors.

[0062] In one embodiment, the first internal electron donor, the third internal electron donor, and the second internal electron donor in the mixture can exist in a weight ratio of first internal electron donor > third internal electron donor > second internal electron donor. Within this range, the effects of the present invention can be easily achieved.

[0063] For example, in the mixture, a first internal electron donor may be present in an amount of about 50 wt% to about 80 wt%, preferably about 60 wt% to about 80 wt%, a second internal electron donor may be present in an amount of about 1 wt% to about 20 wt%, preferably about 5 wt% to about 15 wt%, and a third internal electron donor may be present in an amount of about 10 wt% to about 40 wt%, preferably about 15 wt% to about 35 wt%. Within this range, the effects of the present invention can be readily achieved.

[0064] In one embodiment, in the Ziegler-Natta catalyst used for olefin polymerization, the mixture of internal electron donors may be present in an amount of about 10 wt% to about 20 wt%, for example, about 10 wt% to about 15 wt%. Within this range, the effects of the present invention can be readily achieved.

[0065] In one implementation, in Equation 4, R 4 and R 5 Can be independently branched C3-C 10 Alkyl or C3-C5 alkyl. For example, in formula 4, R 4 and R 5 It can be used independently for C3-C 10 Alkyl or C3-C5 alkyl with branched ends. The first internal electron donor represented by Formula 4 may include at least one compound represented by any one of Formulas 4-1 to 4-3: [Equation 4-1]

[0066] [Equation 4-2]

[0067] [Equation 4-3] .

[0068] In one implementation, in Equation 5, R 7 It can be a straight chain C1-C 10 Alkyl or straight-chain C1-C5 alkyl. In formula 5, R 8 It can be a branch C2-C 10 Alkyl or C2-C5 alkyl. For example, in formula 5, R 8 It can be C2-C 10 Alkyl or C2-C5 alkyl with branched ends. For example, the second internal electron donor represented by Formula 5 may include at least one compound represented by any one of Formulas 5-1 to 5-4: [Equation 5-1]

[0069] [Equation 5-2]

[0070] [Equation 5-3]

[0071] [Equation 5-4] .

[0072] In one implementation, in Equation 6, R 10 and R11 Each can be independently a straight chain C1-C 10 Alkyl or straight-chain C1-C5 alkyl. For example, the third internal electron donor represented by Formula 6 may include at least one compound represented by any one of Formulas 6-1 to 6-3: [Equation 6-1]

[0073] [Equation 6-2]

[0074] [Equation 6-3] .

[0075] According to one embodiment, based on 100 wt% of the total internal electron donor in a Ziegler-Natta catalyst for olefin polymerization, a mixture of a first internal electron donor, a second internal electron donor, and a third internal electron donor may be present in an amount of about 95 wt% or higher, preferably about 99 wt% to about 100 wt%, more preferably about 100 wt%. Within this range, the effects of the present invention can be readily achieved. Hereinafter, "total internal electron donor" may refer to compounds included in the main catalyst of the Ziegler-Natta catalyst for olefin polymerization that are known to those skilled in the art to function at catalytically active sites stabilizing titanium compounds.

[0076] [Titanium compounds] Titanium compounds can be compounds with an active metal center, that is, compounds containing a metal with an active site. Titanium compounds are used to catalyze the basic polymerization reaction of olefin monomers to produce polyolefins.

[0077] Titanium compounds are compounds represented by Formula 1.

[0078] [Formula 1] TiX n (OR 1 ) 4-n (In Equation 1, R 1 Choose either freely substituted or unsubstituted C1-C. 20 Alkyl, substituted or unsubstituted C3-C 20 Cycloalkyl and substituted or unsubstituted C3-C 20 One of the groups composed of aryl groups; X is a halogen atom; n is an integer from 0 to 4; and The substituent in "substituted or unsubstituted" is independently at least one selected from the group consisting of halogen groups, cyano groups, nitro groups, and C1-C8 alkyl groups. In some embodiments, the titanium compound may comprise at least one selected from the group consisting of halides of tetravalent titanium and alkoxides of tetravalent titanium. Preferably, the titanium compound is titanium tetrachloride (TiCl4), titanium ethoxytrichloride (Ti(OC2H5)Cl3), etc.

[0079] [Magnesium compounds] Magnesium compounds are used as catalyst supports, and the properties of active center metals (such as titanium compounds) with active sites, such as activity and stereoregularity, can be tuned according to their molecular structure and the binding strength with electron donors.

[0080] Magnesium compounds are those represented by Formula 2.

[0081] [Equation 2] Mg(OR 2 ) k X 2-k (In Equation 2, R 2 Choose either freely substituted or unsubstituted C1-C. 20 Alkyl, substituted or unsubstituted C3-C 20 Cycloalkyl and substituted or unsubstituted C3-C 20 One of the groups composed of aryl groups; X is a halogen atom; k is an integer between 0 and 2; and The substituent in "substituted or unsubstituted" is independently at least one selected from the group consisting of halogen groups, cyano groups, nitro groups, and C1-C8 alkyl groups. In some embodiments, the magnesium compound may be magnesium dialkyl oxide, magnesium diaryl oxide, magnesium chloride (MgCl2), etc. Preferably, the magnesium compound is magnesium dialkyl oxide that can be obtained in high purity to reduce impurities in the final synthesized catalyst, or magnesium diethoxy that is readily soluble in the solvent used in the catalyst synthesis process.

[0082] [Organoaluminum compounds] As a co-catalyst, organoaluminum compounds can activate the active sites of titanium compounds.

[0083] Organoaluminum compounds are compounds represented by Formula 7.

[0084] [Formula 7] Al(R 13 ) p X 3-p (In Equation 7, R 13 It is selected from hydrogen atoms, substituted or unsubstituted C1-C. 20Alkyl, substituted or unsubstituted C3-C 20 Cycloalkyl and substituted or unsubstituted C3-C 20 One of the groups composed of aryl groups; X is a halogen atom; p is an integer from 0 to 3; and The substituent in "substituted or unsubstituted" is independently at least one selected from the group consisting of halogen groups, cyano groups, nitro groups, and C1-C8 alkyl groups. In some embodiments, the organoaluminum compound may be at least one selected from the group consisting of trimethylaluminum, triethylaluminum, triisobutylaluminum, trioctylaluminum, diethylaluminum hydride, diisobutylaluminum hydride, diethylaluminum chloride, diisobutylaluminum chloride, sesquiethylaluminum chloride, and ethylaluminum dichloride. Preferably, the organoaluminum compound is triethylaluminum, which can improve polymerization activity and facilitate control of the weight-average molecular weight of the polymerized polyolefin.

[0085] [Main Catalyst] The main catalyst may include a titanium compound represented by Formula 1, a magnesium compound represented by Formula 2, and an internal electron donor, wherein the titanium compound represented by Formula 1 and the internal electron donor may be supported on the magnesium compound represented by Formula 2.

[0086] According to one embodiment, the main catalyst can be prepared in powder form. According to one embodiment, a Ziegler-Natta catalyst for olefin polymerization can be prepared by mixing the main catalyst with an organoaluminum compound and an external electron donor.

[0087] The master catalyst prepared in powder form allows for uniform coating of the organoaluminum compound and the external electron donor. The powdered master catalyst can be well dispersed in the organoaluminum compound and the external electron donor, improving dispersion stability and thus facilitating the preparation of polyolefins with the aforementioned specific ranges of density, melt index, and melt index ratio.

[0088] A method for preparing a Ziegler-Natta master catalyst for olefin polymerization may include: a primary stirring step in which a titanium compound represented by Formula 1 is mixed with a magnesium compound represented by Formula 2 and then the mixture is stirred; a secondary stirring step in which a mixture of internal electron donors is added to the product of the primary stirring and then stirred; and a vacuum drying step in which the product of the secondary stirring is dried under vacuum.

[0089] In the initial stirring step, titanium and magnesium compounds can be added to an organic solvent, and the resulting mixture is stirred while the temperature is increased from room temperature to a first temperature at a heating rate of about 0.5°C / min to about 1.5°C / min.

[0090] The organic solvent can be toluene, ether, acetone, alcohol, etc., with toluene being preferred.

[0091] The first temperature can be in the range of about 70°C to about 90°C, preferably about 75°C to about 85°C. In some embodiments, the first temperature can be in the range of about 72°C to about 88°C, for example, about 72°C to about 75°C, about 75°C to about 80°C, about 80°C to about 85°C, or about 85°C to about 88°C. If the first temperature is too low, the internal electron donor may be insoluble in the solvent, and if the first temperature is too high, side reactions of the internal electron donor may occur.

[0092] In the secondary stirring step, an internal electron donor may be added to the primary stirring product, followed by stirring for approximately 1.8 hours to approximately 2.2 hours while the temperature is raised to a second temperature. In some embodiments, stirring may be performed for approximately 1.82 hours to approximately 1.9 hours, for example, approximately 1.9 hours to approximately 2 hours, or approximately 2 hours to approximately 2.2 hours.

[0093] The second temperature can be in the range of about 100°C to about 120°C, preferably about 105°C to about 115°C. In some embodiments, the second temperature can be in the range of about 102°C to about 118°C, for example, about 102°C to about 110°C or about 110°C to about 118°C. If the second temperature is too low, the titanium compound cannot be loaded onto the magnesium compound; while if the second temperature is too high, the solvent may evaporate.

[0094] The preparation method may further include a third stirring step following the secondary stirring step. In some embodiments, after removing the organic solvent and titanium compound, fresh organic solvent and fresh titanium compound may be added to the product from the secondary stirring, which may then be stirred for about 1.8 hours to about 2.2 hours while the temperature is raised from room temperature to a third temperature. In some embodiments, the product from the secondary stirring may be stirred for 1.82 hours to about 1.9 hours, about 1.9 hours to about 2 hours, about 2 hours to about 2.2 hours, or about 2 hours to about 2.2 hours. After stirring, the method may further include washing the product from the third stirring with an organic solvent or the like.

[0095] The third temperature can be in the range of about 100°C to about 120°C, preferably about 105°C to about 115°C. In some embodiments, the third temperature can be in the range of about 102°C to about 118°C, for example, about 102°C to about 110°C or about 110°C to about 118°C.

[0096] The vacuum drying step may include drying the product of secondary or tertiary stirring under vacuum to obtain a Ziegler-Natta main catalyst for olefin polymerization contained in powder form. The method may also include washing the product of secondary or tertiary stirring with an organic solvent or the like before vacuum drying the product of secondary or tertiary stirring.

[0097] Ziegler-Natta catalysts for olefin polymerization In Ziegler-Natta master catalysts for olefin polymerization, the titanium compound and the external electron donor can be present in a molar ratio of about 1:3 to about 1:9, preferably about 1:4 to about 1:8. In some embodiments, the molar ratio of the titanium compound and the external electron donor in the Ziegler-Natta master catalyst for olefin polymerization can be about 1:3.2 to about 1:8.8, for example about 1:3.2 to about 1:5, about 1:5 to about 1:7, or about 1:7 to about 1:8.8. Within this range, the catalytic active sites can have high stability, and there is no problem of activity degradation due to catalytic active site poisoning.

[0098] In Ziegler-Natta master catalysts for olefin polymerization, the organoaluminum compound and the external electron donor may be present in a molar ratio of about 1:0.01 to about 1:0.08, preferably about 1:0.02 to about 1:0.06. In some embodiments, the organoaluminum compound and the external electron donor may be present in a molar ratio of about 1:0.02 to about 1:0.07, for example, about 1:0.02 to about 1:0.04, about 1:0.04 to about 1:0.06, or about 1:0.06 to about 1:0.07. Within this range, the Ziegler-Natta catalyst can promote the preparation of polyolefins with good processability.

[0099] In Ziegler-Natta master catalysts for olefin polymerization, the magnesium compound and the external electron donor can be present in a molar ratio of about 1:4 to about 1:12, preferably about 1:6 to about 1:9. In some embodiments, the magnesium compound and the external electron donor can be present in a molar ratio of about 1:5 to about 1:11, for example, about 1:5 to about 1:7, about 1:7 to about 1:9, or about 1:9 to about 1:11. Within this range, the Ziegler-Natta catalyst can facilitate the preparation of polyolefins with good processability.

[0100] A method for preparing a Ziegler-Natta catalyst for olefin polymerization may include adding a Ziegler-Natta main catalyst for olefin polymerization, an organoaluminum compound represented by Formula 7, and an external electron donor represented by Formula 3 to an organic solvent, followed by stirring. Redundant descriptions of the Ziegler-Natta catalyst will be omitted in the following description of the method for preparing the Ziegler-Natta catalyst for olefin polymerization.

[0101] The organic solvent can be hexane, toluene, ether, acetone, alcohol, etc., with hexane being preferred.

[0102] The stirring can be performed at a stirring rate of about 280 rpm to about 320 rpm, preferably about 290 rpm to about 310 rpm. In some embodiments, the stirring can be performed at a stirring rate of about 285 rpm to about 315 rpm, for example, about 285 rpm to about 295 rpm, about 295 rpm to about 305 rpm, or about 305 rpm to about 315 rpm.

[0103] [Polyolefin Preparation Methods] According to one embodiment, a method for preparing polyolefins includes polymerizing olefin monomers in the presence of a Ziegler-Natta catalyst for olefin polymerization.

[0104] According to one embodiment, the olefin monomer may include an olefin monomer represented by Formula 8: [Formula 8] CH2=CHR 14 (In Equation 8, R 14 It is hydrogen or a C1 to C6 alkyl or aryl group. The method for preparing polyolefins can be a method for preparing polyethylene. Therefore, the method for preparing polyolefins may include polymerizing olefin monomers, preferably ethylene, in the presence of a Ziegler-Natta catalyst for olefin polymerization.

[0105] In polyolefin preparation methods, polymerization can be carried out in a hydrogen atmosphere at a pressure of about 6 to about 8 bar and a temperature of about 80°C to about 90°C. If the temperature is too low, polymerization will not occur due to low catalyst activity; if the temperature is too high, the catalyst activity will decrease rapidly due to over-reaction.

[0106] The polymerization can take about 0.5 hours to about 1.5 hours, preferably about 0.8 hours to about 1.2 hours.

[0107] According to one embodiment, the Ziegler-Natta catalyst for olefin polymerization can be approximately 1 × 10⁻⁶ per mole of olefin monomer. -5 moles to approximately 3 × 10 -5 Mole, preferably about 1.5 × 10 -5 From approximately 2.5 × 10⁻⁶ moles -5 The amount is measured in moles. In some embodiments, the Ziegler-Natta catalyst used for olefin polymerization can be approximately 1.2 × 10⁻⁶ moles relative to 1 mole of olefin monomer. -5 From approximately 2.9 × 10⁻⁶ moles to approximately 2.9 × 10⁻⁶ moles. -5 moles, for example, about 1.2 × 10⁻⁶. -5 From moles to approximately 1.5 × 10 -5 moles, approximately 1.5 × 10⁻⁶ -5 moles to approximately 2 × 10 -5moles, approximately 2 × 10 -5 From approximately 2.5 × 10⁻⁶ moles -5 moles or approximately 2.5 × 10⁻⁶ -5 From approximately 2.9 × 10⁻⁶ moles to approximately 2.9 × 10⁻⁶ moles. -5 The molar amount exists. Within this range, olefin monomers can be used to prepare polyolefins with high polymerization yields.

[0108] [Polyolefin resin] According to one embodiment, a polyolefin resin is provided. The polyolefin resin is prepared by the method described above and has an MFR (MFI) of about 20 to about 25. 21.6 / MFI 2.16 In the implementation, MFR (MFR 21.6 / MFR 2.16 It can be in the range of about 20.2 to about 24.9, for example, about 20.2 to about 21.5, about 21.5 to about 22.5, about 22.5 to about 23.5 or about 23.5 to about 24.8.

[0109] The invention will now be described in more detail with reference to some embodiments. It should be understood that these embodiments are provided for illustrative purposes only and should not be construed as limiting the invention in any way.

[0110] The components used in the various embodiments and comparative examples are as follows: External electron donor: [Equation 3-1]

[0111] [Equation 3-2] ; Internal electron donor: [Equation 4-1] , [Equation 5-1] , [Equation 6-1]

[0112] [Equation 6-2]

[0113] [Equation 6-3] .

[0114] Example 1 Preparation of Ziegler-Natta main catalysts for olefin polymerization 4 g of magnesium compound (Mg(OC2H5)2) support and 8 mL of titanium compound (TiCl4) were added to 12 mL of toluene, followed by primary stirring while the temperature was increased from room temperature to 80 °C at a rate of 1 °C / min. Then, when the reaction temperature reached 80 °C, a mixture of internal electron donors was added to the product of primary stirring, followed by secondary stirring for 2 hours while the temperature was increased from room temperature to 110 °C at a rate of 1 °C / min. After removing the TiCl4 + toluene solution, fresh TiCl4 (10 mL) and toluene (30 mL) were added to the product of secondary stirring, followed by a third stirring for 2 hours while the temperature was increased from room temperature to 110 °C at a rate of 1 °C / min and then maintained at that temperature. Then, the supported catalyst obtained after the third stirring was washed twice with 50 mL of toluene at 100 °C and twice with 100 mL of hexane at 60 °C, and then dried under vacuum to prepare a powdered Ziegler-Natta main catalyst (supported catalyst) for olefin polymerization.

[0115] The mixture of internal electron donors is represented by formula 4-1 (4.5 mmol), formula 5-1 (0.45 mmol), formula 6-1 (0.45 mmol), formula 6-2 (0.45 mmol) and formula 6-3 (0.45 mmol).

[0116] Ziegler-Natta catalysts for olefin polymerization and preparation of polyethylene A 2L high-pressure reactor was dried in an oven and assembled under hot conditions. A nitrogen atmosphere was then generated inside the reactor by alternating nitrogen and vacuum conditions three times. Then, with 1000 ml of hexane (organic solvent) added to the reactor, 15 mg of Ziegler-Natta main catalyst for olefin polymerization (Preparation Example 1), 0.18 ml of external electron donor represented by Formula 3-2, and 2 mmol of triethylaluminum (2 ml of 1M hexane solution) (organoaluminum compound (co-catalyst)) were added to the reactor, and the resulting solution was stirred, thereby preparing the Ziegler-Natta catalyst for olefin polymerization.

[0117] Next, the reactor temperature was raised to 85°C, and hydrogen was injected into the reactor once at 3 bar. Polyethylene was then polymerized for 1 hour while ethylene was continuously added at a constant pressure of 7 bar. The reactor temperature was then lowered to room temperature, and the resulting polymer was collected and dried to prepare polyethylene resin as a white powder.

[0118] Examples 2 to 5 Except for the changes in the internal and external electron donors and their contents as listed in Tables 1 and 2, the Ziegler-Natta main catalyst for olefin polymerization, the Ziegler-Natta catalyst for olefin polymerization, and the polyethylene resin were prepared in the same manner as in Example 1.

[0119] Comparative Examples 1 to 17 Except for the changes in the internal and external electron donors and their contents as listed in Tables 1 and 2, the Ziegler-Natta main catalyst for olefin polymerization, the Ziegler-Natta catalyst for olefin polymerization, and the polyethylene resin were prepared in the same manner as in Example 1.

[0120] Evaluation of the properties of polyethylene 1) Activity (G) PE / G cat (Unit: None): Activity is calculated using the following formula: weight of polyethylene obtained (g) / weight of catalyst used (g) 2) MFI 2.16 (Unit: g / 10min) and MFI 21.6 (Unit: g / 10min): For the polyethylene resin prepared above, the MFI at 190°C and 2.16 kg load was measured using a melt flow index measuring device according to ASTM D1238. 2.16 MFI at 190°C and 21.6 kg load 21.6 .

[0121] 3) Melt Flow Ratio: For the polyethylene resin prepared above, as in 2), the melt flow index (MFI) is measured according to ASTM D 1238. 21.6 and MFI 2.16 Then calculate MFR (MFI) 21.6 / MFI 2.16 ).

[0122] 4) Density (unit: g / cm³) 3 ): Density is measured according to ASTM D1505.

[0123] 5) Tensile strength (break point, unit: kgf / cm) 2 ): Tensile strength was measured using a tensile testing machine. For the polyethylene resin prepared above, tensile strength was measured in each direction, namely MD (machine direction) and TD (transverse direction).

[0124] Table 1

[0125] *In Table 1, “wt%” refers to the weight percentage of each component in the Ziegler-Natta catalyst used for olefin polymerization.

[0126] Table 2

[0127] *In Table 2, “wt%” refers to the weight percentage of each component in the Ziegler-Natta catalyst used for olefin polymerization.

[0128] Table 3

[0129] Referring to Table 3, the Ziegler-Natta catalyst prepared in the examples for olefin polymerization can produce polyolefins that simultaneously meet the density, melt index, and melt flow ratio requirements according to the present invention.

[0130] Conversely, Ziegler-Natta catalysts for olefin polymerization that do not meet the scope of this invention cannot prepare polyolefins that simultaneously meet the density, melt index, and melt flow ratio requirements according to this invention.

[0131] It should be understood that various modifications, alterations, variations, and equivalent implementations can be made by those skilled in the art without departing from the spirit and scope of the invention.

[0132] Industrial applicability Ziegler-Natta catalysts for olefin polymerization provide polyolefins with good processability that meet the density, melt index, and melt flow ratio described herein.

Claims

1. A Ziegler-Natta catalyst for olefin polymerization, comprising: (i) a Ziegler-Natta main catalyst for olefin polymerization, the Ziegler-Natta main catalyst for olefin polymerization comprising a titanium compound represented by Formula 1, a magnesium compound represented by Formula 2, and an internal electron donor; (ii) an organoaluminum compound represented by Formula 7; and (iii) an external electron donor represented by Formula 3; wherein the internal electron donor comprises a mixture of a first internal electron donor represented by Formula 4, a second internal electron donor represented by Formula 5, and a third internal electron donor represented by Formula 6; and wherein a molar ratio of the external electron donor to the mixture is 115 to 130; [Formula 1] TiX n (OR 1 ) 4-n In Formula 1, R 1 is selected from the group consisting of substituted or unsubstituted C1-C 20 alkyl, substituted or unsubstituted C3-C 20 cycloalkyl, and substituted or unsubstituted C3-C 20 aryl; X is a halogen atom; n is an integer of 0 to 4; and the substituents in "substituted or unsubstituted" are independently at least one selected from the group consisting of a halogen group, a cyano group, a nitro group, and a C1-C8 alkyl group; [Formula 2] Mg(OR 2 ) k X 2-k In Formula 2, R 2 selected from the group consisting of substituted or unsubstituted C1-C 20 substituted or unsubstituted C3-C 20 substituted or unsubstituted C3-C 20 substituted or unsubstituted C3-C X is a halogen atom; k is an integer of 0 to 2; and the substituents in "substituted or unsubstituted" are independently at least one selected from the group consisting of a halogen group, a cyano group, a nitro group, and a C1-C8 alkyl group; [Formula 3] In Formula 3, L1and L2are each independently substituted or unsubstituted C1-C8alkyl, wherein the substituents in "substituted or unsubstituted" are independently at least one selected from the group consisting of halogen radicals, cyano radicals, nitro radicals, and C1-C8alkyl radicals; and 20 alkyl, wherein the substituents in "substituted or unsubstituted" are independently at least one selected from the group consisting of halogen radicals, cyano radicals, nitro radicals, and C1-C8alkyl radicals; and L3and L4are each independently selected from the group consisting of substituted or unsubstituted C1-C 20 alkyl and substituted or unsubstituted C3-C 20 cycloalkyl, wherein the substituents in "substituted or unsubstituted" are independently at least one selected from the group consisting of a halogen group, a cyano group, a nitro group, and a C1-C8 alkyl group; [Formula 4] In Formula 4, R 3 is selected from the group consisting of substituted or unsubstituted C1-C 20 alkyl, substituted or unsubstituted C3-C 20 cycloalkyl, and substituted or unsubstituted C3-C 20 aryl, wherein the substituents in "substituted or unsubstituted" are independently at least one selected from the group consisting of halogen radicals, cyano radicals, nitro radicals, and C1-C8 alkyl radicals; R 4 and R 5 each independently is a branched C1-C 20 alkyl; and m is an integer of 0 to 4; [Formula 5] In Formula 5, R 6 independently one selected from the group consisting of substituted or unsubstituted C1-C 20 alkyl, substituted or unsubstituted C3-C 20 cycloalkyl, and substituted or unsubstituted C3-C 20 aryl, wherein the substituents in "substituted or unsubstituted" are independently at least one selected from the group consisting of halogen radicals, cyano radicals, nitro radicals, and C1-C8 alkyl radicals; R 7 is a straight-chain C1-C 20 alkyl group; R 8 is branched C1-C 20 alkyl; and n is an integer of 0 to 4; [Formula 6] In Formula 6, R 9 Each can be independently selected as either substituted or unsubstituted C1-C. 20 Alkyl, substituted or unsubstituted C3-C 20 Cycloalkyl and substituted or unsubstituted C3-C 20 One of the groups consisting of aryl groups, wherein the substituent in "substituted or unsubstituted" is independently selected from at least one of the groups consisting of halogen groups, cyano groups, nitro groups and C1-C8 alkyl groups; R 10 and R 11 each independently is a linear C1-C 20 alkyl; and p is an integer of 0 to 4; [Formula 7] Al(R 13 ) p X 3-p In Formula 7, R 13 is selected from the group consisting of a hydrogen atom, a substituted or unsubstituted C1-C 20 alkyl group, a substituted or unsubstituted C3-C 20 cycloalkyl group and a substituted or unsubstituted C3-C 20 aryl group; and X is a halogen atom; p is an integer of 0 to 3; and the substituents in "substituted or unsubstituted" are independently at least one selected from the group consisting of a halogen group, a cyano group, a nitro group, and a C1-C8 alkyl group.

2. The Ziegler-Natta catalyst for the polymerization of olefins according to claim 1, wherein, The mixture comprises at least one type of the first internal electron donor, at least one type of the second internal electron donor, and at least two types of the third internal electron donor.

3. The Ziegler-Natta catalyst for the polymerization of olefins according to claim 1, wherein, The first internal electron donor, the third internal electron donor, and the second internal electron donor of the mixture exist in a weight ratio relationship of first internal electron donor > third internal electron donor > second internal electron donor.

4. The Ziegler-Natta catalyst for the polymerization of olefins according to claim 1, wherein, In the mixture, the first internal electron donor exists in an amount of 50 wt% to 80 wt%, the second internal electron donor exists in an amount of 1 wt% to 20 wt%, and the third internal electron donor exists in an amount of 10 wt% to 40 wt%.

5. The Ziegler-Natta catalyst for the polymerization of olefins according to claim 1, wherein, The mixture exists in an amount of 10 wt% to 20 wt% in the Ziegler-Natta catalyst for olefin polymerization.

6. The Ziegler-Natta catalyst for the polymerization of olefins according to claim 1, wherein, The first internal electron donor represented by Formula 4 comprises at least one compound represented by any one of Formula 4-1 to Formula 4-3: [Formula 4-1] [Formula 4-2] [Formula 4-3] 。 7. The Ziegler-Natta catalyst for the polymerization of olefins according to claim 1, wherein, The second internal electron donor represented by Formula 5 comprises at least one compound represented by any one of Formula 5-1 to Formula 5-4: [Formula 5-1] [Formula 5-2] [Formula 5-3] [Formula 5-4] 。 8. The Ziegler-Natta catalyst for the polymerization of olefins according to claim 1, wherein, The third internal electron donor represented by Formula 6 comprises at least one compound represented by any one of Formula 6-1 to Formula 6-3: [Formula 6-1] [Formula 6-2] [Formula 6-3] 。 9. The Ziegler-Natta catalyst for the polymerization of olefins according to claim 1, wherein, The titanium compound and the external electron donor are present in the Ziegler-Natta procatalyst for the polymerization of olefins in a molar ratio of 1:3 to 1:

9.

10. The Ziegler-Natta catalyst for the polymerization of olefins according to claim 1, wherein the external electron donor comprises at least one of a first external electron donor and a second external electron donor; the first external electron donor is any one of L3 and L4 in Formula 3 is a substituted or unsubstituted C3-C 20 cycloalkyl, and the second external electron donor is both L3 and L4 in Formula 3 are substituted or unsubstituted C3-C 20 cycloalkyl.

11. The Ziegler-Natta catalyst for the polymerization of olefins according to claim 10, wherein, The external electron donor is the second external electron donor.

12. The Ziegler-Natta catalyst for the polymerization of olefins according to claim 10, wherein, The first external electron donor is represented by Formula 3-1, and the second external electron donor is represented by Formula 3-2: [Formula 3-1] [Formula 3-2] 。 13. A process for the preparation of a polyolefin comprising: An olefin monomer is polymerized in the presence of the Ziegler-Natta catalyst for the polymerization of olefins according to any one of claims 1 to 12.

14. The polyolefin production process of claim 13, wherein, The Ziegler-Natta catalyst for the polymerization of olefins is present in an amount of 1 x 10 -5 to 3 x 10 -5 moles relative to 1 mole of the olefin monomer.

15. A polyolefin resin prepared by the process for the preparation of polyolefins according to claim 13 and having a MFR (MFI 21.6 / MFI 2.16 ) of from 20 to 25.

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