Polyethylene resin and composition comprising same

Abstract

The present invention provides a polyethylene resin which, when combined with recycled polyethylene, retains excellent mechanical properties, has improved resistance to environmental stress cracking, and also prevents discoloration, and a polyethylene resin composition comprising same.

Description

Polyethylene resin and composition containing the same

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0133320 filed September 30, 2024 and Korean Patent Application No. 10-2025-0141622 filed September 29, 2025, and all contents disclosed in the documents of said Korean patent applications are incorporated herein as part of this specification.

[0003]

[0004] The present invention relates to a polyethylene resin that maintains excellent mechanical properties and improves resistance to environmental stress cracking when combined with recycled polyethylene, while simultaneously preventing discoloration, and a polyethylene resin composition containing the same.

[0005]

[0006] The demand for polyethylene resin is steadily increasing and it is being used in various applications.

[0007]

[0008] Recently, as environmental concerns have intensified, regulations aimed at curbing carbon dioxide emissions have been strengthened. In particular, as environmental pollution caused by the increased use of plastics has emerged as a serious issue, regulations at the manufacturing stage are being tightened, such as mandating the use of recycled resins, primarily in the United States. Consequently, manufacturers are required to add a certain amount of recycled resin when producing resin molded products, and eco-friendliness ratings are assigned based on the recycled resin content.

[0009]

[0010] However, since recycled resin is already processed, its properties have already changed during the high-temperature processing, resulting in significantly lower impact strength, tensile strength, chemical resistance, and thermal stability compared to conventional virgin resin. To address this problem, methods have been attempted to include a certain level of virgin resin in compositions containing recycled resin. However, this requires an excessive amount of virgin resin to minimize the degradation of mechanical properties, and issues regarding the deterioration of key properties, such as environmental stress cracking resistance (ESCR), remain unresolved. Furthermore, this problem becomes more severe as the number of processing cycles increases.

[0011]

[0012] In addition, in the case of polyethylene resin products using recycled resin, discoloration issues occur along with a deterioration in physical properties because recycled resin containing some foreign substances and undergoing oxidation is used.

[0013]

[0014] Furthermore, maintaining quality control for polyethylene resin products using recycled resin is difficult due to differences in usage patterns for each product. In such polyethylene resin compositions using recycled resin, it is assumed that the quality of the recycled resin is the lowest, so the response is typically to improve the physical properties of the final polyethylene resin product by increasing the quality of the added virgin polyethylene (booster). However, due to the aging of the recycled resin and internal impurities, there are often limitations on improving the quality of the polyethylene resin composition itself, even after improving the quality of the virgin polyethylene (booster).

[0015]

[0016] Furthermore, while various additives can be introduced to prevent discoloration in polyethylene resin products made from recycled resin, this leads to a deterioration in mechanical properties and processability. Moreover, there is a problem in that it is difficult to satisfy both discoloration prevention and mechanical properties and processability simultaneously due to a trade-off relationship.

[0017]

[0018] Accordingly, there is an urgent need for research and development of polyethylene that prevents discoloration while maintaining excellent mechanical properties and improving resistance to environmental stress cracking as a virgin resin blended with such recycled resin.

[0019]

[0020] The present invention aims to provide a polyethylene resin that maintains excellent mechanical properties and improves resistance to environmental stress cracking when combined with recycled polyethylene, while simultaneously preventing discoloration, and a polyethylene resin composition containing the same.

[0021]

[0022] According to one embodiment of the invention,

[0023] In addition to polyethylene, it further comprises phenolic compounds, phosphorus-based compounds, and amine-based compounds, and

[0024] The total content of the above phenolic compounds, phosphorus compounds, and amine compounds is 0.32% or more and 0.75% or less relative to the weight of the above polyethylene, and

[0025] The content of the above phenolic compound (AO1) and the content of the above amine compound (AO3) satisfy Formula 1 below, and

[0026] The content of the above phenolic compound (AO1), the content of the above phosphorus-based compound (AO2), and the content of the above amine-based compound (AO3) satisfy Formula 2 below, and

[0027] The above-mentioned phosphorus compound is one or more selected from the group consisting of tris(2,4-di-tert-butylphenyl)phosphite and bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, and

[0028] The above amine compound is one or more selected from the group consisting of bis(3,5-di-tert-butyl-4-hydroxyhydrocinnamoyl)hydrazine and (3,3'-bis(3,5-di-tert-butyl-4-hydroxyphenyl)-N,N'-hexamethylenedipropionamide).

[0029] Polyethylene resin is provided.

[0030] [Equation 1]

[0031] 0.6 ≤ AO1 / AO3 ≤ 1.8

[0032] [Equation 2]

[0033] AO2 / (AO1+ AO3) ≥ 1.5

[0034] In the above Equations 1 and 2,

[0035] AO1 is the content of the above-mentioned phenolic compound, and

[0036] AO2 is the content of the above-mentioned phosphorus compound, and

[0037] AO3 is the content of the above amine compound.

[0038]

[0039] In addition, the present invention provides a polyethylene resin composition comprising virgin polyethylene (or Booster PE) and recycled polyethylene (PCW PE, Post consumer waste polyethylene), wherein the virgin polyethylene comprises the polyethylene resin described above.

[0040]

[0041] According to the present invention, by optimizing the inclusion of a phenolic compound, a phosphorus-based compound, and an amine-based compound in the polyethylene resin itself in a predetermined amount, it is possible to provide a polyethylene resin that maintains excellent mechanical properties when combined with recycled polyethylene, improves resistance to environmental stress cracking, and simultaneously prevents discoloration, and a polyethylene resin composition containing the same.

[0042]

[0043] In the present invention, terms such as first, second, etc. are used to describe various components, and these terms are used solely for the purpose of distinguishing one component from another.

[0044]

[0045] Furthermore, the terms used herein are used merely to describe exemplary embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as “comprising,” “comprising,” or “having” are intended to specify the existence of the implemented features, numbers, steps, components, or combinations thereof, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, components, or combinations thereof.

[0046]

[0047] Additionally, terms such as "approximately" and "substantially" used throughout this specification are used to mean at or near the stated value when inherent manufacturing and material tolerances are presented in the stated meaning, and are used to prevent unscrupulous infringers from unfairly exploiting the disclosure in which precise or absolute values ​​are mentioned to aid in understanding the invention.

[0048]

[0049] In addition, in this specification, "part by weight" refers to a relative concept in which the weight of one substance is expressed as a ratio to the weight of another substance. For example, in a mixture containing 50 g of substance A, 20 g of substance B, and 30 g of substance C, the amounts of substance B and substance C are 40 parts by weight and 60 parts by weight, respectively, based on 100 parts by weight of substance A.

[0050]

[0051] In addition, "weight % (% by weight)" refers to an absolute concept in which the weight of a substance is expressed as a percentage of the total weight. In the mixture given as an example above, the content of substance A, substance B, and substance C is 50 weight%, 20 weight%, and 30 weight%, respectively, out of 100% of the total weight of the mixture. At this time, the total content of each component does not exceed 100 weight%.

[0052]

[0053] The present invention is capable of various modifications and may take various forms, and specific embodiments are illustrated and described in detail below. However, this is not intended to limit the invention to the specific disclosed forms, and it should be understood that the invention includes all modifications, equivalents, and substitutions that fall within the spirit and scope of the invention.

[0054]

[0055] The present invention will be described in more detail below.

[0056]

[0057] According to one embodiment of the invention, a polyethylene resin is provided that includes a phenolic compound, a phosphorus compound, and an amine compound in an optimized amount together with polyethylene, so as to maintain excellent mechanical properties even when combined with recycled polyethylene, improve environmental stress cracking resistance (ESCR), and simultaneously prevent discoloration.

[0058]

[0059] Specifically, the polyethylene resin of the present invention further comprises a phenolic compound, a phosphorus compound, and an amine compound together with polyethylene, wherein the total content of the phenolic compound, the phosphorus compound, and the amine compound is 0.32% or more and 0.75% or less relative to the weight of the polyethylene, and the content of the phenolic compound (AO1) and the content of the amine compound (AO3) satisfy Formula 1 below, and the content of the phenolic compound (AO1), the content of the phosphorus compound (AO2), and the content of the amine compound (AO3) satisfy Formula 2 below.

[0060] [Equation 1]

[0061] 0.6 ≤ AO1 / AO3 ≤ 1.8

[0062] [Equation 2]

[0063] AO2 / (AO1+ AO3) ≥ 1.5

[0064] In the above Equations 1 and 2,

[0065] AO1 is the content of the above-mentioned phenolic compound, and

[0066] AO2 is the content of the above-mentioned phosphorus compound, and

[0067] AO3 is the content of the above amine compound.

[0068]

[0069] Here, the content of the phenolic compound (AO1), the content of the phosphorus compound (AO2), and the content of the amine compound (AO3) are based on the weight of the polyethylene, and specifically, they may be expressed in units such as ppm or %, or weight % or parts by weight. At this time, the content of each component is not limited to a specific unit as long as the content ratio can be calculated in the same unit.

[0070]

[0071] In addition, in a polyethylene resin according to one embodiment of the invention, the phosphorus-containing compound is one or more selected from the group consisting of tris(2,4-di-tert-butylphenyl) phosphite and bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite.

[0072]

[0073] In addition, in a polyethylene resin according to one embodiment of the invention, the amine compound is characterized by being one or more selected from the group consisting of bis(3,5-di-tert-butyl-4-hydroxyhydrocinnamoyl)hydrazine and (3,3'-bis(3,5-di-tert-butyl-4-hydroxyphenyl)-N,N'-hexamethylenedipropionamide).

[0074]

[0075] In particular, the above polyethylene contains, together with polyethylene, a phenolic compound, a specific phosphorus compound, and an amine compound in an optimized amount. By using a component that has a phosphite structure in which two or more or three or more bulky substituents, such as a tert-butyl substituted phenyl group, are bonded to a phosphorus atom, or a structure in which two phosphite (P(III)) groups are bonded to a pentaerythritol backbone, and has a large steric hindrance, and by using a component that has a non-hindered structure in which the area around the nitrogen atom is open for the amine compound, when combined with recycled polyethylene, not only can mechanical properties such as drop impact strength be maintained to an excellent degree while environmental stress cracking resistance (ESCR) is also improved to an excellent degree, and at the same time, discoloration of the final resin product can be prevented.

[0076]

[0077] The polyethylene of the present invention will be described in more detail below.

[0078]

[0079] Specifically, the polyethylene according to one embodiment of the present invention may be an ethylene homopolymer or an ethylene / alpha-olefin copolymer.

[0080]

[0081] The above alpha-olefin may be one or more selected from the group consisting of 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicocene, and mixtures thereof.

[0082]

[0083] For example, the polyethylene according to the present invention may not contain the aforementioned alpha-olefin or may contain it in an amount of 10 weight% or less. That is, the alpha-olefin may be contained in an amount of 0 to 10 weight% or less. Specifically, the alpha-olefin may be 8 weight% or less, or 6.5 weight% or less, or 5 weight% or less, or 4.5 weight% or less, or 4 weight% or less, or 3.5 weight% or less, or 3 weight% or less, or 2.5 weight% or less, or 2.2 weight% or less, or 2 weight% or less, or 1.8 weight% or less, or 1.5 weight% or less, but is not limited thereto. In addition, when the polyethylene is an ethylene / alpha-olefin copolymer, the alpha-olefin may be 0.1 wt% or more, or 0.3 wt% or more, or 0.5 wt% or more, or 0.7 wt% or more, or 0.85 wt% or more, or 0.9 wt% or more, or 1.0 wt% or more, or 1.2 wt% or more, but is not limited thereto.

[0084]

[0085] For example, when the polyethylene according to the present invention is a copolymer, 1-hexene or 1-butene can be used as the alpha-olefin copolymerized with ethylene, and more specifically, 1-hexene can be used.

[0086]

[0087] In addition, the polyethylene may be a dry blend of one or more or two or more ethylene homopolymers as described above, or a dry blend of one or more or two or more ethylene / alpha-olefin copolymers.

[0088]

[0089] Meanwhile, the polyethylene according to one embodiment of the present invention has a density (ASTM D 1505, 23 °C) of 0.935 g / cm³ 3 Above or 0.935 g / cm³ 3Up to 0.960 g / cm³ 3 It may be high-density polyethylene (HDPE) that satisfies the condition.

[0090]

[0091] More specifically, the density of the polyethylene is 0.938 g / cm³ 3 Above, 0.940 g / cm³ 3 Above, 0.942 g / cm³ 3 Above, 0.945 g / cm³ 3 Above, or 0.946 g / cm³ 3 It may be greater than 0.958 g / cm³ 3 Below, 0.956 g / cm³ 3 Below, 0.955 g / cm³ 3 Less than or equal to 0.952 g / cm³ 3 It may be less than.

[0092]

[0093] In the present invention, density (g / cm³) 3 ) can be measured according to ASTM D 1505 standards, and, for example, may be a value measured at 23 ℃. For example, such density (g / cm³) 3 The method for measuring ) is as described in Synthetic Example 1 below.

[0094]

[0095] When the density of the polyethylene satisfies the range described above, when mixed with recycled polyethylene, it is possible to improve environmental stress cracking resistance (ESCR) while minimizing the degradation of mechanical properties such as drop impact strength.

[0096]

[0097] Meanwhile, the polyethylene according to the present invention may have a widened molecular weight distribution (PDI, Mw / Mn) by optimizing the molecular structure along with the density as described above.

[0098]

[0099] Specifically, the polyethylene may have a molecular weight distribution (Mw / Mn) of 20 or more, or 20 to 50. Preferably, the molecular weight distribution (Mw / Mn) of the polyethylene may be 21 or more, 22 or more, or 23 or more, and may also be 45 or less, 40 or less, 35 or less, or 30 or less.

[0100]

[0101] By having the molecular weight distribution (Mw / Mn) as described above, the ratio of the low molecular weight region within the molecular structure of the polyethylene is strengthened while the ratio of the high molecular weight region is maintained, and when combined with recycled polyethylene, excellent mechanical properties are maintained and environmental stress cracking resistance (ESCR) can be improved.

[0102]

[0103] For example, the polydispersity index (PDI) in the above GPC curve graph is measured using gel permeation chromatography (GPC). Specifically, it can be measured using the polystyrene conversion assay method with gel permeation chromatography (GPC, manufactured by Polymer Char).

[0104]

[0105] Here, the polydispersity index (PDI) can be calculated by measuring the weight-average molecular weight (Mw) and number-average molecular weight (Mn) of polyethylene and dividing the weight-average molecular weight by the number-average molecular weight.

[0106]

[0107] Specifically, the Polymer Char GPC-IR instrument is used as the gel permeation chromatography (GPC) device, and a Polymer Laboratories PLgel MIX-B 300 mm long column can be used. In this case, the measurement temperature is 160 o C, and 1,2,4-trichlorobenzene can be used as a solvent, and a flow rate of 1 mL / min can be applied. Each of the above polyethylene samples was analyzed using a GPC analyzer (GPC-IR) in 1,2,4-trichlorobenzene containing 0.0125% butylated hydroxytoluene (BHT) at 160 o C, pre-treated by dissolving for 2 hours, prepared at a concentration of 10 mg / 10 mL, and supplied in an amount of 200 microliters (μL). Values ​​of Mw and Mn can be derived using a calibration curve formed using a polystyrene standard specimen. Nine types of polystyrene standard specimens with weight-average molecular weights can be used: 2000 g / mol, 10000 g / mol, 30000 g / mol, 70000 g / mol, 200000 g / mol, 700000 g / mol, 2000000 g / mol, 4000000 g / mol, and 10000000 g / mol.

[0108]

[0109] In addition, the polyethylene may have a weight-average molecular weight of 100,000 g / mol or more, or between 100,000 g / mol and 500,000 g / mol. Preferably, the weight-average molecular weight of the polyethylene may be 105,000 g / mol or more, or 110,000 g / mol or more, or 115,000 g / mol or more, or 120,000 g / mol or more, or 122,000 g / mol or more, or 125,000 g / mol or more. However, considering compatibility with recycled polyethylene, the weight-average molecular weight may be 480,000 g / mol or less, or 450,000 g / mol or less, or 400,000 g / mol or less, or 350,000 g / mol or less, or 300,000 g / mol or less, or 250,000 g / mol or less, or 200,000 g / mol or less, or 180,000 g / mol or less, or 150,000 g / mol or less, or 140,000 g / mol or less.

[0110]

[0111] By having the weight average molecular weight (Mw) as described above, the molecular weight distribution of the polyethylene is optimized, and when combined with recycled polyethylene, the environmental stress cracking resistance (ESCR) can be improved along with excellent mechanical properties.

[0112]

[0113] Meanwhile, the polyethylene according to one embodiment of the invention can optimize the molecular structure along with the density as described above, and can optimize the melt index while securing the molecular weight distribution and weight-average molecular weight within a predetermined range.

[0114]

[0115] The above polyethylene has a melt index (MI). 2.16(ASTM D 1238, 190 ℃, 2.16 kg) may be 0.10 g / 10 min to 1.2 g / 10 min. Preferably, the melt index (MI) of the polyethylene 2.16 (ASTM D 1238, 190 ℃, 2.16 kg) may be 0.15 g / 10 min or more, 0.18 g / 10 min or more, 0.2 g / 10 min or more, or 0.22 g / 10 min or more, and may be 1.18 g / 10 min or less, 1.15 g / 10 min or less, 1.12 g / 10 min or less, or 1.10 g / 10 min or less. For example, such a melt index (MI 2.16 The method for measuring (ASTM D 1238, 190 ℃, 2.16 kg) is as described in Synthesis Example 1 below.

[0116]

[0117] As described above, the melt index (MI) of polyethylene 2.16 By possessing ), the molecular weight distribution of polyethylene is optimized, and when blended with recycled polyethylene, environmental stress cracking resistance (ESCR) can be improved along with excellent mechanical properties. In particular, considering compatibility with recycled polyethylene, the melt index (MI) of polyethylene 2.16 , ASTM D 1238, 190 ℃, 2.16 kg) is preferably 0.1 g / 10 min to 1.2 g / 10 min.

[0118]

[0119] Meanwhile, the polyethylene of the present invention can be produced by homopolymerizing ethylene in the presence of a metallocene catalyst in a slurry loop process, or by copolymerizing ethylene with a comonomer such as an alpha-olefin, and a more detailed synthesis method can be referenced in the examples.

[0120]

[0121] For example, the polyethylene may be a dry blend of one or more ethylene homopolymers or two or more ethylene copolymers prepared in the presence of a metallocene catalyst as described above, or a dry blend of one or more ethylene / alpha-olefin copolymers or two or more ethylene / alpha-olefin copolymers.

[0122]

[0123] In addition, the above-mentioned novel polyethylene may be manufactured by introducing hydrogen gas in the presence of a catalyst composition comprising one first metallocene compound represented by the following chemical formula 1 and two or more second metallocene compounds represented by the following chemical formula 2.

[0124] [Chemical Formula 1]

[0125] (Cp 1 R a ) n (Cp 2 R b )M 1 Z 1 3-n

[0126] In the above chemical formula 1,

[0127] M 1 It is a Group 4 transition metal;

[0128] Cp 1 and Cp 2 are each cyclopentadiennyl, and these are C 1-20 Substituted with or unsubstituted with hydrocarbons;

[0129] R a and R b are identical or different from each other, and independently hydrogen, C 1-20 Alkyl, C 1-20 Alkoxy, C 2-20 Alkoxyalkyl, C 6-20 Aril, C 6-20 Aryloxy, C 2-20 Alkenyl, C 7-40 Alkylaryl, C 7-40 Arylalkyl, C 8-40 Aryl alkenil, C 2-20C comprising alkynyl, or one or more heteroatoms selected from the group consisting of N, O, and S. 2-20 It is heteroaryl, provided that R a and R b At least one of them is C 1-20 alkyl or C 7-20 It is an arylalkyl, and one of the others is C 2-20 It is an alkoxyalkyl;

[0130] Z 1 Silver is a halogen, C 1-20 Alkyl, C 2-20 Alkenyl, C 7-40 Alkylaryl, C 7-40 Arylalkyl, C 6-20 Aryl, substituted or unsubstituted C 1-20 Alkylidene, substituted or unsubstituted amino group, C 2-20 Alkylalkoxy, or C 7-40 It is an aryl alkoxy;

[0131] n is 1 or 0 and;

[0132] [Chemical Formula 2]

[0133]

[0134] In the above chemical formula 2,

[0135] C1 is any one of the ligands represented by the following chemical formulas 3 to 6, and

[0136] [Chemical Formula 3]

[0137]

[0138] [Chemical Formula 4]

[0139]

[0140] [Chemical Formula 5]

[0141]

[0142] [Chemical Formula 6]

[0143]

[0144] In the above chemical formulas 3 to 6,

[0145] R1 to R6 are identical or different from one another, and each independently contains hydrogen, C 1-30 Alkyl, C 1-30 Alkoxy, C 2-30 Alkoxyalkyl, C 6-30 Aril, C 6-30 Aryloxy, C 2-30 Alkenyl, C 2-30 Alkinyl, C 3-30 Cycloalkyl, C 7-40 Alkylaryl, C 8-40 Alkenylaryl, C 8-40 Alkynylaryl, C 7-40 Arylalkyl, C 8-40 Aryl alkenyl, or C 8-40 It is Arylalkinil, and

[0146] M is Ti, Zr, or Hf, and

[0147] Z is -O-, -S-, -NR7- or -PR7-, and

[0148] R7 is hydrogen, C 1-30 Alkyl, C 6-30 Aril, C 2-30 Alkenyl, C 2-30 Alkinyl, C 3-30 Cycloalkyl, C 7-40 Alkylaryl, C 8-40 Alkenylaryl, C 8-40 Alkynylaryl, C 7-40 Arylalkyl, C 8-40 Aryl alkenil, C 8-40 Arylalkinyl, C 1-30 Alkoxysilyl group, C 6-30 Aryloxysilyl, C 1-30 Alkylsilyl group, or C 1-30 It is a silylalkyl group, and

[0149] X1 and X2 are identical or different from each other and each independently halogen, C 1-30 Alkyl, C 2-30 Alkenyl, C 7-30 Alkylaryl, C 7-30 Arylalkyl, C 6-20 Aryl, substituted or unsubstituted C 1-30 Alkylidene, substituted or unsubstituted amino group, C 2-30Alkylalkoxy, or C 7-30 It is an aryl alkoxy, and

[0150] T is or And,

[0151] T1 is C, Si, Ge, Sn, or Pb, and

[0152] Y1 is hydrogen, hydrogen, C 1-30 Alkyl, C 1-30 Alkoxy, C 2-30 Alkoxyalkyl, C 6-30 Aril, C 6-30 Aryloxy, C 2-30 Alkenyl, C 2-30 Alkinyl, C 3-30 Cycloalkyl, C 7-40 Alkylaryl, C 8-40 Alkenylaryl, C 8-40 Alkynylaryl, C 7-40 Arylalkyl, C 8-40 Aryl alkenyl, or C 8-40 Arylalkinyl, silyl group (-SiH3), C 1-30 Alkoxysilyl group, C 2-30 Alkoxyalkylsilyl group, C 6-30 Aryloxysilyl, C 1-30 Haloalkyl, C 6-30 Haloaryl, or -NR9R 10 And,

[0153] Y2 is C 2-30 Alkoxyalkyl, or C 7-40 It is an aryloxyalkyl, and

[0154] R9 and R 10 Each independently hydrogen, C 1-30 Alkyl, C 6-30 Aril, C 2-30 Alkenyl, C 2-30 Alkinyl, C 3-30 Cycloalkyl, C 7-40 Alkylaryl, C 8-40 Alkenylaryl, C 8-40 Alkynylaryl, C 7-40 Arylalkyl, C 8-40 Aryl alkenyl, or C 8-40They are arylalkynyl, or linked together to form aliphatic or aromatic rings.

[0155]

[0156] Meanwhile, unless otherwise specifically limited in this specification, the following terms may be defined as follows.

[0157]

[0158] Halogens can be fluorine (F), chlorine (Cl), bromine (Br), or iodine (I).

[0159]

[0160] C 1-30 The alkyl group may be a straight-chain, branched-chain, or cyclic alkyl group. Specifically, C 1-20 The alkyl group is C 1-15 Straight-chain alkyl group; C 1-10 Straight-chain alkyl group; C 1-5 Straight-chain alkyl group; C 3-20 Branched or cyclic alkyl group; C 3-15 Branched or cyclic alkyl group; or C 3-10 It may be a branched chain or a cyclic alkyl group. More specifically, C 1-20 The alkyl group of may be a methyl group, ethyl group, n-propyl group, iso-propyl group, n-butyl group, iso-butyl group, tert-butyl group, n-pentyl group, iso-pentyl group, neo-pentyl group, or cyclohexyl group, etc.

[0161]

[0162] C 2-30 The alkenyl group can be a straight-chain, branched-chain, or cyclic alkenyl group. Specifically, C 2-30 The alkenyl group is C 2-20 Straight-chain alkenyl group, C 2-10 Straight-chain alkenyl group, C 2-5 Straight-chain alkenyl group, C 3-20 Branched-chain alkenyl group, C 3-15 Branched-chain alkenyl group, C 3-10 Branched-chain alkenyl group, C 5-20 The cyclic alkenyl group or C 5-10 It may be a cyclic alkenyl group. More specifically, C2-20 The alkenyl group of may be an ethenyl group, a propenyl group, a butenyl group, a pentenyl group, or a cyclohexanyl group, etc.

[0163]

[0164] C 6-30 Aryl can refer to monocyclic, bicyclic, or tricyclic aromatic hydrocarbons. Specifically, C 6-30 The aryl group can be a phenyl group, a naphthyl group, or anthracenyl group, etc.

[0165]

[0166] C 7-40 Alkylaryl may refer to a substituent in which one or more hydrogens of an aryl are substituted by an alkyl group. Specifically, C 7-40 The alkylaryl may be methylphenyl, ethylphenyl, n-propylphenyl, iso-propylphenyl, n-butylphenyl, iso-butylphenyl, tert-butylphenyl, or cyclohexylphenyl, etc.

[0167]

[0168] C 7-40 Arylalkyl may refer to a substituent in which one or more hydrogens of an alkyl group are substituted by an aryl group. Specifically, C 7-40 The arylalkyl group may be a benzyl group, phenylpropyl or phenylhexyl, etc.

[0169]

[0170] The above C 1-20 Examples of alkoxy groups include methoxy groups, ethoxy groups, phenyloxy groups, cyclohexyloxy groups, etc., but are not limited to these.

[0171]

[0172] The above C 2-20The alkoxyalkyl group is a functional group in which one or more hydrogens of the alkyl group described above are substituted with an alkoxy group, specifically, alkoxyalkyl groups such as methoxymethyl group, methoxyethyl group, ethoxymethyl group, iso-propoxymethyl group, iso-propoxyethyl group, iso-propoxyhexyl group, tert-butoxymethyl group, tert-butoxyethyl group, tert-butoxyhexyl group; or aryloxyalkyl groups such as phenoxyhexyl group, but is not limited thereto.

[0173]

[0174] The above C 1-20 alkylsilyl group or C 1-20 The alkoxysilyl group is a functional group in which 1 to 3 hydrogens of -SiH3 are substituted with 1 to 3 alkyl groups or alkoxy groups as described above, and specifically, examples include alkylsilyl groups such as methylsilyl, dimethylsilyl, trimethylsilyl, dimethylethylsilyl, diethylmethylsilyl, or dimethylpropylsilyl; alkoxysilyl groups such as methoxysilyl, dimethoxysilyl, trimethoxysilyl, or dimethoxyethoxysilyl; and alkoxyalkylsilyl groups such as methoxydimethylsilyl, diethoxymethylsilyl, or dimethoxypropylsilyl, but are not limited thereto.

[0175]

[0176] The above C 1-20 The silylalkyl group is a functional group in which one or more hydrogens of the alkyl group described above are substituted with a silyl group, and specifically, examples include -CH2-SiH3, methylsilylmethyl group or dimethylethoxysilylpropyl group, but are not limited thereto.

[0177]

[0178] The above sulfonate group has the structure -O-SO2-R', where R' is C 1-20 It may be an alkyl group. Specifically, C 1-20 Sulfonate groups include methanesulfonate groups or phenylsulfonate groups, but are not limited to these.

[0179]

[0180] The above heteroaryl comprises one or more of N, O, and S as heteroelements, C 2-20 As heteroaryls, specific examples include xanthene, thioxanthen, thiophene group, furan group, pyrrole group, imidazole group, thiazole group, oxazole group, oxadiazole group, triazole group, pyridyl group, bipyridyl group, pyrimidyl group, triazine group, acridyl group, pyridazine group, pyrazinyl group, quinolinyl group, quinazolinyl group, quinoxalinyl group, phthalazinyl group, pyridopyrimidinyl group, pyridopyrazinyl group, pyrazinopyrazinyl group, isoquinoline group, indole group, carbazole group, benzoxazole group, benzimidazole group, benzothiazole group, benzocarbazole group, benzothiophen group, dibenzothiophen group, benzofuranyl group, phenanthroline, There are isooxazolyl groups, thiadiazolyl groups, phenothiazinyl groups and dibenzofuranyl groups, but are not limited to these.

[0181]

[0182] The substituents described above may be optionally substituted with one or more substituents selected from the group consisting of hydroxyl groups; halogens; alkyl groups or alkenyl groups, aryl groups, alkoxy groups; alkyl groups or alkenyl groups, aryl groups, alkoxy groups comprising one or more heteroatoms of groups 14 to 16; silyl groups; alkylsilyl groups or alkoxysilyl groups; phosphine groups; phosphide groups; sulfonate groups; and sulfone groups, within the range of producing the same or similar effects as the desired effect.

[0183]

[0184] Furthermore, the fact that two adjacent substituents are connected to form an aliphatic or aromatic ring means that the atom(s) of the two substituents and the valence (atoms) to which the two substituents are bonded are connected to form a ring. Specifically, -NR9R 10 R9 and R 10Examples of these interconnected groups forming an aliphatic ring include piperidinyl groups, and -NR9R 10 R9 and R 10 Examples of groups connected to form an aromatic ring include pyrrolyl groups.

[0185]

[0186] In addition, group 4 transition metals include titanium (Ti), zirconium (Zr), hafnium (Hf), etc., but are not limited to these.

[0187]

[0188] For example, the first metallocene compound represented by the above chemical formula 1 is Cp 1 and Cp 2 As a non-crosslinked compound containing a ligand of, Cp 1 and Cp 2 The ligands of may be identical or different from each other, and are each cyclopentadiennyl, and C 1-10 It can be substituted with 1 or more alkyl groups or 1 to 3.

[0189]

[0190] Also, the above Cp 1 and Cp 2 The ligand of can easily control characteristics such as the chemical structure, molecular weight, molecular weight distribution, mechanical properties, and transparency of the olefin polymer produced by adjusting the degree of steric hindrance effect according to, for example, the type of substituted functional group. Specifically, the above Cp 1 and Cp 2 The ligands of are R, respectively. a and R b It is replaced with, at this time, the above R a and R b are identical or different from each other, and independently, hydrogen, C 1-20 Alkyl, C 2-20 Alkoxyalkyl, C 7-40 C comprising arylalkyl, or one or more heteroatoms selected from the group consisting of N, O, and S.2-12 It can be heteroaryl, and more specifically, C 1-10 Alkyl, C 2-10 Alkoxyalkyl, C 7-20 C comprising arylalkyl, or one or more heteroatoms selected from the group consisting of N, O, and S. 4-12 It can be heteroaryl. However, R a and R b At least one of them is C 1-20 alkyl or C 7-20 It is an arylalkyl, and one of the others is C 2-20 It is an alkoxyalkyl. For example, R a One or more of them are C 1-20 alkyl or C 7-20 It is an arylalkyl, and R a The remainder is hydrogen, and R b One of them is C 2-20 It is an alkoxyalkyl, and R b The remainder is hydrogen, or C 1-20 alkyl or C 7-20 It can be an arylalkyl.

[0191]

[0192] Also, the above Cp 1 and Cp 2 Between the ligands of M 1 Z 1 3-n This exists, M 1 Z 1 3-n can affect the storage stability of metal complexes. To ensure this effect more effectively, Z 1 Each independently is a halogen or C 1-20 It may be an alkyl group, and more specifically, it may be F, Cl, Br, or I independently. Also, the above M 1 It may be Ti, Zr or Hf; Zr or Hf; or Zr.

[0193]

[0194] Among the first transition metal compounds above, Cp in Chemical Formula 11 and Cp 2 are each an unsubstituted or substituted cyclopentadienyl group, and R a and R b Each independently hydrogen, C 1-10 Alkyl, C 2-10 Alkoxyalkyl, or C 7-20 It is an arylalkyl, but R a and R b At least one of them may be an alkyl group such as methyl or butyl, or an arylalkyl group such as phenylpropyl, and the remainder may be an alkoxyalkyl group such as a t-butoxyhexyl group, more specifically a -(CH2)n-OR substituent (wherein R is a straight-chain or branched-chain alkyl group having 1 to 6 carbon atoms, and n is an integer from 2 to 4).

[0195]

[0196] The first metallocene compound represented by the above chemical formula 1 may be, for example, a compound represented by one of the following structural formulas, but is not limited thereto.

[0197]

[0198]

[0199] In addition, the second metallocene compound comprises an aromatic ring compound containing thiophene as a different ligand and a base compound containing a group 14 or 15 atom, the different ligands are cross-linked by -T-, and has a structure in which M(X1)(X2) exists between the different ligands.

[0200]

[0201] More specifically, in the above chemical formula 2, M is Ti, Zr, or Hf, and more specifically, may be Ti.

[0202]

[0203] Also, R1 to R4 are each independently hydrogen, or C 1-20 It is an alkyl, and more specifically, it can be hydrogen or methyl.

[0204]

[0205] Also, R5 and R6 each independently C 1-10 It is alkyl, and more specifically, both R5 and R6 can be methyl.

[0206]

[0207] Also, Z is -NR7-, and the above R7 is C 1-10 Alkyl, more specifically C such as t-butyl 3-10 It can be a branched alkyl.

[0208]

[0209] Also, T is And, the above T1 is C or Si, and Y1 is C 1-20 Alkyl, C 1-20 Alkoxy, C 2-20 Alkoxyalkyl, C 6-20 Aril, C 7-30 Alkylaryl, C 7-30 Arylalkyl, C 6-20 Aryloxy, or C 7-30 It is aryloxyalkyl, and Y2 is C 2-20 Alkoxyalkyl, or C 7-30 It is an aryloxyalkyl, and more specifically, Y1 can be any one of a methyl group, an ethyl group, an n-propyl group, and an n-butyl group, and Y2 is C 2-20 Alkoxyalkyl, or C 7-30 It is an aryloxyalkyl, and more specifically, Y2 may be any one of a methoxymethyl group, a methoxyethyl group, an ethoxymethyl group, an iso-propoxymethyl group, an iso-propoxyethyl group, an iso-propoxyhexyl group, a tert-butoxymethyl group, a tert-butoxyethyl group, a tert-butoxyhexyl group, and a phenoxyhexyl group.

[0210]

[0211] Also, X1 and X2 are each independently halogen or C 1-20 It is an alkyl, and more specifically, it can be chloro or methyl.

[0212]

[0213] For example, as the second metallocene compound, compounds represented by the following chemical formulas 2a to 2d may be exemplified, and among the compounds represented by the following chemical formulas 2a to 2d, two or more compounds of different structures are included.

[0214]

[0215] According to one embodiment of the present invention, as the second metallocene compound, a combination of two compounds represented by the following formula 2a and two compounds represented by the following formula 2b, or a combination of two compounds represented by the following formula 2a and two compounds represented by the following formula 2c, or a combination of two compounds represented by the following formula 2a and two compounds represented by the following formula 2d, or a combination of two compounds represented by the following formula 2b and two compounds represented by the following formula 2c, or a combination of two compounds represented by the following formula 2b and two compounds represented by the following formula 2d, or a combination of two compounds represented by the following formula 2c and two compounds represented by the following formula 2d may be used.

[0216]

[0217] In this way, by using a mixture of two or more compounds with different structures among the compounds represented by the following chemical formulas 2a to 2d as the second metallocene compound together with one first metallocene compound, it is possible to manufacture polyethylene with optimized melt index while optimizing the molecular structure along with density and securing the molecular weight distribution and weight-average molecular weight within a predetermined range.

[0218] [Chemical Formula 2a]

[0219]

[0220] [Chemical Formula 2b]

[0221]

[0222] [Chemical Formula 2c]

[0223]

[0224] [Chemical Formula 2d]

[0225]

[0226] In the above chemical formulas 2a to 2d, R1 to R7, M, X1, X2, T1, Y1, and Y2 are as previously defined.

[0227]

[0228] More specifically, in the second metallocene compound of the above formulas 2a to 2d, M is Ti, Zr, or Hf, more specifically Ti; and R1 to R4 are each independently hydrogen, or C 1-20 It is alkyl, more specifically hydrogen or methyl; R5 and R6 are each independently C 1-10 It is alkyl, more specifically, both R5 and R6 are methyl; and the above R7 is C 1-10 It is an alkyl, and more specifically, C such as t-butyl. 3-10 It is a branched alkyl; above, T1 is C or Si, and Y1 is C 1-20 Alkyl, C 1-20 Alkoxy, C 2-20 Alkoxyalkyl, C 6-20 Aril, C 7-30 Alkylaryl, C 7-30 Arylalkyl, C 6-20 Aryloxy, or C 7-30 It is aryloxyalkyl, and Y2 is C 2-20 Alkoxyalkyl, or C 7-30 It is an aryloxyalkyl, more specifically, Y1 is any one of a methyl group, an ethyl group, an n-propyl group, and an n-butyl group, and Y2 is C 2-20 Alkoxyalkyl, or C 7-30 It is an aryloxyalkyl, more specifically, Y2 is any one of a methoxymethyl group, a methoxyethyl group, an ethoxymethyl group, an iso-propoxymethyl group, an iso-propoxyethyl group, an iso-propoxyhexyl group, a tert-butoxymethyl group, a tert-butoxyethyl group, a tert-butoxyhexyl group, and a phenoxyhexyl group, and X1 and X2 are each independently a halogen or C 1-20It may be a compound that is alkyl, and more specifically, chloro or methyl.

[0229]

[0230] More specifically, specific examples of the second metallocene compound may include compounds having the following structures, but are not limited thereto:

[0231] , ,

[0232] , ,

[0233] , .

[0234]

[0235] Meanwhile, the first and second metallocene compounds in the catalyst composition may be included in a molar ratio of 1:0.3 to 1:3, and more specifically, in a molar ratio of 1:0.3 or higher, or 1:0.4 or higher, or 1:0.5 or higher, and in a molar ratio of 1:3 or lower, or 1:2 or lower.

[0236]

[0237] In addition, two types of second metallocene compounds of different structures in the catalyst composition may be included in a molar ratio of 1:0.1 to 1:1, and more specifically, in a molar ratio of 1:0.1 or higher, or 1:0.2 or higher, or 1:0.4 or higher, and in a molar ratio of 1:1 or lower, or 1:0.8 or lower.

[0238]

[0239] Meanwhile, the catalyst composition may further include a carrier, in which case the first and second metallocene compounds are used in a state supported on the carrier.

[0240]

[0241] Specific examples of the above carriers include silica, alumina, magnesia, silica-alumina, silica-magnesia, etc., and these may further include oxide, carbonate, sulfate, and nitrate components such as Na2O, K2CO3, BaSO4, and Mg(NO3)2.

[0242]

[0243] In addition, the catalyst composition may further include a co-catalyst to improve high activity and process stability, and the co-catalyst may be, more specifically, an alkylaluminoxan-based co-catalyst such as methylaluminoxan, ethylaluminoxan, isobutylaluminoxan, or butylaluminoxan.

[0244]

[0245] In a polyethylene resin according to one embodiment of the present invention, the polyethylene described above, into which a phenolic compound, a phosphorus-based compound, and an amine-based compound are introduced, is prepared by polymerizing ethylene using the catalyst composition described above. The polymerization process can be carried out as a monomodal (or unimodal) polymerization process in which the polymerization reaction is carried out under single polymerization reaction conditions using a single catalyst in a single reactor, and more specifically, it can be carried out in a single loop-type slurry reactor in the presence of the hybrid supported catalyst described above.

[0246]

[0247] For example, the polymerization process described above can be carried out by additionally adding an alpha-olefin copolymer along with ethylene.

[0248]

[0249] The above alpha-olefin may be one or more selected from the group consisting of 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicocene, and mixtures thereof. Preferably, 1-hexene or 1-butene may be used as the alpha-olefin, and more specifically, 1-hexene may be used.

[0250]

[0251] For example, in the polymerization process described above, the alpha-olefin described above may be introduced in an amount of 12% by weight or less relative to the amount of ethylene introduced. Specifically, the alpha-olefin may be introduced in an amount of 10% by weight or less, or 8% by weight or less, or 7.5% by weight or less, or 7% by weight or less, or 6.5% by weight or less, or 6% by weight or less, or 5.8% by weight or less, or 5.5% by weight or less, but is not limited thereto. In addition, the alpha-olefin may be introduced in an amount of 0.1% by weight or more, or 0.3% by weight or more, or 0.5% by weight or more, or 0.7% by weight or more, or 0.85% by weight or more, or 0.9% by weight or more, or 1.0% by weight or more, or 1.2% by weight or more, or 1.4% by weight or more, or 1.6% by weight or more, but is not limited thereto.

[0252]

[0253] In addition, the polyethylene in the present invention can be manufactured by introducing hydrogen gas in the presence of the catalyst composition described above.

[0254]

[0255] Specifically, the polymerization step can be performed by introducing hydrogen gas at a concentration of about 150 ppm to about 480 ppm based on ethylene content. More specifically, hydrogen gas can be introduced at a concentration of about 160 ppm or more, or about 180 ppm or more, or about 200 ppm or more, and at the same time, at a concentration of about 460 ppm or less, or about 450 ppm or less, or about 445 ppm or less, or about 440 ppm or less, or about 435 ppm or less, or about 430 ppm or less.

[0256]

[0257] At this time, the polymerization temperature may be 25 ℃ to 500 ℃, and preferably 25 ℃ to 200 ℃, or 60 ℃ to 120 ℃, or 70 ℃ to 100 ℃, or 72 ℃ to 95 ℃, or 75 ℃ to 90 ℃, or 78 ℃ to 88 ℃, or 80 ℃ to 85 ℃.

[0258]

[0259] In addition, the polymerization pressure may be 1 Kgf / ㎠ to 100 Kgf / ㎠, preferably 1 Kgf / ㎠ to 70 Kgf / ㎠, or 2 Kgf / ㎠ to 50 Kgf / ㎠, or 5 Kgf / ㎠ to 50 Kgf / ㎠, or 8 Kgf / ㎠ to 45 Kgf / ㎠, or 10 Kgf / ㎠ to 42 Kgf / ㎠.

[0260]

[0261] Meanwhile, a polyethylene resin according to one embodiment of the present invention further comprises, together with the polyethylene described above, a phenolic compound, a phosphorus-based compound, and an amine-based compound.

[0262]

[0263] Specifically, the phenolic compounds are pentaerythritol tetrakis(3,5-di-tert-butyl-4-hydroxyhydrocinnamate, product name: Irganox 1010), octadecyl-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (product name: Irganox 1076), and 3,3',3',5,5',5'-hexa-tert-butyl-a,a',a'-(mesitylene-2,4,6-triyl)tri-p-cresol It may be one or more selected from the group consisting of (3,3',3',5,5',5'-hexa-tert-butyl-a,a',a'-(mesitylene-2,4,6-triyl) tri-p-cresol, product name: Irgaonx 1330). Among these, pentaerythritol tetrakis(3,5-di-tert-butyl-4-hydroxyhydrocinnamate) is preferred in that it maintains excellent mechanical properties and improves resistance to environmental stress cracking while simultaneously minimizing the yellow index to prevent discoloration.

[0264]

[0265] In addition, the above-mentioned phosphorus compound has a phosphite structure in which two or more or three or more bulky substituents, such as tert-butyl substituted phenyl groups, are bonded to a phosphorus atom, or a structure in which two phosphite (P(III)) groups are bonded to a pentaerythritol backbone, and has the characteristics of having excellent stability against oxidation due to a large steric hindrance, as well as excellent hydrolytic stability and thermal stability.

[0266]

[0267] For example, the above-mentioned phosphorus compound is one or more selected from the group consisting of tris(2,4-di-tert-butylphenyl)phosphite (product name: Irafos 1680) and bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite (product name: Eunox AO-626). Among these, tris(2,4-di-tert-butylphenyl)phosphite is preferred in that it maintains excellent mechanical properties and improves resistance to environmental stress cracking while simultaneously minimizing the yellow index to prevent discoloration.

[0268]

[0269] In addition, the above amine-based compound may be a non-hindered amine-based compound. Such non-hindered amines have a structure in which the area around the nitrogen atom is open, and differ structurally from hindered amines in which bulky alkyl groups are substituted around the nitrogen. In particular, such non-hindered amines have high reactivity and are characterized by effective antioxidant performance. Furthermore, along with the antioxidant effect, such amine-based compounds can act as metal scavengers and prevent oxidation of metallic foreign substances present in recycled polyethylene (PCW).

[0270]

[0271] For example, the above amine compound is one or more selected from the group consisting of bis(3,5-di-tert-butyl-4-hydroxyhydrocinnamoyl)hydrazine (product name: Irganox MD 1024) and (3,3'-bis(3,5-di-tert-butyl-4-hydroxyphenyl)-N,N'-hexamethylenedipropionamide) (product name: Irganox 1098). Among these, bis(3,5-di-tert-butyl-4-hydroxyhydrocinnamoyl)hydrazine is desirable in that it acts as a metal scavenger and prevents oxidation of metallic foreign matter in recycled polyethylene (PCW), thereby maintaining excellent mechanical properties and preventing discoloration in the final product while significantly improving environmental stress crack resistance.

[0272]

[0273] Meanwhile, a polyethylene resin according to one embodiment of the present invention additionally includes a phenolic compound, a phosphorus compound, and an amine compound together with the polyethylene described above, and by optimizing the total content of the phenolic compound, the phosphorus compound, and the amine compound, it can maintain excellent mechanical properties and improve resistance to environmental stress cracking when combined with recycled polyethylene, while simultaneously preventing discoloration.

[0274]

[0275] Specifically, the total content of the phenolic compound, phosphorus compound, and amine compound is 0.32% or more and 0.75% or less relative to the weight of the polyethylene. Preferably, the total content of the phenolic compound, phosphorus compound, and amine compound may be 0.33% or more, or 0.35% or more, or 0.37% or more, or 0.38% or more, or 0.39% or more, or 0.4% or more, and may also be 0.73% or less, or 0.7% or less, or 0.68% or less, or 0.65% or less, or 0.63% or less, or 0.6% or less.

[0276]

[0277] In addition, the above-mentioned phenolic compounds, phosphorus compounds, and amine compounds may be included in an optimized content range for each component within the range of maintaining the total content range described above.

[0278]

[0279] Specifically, the content of the phenolic compound may be 0.03% or more and 0.15% or less relative to the weight of the polyethylene. Preferably, the content of the phenolic compound may be 0.035% or more, or 0.038% or more, or 0.04% or more, or 0.042% or more, or 0.045% or more, or 0.048% or more, or 0.05% or more, and may also be 0.14% or less, or 0.13% or less, or 0.12% or less, or 0.11% or less, or 0.1% or less.

[0280]

[0281] In addition, the content of the phosphorus compound may be 0.25% or more and 0.45% or less relative to the weight of the polyethylene. Preferably, the content of the phenolic compound may be 0.25% or more, or 0.027% or more, or 0.028% or more, or 0.029% or more, or 0.03% or more, and may also be 0.44% or less, or 0.43% or less, or 0.42% or less, or 0.41% or less, or 0.4% or less.

[0282]

[0283] In addition, the content of the amine-based compound may be 0.03% or more and 0.15% or less relative to the weight of the polyethylene. Preferably, the content of the phenol-based compound may be 0.035% or more, or 0.038% or more, or 0.04% or more, or 0.042% or more, or 0.045% or more, or 0.048% or more, or 0.05% or more, and may also be 0.14% or less, or 0.13% or less, or 0.12% or less, or 0.11% or less, or 0.1% or less.

[0284]

[0285] Meanwhile, a polyethylene resin according to one embodiment of the present invention is characterized by including a phenolic compound, a phosphorus compound, and an amine compound within the total content range described above, while optimizing the content ratio of the phenolic compound, the phosphorus compound, and the amine compound.

[0286]

[0287] Specifically, the content of the phenolic compound (AO1) and the content of the amine compound (AO3) satisfy Formula 1 below.

[0288] [Equation 1]

[0289] 0.6 ≤ AO1 / AO3 ≤ 1.8

[0290] In the above Equation 1,

[0291] AO1 is the content of the above-mentioned phenolic compound, and

[0292] AO3 is the content of the above amine compound.

[0293]

[0294] Formula 1 above represents the correlation between the content of the phenolic compound (AO1) and the content of the amine compound (AO3), that is, the content ratio of the content of the phenolic compound (AO1) to the content of the amine compound (AO3) is 0.6 or more and 1.8 or less, preferably 0.65 or more, or 0.7 or more, or 0.75 or more, or 0.8 or more, or 0.85 or more, or 0.9 or more, and may be 1.7 or less, or 1.5 or less, or 1.3 or less, or 1.25 or less, or 1.2 or less, or 1.15 or less, or 1.1 or less.

[0295]

[0296] In addition, the content of the phenolic compound (AO1), the content of the phosphorus compound (AO2), and the content of the amine compound (AO3) satisfy Formula 2 below.

[0297] [Equation 2]

[0298] AO2 / (AO1+ AO3) ≥ 1.5

[0299] In the above Equation 2,

[0300] AO1 is the content of the above-mentioned phenolic compound, and

[0301] AO2 is the content of the above-mentioned phosphorus compound, and

[0302] AO3 is the content of the above amine compound.

[0303]

[0304] Formula 2 above represents the correlation of the sum of the content of the phosphorus compound (AO2), the content of the phenol compound (AO1), and the content of the amine compound (AO3), that is, the ratio of the content of the phosphorus compound (AO2) / [content of the phenol compound (AO1) + content of the amine compound (AO3)] is 1.5 or higher. More specifically, the ratio of the sum of the content of the phosphorus compound (AO2), the content of the phenol compound (AO1), and the content of the amine compound (AO3) according to Formula 2 above may be 1.52 or higher, or 1.55 or higher, or 1.58 or higher, or 1.6 or higher, or 1.65 or higher, or 1.7 or higher, or 1.75 or higher, or 1.8 or higher, or 1.85 or higher, or 1.9 or higher, or 1.95 or higher, or 2 or higher. However, considering the optimized content range of the above-mentioned phenolic compound, phosphorus compound, and amine compound, it may be 20 or less, or 18 or less, or 15 or less, or 12 or less, or 10 or less, or 8.5 or less, or 8 or less, or 7.5 or less, or 7 or less, or 6.5 or less, or 6 or less, or 5.5 or less, or 5 or less, or 4.8 or less, or 4.5 or less, or 4.3 or less, or 4 or less, or 3.8 or less, or 3.5 or less, or 3.3 or less, or 3 or less.

[0305]

[0306] In particular, phenolic compounds, phosphorus compounds, and amine compounds must maintain the content ratio described above in order to ensure excellent mechanical properties and improved resistance to environmental stress cracking, while simultaneously preventing discoloration, under the mutual antagonism and interactions with chromophores within the molecular structure of polyethylene.

[0307]

[0308] In addition, the content of the phenolic compound (AO1) and the content of the phosphorus compound (AO2) satisfy the following Formula 3.

[0309] [Equation 3]

[0310] 0.1 ≤ AO1 / AO2 ≤ 0.3

[0311] In the above Equation 3,

[0312] AO1 is the content of the above-mentioned phenolic compound, and

[0313] AO2 is the content of the above-mentioned phosphorus compound.

[0314]

[0315] Formula 3 above represents the correlation between the content of the phenolic compound (AO1) and the content of the phosphorus compound (AO2), that is, the content ratio of the content of the phenolic compound (AO1) to the content of the phosphorus compound (AO2) may be 0.1 or more and 0.3 or less, preferably 0.105 or more, or 0.11 or more, or 0.115 or more, or 0.12 or more, or 0.125 or more, and 0.29 or less, or 0.28 or less, or 0.27 or less, or 0.26 or less, or 0.25 or less.

[0316]

[0317] In particular, it is desirable to maintain the content ratios of phenolic compounds, phosphorus compounds, and amine compounds as described above in terms of mutual antagonism and interactions with chromophores within the molecular structure.

[0318]

[0319] Meanwhile, according to another embodiment of the invention, a polyethylene resin composition is provided comprising virgin polyethylene (or Booster PE) and recycled polyethylene (PCW PE, Post consumer waste polyethylene), wherein the virgin polyethylene is the polyethylene resin of the above-described embodiment or a mixture thereof.

[0320]

[0321] In particular, the polyethylene resin composition according to the present invention uses a polyethylene resin that includes, as described above, a phenolic compound, a phosphorus compound, and an amine compound in an optimized amount together with polyethylene. This allows for maintaining excellent mechanical properties when combined with recycled polyethylene and improving environmental stress cracking resistance (ESCR), while simultaneously preventing discoloration. Furthermore, when combined with recycled polyethylene, it is possible to secure a high drop impact strength comparable to that of virgin resin.

[0322]

[0323] For example, if phenolic compounds, phosphorus compounds, and amine compounds are not optimally added to the polyethylene resin itself, but are added during blending and extrusion with recycled polyethylene, it becomes difficult to improve mechanical properties such as drop impact strength or environmental stress crack resistance (ESCR) while simultaneously improving discoloration issues, and thus, even if the quality of the new polyethylene (booster) is improved, there are limitations to the improvement of the quality of the final product.

[0324]

[0325] Accordingly, the polyethylene resin composition of the present invention, by using the polyethylene resin of the above-described embodiment, can produce a molded article that not only has excellent environmental stress cracking resistance (ESCR) and high mechanical properties, but also minimizes discoloration, even when combined with recycled polyethylene resin.

[0326]

[0327] Specifically, in the polyethylene composition, the virgin polyethylene may be included in an amount of 5% or more by weight or from 5% to 85% by weight based on the total weight of the composition, and the recycled polyethylene may be included in an amount of 15% or more by weight or from 15% to 95% by weight based on the total weight of the composition. In particular, to enhance the carbon dioxide emission suppression effect of the polyethylene composition and to reduce costs, the content of the virgin polyethylene may be 85% or less by weight, or 50% or less by weight, or 30% or less by weight, and the content of the recycled polyethylene resin (PCW PE) may be 15% or more by weight, or 20% or more by weight, or 30% or more by weight. In addition, in terms of improving the flexural modulus and drop impact strength of the polyethylene composition and achieving physical properties equivalent to those of virgin resin, the content of the virgin polyethylene (Booster PE) may be 5 weight% or more, or 7 weight% or more, or 10 weight% or more, and the content of the recycled polyethylene resin (PCW PE) may be 95 weight% or less, or 80 weight% or less, or 60 weight% or less.

[0328]

[0329] Here, the total sum of the new polyethylene content and the recycled polyethylene content does not exceed 100%.

[0330]

[0331] Meanwhile, the above-mentioned novel polyethylene may additionally include high-density polyethylene together with the polyethylene of the above-described embodiment.

[0332]

[0333] For example, the high-density polyethylene among the above-mentioned new polyethylene may be included in an amount of 80% by weight or less, or 0 to 80% by weight or less, based on the total weight of the entire composition. In particular, to enhance the carbon dioxide emission suppression effect of the polyethylene composition and to reduce costs, the content of high-density polyethylene among the above-mentioned new polyethylene may be 80% by weight or less, 70% by weight or less, or 60% by weight or less. The content of high-density polyethylene among the above-mentioned new polyethylene may be 5% by weight or more, 20% by weight or more, or 40% by weight or more.

[0334]

[0335] Specifically, the high-density polyethylene additionally included as the novel polyethylene has a density (ASTM D 1505, 23 °C) of 0.955 g / cm³ 3 Above or 0.955 g / cm³ 3 Up to 0.965 g / cm³ 3 It may be. More specifically, the density of the high-density polyethylene is 0.956 g / cm³ 3 Above, or 0.957 g / cm³ 3 Above, or 0.958 g / cm³ 3 It may be greater than 0.963 g / cm³ 3 Less than or equal to 0.962 g / cm³ 3 Less than or equal to 0.961 g / cm³ 3 Less than or equal to 0.960 g / cm³ 3 It may be less than.

[0336]

[0337] In addition, the above high-density polyethylene has a melt index (MI 2.16 , 190 o C (measured under a 2.16 kg load) may be 0.1 g / 10 min to 0.5 g / 10 min.

[0338]

[0339] In addition, the above high-density polyethylene may have an environmental stress cracking resistance (ESCR) of 200 hours or more or 200 to 400 hours as measured according to ASTM D 1693 (Condition B, F50, Igepal 10%).

[0340]

[0341] Meanwhile, when the above polyethylene resin composition is combined with a recycled polyethylene resin including high-density polyethylene together with the polyethylene resin of the above-described embodiment, the content of the polyethylene resin that additionally includes a phenolic compound, a phosphorus compound, and an amine compound in an optimized amount together with the polyethylene resin of the above-described embodiment, i.e., polyethylene, may be 33 parts by weight or less when the content of the recycled polyethylene resin (PCW PE) is 100 parts by weight.

[0342]

[0343] Meanwhile, the above recycled polyethylene (PCW PE) has a density (ASTM D 1505, 23 ℃) of 0.940 g / cm³ 3 Up to 0.960 g / cm³ 3 It can be represented by such characteristics. More specifically, the density of the recycled polyethylene (PCW PE) (ASTM D 1505, 23 ℃) is 0.943 g / cm³. 3 Above, or 0.945 g / cm³ 3 Above, or 0.948 g / cm³ 3 Above, 0.950 g / cm³ 3 It may be greater than 0.958 g / cm³ 3 Less than or equal to 0.956 g / cm³ 3 Less than or equal to 0.955 g / cm³ 3 Less than or equal to 0.953 g / cm³ 3 It may be less than.

[0344]

[0345] In addition, the above recycled polyethylene (PCW PE) has a melt index (MI 2.16 , 190 o C (measured under a 2.16 kg load) may be 0.1 g / 10 min to 0.7 g / 10 min.

[0346]

[0347] In addition, the above recycled polyethylene (PCW PE) may have an environmental stress cracking resistance (ESCR) of 20 to 60 hours as measured according to ASTM D 1693 (Condition B, F50, Igepal 10%).

[0348]

[0349] Meanwhile, the polyethylene resin composition according to the present invention can secure excellent drop impact strength comparable to that of virgin resin while increasing the recycled polyethylene content, improve environmental stress cracking resistance (ESCR), and also secure a low yellow index (YI) to prevent discoloration of the final product.

[0350]

[0351] Specifically, the polyethylene composition may have an environmental stress cracking resistance (ESCR) of 200 hours or more, measured according to ASTM D 1693 (Condition B, F50, Igepal 10%). With the excellent ESCR characteristics described above, the polyethylene composition of the present invention can prevent discoloration along with excellent mechanical properties when used as a blow container, and simultaneously secure excellent processability and high drop strength.

[0352]

[0353] For example, the method for measuring the environmental stress cracking resistance (ESCR) of the above polyethylene composition is as described in the test examples described below. However, the method for measuring the environmental stress cracking resistance (ESCR) of the above polyethylene composition is not limited thereto and may be measured by other methods known in the art to which the present invention belongs.

[0354]

[0355] In addition, the Yellow Index (YI) measured at room temperature (20°C) using UltraScan PRO (manufactured by HunterLab) in accordance with ASTM D 1925 may be 3 or less. For example, the method for measuring the Yellow Index (YI) is as described in the test examples described below. However, the method for measuring the Yellow Index (YI) is not limited thereto and may be measured by other methods known in the technical field to which the present invention belongs. Preferably, the Yellow Index (YI) may be 2.8 or less, or 2.6 or less, or 2.55 or less, or 2.5 or less, or 2.45 or less, or 2.4 or less, or 2.3 or less, or 2.2 or less, or 2.18 or less. However, in substantial terms of the polyethylene composition, the Yellow Index (YI) may be -15 or higher, or -12 or higher, or -10 or higher, or -8 or higher, or -5 or higher, or -3 or higher, or -1 or higher, or 0.1 or higher, or 0.3 or higher, or 0.5 or higher, or 0.8 or higher, or 0.9 or higher, or 0.92 or higher, or 0.94 or higher, or 0.95 or higher.

[0356]

[0357] In addition, the polyethylene composition may have a drop impact strength of 7 or more, measured by the number of drops until a crack occurs under conditions of an impact energy of 15.5 J, an impact velocity of 4.55 m / s, and a temperature of 5 ℃ according to the ASTM D 3763 method. For example, the method for measuring the drop impact strength is as described in the test examples described below. However, the method for measuring the drop impact strength is not limited thereto and may be measured by other methods known in the art to which the present invention belongs.

[0358]

[0359] In addition, the polyethylene composition has a density (ASTM D 1505, 23 °C) of 0.945 g / cm³ 3 or greater, or 0.945 to 0.960 g / cm³ 3 It could be.

[0360]

[0361] In addition, the above polyethylene composition has a melt index (MI) measured at 190°C and a 2.16 kg load according to ASTM D 1238. 2.16 ) may be 0.2 g / 10min to 0.5 g / 10min, or 0.25 g / 10min to 0.33 g / 10min.

[0362]

[0363] In addition, the polyethylene resin composition may have a weight-average molecular weight of 144,000 g / mol to 151,500 g / mol and a molecular weight distribution (Mw / Mn) of 15.1 to 16.5.

[0364]

[0365] At this time, the density and melt index (MI) of the polyethylene resin composition are 2.16The measurement methods for ), weight-average molecular weight, molecular weight distribution (Mw / Mn), etc., are as described above with respect to polyethylene, and can be used to measure polyethylene resin compositions instead of polyethylene using these methods, and specific details are omitted.

[0366]

[0367] Preferred embodiments are presented below to aid in understanding the present invention. However, the following embodiments are provided merely to facilitate a better understanding of the invention and do not limit the scope of the invention.

[0368]

[0369] <Example>

[0370] Synthesis Example 1: Preparation of Polyethylene

[0371] High-density new polyethylene was manufactured through a single slurry polymerization process as follows.

[0372]

[0373] First, 25 kg / h of isobutane and 30 kg / h of ethylene were injected into a single slurry loop reactor, along with hydrogen at a flow rate of 390 ppm. Subsequently, a catalyst (molar ratio of first metallocene compound (1), second metallocene compound (2), and second metallocene compound (3) = 1:0.41:0.2) in which the first metallocene compound (1), second metallocene compound (2), and second metallocene compound (3) were hybrid-supported on a silica carrier (Grace Davison, SP2212) and a comonomer (1-hexene) were injected. The comonomer used here was 1-hexene, and the input amount was 2.7 wt% relative to the ethylene input amount. At this time, the reactor was maintained between 80 and 85 ℃, and the pressure was 42 kg / cm². 3 The copolymerization process was carried out by maintaining the solvent, and subsequently, the high-density virgin polyethylene (HDPE, Virgin polyethylene) of Example 1-1 was produced in powder form through a solvent removal facility and a dryer.

[0374] (1)

[0375] (2) (3).

[0376]

[0377] For the high-density new polyethylene manufactured as described above, the physical properties were evaluated using the following method.

[0378]

[0379] (1) Melt index

[0380] 190 according to the American Society for Testing and Materials standard ASTM D 1238 (Condition E) o Each melt index (MI) under C with loads of 2.16 kg and 21.6 kg 2.16 ) and Melt Index (MI 21.6 ) was measured and expressed as the weight (g) of the polymer that melted out over 10 minutes.

[0381]

[0382] (2) Density

[0383] Density of polyethylene (g / cm³) according to the American Society for Testing and Materials (ASTM) D 1505 standard 3 ) was measured.

[0384]

[0385] (3) Weight-average molecular weight (Mw, g / mol) and molecular weight distribution (PDI, polydispersity index, Mw / Mn)

[0386] The weight-average molecular weight (Mw) and number-average molecular weight (Mn) of polyethylene were measured using gel permeation chromatography (GPC, manufactured by Polymer Char), and the molecular weight distribution (PDI, Mw / Mn) was calculated by dividing the weight-average molecular weight by the number-average molecular weight.

[0387]

[0388] Specifically, a Polymer Char GPC-IR instrument was used as the gel permeation chromatography (GPC) device, and a Polymer Laboratories PLgel MIX-B 300 mm long column was used. The measurement temperature was 160 °C, 1,2,4-trichlorobenzene was used as the solvent, and the flow rate was set to 1 mL / min. Polyethylene samples according to the examples and comparative examples were each pretreated by dissolving them in trichlorobenzene (1,2,4-trichlorobenzene) containing 0.0125% butylated hydroxytoluene (BHT) at 160 °C for 2 hours using a GPC analyzer (GPC-IR), prepared to a concentration of 10 mg / 10 mL, and supplied in an amount of 200 μL. The values ​​of Mw and Mn were derived using a calibration curve formed using a polystyrene standard specimen. Nine types of polystyrene standard specimens with weight-average molecular weights of 2000 g / mol, 10000 g / mol, 30000 g / mol, 70000 g / mol, 200000 g / mol, 700000 g / mol, 2000000 g / mol, 4000000 g / mol, and 10000000 g / mol were used.

[0389]

[0390] The density of high-density polyethylene measured in this way is 0.946 g / cm³ 3 and melt index (MI 2.16 (ASTM D 1238, 190 ℃, 2.16 kg) was 0.51 g / 10 min, the weight-average molecular weight was 132300 g / mol, and the molecular weight distribution (Mw / Mn) was 24.9.

[0391]

[0392] Example 1-1: Preparation of Novel Polyethylene Resin

[0393] The new polyethylene resin of Example 1-1 was prepared by adding a phenolic compound, a phosphorus compound, and an amine compound in the amounts shown in Table 1 below to the polyethylene obtained in Synthesis Example 1 above, i.e., the high-density new ethylene / 1-hexene copolymer, in a dry blend manner.

[0394]

[0395] Specifically, in Table 1 below, the AO 1010 compound as a phenolic compound is Pentaerythritol tetrakis(3,5-di-tert-butyl-4-hydroxyhydrocinnamate) (CAS No.: 6683-19-8, Product Name: Irganox 1010), and has the following structural formula.

[0396] .

[0397]

[0398] In addition, the AO 1680 compound as a phosphorus-containing compound in Table 1 below is Tris(2,4-di-tert-butylphenyl) phosphite (CAS No.: 31570-04-4, Product Name: Irafos 1680), and has the following structural formula.

[0399] .

[0400]

[0401] In addition, the AO 1024 compound as an amine compound in Table 1 below is bis(3,5-di-tert-Butyl-4-hydroxyhydrocinnamoyl)hydrazine (CAS No.: 32687-78-8, Product Name: Irganox MD 1024) and has the following structural formula.

[0402] .

[0403]

[0404] In Table 1 below, the content of phenolic compounds, phosphorus compounds, and amine compounds is the value added based on the weight of polyethylene.

[0405]

[0406] In addition, Equation 1, which is a correlation equation related to the content of the phenolic compound (AO1) and the content of the amine compound (AO3), is as follows.

[0407] [Equation 1]

[0408] 0.6 ≤ AO1 / AO3 ≤ 1.8

[0409] In the above Equation 1,

[0410] AO1 is the content of the above-mentioned phenolic compound, and

[0411] AO3 is the content of the above amine compound.

[0412]

[0413] In addition, Equation 2, which is a correlation equation related to the content of the phenolic compound (AO1), the content of the phosphorus compound (AO2), and the content of the amine compound (AO3), is as follows.

[0414] [Equation 2]

[0415] AO2 / (AO1+ AO3) ≥ 1.5

[0416] In the above Equation 2,

[0417] AO1 is the content of the above-mentioned phenolic compound, and

[0418] AO2 is the content of the above-mentioned phosphorus compound, and

[0419] AO3 is the content of the above amine compound.

[0420]

[0421] Examples 1-2 to 1-7: Preparation of Novel Polyethylene Resin

[0422] New polyethylene resins of Examples 1-2 to 1-7 were prepared by preparing polyethylene resin in the same manner as in Example 1-1, but with different amounts of phenolic compounds, phosphorus compounds, and amine compounds as shown in Table 1 below.

[0423]

[0424] Specifically, in Table 1 below, the AO 1010 compound as a phenolic compound is as described above, and the AO 1076 compound as a phenolic compound is Octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate (CAS No.: 2082-79-3, Product Name: Irganox 1076) and has the following structural formula.

[0425] .

[0426]

[0427] In addition, the AO 1330 compound as a phenolic compound in Table 1 below is 1,3,5-Trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene (CAS No.: 1709-70-2, Product Name: Irganox 1330), and has the following structural formula.

[0428] .

[0429]

[0430] In addition, in Table 1 below, the AO 1680 compound as a phosphorus-containing compound is as described above, and the AO 626 compound as a phosphorus-containing compound is the commercial product Eunox AO-626 (Manufacturer: Eutec Chemical Co., Ltd).

[0431]

[0432] In addition, the AO 1024 compound as an amine compound in Table 1 below is as described above.

[0433]

[0434] Comparative Examples 1-1 to 1-12: Preparation of Novel Polyethylene Resin

[0435] New polyethylene resins of Comparative Examples 1-1 to 1-12 were prepared by preparing a new polyethylene resin in the same manner as in Example 1-1, but with different amounts of phenolic compounds, phosphorus compounds, and amine compounds as shown in Table 1 below.

[0436]

[0437] Specifically, in Table 1 below, the AO 1010 compound as a phenolic compound is as described above.

[0438]

[0439] In addition, in Table 1 below, the AO 1680 compound as a phosphorus compound is as described above, and the AO 10 compound as a phosphorus compound is the commercial product 2,2′-Methylenebis(4,6-di-tert-butylphenyl) 2-ethylhexyl phosphite (product name, HP-10; manufacturer: Adeka).

[0440]

[0441] In addition, in Table 1 below, the AO 1024 compound as an amine compound is as described above, and the AO 119 compound as an amine compound is the commercial product Chimassorb 119 (manufacturer: BASF).

[0442]

[0443] Additive Components / Content (ppm) Total Additive Content (ppm) Content of Formula 1 Ratio Content of Formula 2 Biphenol Compounds (AO1) Phosphorus Compounds (AO2) Amine Compounds (AO3) Example 1-1 AO 1010 / 500 AO 1680 / 4000 AO 1024 / 500 5000 14 Example 1-2 AO 1010 / 1000 AO 1680 / 4000 AO 1024 / 1000 6000 12 Example 1-3 AO 1010 / 750 AO 1680 / 3000 AO 1024 / 750 4500 12 Example 1-4 AO 1010 / 500 AO 1680 / 3000 AO 1024 / 500400013 Example 1-5 AO 1076 / 500 AO 1680 / 4000 AO 1024 / 500500014 Example 1-6 AO 1330 / 500 AO 1680 / 4000 AO 1024 / 500500014 Example 1-7 AO 1010 / 500 AO 626 / 4000 AO 1024 / 500500014 Comparative Example 1-1 AO 1010 / 1000 AO 1680 / 2000 None 3000-2 Comparative Example 1-2 AO 1010 / 500 AO 1680 / 1000 None 1500-2 Comparative Example 1-3 AO 1010 / 1000AO 1680 / 4000 None 5000 -4 Comparative Example 1-4 AO 1010 / 4000 AO 1680 / 1000 None 5000 -0.25 Comparative Example 1-5 AO 1010 / 500 AO 1680 / 2000 AO 1024 / 500 3000 12 Comparative Example 1-6 AO 1010 / 1200 AO 1680 / 2400 AO 1024 / 1200 4800 11 Comparative Example 1-7 AO 1010 / 2000 AO 1680 / 4000 AO 1024 / 2000 8000 11 Comparative Example 1-8 AO 1010 / 600 AO 1680 / 4000 AO 1024 / 120048000.52.22 Comparative Example 1-9AO 1010 / 1200AO 1680 / 4000AO 1024 / 600480022.22 Comparative Example 1-10 AO 1010 / 500 AO 10 / 4000 AO 1024 / 500 5000 14 Comparative Example 1-11 AO 1010 / 500 AO 1680 / 4000 AO 119 / 500 5000 14 Comparative Example 1-12 AO 1010 / 1000 AO 1680 / 6000 AO 1024 / 1000 8000 13.

[0444]

[0445] Example 2-1: Preparation of a polyethylene resin composition (PCR Compound) mixed with recycled polyethylene (PCW PE)

[0446] 10 wt% of the virgin polyethylene resin prepared in Example 1-1 and 60 wt% of high-density polyethylene (product of Lotte Chemical, product name 6200B) were used as virgin polyethylene, and 30 wt% of recycled polyethylene (PCW PE, Post consumer waste polyethylene) were dry blended and then extruded through a twin screw extruder to prepare a polyethylene composition (PCR Compound).

[0447]

[0448] Specifically, the high-density polyethylene is a commercially available Booster Grade high-density polyethylene (HDPE) product for PCR manufactured using a Ziegler-Natta catalyst (Z / N, Zeigier-Natta catalyst) (product of Lotte Chemical, product name 6200B).

[0449]

[0450] In addition, the above-mentioned recycled polyethylene (BSN Baeksan natural color product of Baeksan Plastic Co., Ltd.) has a melt index MI 2.16 (190 according to ASTM D 1238 (Condition E) o (Measured under a 2.16 kg load at C) is at the level of 0.15–0.2 g / 10 min, and the density (measured according to ASTM D 1505 standard) is 0.951–0.953 g / cm³3 , ESCR (measured the time to F50 (50% destruction) under 50°C conditions using 10% Igepal CO-630 Solution according to ASTM D 1693) is at the 40–50 hour level.

[0451]

[0452] Examples 2-2 to 2-7: Preparation of Polyethylene Resin Composition (PCR Compound) Mixed with Recycled Polyethylene (PCW PE)

[0453] Polyethylene resin compositions (PCR Compounds) of Examples 2-2 to 2-4 were prepared by using the same method as in Example 2-1, but using the new polyethylene resins of Examples 1-2 to 1-7 instead of the polyethylene resin of Example 1-1, and mixing recycled polyethylene (PCW PE) in the same method as in Example 2-1.

[0454]

[0455] Comparative Examples 2-1 to 2-12: Preparation of polyethylene resin compositions (PCR Compound) mixed with recycled polyethylene (PCW PE)

[0456] Polyethylene resin compositions (PCR Compounds) were prepared in the same manner as in Example 2-1, but using the new polyethylene resins of Comparative Examples 1-1 to 1-12 instead of the polyethylene resin of Example 1-1, and mixing recycled polyethylene (PCW PE) in the same manner as in Example 2-1 to prepare the polyethylene resin compositions (PCR Compounds) of Comparative Examples 2-1 to 2-12.

[0457]

[0458] Comparative Example 2-13: Preparation of a polyethylene resin composition (PCR Compound) mixed with recycled polyethylene (PCW PE)

[0459] A polyethylene resin composition (PCR Compound) was prepared by mixing recycled polyethylene (PCW PE) in the same manner as Comparative Example 2-2, but after dry blending the virgin polyethylene and recycled polyethylene (PCW PE, Post consumer waste polyethylene), the phenolic compound Pentaerythritol tetrakis(3,5-di-tert-butyl-4-hydroxyhydrocinnamate) (CAS No.: 6683-19-8, Product Name: Irganox 1010) and the phosphorus compound Tris(2,4-di-tert-butylphenyl) phosphite (CAS No.: 31570-04-4, Product Name: Irafos 1680) were added at 500 ppm and 1000 ppm, respectively, relative to the weight of the high-density virgin polyethylene of Synthesis Example 1, to prepare the polyethylene resin composition (PCR Compound) of Comparative Example 2-13.

[0460]

[0461] Comparative Example 2-14: Preparation of a polyethylene resin composition (PCR Compound) mixed with recycled polyethylene (PCW PE)

[0462] A polyethylene resin composition (PCR Compound) mixed with recycled polyethylene (PCW PE) was prepared in the same manner as in Comparative Example 2-2, wherein, after dry blending virgin polyethylene and recycled polyethylene (PCW PE, Post consumer waste polyethylene), the phenolic compound Pentaerythritol tetrakis(3,5-di-tert-butyl-4-hydroxyhydrocinnamate) (CAS No.: 6683-19-8, Product Name: Irganox 1010), the phosphorus-based compound Tris(2,4-di-tert-butylphenyl) phosphite (CAS No.: 31570-04-4, Product Name: Irafos 1680), and the amine-based compound bis(3,5-di-tert-butyl-4-hydroxyhydrocinnamoyl)hydrazine (CAS No.: 32687-78-8, Product Name: Irganox MD 1024) were added during extrusion to the high density of Synthesis Example 1. Polyethylene resin compositions (PCR Compound) of Comparative Example 2-14 were prepared by adding 500 ppm, 3000 ppm, and 1000 ppm, respectively, relative to the weight of the new polyethylene.

[0463]

[0464] <Test Example: Evaluation of Physical Properties of Polyethylene Resin Composition>

[0465] For the polyethylene resin compositions (PCR Compound) of Examples 2-1 to 2-7 and Comparative Examples 2-1 to 2-14 prepared as described above, physical properties were evaluated in the following manner, and the measurement results are shown in Table 2 below.

[0466]

[0467] (1) Measurement of Yellow Index (YI)

[0468] The YI value at room temperature (20 ℃) ​​was measured using UltraScan PRO (manufactured by HunterLab) in accordance with ASTM D 1925.

[0469]

[0470] (2) Falling impact

[0471] A disc was manufactured based on a polyethylene resin composition (PCR Compound) in the following manner, and the number of times a crack occurred in the disc was measured by dropping a weight onto the disc, and the result was expressed as drop impact (times) in Table 2 below.

[0472]

[0473] 2-1. Manufacturing of Drop Impact Discs

[0474] - The disc was manufactured using an injection molding machine, with the temperature gradient set to 210–230 ℃, PCR Compound injected, and produced at an injection speed of 11 mm / s and a holding pressure of 450 bar.

[0475] - Disc size (diameter 50 mm, thickness 2 mm).

[0476]

[0477] 2-2. Drop Impact Evaluation

[0478] - Measure the drop impact strength corresponding to the face impact strength using the ASTM D 3763 method.

[0479] - Specifically, using the Instron 9440 (Impact Drop Tower) product, the number of times a crack occurs is measured by dropping a weight after fixing the disc (Impact energy 15.5 J, Impact velocity 4.55 m / s, Temperature 5 ℃)

[0480]

[0481] After performing drop impact strength tests on 10 or more drop impact discs using the method described above, the number of times cracks occurred as measured was averaged and shown in Table 2 below.

[0482]

[0483] Here, it was confirmed that the drop impact discs prepared with the polyethylene resin compositions (PCR Compound) of Examples 2-1 to 2-7 all had at least 7 cracks.

[0484]

[0485] (3) ESCR measurement value

[0486] According to the method of ASTM D 1693-07, the time to F50 (50% destruction) for a polyethylene resin composition (PCR Compound) was measured using 10% Igepal CO-630 Solution at a temperature of 50 ℃ under Condition B, and is expressed as ESCR (hr) in Table 2 below.

[0487]

[0488] Yellow Index (YI) Drop Impact Intensity (Number of Times) ESCR (hr) Example 2-10.977.1222 Example 2-21.987.2265 Example 2-31.847.2215 Example 2-41.567.205 Example 2-50.857.1215 Example 2-62.457.3226 Example 2-71.117.210 Comparative Example 2-12.166.8190 Comparative Example 2-21.425.8140 Comparative Example 2-31.067.4190 Comparative Example 2-46.196.6190 Comparative Example 2-52.446.2192 Comparative Example 2-62.376.5194 Comparative Example 2-73.026.7180 Comparative Example 2-81.426.9109 Comparative Example 2-91.536.8133 Comparative Example 2-100.756.9209 Comparative Example 2-111.257.2186 Comparative Example 2-123.287.1275 Comparative Example 2-134.336.9193 Comparative Example 2-143.887.2266

[0489]

[0490] Referring to Table 2 above, it can be seen that the polyethylene resin compositions (PCR Compound) of Examples 2-1 to 2-7, which are compounded with recycled polyethylene (PCW PE) using the polyethylene resins of Examples 1-1 to 1-7 that include polyethylene along with phenolic compounds, phosphorus compounds, and amine compounds in optimized amounts according to the present invention, maintain excellent mechanical properties with a drop impact strength corresponding to face impact strength measured by the ASTM D 3763 method, with the number of times the weight is dropped until crack occurs being 7 or more, and significantly improve environmental stress cracking resistance (ESCR) to 205 hours or more. In addition, the Yellow Index (YI) measured according to ASTM D 1925 is 0.97 to 1.98, which can prevent discoloration of the final product to the maximum extent.

[0491]

[0492] However, in the case of the polyethylene resin compositions (PCR Compound) of Comparative Examples 2-1 to 2-14, that is, when using the polyethylene resin of Comparative Examples 1-1 to 1-12, in which the content range of each is not optimized even if the polyethylene resin contains phenolic compounds, phosphorus compounds, and amine compounds as in the polyethylene resin compositions (PCR Compound) of Comparative Examples 2-1 to 2-12, and when adding these phenolic compounds, phosphorus compounds, and amine compounds during extrusion by compounding with recycled polyethylene (PCW PE) in the conventional manner as in the polyethylene resin compositions (PCR Compound) of Comparative Examples 2-13 to 2-14, it is difficult to simultaneously improve mechanical properties such as drop impact strength, environmental stress crack resistance (ESCR), and the yellowness index (YI) which can prevent discoloration of the final product.

Claims

1. In addition to polyethylene, it further comprises phenolic compounds, phosphorus-based compounds, and amine-based compounds, and The total content of the above phenolic compounds, phosphorus compounds, and amine compounds is 0.32% or more and 0.75% or less relative to the weight of the above polyethylene, and The content of the above phenolic compound (AO1) and the content of the above amine compound (AO3) satisfy Formula 1 below, and The content of the above phenolic compound (AO1), the content of the above phosphorus-based compound (AO2), and the content of the above amine-based compound (AO3) satisfy Formula 2 below, and The above-mentioned phosphorus compound is one or more selected from the group consisting of tris(2,4-di-tert-butylphenyl)phosphite and bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite, and The above amine compound is one or more selected from the group consisting of bis(3,5-di-tert-butyl-4-hydroxyhydrocinnamoyl)hydrazine and (3,3'-bis(3,5-di-tert-butyl-4-hydroxyphenyl)-N,N'-hexamethylenedipropionamide). Polyethylene resin: [Equation 1] 0.6 ≤ AO1 / AO3 ≤ 1.8 [Equation 2] AO2 / (AO1+ AO3) ≥ 1.5 In the above Equations 1 and 2, AO1 is the content of the above-mentioned phenolic compound, and AO2 is the content of the above-mentioned phosphorus compound, and AO3 is the content of the above amine compound.

2. In Paragraph 1, The above polyethylene is an ethylene homopolymer or an ethylene / alpha-olefin copolymer, Polyethylene resin.

3. In Paragraph 2, The above alpha-olefin is one or more selected from the group consisting of 1-butene, 1-pentene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1-hexadecene, 1-octadecene, 1-eicocene, and mixtures thereof. Polyethylene resin.

4. In Paragraph 1, The above polyethylene is, Density is 0.935 g / cm³ 3 That is all, The molecular weight distribution (Mw / Mn) is 20 or greater, and The weight-average molecular weight is 100,000 g / mol or more, and Melt Index (MI) measured at 190°C and a 2.16 kg load according to ASTM D 1238 2.16 ) having 0.1 g / 10 min to 1.2 g / 10 min, Polyethylene resin.

5. In Paragraph 1, The content of the above phenolic compound (AO1) and the content of the above phosphorus compound (AO2) satisfy Formula 3 below, Polyethylene resin: [Equation 3] 0.1 ≤ AO1 / AO2 ≤ 0.3 In the above Equation 3, AO1 is the content of the above-mentioned phenolic compound, and AO2 is the content of the above-mentioned phosphorus compound.

6. In Paragraph 1, The above phenolic compounds are pentaerythritol tetrakis(3,5-di-tert-butyl-4-hydroxyhydrocinnamate), octadecyl-[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], and 3,3',3',5,5',5'-hexa-tert-butyl-a,a',a'-(mesitylene-2,4,6-triyl)tri-p-cresol One or more selected from the group consisting of tri-p-cresol, Polyethylene resin.

7. In Paragraph 1, The content of the above phenolic compound is 0.03% or more and 0.15% or less relative to the weight of the above polyethylene, Polyethylene resin.

8. In Paragraph 1, The content of the above phosphorus compound is 0.25% or more and 0.45% or less relative to the weight of the above polyethylene, Polyethylene resin.

9. In Paragraph 1, The content of the above amine-based compound is 0.03% or more and 0.15% or less relative to the weight of the above polyethylene, Polyethylene resin.

10. A polyethylene resin composition comprising virgin polyethylene and recycled polyethylene (PCW PE, Post consumer waste polyethylene), The above-mentioned novel polyethylene is a polyethylene resin or a mixture thereof according to any one of claims 1 to 9, Polyethylene resin composition.

11. In Paragraph 10, The above-mentioned novel polyethylene is included in an amount of 5% by weight or more based on the total weight of the entire composition, and The above recycled polyethylene is included in an amount of 15 weight percent or more based on the total weight of the entire composition, Polyethylene resin composition.

12. In Paragraph 10, The above-mentioned novel polyethylene further comprises high-density polyethylene, Polyethylene resin composition.

13. In Paragraph 10, The above recycled polyethylene has a melt index (MI) measured at 190°C and a 2.16 kg load according to ASTM D 1238. 2.16 ) having 0.1 g / 10 min to 0.7 g / 10 min, Polyethylene resin composition.

14. In Paragraph 10, The above recycled polyethylene has a density of 0.940 g / cm³ 3 Up to 0.960 g / cm³ 3 person, Polyethylene resin composition.

15. In Paragraph 10, The above polyethylene resin composition is, Environmental stress crack resistance (ESCR) measured according to ASTM D 1693 (Condition B, F50, Igepal 10%) is 200 hours or more, Polyethylene resin composition.

16. In Paragraph 10, The above polyethylene resin composition is, With a Yellow Index (YI) of 3 or less as measured according to ASTM D 1925, Polyethylene resin composition.

17. In Paragraph 10, The above polyethylene resin composition is, A drop impact strength of 7 or more, measured by the number of drops until cracking occurs under conditions of impact energy 15.5 J, impact velocity 4.55 m / s, and temperature 5 ℃ according to the ASTM D 3763 method, Polyethylene resin composition.

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