Ethylene-alpha-olefin copolymer resin composition, method for preparing the same, and molded article manufactured therefrom

Abstract

The present invention relates to an ethylene-alpha-olefin copolymer resin composition comprising an ethylene-alpha-olefin copolymer having a ratio of weight average molecular weight to number average molecular weight (Mw / Mn) of 2 to 2.7 and satisfying the following formula 1, a method for preparing the same, and a molded article manufactured therefrom, [Formula 1] -1.5 ≤ HMW 20 - LMW 20 ≤ 1.5, in the above formula 1, HMW 20 refers to the average number of short chain branches (SCB) per 1,000 carbons in a 20% higher molecular weight fraction based on the weight average molecular weight (Mw) measured by an infrared gel permeation chromatography, and LMW 20 refers to the average number of short chain branches (SCB) per 1,000 carbons in a 20% lower molecular weight fraction based on the weight average molecular weight (Mw) measured by an infrared gel permeation chromatography.

Description

Technical Field

[0001] This invention relates to an ethylene-α-olefin copolymer resin composition, a method for preparing the same, and molded articles made therefrom. Background Technology

[0002] The solar power market has been growing steadily since 2018, when it reached grid parity (the point at which the cost of alternative energy generation equals that of fossil fuel generation). In particular, with the increasing importance of energy supply stability, solar power is becoming a core alternative for achieving energy self-sufficiency. Therefore, demand for solar power is expected to continue to increase, and demand for solar cell encapsulation materials used in solar cell modules is also expected to rise accordingly.

[0003] The materials used as encapsulation materials for solar cells mainly include ethylene vinyl acetate copolymer, ethylene alpha-olefin copolymer, and polyolefin elastomer copolymer.

[0004] Solar cell encapsulation materials should be highly transparent to allow the solar cells to absorb a large amount of light, maximizing power generation, and effectively protect the solar cells from physical impacts. Furthermore, they must effectively prevent external substances such as oxygen and moisture (H2O) from penetrating the encapsulation material and corroding the solar cells or reducing their efficiency.

[0005] In the past, although p-type back surface field (BSF) and p-type passivated emitter and rear contact (PERC) solar cells were commonly used, the proportion of n-type tunnel oxide passivated contact (TOPCon) solar cells is increasing as the demand for high-efficiency solar cells grows.

[0006] Unlike p-type back surface field (p-type BSF) and p-type passivated emitter and back contact (p-type PERC) solar cells, n-type tunneling oxide passivated contact (n-type TOPCon) solar cells are susceptible to oxygen and moisture. Therefore, the encapsulation materials used in n-type TOPCon solar cells require a high level of hermeticity. With low hermeticity, corrosion of the solar cell due to potential-induced degradation (PID) becomes severe. While increasing the thickness of the encapsulation material could solve this problem, it would increase the cost of the solar module and is therefore not advisable.

[0007] Therefore, in practice, there is a need for a solar cell encapsulation material that has high output retention after potential-induced degradation (PID) evaluation due to its low oxygen and moisture permeability, i.e., excellent anti-PID characteristics.

[0008] (Prior technical documents)

[0009] (Patent Documents)

[0010] Korean Patent Publication No. 10-2713280 Summary of the Invention

[0011] (The problem the invention aims to solve)

[0012] The present invention, which aims to solve the problems described above, provides an ethylene-α-olefin copolymer resin composition with low oxygen and moisture transmittance and excellent output retention and light transmittance after potential-induced decay (PID) evaluation.

[0013] In addition, the present invention provides a method for preparing the above-mentioned ethylene-α-olefin copolymer resin composition.

[0014] In addition, the present invention provides a molding article manufactured from the above-described ethylene-α-olefin copolymer resin composition.

[0015] The problems to be solved by this invention are not limited to those mentioned above. Those skilled in the art will clearly understand from the following description other problems not mentioned.

[0016] (The measures taken to solve the problem)

[0017] To address the aforementioned problems, the present invention provides an ethylene-α-olefin copolymer resin composition comprising an ethylene-α-olefin copolymer, wherein the weight-average molecular weight to number-average molecular weight ratio (Mw / Mn) of the ethylene-α-olefin copolymer resin composition is 2 to 2.7, and satisfies the following formula:

[0018] [Formula 1]

[0019] -1.5≤HMW 20 -LMW 20 ≤1.5

[0020] In Equation 1 above,

[0021] HMW 20 It refers to the average number of short branches (SCBs) per 1,000 carbons in the top 20% of the molecular weight, based on the weight-average molecular weight (Mw) determined by infrared gel permeation chromatography.

[0022] LMW 20 It refers to the average number of short branches (SCBs) per 1,000 carbons in the lower 20% of the molecular weight fraction, based on the weight-average molecular weight (Mw) determined by infrared gel permeation chromatography.

[0023] The aforementioned α-olefins can be any one or more of propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, and 1-eicosene.

[0024] The zero shear viscosity of the above-mentioned ethylene-α-olefin copolymer resin composition, measured at 180°C using an advanced rheometer expansion system (ARES), can be from 4,000 poise to 100,000 poise.

[0025] The weight-average molecular weight of the above-mentioned ethylene-α-olefin copolymer resin composition can be from 30,000 g / mol to 150,000 g / mol.

[0026] The ratio of Z-average molecular weight to weight-average molecular weight (Mz / Mw) of the above-mentioned ethylene-α-olefin copolymer resin composition can be from 1.5 to 3.

[0027] The number of short branches in each 1,000 carbon atoms of the above-mentioned ethylene-α-olefin copolymer resin composition may be from 30 to 65.

[0028] The melt flow index (MI) of the above-mentioned ethylene-α-olefin copolymer resin composition under a load of 2.16 kg and a temperature of 190 °C is... 2.16 It can be from 1g / 10min to 25g / 10min.

[0029] The melt flow rate MI of the above-mentioned ethylene-α-olefin copolymer resin composition under a load of 21.6 kg and a temperature of 190 °C 21.6 The melt flow rate MI under a load of 2.16 kg and a temperature of 190 °C 2.16 The ratio (MFRR) can be between 20 and 35.

[0030] The density of the above-mentioned ethylene-α-olefin copolymer resin composition can be 0.860 g / cm³. 3 Up to 0.880 g / cm 3 .

[0031] The above-mentioned ethylene-α-olefin copolymer resin composition may further include one or more additives selected from crosslinking agents, co-crosslinking agents, silane coupling agents, ultraviolet stabilizers, ultraviolet absorbers, and antioxidants.

[0032] Relative to 100 parts by weight of the above-mentioned ethylene-α-olefin copolymer resin composition, the crosslinking agent comprises 0.01 to 1.5 parts by weight of the above-mentioned crosslinking agent. The crosslinking agent may be selected from tert-butyl-2-ethylhexyl monoperoxycarbonate, 1,1-di(tert-amylperoxy)cyclohexane, 1,1-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-di(tert-butylperoxy)cyclohexane, 2,5-dimethyl-2,5-di-(2-ethylhexanoylperoxy)hexane, tert-amylperoxy-2-ethylhexanoate, tert-butylperoxy-2-ethylhexanoate, and tert-amyl(2-ethylhexyl)monoperoxycarbonate. One or more of the following: ester, tert-butylisopropyl monoperoxycarbonate, 2,5-dimethyl-2,5-di(toluylperoxy)hexane, tert-butyl-(2-ethylhexyl)monoperoxycarbonate, tert-pentylperoxybenzoate, tert-butylperoxyacetate, tert-butylperoxy-3,5,5-trimethylhexanoate, tert-butylperoxybenzoate, dicumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, α,α'-di(tert-butylperoxy)diisopropylbenzene, di-tert-pentylperoxide, di-tert-butylperoxide, and 2,5-dimethyl-2,5-di(tert-butylperoxy)hex-3-yne.

[0033] Relative to 100 parts by weight of the above-mentioned ethylene-α-olefin copolymer resin composition, the composition comprises 0.01 to 3 parts by weight of the above-mentioned crosslinking agent, wherein the crosslinking agent may be one or more selected from polyallylic compounds and acrylate compounds.

[0034] Relative to 100 parts by weight of the above-mentioned ethylene-α-olefin copolymer resin composition, the composition comprises 0.01 parts by weight to 3 parts by weight of the above-mentioned silane coupling agent, wherein the silane coupling agent may be one or more selected from γ-methacryloyloxypropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, and γ-epoxypropoxypropyltrimethoxysilane.

[0035] In addition, to solve the above problems, the present invention provides a method for preparing the above-mentioned ethylene-α-olefin copolymer resin composition, the method comprising: supplying a transition metal catalyst composition, hydrogen, ethylene and α-olefin to a reactor; and performing a copolymerization reaction at a temperature of 110°C to 170°C.

[0036] The aforementioned transition metal catalyst composition may comprise a transition metal compound represented by the following chemical formula 1 and a co-catalyst.

[0037] [Chemical Formula 1]

[0038]

[0039] In the above chemical formula 1,

[0040] M is a group 4 transition metal;

[0041] R1 and R2 are each independently (C11-C20) alkyl groups;

[0042] R3 and R4 are independently hydrogen or (C1-C10) alkyl-substituted or unsubstituted (C6-C20) aryl groups;

[0043] X1 and X2 are independently halogen, (C1-C20)alkyl, (C6-C20)aryl(C1-C20)alkyl, (C3-C20)cycloalkyl, (C6-C20)aryl, ((C1-C20)alkyl(C6-C20)aryl)(C1-C20)alkyl, (C1-C20)alkoxy, (C6-C20)aryloxy, (C1-C20)alkyl(C6-C20)aryloxy, (C1-C20)alkoxy(C6-C20)aryloxy, -OSiR a R b R c -SR d -NR e R f -PR g R h Or (C1-C20) alkylene;

[0044] R aTo R d They are independently (C1-C20)alkyl, (C6-C20)aryl, (C6-C20)aryl(C1-C20)alkyl, (C1-C20)alkyl(C6-C20)aryl or (C3-C20)cycloalkyl;

[0045] R e To R h Each of the following can be independently (C1-C20)alkyl, (C6-C20)aryl, (C6-C20)aryl(C1-C20)alkyl, (C1-C20)alkyl(C6-C20)aryl, (C3-C20)cycloalkyl, tri(C1-C20)alkylsilyl or tri(C6-C20)arylsilyl;

[0046] If one of X1 or X2 is a (C1-C20) alkylene group, the other one is absent.

[0047] The molar ratio of the aforementioned transition metal compound to the cocatalyst can be from 1:2 to 1:7.

[0048] The hydrogen can be supplied at a rate of 0.3 g / kg to 0.6 g / kg relative to the ethylene supply, and the α-olefin can be supplied at a rate of 0.9 kg / kg to 1.6 kg / kg relative to the ethylene supply.

[0049] In addition, to solve the above-mentioned problems, the present invention provides a molding article made from the above-mentioned ethylene-α-olefin copolymer resin composition.

[0050] The aforementioned molded articles can be encapsulation materials for solar cells.

[0051] (The effect of the invention)

[0052] The ethylene-α-olefin copolymer resin composition according to the present invention has excellent output retention and high light transmittance after potential-induced decay (PID) evaluation due to its low oxygen and moisture transmittance, and can therefore be used as an encapsulation material for solar cells to improve the performance of solar cells.

[0053] The effects of the present invention are not limited to those mentioned above, and those skilled in the art will clearly understand from the following description other effects not mentioned. Detailed Implementation

[0054] The advantages and features of the present invention, as well as the methods of implementing them, will become clear from reference to the various embodiments detailed below. However, the present invention is not limited to the embodiments disclosed below but can be embodied in various different ways. These embodiments are provided only to make the disclosure of the invention complete and to fully inform those skilled in the art of the scope of the invention, which is defined only by the scope of the claims.

[0055] Before proceeding with the description, the meanings of the terms used in this specification will be briefly explained. However, it should be noted that the explanations of the terms are intended to aid in understanding this specification, and therefore, unless explicitly stated otherwise, they are not intended to limit the technical concept of the invention.

[0056] The terminology used in this specification is for illustrative purposes and not for limiting the invention. In this specification, singular forms include plural forms unless specifically mentioned herein. The terms "comprises" and / or "comprising" as used in the specification do not exclude the presence or addition of more than one of the mentioned constituent elements. Throughout the specification, "and / or" includes each of the mentioned constituent elements and all combinations thereof. While expressions such as "first," "second," etc., are used to describe a wide variety of constituent elements, these constituent elements are not, of course, limited by these terms. These terms are used merely to distinguish one constituent element from others. Therefore, the first constituent element mentioned below can, of course, also be a second constituent element within the technical concept of this invention.

[0057] Unless otherwise defined, all terms used in this specification (including technical and scientific terms) are to be used in the sense that would be commonly understood by one of ordinary skill in the art. Furthermore, terms defined in commonly used dictionaries should not be interpreted ideally or excessively unless explicitly and specifically defined.

[0058] The present invention will now be described in more detail.

[0059] According to one specific implementation, the present invention provides an ethylene-α-olefin copolymer resin composition comprising an ethylene-α-olefin copolymer, wherein the weight-average molecular weight ratio (Mw / Mn) relative to the number-average molecular weight is 2 to 2.7, and satisfies Formula 1 below.

[0060] [Formula 1]

[0061] -1.5≤HMW 20 -LMW 20 ≤1.5

[0062] In Equation 1 above,

[0063] HMW 20 It refers to the average number of short branches (SCBs) per 1,000 carbons in the top 20% of the molecular weight, based on the weight-average molecular weight (Mw) determined by gel permeation chromatography (GPC).

[0064] LMW 20 It refers to the average number of short branches (SCBs) per 1,000 carbons in the lower 20% of the molecular weight fraction, based on the weight-average molecular weight (Mw) determined by infrared gel permeation chromatography.

[0065] The ethylene-α-olefin copolymer resin composition of the present invention is easy to process, has high light transmittance, and low oxygen and moisture transmittance, thus exhibiting excellent output retention after potential-induced decay (PID) evaluation.

[0066] In one specific implementation, the ethylene-α-olefin copolymer described above may be a copolymer comprising units derived from ethylene and units derived from α-olefins. Here, the α-olefin may be any one or more of propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, and 1-eicosene.

[0067] In one specific implementation, the weight-average molecular weight (Mw) of the above-mentioned ethylene-α-olefin copolymer resin composition, as determined by infrared gel permeation chromatography, is 30,000 g / mol to 150,000 g / mol, 35,000 g / mol to 100,000 g / mol, or 40,000 g / mol to 80,000 g / mol. With a weight-average molecular weight within the aforementioned range, it is easy to process and has low oxygen and moisture permeability, thus exhibiting excellent resistance to potential-induced degradation (Anti-PID) and effectively protecting the solar cell.

[0068] In one specific implementation example, for the above-described ethylene-α-olefin copolymer resin composition, the ratio of weight-average molecular weight to number-average molecular weight (Mw / Mn) as determined by infrared gel permeation chromatography can be 2 to 2.7, 2 to 2.5, 2.2 to 2.5, or 2.5 to 2.7. Having a weight-average molecular weight ratio (Mw / Mn) relative to the number-average molecular weight within the aforementioned range results in low oxygen and water permeability, thus exhibiting excellent resistance to potential-induced degradation (Anti-PID) and effectively protecting the solar cell.

[0069] In one specific implementation, the ratio of the Z-average molecular weight (Mz / Mw) of the ethylene-α-olefin copolymer resin composition to the weight-average molecular weight can be 1.5 to 3, 1.5 to 2.8, or 1.5 to 2.5. The weight-average molecular weight and Z-average molecular weight can be determined using infrared gel permeation chromatography. Having a Z-average molecular weight to weight-average molecular weight ratio (Mz / Mw) within the aforementioned range results in low oxygen and water permeability, thus exhibiting excellent resistance to potential-induced degradation (Anti-PID) and effectively protecting the solar cell.

[0070] In one specific implementation, the zero shear viscosity of the aforementioned ethylene-α-olefin copolymer resin composition, measured by an ARES rheometer at 180°C, can be 4,000 poise to 100,000 poise, 4,000 poise to 60,000 poise, or 5,000 poise to 40,000 poise. Due to its zero shear viscosity within the aforementioned range, it is easy to process and does not experience misalignment during lamination, resulting in a low defect rate and excellent creep characteristics during solar cell module processing.

[0071] In one specific implementation, the number of short chain branches (SCBs) per 1,000 carbon atoms in the above-described ethylene-α-olefin copolymer resin composition, as determined by gel permeation chromatography, can be 30 to 65, 35 to 55, 45 to 55, 40 to 55, or 35 to 50. As a specific example, when using an α-olefin with 4 carbon atoms, the number of short chain branches per 1,000 carbon atoms can be 45 to 55; when using an α-olefin with 6 carbon atoms, the number of short chain branches per 1,000 carbon atoms can be 40 to 55; and when using an α-olefin with 8 carbon atoms, the number of short chain branches per 1,000 carbon atoms can be 35 to 50. With a number of short chain branches within the aforementioned range, excellent transparency is achieved, resulting in increased light transmittance, while low oxygen and moisture transmittance effectively protects the solar cell.

[0072] In one specific implementation example, the melt flow index (MI) of the above-mentioned ethylene-α-olefin copolymer resin composition at a load of 2.16 kg and a temperature of 190 °C is... 2.16 The flow rate can be from 1 g / 10 min to 25 g / 10 min, from 4 g / 10 min to 20 g / 10 min, or from 4 g / 10 min to 15 g / 10 min. The melt flow index (MI) of the above ethylene-α-olefin copolymer resin composition is... 2.16 The melt flow index (MI) was determined using an orifice with an inner diameter of 2.75 mm and a load of 2.16 kg at a temperature of 190°C, within the range described above. 2.16 Under these conditions, oxygen and moisture permeability are low, thus effectively protecting the solar cells.

[0073] In one specific implementation example, the melt flow rate MI of the above-mentioned ethylene-α-olefin copolymer resin composition under a load of 21.6 kg and a temperature of 190 °C is... 21.6 The melt flow rate MI under a load of 2.16 kg and a temperature of 190 °C 2.16 The ratio (MI) 21.6 / MI 2.16 The MFRR (Melt Flow Rate Ratio) can be 20 to 35, 20 to 30, or 22 to 28. With a melt flow rate ratio within the range described above, oxygen and moisture permeability are low, thus effectively protecting the solar cell.

[0074] In one specific implementation example, the density of the above-mentioned ethylene-α-olefin copolymer resin composition may be 0.860 g / cm³. 3 Up to 0.880 g / cm 3 0.865g / cm3 Up to 0.880 g / cm 3 Or 0.870 g / cm 3 Up to 0.880 g / cm 3 With a density within the range described above, oxygen and moisture permeability are low, thus effectively protecting the solar cell.

[0075] In one specific implementation, the ethylene-α-olefin copolymer resin composition described above may further include one or more additives selected from crosslinking agents, co-crosslinking agents, silane coupling agents, ultraviolet stabilizers, ultraviolet absorbers, and antioxidants.

[0076] The type of crosslinking agent is not particularly limited. For example, it can be selected from tert-butyl-2-ethylhexyl monoperoxycarbonate, 1,1-di(tert-pentylperoxy)cyclohexane, 1,1-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-di(tert-butylperoxy)cyclohexane, 2,5-dimethyl-2,5-di-(2-ethylhexanoylperoxy)hexane, tert-pentylperoxy-2-ethylhexanoate, tert-butylperoxy-2-ethylhexanoate, tert-pentyl(2-ethylhexyl) monoperoxycarbonate, tert-butylisopropyl monoperoxycarbonate, 2,5 One or more of the following crosslinking agents are selected: dimethyl-2,5-di(toluylperoxy)hexane, tert-butyl-(2-ethylhexyl)monoperoxycarbonate, tert-amylperoxybenzoate, tert-butylperoxyacetate, tert-butylperoxy-3,5,5-trimethylhexanoate, tert-butylperoxybenzoate, dicumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, α,α'-di(tert-butylperoxy)diisopropylbenzene, di-tert-amyl peroxide, di-tert-butyl peroxide, and 2,5-dimethyl-2,5-di(tert-butylperoxy)hex-3-yne. Adding one or more of the above-mentioned crosslinking agents can improve the service life of solar cell encapsulation materials.

[0077] Regarding the aforementioned crosslinking agent, it may comprise 0.01 to 1.5 parts by weight, 0.1 to 1.5 parts by weight, or 0.3 to 1 part by weight, relative to 100 parts by weight of the ethylene-α-olefin copolymer resin composition. When the crosslinking agent is contained in a range smaller than those described above, sufficient crosslinking degree cannot be achieved; when the crosslinking agent is contained in a range exceeding those described above, bubbles are generated during lamination, thereby increasing the rejection rate, and therefore this is not preferred.

[0078] The aforementioned crosslinking agent can be one or more selected from polyallyl compounds and acrylate compounds. When one or more of the aforementioned crosslinking agents are included, the lifespan of the solar cell encapsulation material can be improved.

[0079] The types of polyallyl compounds mentioned above are not particularly limited. For example, they may be selected from one or more of triallyl isocyanurate, triallyl cyanurate, diallyl phthalate, diallyl fumarate, and diallyl maleate.

[0080] The types of acrylate compounds mentioned above are not particularly limited. For example, they may be selected from one or more of ethylene glycol diacrylate, ethylene glycol dimethacrylate, and trimethylolpropane trimethacrylate.

[0081] The aforementioned co-crosslinking agent may be included in 0.01 to 3 parts by weight, 0.1 to 3 parts by weight, or 0.3 to 1 part by weight, relative to 100 parts by weight of the ethylene-α-olefin copolymer resin composition. When the co-crosslinking agent is included in a range less than those described above, sufficient crosslinking degree is not achieved; when the co-crosslinking agent is included in a range greater than those described above, long-term physical properties deteriorate due to residual co-crosslinking agent, which is therefore not preferred.

[0082] The type of silane coupling agent is not particularly limited, but may be, for example, one or more selected from γ-methacryloyloxypropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, and γ-epoxypropoxypropyltrimethoxysilane. When one or more of the above-mentioned silane coupling agents are included, the adhesion strength between the solar cell encapsulation material and the glass can be improved.

[0083] Relative to 100 parts by weight of the ethylene-α-olefin copolymer resin composition, the composition may contain 0.01 to 3 parts by weight, 0.1 to 3 parts by weight, or 0.1 to 1 part by weight of the aforementioned silane coupling agent. When the silane coupling agent is contained in a range smaller than described above, the adhesive strength is low, leading to easy moisture penetration and thus compromising the long-term performance of the solar cell module. When the silane coupling agent is contained in a range exceeding described above, the solar cell encapsulation material discolors, resulting in reduced light transmittance, which is therefore not preferred.

[0084] The types of ultraviolet stabilizers mentioned above are not particularly limited, and for example, they can be one or more selected from bis-2,2,6,6,-tetramethyl-4-piperidinyl sebacate, bis-1-methyl-2,2,6,6,-tetramethyl-4-piperidinyl sebacate, 2(2'-hydroxy-3',5'-di-tert-butylphenyl)benzotriazole and 2-(2-hydroxy-3,5-di-tert-pentylphenyl)-2H-benzotriazole.

[0085] The content of the aforementioned UV stabilizers is not particularly limited and can be adjusted appropriately according to the purpose.

[0086] The types of ultraviolet absorbers mentioned above are not particularly limited, and for example, they can be selected from one or more of 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-2'-carboxybenzophenone, 2-hydroxy-4-octyloxybenzophenone, 2-hydroxy-4-dodecyloxybenzophenone, 2-hydroxy-4-octadecyloxybenzophenone, 2-hydroxy-4-benzyloxybenzophenone, 2-hydroxy-4-methoxy-5-sulfobenzophenone, 2-hydroxy-5-chlorobenzophenone, 2,4-dihydroxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, and 2,2',4,4'-tetrahydroxybenzophenone.

[0087] The content of the aforementioned ultraviolet absorbers is not particularly limited and can be adjusted appropriately according to the purpose.

[0088] The types of antioxidants mentioned above are not particularly limited, and may include, for example, those selected from 1,3,5-trimethyl-2,4,6-tris(3,5-di-tert-butyl-4-hydroxybenzyl)benzene, 1,6-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propamido]hexane, 1,6-bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propamido]propane, tetrakis(methylene(3,5-di-tert-butyl-4-hydroxyhydrocinnamate)]methane, pentaerythritol-tetramethylbenzylene oxide, etc. One or more of the following: (3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate), 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-1,3,5-triazine-2,4,6-trione, bis(octadecyl)hydroxyamine, tris(2,4-di-tert-butylphenyl)-phosphite, bis(2,6-di-tert-butyl-4-methylphenyl)pentaerythritol-di-phosphite, and bis(2,4-di-tert-butylphenyl)pentaerythritol-di-phosphite.

[0089] The content of the above antioxidants is not particularly limited and can be adjusted appropriately according to the purpose.

[0090] The above-mentioned additives can be added during the processing of the ethylene-α-olefin copolymer resin composition or during the manufacture of molded articles used as encapsulation materials for solar cells.

[0091] In addition, according to the present invention, a method for preparing an ethylene-α-olefin copolymer resin composition according to the present invention is provided, the method comprising: supplying a transition metal catalyst composition, hydrogen, ethylene and α-olefin to a reactor; and performing a copolymerization reaction at a temperature of 110°C to 170°C.

[0092] In one specific implementation, the above-described transition metal catalyst composition may comprise a transition metal compound represented by the following chemical formula 1 and a co-catalyst.

[0093] [Chemical Formula 1]

[0094]

[0095] In the above chemical formula 1,

[0096] M is a group 4 transition metal;

[0097] R1 and R2 are each independently (C11-C20) alkyl groups;

[0098] R3 and R4 are independently hydrogen or (C1-C10) alkyl-substituted or unsubstituted (C6-C20) aryl groups;

[0099] X1 and X2 are independently halogen, (C1-C20)alkyl, (C6-C20)aryl(C1-C20)alkyl, (C3-C20)cycloalkyl, (C6-C20)aryl, ((C1-C20)alkyl(C6-C20)aryl)(C1-C20)alkyl, (C1-C20)alkoxy, (C6-C20)aryloxy, (C1-C20)alkyl(C6-C20)aryloxy, (C1-C20)alkoxy(C6-C20)aryloxy, -OSiR a R b R c -SR d -NR e R f -PR g R h Or (C1-C20) alkylene;

[0100] R a To R d They are independently (C1-C20)alkyl, (C6-C20)aryl, (C6-C20)aryl(C1-C20)alkyl, (C1-C20)alkyl(C6-C20)aryl or (C3-C20)cycloalkyl;

[0101] R e To R h They are independently (C1-C20)alkyl, (C6-C20)aryl, (C6-C20)aryl(C1-C20)alkyl, (C1-C20)alkyl(C6-C20)aryl, (C3-C20)cycloalkyl, tri(C1-C20)alkylsilyl or tri(C6-C20)arylsilyl;

[0102] If one of X1 or X2 is a (C1-C20) alkylene group, the other one is absent.

[0103] In this invention, "alkyl" refers to a monovalent straight-chain or branched saturated hydrocarbon free radical composed only of carbon atoms and hydrogen atoms. Examples of such alkyl free radicals include, but are not limited to, methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, hexyl, octyl, and nonyl.

[0104] The "aryl" described in this invention refers to an organic free radical derived from an aromatic hydrocarbon by losing a hydrogen atom. It includes monocyclic or fused-ring systems that suitably contain 4 to 7 ring atoms, preferably 5 or 6 ring atoms, and even includes configurations where multiple aryl groups are linked by single bonds. Fused-ring systems may contain aliphatic rings such as saturated or partially saturated rings, and must contain more than one aromatic ring. Furthermore, the aforementioned aliphatic rings may also contain nitrogen, oxygen, sulfur, carbonyl, etc. Specific examples of the aforementioned aryl free radicals include phenyl, naphthyl, biphenyl, indenyl, fluorenyl, phenanthryl, anthraceneyl, triphenylene, pyrene, etc. Examples include, but are not limited to, alkyl, tetraphenyl, 9,10-dihydroanthrayl, etc.

[0105] In this invention, "cycloalkyl" refers to a monovalent saturated carbocyclic radical composed of one or more rings. Examples of cycloalkyl radicals include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl.

[0106] In this invention, "halogen" or "halogen" refers to fluorine, chlorine, bromine, or iodine atoms.

[0107] In this invention, "alkoxy" refers to -O-(alkyl) groups containing -OCH3, -OCH2CH3, -O(CH2)2CH3, -O(CH2)3CH3, -O(CH2)4CH3, -O(CH2)5CH3 and similar groups, wherein the alkyl group is the same as defined above.

[0108] In this invention, "alkylene" refers to a straight-chain or branched saturated divalent hydrocarbon group having a divalent valence on a common carbon atom.

[0109] In this invention, "aryloxy group" refers to -O-aryl free radical, wherein aryl is defined as above.

[0110] The transition metal compound represented by the above chemical formula 1 is a transition metal compound having the following structure: a group 4 transition metal in the periodic table as the central metal is attached to an electron-rich and widely delocalized cyclopentadienyl group and a fluorenyl group that can be easily substituted to improve solubility and performance and is substituted at positions 2 and 7, which are far from the active site. The cyclopentadienyl group and the fluorenyl group are carbon-linked, thereby exhibiting excellent catalytic activity in the polymerization of ethylene and α-olefins.

[0111] In a specific implementation example, M of the above chemical formula 1 can be Ti, Zr or Hf, R1 to R2 can be (C11-C20) alkyl, R3 and R4 can be hydrogen or (C1-C10) alkyl substituted or unsubstituted (C6-C20) aryl, and X1 and X2 can be halogen, (C1-C20) alkyl or (C6-C20) aryl, respectively.

[0112] In a specific implementation example, M of the above chemical formula 1 can be Hf, R1 to R2 can be (C11-C20) alkyl, R3 and R4 can be (C6-C12) aryl, and X1 and X2 can be halogen, (C1-C6) alkyl or (C6-C12) aryl, respectively.

[0113] In one specific implementation, X1 and X2 of the above chemical formula 1 can be independently halogen, (C1-C3) alkyl or (C6-C10) aryl, and more specifically, X1 and X2 of the above chemical formula 1 can be independently Cl, methyl, phenyl or benzyl.

[0114] In one specific implementation, the aforementioned transition metal compound may be [1-(η5-cyclopentadien-1-yl)-1-(η5-2,7-di-n-dodecylfluorenyl)-1,1-diphenylmethane] hafnium dichloride, [1-(η5-cyclopentadien-1-yl)-1-(η5-2,7-di-n-dodecylfluorenyl)-1,1-diphenylmethane] dibenzyl hafnium, or [1-(η5-cyclopentadien-1-yl)-1-(η5-2,7-di-n-dodecylfluorenyl)-1,1-diphenylmethane] dimethyl hafnium.

[0115] In one specific implementation, in order to serve as an active catalyst component for the preparation of copolymers of ethylene and α-olefins, the aforementioned transition metal compound may use a co-catalyst that cationizes the central metal by extracting the X1 and X2 ligands of the aforementioned transition metal compound of chemical formula 1, thereby enabling it to function as an anion with weak binding force.

[0116] The aforementioned cocatalyst can be selected from one or more aluminum compounds and boron compounds.

[0117] The aluminum compound used as the above-mentioned cocatalyst may be one or more selected from aluminum oxanes, organoaluminum compounds, and organoaluminum oxide compounds. Specifically, the aluminum compound may be one or more selected from aluminum oxane compounds of chemical formula 2 or 3, organoaluminum compounds of chemical formula 4, or organoaluminum oxide compounds of chemical formula 5 or 6.

[0118] [Chemical Formula 2]

[0119] (-Al(R 11 )-O-) m

[0120] [Chemical Formula 3]

[0121] (R 11 )2Al-(-O(R 11 )-) q -(R 11 )2

[0122] [Chemical Formula 4]

[0123] (R 12 ) r Al(E) 3-r

[0124] [Chemical Formula 5]

[0125] (R 13 )2AlOR 14

[0126] [Chemical Formula 6]

[0127] R 13 Al(OR 14 )2

[0128] In the above chemical formulas 2 to 6, R 11 It is (C1-C20) alkyl, preferably methyl or isobutyl, where m and q are integers from 5 to 20; R 12 and R 13 They are (C1-C20) alkyl groups; E is hydrogen or halogen; r is an integer from 1 to 3; R 14 It is (C1-C20)alkyl or (C6-C20)aryl.

[0129] Specific examples of aluminum compounds that can be used include methylaluminoxane, modified methylaluminoxane, and tetraisobutylaluminoxane; examples of organoaluminum compounds include: trialkylaluminum, including trimethylaluminum, triethylaluminum, tripropylaluminum, triisobutylaluminum, trihexylaluminum, and trioctylaluminum; dialkylaluminum chloride, including dimethylaluminum chloride, diethylaluminum chloride, dipropylaluminum chloride, diisobutylaluminum chloride, and dihexylaluminum chloride; alkylaluminum chloride, including methylaluminum chloride, ethylaluminum chloride, propylaluminum chloride, isobutylaluminum chloride, and hexylaluminum chloride; and dialkylaluminum hydride, including dimethylaluminum hydride, diethylaluminum hydride, dipropylaluminum hydride, diisobutylaluminum hydride, and dihexylaluminum hydride.

[0130] More preferably, the aluminum compound may be one or more selected from methylaluminoxane, modified methylaluminoxane, tetraisobutylaluminoxane, trimethylaluminum, triethylaluminum, trioctylaluminum and triisobutylaluminum.

[0131] In this invention, the boron compound that can be used as a cocatalyst can be selected from boron compounds represented by the following chemical formulas 7 to 9.

[0132] [Chemical Formula 7]

[0133] B(R 21 )3

[0134] [Chemical Formula 8]

[0135] [R 22 ] + [B(R 21 )4] -

[0136] [Chemical Formula 9]

[0137] [(R 23 ) p ZH] + [B(R 21 )4] -

[0138] In the above chemical formulas 7 to 9,

[0139] B represents boron atoms; R 21 The phenyl group is further substituted with 3 to 5 substituents selected from fluorine, fluorinated or unsubstituted (C1-C20) alkyl groups, and fluorinated or unsubstituted (C1-C20) alkoxy groups; R 22It is a (C5-C7) aromatic radical or a (C1-C20) alkyl(C6-C20) aryl radical, or a (C6-C20) aryl(C1-C20) alkyl radical, such as a triphenylmethylium radical; Z is a nitrogen atom or a phosphorus atom; R 23 An anilinium radical is an alkyl radical that is substituted with two (C1-C10) alkyl groups along with a (C1-C50) alkyl radical or a nitrogen atom; and p is an integer of 2 or 3.

[0140] Preferably, the boron compound used as the cocatalyst can be one or more selected from dimethylphenylammonium tetra(phenyl)borate, trimethylmethyltetra(phenyl)borate, dimethylphenylammonium tetra(pentafluorophenyl)borate, trimethylammonium tetra(pentafluorophenyl)borate, triethylammonium tetra(pentafluorophenyl)borate, tripropylammonium tetraphenylborate, tributylammonium tetra(pentafluorophenyl)borate, trimethylammonium tetra(pentafluorophenyl)borate, triethylammonium tetra(pentafluorophenyl)borate, tripropylammonium tetra(pentafluorophenyl)borate, tributylammonium tetra(pentafluorophenyl)borate, phenylammonium tetraphenylborate, phenylammonium tetra(pentafluorophenyl)borate, pyridinium tetra(pentafluorophenyl)borate, and silver tetra(pentafluorophenyl)borate.

[0141] The aforementioned cocatalyst can act as a scavenger to remove toxic impurities from the reactants.

[0142] In one specific implementation, the molar ratio of the aforementioned transition metal compound to the cocatalyst can be 1:2 to 1:7, 1:3 to 1:7, or 1:4 to 1:6. When using the transition metal compound and cocatalyst in the molar ratios within the aforementioned range, the activity of the transition metal compound is excellent even without excessively increasing costs.

[0143] In one specific implementation, the hydrogen can be supplied at a rate of 0.3 g / kg to 0.6 g / kg, 0.3 g / kg to 0.58 g / kg, or 0.33 g / kg to 0.55 g / kg relative to the amount of ethylene supplied. When hydrogen is supplied at the levels described above, the melt flow index of the ethylene-α-olefin copolymer can be adjusted to prepare an ethylene-α-olefin copolymer resin composition with desired physical properties.

[0144] In one specific implementation, the α-olefin can be supplied at a rate of 0.9 kg / kg to 1.6 kg / kg or 0.9 kg / kg to 1.5 kg / kg relative to the ethylene supply. When the α-olefin is supplied at a content within the range described above, the molded articles of the ethylene-α-olefin copolymer resin composition produced will have excellent light transmittance, oxygen transmittance, and moisture transmittance.

[0145] In one specific implementation, the method for preparing ethylene polymers using a transition metal catalyst composition in the aforementioned reactor can be carried out by contacting the transition metal catalyst, co-catalyst, ethylene, and α-olefin in the presence of a suitable organic solvent. In this case, the transition metal compound, co-catalyst, and α-olefin component can be added to the reactor individually or pre-mixed before being added to the reactor.

[0146] The aforementioned organic solvent can be a C5-C12 aliphatic hydrocarbon compound solvent, such as one or more selected from toluene, butane, isobutane, pentane, hexane, heptane, octane, isooctane, nonane, decane, dodecane, cyclohexane, and methylcyclohexane.

[0147] In one specific implementation example, the operating temperature of the reactor can be 110°C to 170°C, 120°C to 160°C, or 130°C to 150°C, and the pressure can be 10 to 100 bar or 15 to 50 bar.

[0148] In one specific implementation, the aforementioned α-olefin can be any one or more of propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, and 1-eicosene.

[0149] In one specific implementation, the ethylene-α-olefin copolymer according to the present invention can be prepared by copolymerization reaction in the above-described reactor.

[0150] Through the above copolymerization reaction, ethylene-α-olefin copolymer resin compositions can be prepared by selectively mixing additives into ethylene-α-olefin copolymers.

[0151] Here, the specific description of the above-mentioned additives and ethylene-α-olefin copolymer resin composition can be the same as the description above.

[0152] In addition, according to the present invention, a molding article manufactured from the above-described ethylene-α-olefin copolymer resin composition is provided.

[0153] The aforementioned molded articles can be encapsulation materials for solar cells.

[0154] When a solar cell encapsulation material sheet is manufactured using the ethylene-α-olefin copolymer resin composition according to the present invention, the oxygen and moisture transmittance are low, and the output retention and light transmittance are excellent after potential-induced decay (PID) evaluation.

[0155] Specific embodiments of the present invention are presented below. However, the embodiments described below are merely illustrative or descriptive of the invention, and the invention should not be limited to these embodiments. Furthermore, content not described herein can be fully deduced by those skilled in the art, and therefore its description is omitted.

[0156] [Preparation Example]

[0157] Preparation Example 1: Synthesis of [1-(η5-cyclopentadien-1-yl)-1-(η5-2,7-di-n-dodecylfluorenyl)-1,1-diphenylmethane]hafnium dichloride (compound 1)

[0158] Step 1: Synthesis of Compound 1-1

[0159]

[0160] Pd[P(t-Bu)3]2 (1.1 mol%, 0.26 g, 0.51 mmol) and 2,7-dibromo-9H-fluorene (15 g, 46 mmol) were added to a Schlenk flask. Toluene (200 mL) was then added, followed by n-dodecylboronic acid (2.4 equivalents, 11.2 g), and then toluene (300 mL). After 2 hours, the mixture was extracted three times with saturated aqueous NH4Cl solution and ether (diethyl ether). The organic layer was collected, dried over MgSO4, filtered, and subjected to reduced pressure. Column purification (silica, hexane / ethyl acetate = 10:1) yielded a yellow liquid compound 1-1 (6.3 g, 49% yield).

[0161] ¹H NMR (500 MHz, chloroform-d) δ 7.90 (d, J = 7.8 Hz, 2H), 7.47 (s, 2H), 7.30 (d, J = 7.8 Hz, 2H), 3.87 (s, 2H), 2.64 (t, J = 7.4 Hz, 4H), 1.61 (t, J = 7.3 Hz, 4H), 1.26 (m, 36H), 0.88 (t, J = 7.3 Hz, 6H)

[0162] Step 2: Synthesis of Compounds 1-2

[0163]

[0164] 2,7-di-n-dodecylfluorene (12 g, 43.1 mmol) was dissolved in tetrahydrofuran (THF) (87 mL), followed by the addition of nBuLi (1.6 M in hexane, 27.1 mL, 43.1 mmol) and stirring at room temperature. After 3 hours, 6,6-diphenylfulvene (10 g, 43.1 mmol) was added. The reaction solution was stirred for 16 hours, followed by the addition of 40 mL of aqueous NH4Cl solution to terminate the reaction. The product was extracted as an organic layer, dried over MgSO4, filtered, and subjected to reduced pressure. The resulting yellow solid was washed with ethanol to give white solid compounds 1-2 (20 g, 91% yield).

[0165] ¹H NMR (500 MHz, chloroform-d) δ 6.96–7.34 (m, 20H), 5.43 (s, 1H), 2.64 (t, J = 7.4 Hz, 4H), 1.61 (t, J = 7.3 Hz, 4H), 1.26 (m, 36H), 0.88 (t, J = 7.3 Hz, 6H)

[0166] Third step: [1-(η5-cyclopentadien-1-yl)-1-(η5-2,7-di-n-dodecylfluorenyl)-1,1-diphenyl] Synthesis of Hafnium dichloride (compound 1) [methane]

[0167]

[0168] Compounds 1-2 (5 g, 9.82 mmol) were dissolved in 60 mL of diethyl ether, and nBuLi (1.6 M, 13.5 mL, 21.6 mmol in hexane) was added and the mixture was stirred for 16 hours. After the reaction was complete, the diethyl ether was removed by vacuum drying, followed by the addition of hexane solution and decantation under reduced pressure. In a glove box, solid lithium (5.1 g, 9.79 mmol) and hafnium tetrachloride (HfCl4) (3.13 g, 9.79 mmol) were dissolved in 80 mL of diethyl ether. After stirring at room temperature for 16 hours, the diethyl ether was removed by vacuum drying, followed by the addition of 80 mL of toluene. The mixture was heated at 50 °C for 2 hours, and the byproduct LiCl was precipitated and filtered. The filtrate was dried under vacuum to obtain a crystalline form, yielding yellow crystalline compound 1 (4.5 g) (recrystallized from toluene in 60% yield).

[0169] ¹H NMR (500 MHz, chloroform-d) δ 8.02 (d, J = 8.5 Hz, 2H), 7.96 (dd, J = 8.0, 2.0 Hz, 2H), 7.87 (dt, J = 7.0, 1.0 Hz, 2H), 7.46 (m, 2H), 7.36 (m, 6H), 6.32 (t, J = 2.5 Hz, 2H), 6.16 (s, 2H), 5.70 (t, J = 2.5 Hz, 2H), 2.64 (t, J = 7.4 Hz, 4H), 1.61 (t, J = 7.3 Hz, 4H), 1.26 (m, 36H), 0.88 (t, J = 7.3 Hz, 6H)

[0170] Preparation Example 2: Synthesis of [1-(η5-cyclopentadien-1-yl)-1-(η5-fluorenyl)-1,1-diphenylmethane]hafnium dichloride (compound 2)

[0171] [1-(η5-cyclopentadien-1-yl)-1-(η5-fluorenyl)-1,1-diphenylmethane]hafnium dichloride (compound 2) was synthesized according to the process shown in the literature [A. Razavi, J. Latwood, J. Organometallic. Chen, 459 (1993), 117-123].

[0172] ¹H NMR (500 MHz, chloroform-d) δ 8.19 (d, J = 8.5 Hz, 2H), 7.95 (d, J = 8.3 Hz, 2H), 7.88 (d, J = 8.5 Hz, 2H), 7.55 (t, J = 8.0 Hz, 2H), 7.44 (t, J = 8.2 Hz, 2H), 7.31 (m, 4H), 7.01 (t, J = 8.1 Hz, 2H), 6.47 (d, J = 7.1 Hz, 2H), 6.33 (s, 2H), 5.75 (s, 2H)

[0173] Preparation Example 3: Preparation of [1-(η5-cyclopentadien-1-yl)-1-(η5-2,7-di-n-butylfluorenyl)-1,1-diphenylmethane]hafnium dichloride (compound 3)

[0174] Step 1: Synthesis of Compound 3-1

[0175]

[0176] In a Schlenk flask, Pd[P(t-Bu)3]2 (1.1 mol%, 0.26 g, 0.51 mmol), 2,7-dibromo-9H-fluorene (15 g, 46 mmol), and toluene (200 mL) were added, followed by the addition of n-Butylboronic acid (2.4 equivalents, 11.2 g), and then toluene (300 mL). After 2 hours, the mixture was extracted three times with saturated NH4Cl aqueous solution and diethyl ether. The organic layer was collected, dried with MgSO4, filtered, and subjected to reduced pressure. Column purification (silica, hexane: ethyl acetate = 10:1) yielded a yellow liquid compound 3-1 (6.3 g, 49% yield).

[0177] ¹H NMR (500 MHz, chloroform-d) δ 7.68 (d, J = 7.7 Hz, 2H), 7.38 (s, 2H), 7.21 (d, J = 7.7 Hz, 2H), 3.86 (s, 2H), 2.72 (t, J = 7.5 Hz, 4H), 1.70 (app.p, J = 7.2 Hz, 4H), 1.44 (app.h, J = 7.0 Hz, 4H), 1.00 (t, J = 7.2 Hz, 6H)

[0178] Step 2: Synthesis of compound 3-2

[0179]

[0180] 2,7-Di-n-butylfluorene (12 g, 43.1 mmol) was dissolved in tetrahydrofuran (THF) (87 mL), followed by the addition of nBuLi (1.6 M in hexane, 27.1 mL, 43.1 mmol) and stirring at room temperature. After 3 hours, 6,6-Diphenylfulvene (10 g, 43.1 mmol) was added. The reaction solution was stirred for 16 hours, and the reaction was terminated by the addition of NH4Cl aqueous solution (40 mL). The product was extracted as an organic layer, dried over MgSO4, filtered, and subjected to reduced pressure. The resulting yellow solid was washed with ethanol to give a white solid compound 3-2 (20 g, yield 91%).

[0181] ¹H NMR (500 MHz, chloroform-d) δ 6.96–7.34 (m, 20H), 5.43 (s, 1H), 2.72 (m, 4H), 1.70 (m, 4H), 1.44 (m, 4H), 0.90 (t, J = 7.2 Hz, 6H)

[0182] Third step: [1-(η5-cyclopentadien-1-yl)-1-(η5-2,7-di-n-butylfluorenyl)-1,1-diphenylmethyl] Synthesis of Hafnium dichloride (compound 3)

[0183]

[0184] Compound 3-2 (5 g, 9.82 mmol) was dissolved in 60 mL of diethyl ether, and then nBuLi (1.6 M, 13.5 mL, 21.6 mmol in hexane) was added and stirred for 16 hours. After the reaction was complete, the diethyl ether was removed by vacuum drying, followed by the addition of hexane solution and decantation under reduced pressure. In a glove box, solid lithium (5.1 g, 9.79 mmol) and hafnium tetrachloride (HfCl4) (3.13 g, 9.79 mmol) were dissolved in 80 mL of diethyl ether. After stirring at room temperature for 16 hours, the diethyl ether was removed by vacuum drying, followed by the addition of 80 mL of toluene. The mixture was heated at 50 °C for 2 hours, and the byproduct LiCl was precipitated and filtered. The filtrate was dried under vacuum to obtain a crystalline form, yielding yellow crystalline compound 3 (4.5 g) (recrystallized from toluene in 60% yield).

[0185] ¹H NMR (500 MHz, chloroform-d) δ 8.02 (d, J = 8.5 Hz, 2H), 7.96 (dd, J = 8.0, 2.0 Hz, 2H), 7.87 (dt, J = 7.0, 1.0 Hz, 2H), 7.46 (m, 2H), 7.36 (m, 6H), 6.32 (t, J = 2.5 Hz, 2H), 6.16 (s, 2H), 5.70 (t, J = 2.5 Hz, 2H), 2.38 (m, 4H), 1.38 (m, 4H), 1.23 (m, 4H), 0.86 (t, J = 7.2 Hz, 6H)

[0186] [Example]

[0187] Example 1

[0188] Ethylene (C2), hydrogen, hexane, and 1-octene were injected into a 25-liter continuous reactor and heated to 150°C. A transition metal catalyst composition, consisting of a mixture of the compound from Preparation Example 1 and the co-catalyst phenylammonium borate at a molar ratio of 1:5, and triisobutylaluminum were injected into the reactor at a rate of 50 g / hr. The specific process conditions are shown in Table 1 below.

[0189] After mixing 0.02 parts by weight of Iragnox-1076 as an antioxidant into 100 parts by weight of the ethylene-α-olefin copolymer obtained in the above process, a particulate ethylene-α-olefin copolymer resin composition was prepared using a twin-screw extruder.

[0190] Example 2

[0191] Except for the process conditions according to Table 1 below, an ethylene-α-olefin copolymer resin composition was prepared using the same method as in Example 1 above.

[0192] Example 3

[0193] Except for the process conditions according to Table 1 below, an ethylene-α-olefin copolymer resin composition was prepared using the same method as in Example 1 above.

[0194] Example 4

[0195] Except for the process conditions according to Table 1 below, an ethylene-α-olefin copolymer resin composition was prepared using the same method as in Example 1 above.

[0196] [Comparative Example]

[0197] Comparative Example 1

[0198] Except for the process conditions according to Table 2 below, the ethylene-α-olefin copolymer resin composition was prepared using the same method as in Example 1 above.

[0199] Comparative Example 2

[0200] Except for the process conditions according to Table 2 below, the ethylene-α-olefin copolymer resin composition was prepared using the same method as in Example 1 above.

[0201] Comparative Example 3

[0202] Except that the compound of Preparation Example 2 was used instead of the compound of Preparation Example 1 and the process conditions were performed according to Table 2 below, an ethylene-α-olefin copolymer resin composition was prepared in the same manner as in Example 1 above.

[0203] Comparative Example 4

[0204] Except for the process conditions according to Table 2 below, the ethylene-α-olefin copolymer resin composition was prepared using the same method as in Example 1 above.

[0205] Comparative Example 5

[0206] Except that the compound of Preparation Example 3 was used instead of the compound of Preparation Example 1 and the process conditions were performed according to Table 2 below, an ethylene-α-olefin copolymer resin composition was prepared in the same manner as in Example 1 above.

[0207] [Table 1]

[0208] Example 1 Example 2 Example 3 Example 4 Reactor temperature 150 150 150 150 Catalyst (g / hr) 0.15 0.15 0.15 0.15 Co-catalyst (g / hr) 0.75 0.75 0.75 0.75 TiBA (g / hr) 50 50 50 50 <![CDATA[Hydrogen (g / kg_C2)]]> 0.53 0.49 0.35 0.34 <![CDATA[1-Octene (kg / kg_C2)]]> 1.46 0 1.34 0 <![CDATA[1-butene (kg / kg_C2)]]> 0 1.02 0 0.96

[0209] [Table 2]

[0210]

[0211] [Experimental Example]

[0212] Experimental Example 1: Determination of physical properties of ethylene-α-olefin copolymer resin compositions

[0213] The following physical properties were determined for the ethylene-α-olefin copolymer resin compositions prepared in Examples 1 to 4 and Comparative Examples 1 to 5 above, and the results are shown in Tables 3 and 4 below.

[0214] Melt flow index (MI)

[0215] According to ASTM D1238, MI was measured at 190°C with loads of 2.16 kg and 21.6 kg, respectively. 2.16 and MI 21.6 .

[0216] Melt flow rate ratio (MFRR)

[0217] Using MI measured according to ASTM D1238 2.16 and MI 21.6 MI was calculated under a load of 21.6 kg and a temperature of 190 °C. 21.6 / MI under a load of 2.16 kg and a temperature of 190 °C 2.16 .

[0218] density

[0219] The determination was based on ASTM D1505.

[0220] Zero shear viscosity

[0221] Measurements were performed using an advanced rheometer expansion system (ARES) rheometer under conditions of frequency sweep at 180°C, strain of 5%, and a range of 0.01 to 400 rad / s. The zero-shear viscosity was then calculated using the Carreau model.

[0222] Infrared gel permeation chromatography

[0223] (1) Number-average molecular weight (Mn), weight-average molecular weight (Mw), Z-average molecular weight (Mz) and their ratios

[0224] The determination was performed using a Polymer Char GPC-IR instrument. 12 mg of the sample was added to 8 mL of 1,2,4-trichlorobenzene (containing 125 ppm BHT) and dissolved at 160 °C for 2 hours. The solution used was 1,2,4-trichlorobenzene (containing 125 ppm BHT), and the column was connected to one Olexis guard and three Olexis guards (Column; PLgel Olexisguard X 1 + PLgel Olexis X 3). 200 μL was injected for analysis. For molecular weight calculation, column calibration was performed using polystyrene standards, and the molecular weight was calculated using the Mark-Houwink constant (K = 44.6, a = 0.725). The number-average molecular weight (Mn), weight-average molecular weight (Mw), Z-average molecular weight (Mz), and their ratios were calculated.

[0225] (2) Number of short branches per 1,000 carbons (SCB / 1,000TC)

[0226] The number of short branches represents the number of short branches present per 1,000 carbons, corrected using a standard known to its value (1-octene copolymer provided by Polymer Char).

[0227] Specifically, gel permeation chromatography (GPC-IR) is a method for determining the SCB content in each slice of a GPC column as it passes through an IR detector, representing segments separated by molecular weight. Here, the SCB content of the sample can be calculated using a standard with a known SCB / 1,000TC value and a calibration line prepared by utilizing the obtained CH2 / CH3 area ratio. In this invention, a calibration line was prepared using a 1-octene copolymer standard (provided by Polymer Char).

[0228] The above-mentioned number of short branches (SCB / 1,000TC) is an average value of the number of methyl groups after removing the terminal methyl groups from the number of methyl groups (-CH3) present in every 1,000 carbons in the sample, as shown in the following formula, which refers to the value calculated from the total (Bulk)CH3 / 1,000TC through end chain correction.

[0229] SCB / 1,000TC = Bulk CH3 / 1,000TC - Chain ends / 1,000TC

[0230] In the above formula, Bulk CH3 / 1,000TC is the average number of methyl (-CH3) groups present in every 1,000 carbons in the sample, which is the value calculated from the area CH2 / Area CH3 ratio of the entire sample and the composition calibration line.

[0231] End chain correction is determined by the following formula.

[0232] The number of end chains in every 1,000 carbons (Chain ends / 1,000TC) = (A×14,000) / M.

[0233] A: Number of end groups (2 in the case of linear polyethylene, >2 in long-chain branched (LCB) polymers)

[0234] M: Given molar molecular mass

[0235] When the chain-terminal group ends with a vinyl group (-CH=CH2), its value is applied as 0 for endchain correction.

[0236] (3) CCD

[0237] The chemical composition distribution (CCD) was calculated based on the morphology of short branches determined by infrared gel permeation chromatography according to Equation 1 below.

[0238] [Formula 1]

[0239] -1.5≤HMW 20 -LMW 20 ≤1.5

[0240] In Equation 1 above,

[0241] HMW 20 It refers to the average number of short branches (SCBs) per 1,000 carbons in the top 20% of the molecular weight, based on the weight-average molecular weight (Mw) determined by infrared gel permeation chromatography.

[0242] LMW 20 It refers to the average number of short branches (SCBs) per 1,000 carbons in the lower 20% of the molecular weight fraction, based on the weight-average molecular weight (Mw) determined by infrared gel permeation chromatography.

[0243] Specifically, it is the difference between the average number of short branches in the high 20% (equivalent to high molecular weight) and the average number of short branches in the low 20% (equivalent to low molecular weight) when the weight-average molecular weight (Mw) is determined by infrared gel permeation chromatography. If the value exceeds 1.5, it is defined as a broad orthogonal composition distribution (BOCD) structure; if it is within ±1.5, it is defined as a narrow composition distribution (NCD) structure; and if it is less than -1.5, it is defined as a broad composition distribution (BCD) structure.

[0244] [Table 3]

[0245]

[0246] [Table 4]

[0247]

[0248] Experimental Example 2: Determination of Physical Properties of Molded Products

[0249] The oxygen transmittance, moisture transmittance, and light transmittance of the molded articles of ethylene-α-olefins of Examples 1 to 4 and Comparative Examples 1 to 5 were determined using the following methods, and the results are shown in Tables 5 and 6 below.

[0250] oxygen transmission rate

[0251] A 100 μm thick film was produced using a casting film machine at 200 °C. The film was measured using VOT's OX-TRAN 2 / 22 standard based on ASTM D3985.

[0252] Water permeability

[0253] A 100 μm thick film was produced using a casting film machine at 200 °C. The film was measured using a VOT PERMATRAN 3 / 34G instrument based on ASTM F1249.

[0254] Experiment Example 3: Performance Evaluation of Solar Cells

[0255] A sheet of encapsulating material for solar cells was manufactured using the ethylene-α-olefin copolymer resin compositions according to Examples 1 to 4 and Comparative Examples 1 to 5. The output before and after potential-induced decay (PID) was measured, and the retention was calculated and shown in Tables 5 and 6 below.

[0256] During the manufacturing process, for each 100 parts by weight of ethylene-α-olefin copolymer resin composition, 1.0 part by weight of Luperox TBEC (tert-butyl-2-ethylhexyl monoperoxycarbonate) from Arkema was mixed as a crosslinking agent; 0.5 parts by weight of TAICROS (tracenepropyl isocyanurate) from Evonik was mixed as a co-crosslinking agent; 0.3 parts by weight of Chimassorb 81 (2-hydroxy-4-octyloxybenzophenone) from Ciba was mixed as a UV absorber; 0.1 parts by weight of Tinuvin 770 (bis-2,2,6,6-tetramethyl-4-piperidinyl sebacate) from Ciba was mixed as a UV stabilizer; and 0.2 parts by weight of OFS6030 (methacryloyloxypropyltrimethoxysilane) from Dow Corning was mixed as a silane coupling agent. Subsequently, in a single-screw co-extruder with a screw diameter of 40 mm and a T-die width of 400 mm, the extruder temperature was set to 100 °C and the screw rotation speed was adjusted to produce a 450 μm thick ethylene-α-olefin copolymer solar cell encapsulation material sheet.

[0257] Light transmittance

[0258] After the aforementioned ethylene-α-olefin copolymer solar cell encapsulation material sheets were placed between two sheets of low-iron-content solar cell glass, they were laminated at 150°C. The light transmittance was then measured using a UV-Vis spectrometer. The transmittance was measured in the 200–900 nm region, and then averaged for the 450–700 nm region.

[0259] Output measurements before and after evaluation of potential-induced decay (PID)

[0260] To evaluate the performance of solar cells, a small module (using four solar cells) was fabricated by laminating a structure of glass / encapsulation material sheets for ethylene-α-olefin copolymer solar cells manufactured in the above manner / n-type tunneling oxide passivated contact (n-type TOPCon) solar cells (JiangsuRunergy new technology, 7.43W / unit) / encapsulation material sheets for ethylene-α-olefin copolymer solar cells manufactured in the above manner / glass. After mounting an aluminum frame on the small module, the maximum output (Power_max, Pmax) before potential-induced decay (PID) evaluation was determined by plotting the current-voltage curve (I-V curve) using a solar simulator. To evaluate PID, the module was placed in a constant temperature and humidity chamber at 85°C and 85% relative humidity, and then kept under a voltage of 2000V for 96 hours before being removed. The maximum output (Pmax) after PID evaluation was then measured using a solar simulator.

[0261] [Table 5]

[0262]

[0263]

[0264] [Table 6]

[0265]

[0266] Referring to Tables 5 and 6 above, the ethylene-α-olefin copolymer resin compositions of Examples 1 to 4 according to the present invention exhibit superior output retention after potential-induced decay (PID) evaluation compared to the ethylene-α-olefin copolymer resin compositions of Comparative Examples 1 to 5. This is because the ethylene-α-olefin copolymer resin compositions of Examples 1 to 4 effectively protect the solar cell from external substances such as oxygen and moisture, thereby minimizing corrosion of (1) the deposited layer and (2) the aluminum electrode.

[0267] (1) SiN x +H₂O→SiN x-1 (OH)2+2H + +2e - (n-type cell) → SiN x-1 (OH)2+H2

[0268] (2) 4Al + 3O₂ → 2Al₂O₃

[0269] In addition, although Comparative Example 3 had excellent output retention after potential-induced decay (PID) evaluation due to its low oxygen and moisture transmittance, it was difficult to use as an encapsulation material for solar cells due to its low light transmittance.

[0270] In addition, Comparative Example 5 was explained as having a high oxygen and water permeability due to its BOCD structure, resulting in poor output retention after potential-induced decay (PID) evaluation.

[0271] While embodiments of the present invention have been described above, those skilled in the art will understand that the invention can be implemented in other specific ways without altering its technical concept or essential features. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive.

Claims

1. An ethylene-α-olefin copolymer resin composition comprising an ethylene-α-olefin copolymer, characterized in that, Its weight-average molecular weight to number-average molecular weight ratio, Mw / Mn, is 2 to 2.7, and satisfies the following equation: [Formula 1] -1.5≤HMW 20 -LMW 20 ≤1.5 In Equation 1 above, HMW 20 It refers to the average number of short branches per 1,000 carbons in the top 20% of the molecular weight fraction, based on the weight-average molecular weight Mw determined by infrared gel permeation chromatography. LMW 20 It refers to the average number of short branches per 1,000 carbons in the lower 20% of the molecular weight fraction, based on the weight-average molecular weight Mw determined by infrared gel permeation chromatography.

2. The ethylene-α-olefin copolymer resin composition according to claim 1, wherein, The aforementioned α-olefins are any one or more of propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1-dodecene, 1-tetradecene, 1-hexadecene, and 1-eicosene.

3. The ethylene-α-olefin copolymer resin composition according to claim 1, wherein, The zero-shear viscosity of the above-mentioned ethylene-α-olefin copolymer resin composition, measured by an ARES rheometer at 180°C, is 4,000 poise to 100,000 poise.

4. The ethylene-α-olefin copolymer resin composition according to claim 1, wherein, The weight-average molecular weight of the above-mentioned ethylene-α-olefin copolymer resin composition is from 30,000 g / mol to 150,000 g / mol.

5. The ethylene-α-olefin copolymer resin composition according to claim 1, wherein, The ratio of the Z-average molecular weight to the weight-average molecular weight, Mz / Mw, of the above-mentioned ethylene-α-olefin copolymer resin composition is 1.5 to 3.

6. The ethylene-α-olefin copolymer resin composition according to claim 1, wherein, The number of short branches in each 1,000 carbon atoms of the above-mentioned ethylene-α-olefin copolymer resin composition is 30 to 65.

7. The ethylene-α-olefin copolymer resin composition according to claim 1, wherein, The melt flow index (MI) of the above-mentioned ethylene-α-olefin copolymer resin composition under a load of 2.16 kg and a temperature of 190 °C 2.16 The concentration ranges from 1g / 10min to 25g / 10min.

8. The ethylene-α-olefin copolymer resin composition according to claim 1, wherein, The melt flow rate MI of the above-mentioned ethylene-α-olefin copolymer resin composition under a load of 21.6 kg and a temperature of 190 °C 21.6 The melt flow rate MI under a load of 2.16 kg and a temperature of 190 °C 2.16 The ratio of MFRR is 20 to 35.

9. The ethylene-α-olefin copolymer resin composition according to claim 1, wherein, The density of the above-mentioned ethylene-α-olefin copolymer resin composition is 0.860 g / cm³. 3 Up to 0.880 g / cm 3 .

10. The ethylene-α-olefin copolymer resin composition according to claim 1, wherein, The above-mentioned ethylene-α-olefin copolymer resin composition further comprises one or more additives selected from crosslinking agents, co-crosslinking agents, silane coupling agents, ultraviolet stabilizers, ultraviolet absorbers, and antioxidants.

11. The ethylene-α-olefin copolymer resin composition according to claim 10, wherein, Relative to 100 parts by weight of the above-described ethylene-α-olefin copolymer resin composition, the crosslinking agent comprises 0.01 to 1.5 parts by weight. The aforementioned crosslinking agent is selected from tert-butyl-2-ethylhexyl monoperoxycarbonate, 1,1-di(tert-pentylperoxy)cyclohexane, 1,1-di(tert-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-di(tert-butylperoxy)cyclohexane, 2,5-dimethyl-2,5-di-(2-ethylhexanoylperoxy)hexane, tert-pentylperoxy-2-ethylhexanoate, tert-butylperoxy-2-ethylhexanoate, tert-pentyl(2-ethylhexyl) monoperoxycarbonate, tert-butylisopropyl monoperoxycarbonate, 2,5-dimethyl-2,5-ethylhexylperoxycarbonate, and 2,5-dimethyl-2,5-ethylhexylperoxycarbonate. One or more of the following: di(toluylperoxy)hexane, tert-butyl-(2-ethylhexyl)monoperoxycarbonate, tert-pentylperoxybenzoate, tert-butylperoxyacetate, tert-butylperoxy-3,5,5-trimethylhexanoate, tert-butylperoxybenzoate, dicumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, α,α'-di(tert-butylperoxy)diisopropylbenzene, di-tert-pentylperoxide, di-tert-butylperoxide, and 2,5-dimethyl-2,5-di(tert-butylperoxy)hex-3-yne.

12. The ethylene-α-olefin copolymer resin composition according to claim 10, wherein, Relative to 100 parts by weight of the above-mentioned ethylene-α-olefin copolymer resin composition, the composition contains 0.01 parts by weight to 3 parts by weight of the above-mentioned crosslinking agent. The aforementioned crosslinking agent is selected from one or more of polyallyl compounds and acrylate compounds.

13. The ethylene-α-olefin copolymer resin composition according to claim 10, wherein, Relative to 100 parts by weight of the above-mentioned ethylene-α-olefin copolymer resin composition, it contains 0.01 parts by weight to 3 parts by weight of the above-mentioned silane coupling agent. The aforementioned silane coupling agent is selected from one or more of γ-methacryloxypropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, and γ-epoxypropoxypropyltrimethoxysilane.

14. A method for preparing the ethylene-α-olefin copolymer resin composition according to claim 1, characterized in that, include: The step of supplying a transition metal catalyst composition, hydrogen, ethylene, and α-olefins to a reactor; as well as The copolymerization process is carried out at temperatures ranging from 110°C to 170°C.

15. The method for preparing the ethylene-α-olefin copolymer resin composition according to claim 14, wherein, The above transition metal catalyst composition comprises a transition metal compound represented by the following chemical formula 1 and a co-catalyst: [Chemical Formula 1] In the above chemical formula 1, M is a group 4 transition metal; R1 and R2 are each independently (C11-C20) alkyl groups; R3 and R4 are independently hydrogen or (C1-C10) alkyl-substituted or unsubstituted (C6-C20) aryl groups; X1 and X2 are independently halogen, (C1-C20)alkyl, (C6-C20)aryl(C1-C20)alkyl, (C3-C20)cycloalkyl, (C6-C20)aryl, ((C1-C20)alkyl(C6-C20)aryl)(C1-C20)alkyl, (C1-C20)alkoxy, (C6-C20)aryloxy, (C1-C20)alkyl(C6-C20)aryloxy, (C1-C20)alkoxy(C6-C20)aryloxy, -OSiR a R b R c -SR d -NR e R f -PR g R h Or (C1-C20) alkylene; R a To R d They are independently (C1-C20)alkyl, (C6-C20)aryl, (C6-C20)aryl(C1-C20)alkyl, (C1-C20)alkyl(C6-C20)aryl or (C3-C20)cycloalkyl; R e To R h Each of the following can be independently (C1-C20)alkyl, (C6-C20)aryl, (C6-C20)aryl(C1-C20)alkyl, (C1-C20)alkyl(C6-C20)aryl, (C3-C20)cycloalkyl, tri(C1-C20)alkylsilyl or tri(C6-C20)arylsilyl; If one of X1 or X2 is a (C1-C20) alkylene group, the other one is absent.

16. The method for preparing the ethylene-α-olefin copolymer resin composition according to claim 15, wherein, The molar ratio of the aforementioned transition metal compound to the cocatalyst is 1:2 to 1:

7.

17. The method for preparing the ethylene-α-olefin copolymer resin composition according to claim 14, wherein, The aforementioned hydrogen is supplied at a rate of 0.3 g / kg to 0.6 g / kg relative to the ethylene supply. The aforementioned α-olefins are supplied at a rate of 0.9 kg / kg to 1.6 kg / kg relative to the ethylene supply.

18. A molded article, characterized in that, It is made from the ethylene-α-olefin copolymer resin composition of claim 1.

19. The molded article according to claim 18, wherein, The aforementioned molded products are encapsulation materials for solar cells.

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