Ethylene / α-olefin copolymer and composition for sealing film containing same

Abstract

The present invention relates to an ethylene / α-olefin copolymer having excellent physical properties, which exhibits a high degree of crosslinking and shortens the impregnation time of a crosslinking agent, and a composition for an encapsulant film containing the same.

Description

[Technical Field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 2021-0148244, filed November 1, 2021, and all contents disclosed in the documents of that Korean patent application are incorporated herein by reference.

[0002] The present invention relates to an ethylene / α-olefin copolymer with excellent physical properties that shortens the impregnation time of a crosslinking agent and shows a high degree of crosslinking, and to a composition for an encapsulant film containing the copolymer. [Background technology]

[0003] As global environmental issues and energy problems become increasingly serious, solar cells are attracting attention as a means of generating energy without the risk of environmental pollution or depletion. When solar cells are used outdoors, such as on the roof of a building, they are generally used in the form of a solar cell module. When manufacturing a solar cell module, to obtain a crystalline solar cell module, the following layers are laminated in this order: front glass / solar cell encapsulant / crystalline solar cell element / solar cell encapsulant / rear glass (or rear protective sheet). As the solar cell encapsulant, ethylene / vinyl acetate copolymer or ethylene / α-olefin copolymer, which have excellent transparency, flexibility, adhesiveness, etc., are generally used.

[0004] Solar cell encapsulants have been steadily researched to improve the functions normally required. Among the various physical properties of ethylene / α-olefin copolymers, the degree of crosslinking in particular can be used as an indicator of mechanical strength and heat resistance evaluation. The higher the degree of crosslinking, the better the mechanical strength and heat resistance will be when used as an encapsulant, and the higher the long-term stability of the module will be.

[0005] Meanwhile, solar cells are generally located in harsh environments, especially in hot and humid regions, so continued research is needed to find ways to effectively protect solar cell modules in such environments and prevent problems such as output degradation. In particular, improving the degree of crosslinking is necessary to improve mechanical strength and heat resistance. However, polar substances used for crosslinking, such as crosslinking agents, crosslinking coagents, and peroxides, have low affinity with non-polar ethylene / α-olefin copolymers, which lengthens the time required to impregnate the crosslinking agent components, limiting the extent to which the degree of crosslinking can be improved. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent Publication No. 2010-258439 Summary of the Invention [Problem to be solved by the invention]

[0007] An object of the present invention is to provide an ethylene / α-olefin copolymer having excellent physical properties such as a shortened impregnation time with a crosslinking agent and a high degree of crosslinking, and a method for producing the same. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention provides an ethylene / α-olefin copolymer and a composition for an encapsulant film containing the copolymer. (1) The present invention provides an ethylene / α-olefin copolymer that satisfies the following requirements (a) to (d): (a) The d-spacing measured by SAXS (Small-Angle X-Ray Scattering) is 12 nm or more; (b) the crystallinity as measured by WAXS (Wide-Angle X-ray Scattering) is 14% or less; (c) The hardness (shore A) measured at 40°C is 65 or less, and (d) The melting temperature measured by DSC (Differential Scanning Calorimetry) is 70°C or less.

[0009] (2) The present invention provides the ethylene / α-olefin copolymer according to (1) above, which has a crystallinity of 13% or less. (3) The present invention provides the ethylene / α-olefin copolymer according to (1) or (2) above, which has a hardness (shore A) of 63 or less.

[0010] (4) The present invention provides the ethylene / α-olefin copolymer according to any one of (1) to (3) above, which has a melting temperature of 50 to 65°C. (5) The present invention provides the ethylene / α-olefin copolymer according to any one of the above (1) to (4), which has a density of 0.85 to 0.89 g / cc.

[0011] (6) The present invention provides the ethylene / α-olefin copolymer according to any one of (1) to (5) above, which has a melt index (MI, under conditions of 190°C and a load of 2.16 kg) of 1 to 100 dg / min.

[0012] (7) The present invention provides a melting index (MI 2.16 , 190℃, 2.16kg load) 10 The melt flow index (MFRR, Melt Flow Rate Ratio, MI) is the value of the melt flow index (MFRR, Melt Flow Rate Ratio, MI) 10 / MI 2.16 ) is 8.0 or less.

[0013] (8) The present invention provides the ethylene / α-olefin copolymer according to any one of (1) to (7) above, wherein the α-olefin comprises at least one selected from the group consisting 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.

[0014] (9) The present invention provides the ethylene / α-olefin copolymer according to any one of (1) to (8) above, wherein the α-olefin is contained in an amount of more than 0 and not more than 99 mol % based on the ethylene / α-olefin copolymer.

[0015] (10) The present invention provides a composition for an encapsulant film, comprising the ethylene / α-olefin copolymer according to any one of (1) to (9) above. [Effects of the Invention]

[0016] The ethylene / α-olefin copolymer of the present invention has a high proportion of amorphous regions and a low degree of crystallinity, and therefore exhibits high absorbency, allowing it to be impregnated with a crosslinking agent within a short period of time and exhibiting an excellent degree of crosslinking. [Brief explanation of the drawings]

[0017] [Figure 1] 1 shows the results of deconvolution of the peaks in Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0018] The present invention will now be described in more detail so that the present invention may be more easily understood. The terms and words used in the description of the present invention and the claims should not be interpreted in a limited way to their ordinary or dictionary meanings, but should be interpreted in a way that is consistent with the technical idea of ​​the present invention, based on the principle that the inventors can appropriately define the concepts of terms in order to best describe their inventions. The present invention will be described in detail below.

[0019] <Ethylene / α-olefin copolymer> The ethylene / α-olefin copolymer of the present invention is characterized by satisfying the following conditions (a) to (d). (a) d-spacing measured by SAXS (Small-Angle X-Ray Scattering) is 12 nm or more; (b) the crystallinity as measured by WAXS (Wide-Angle X-ray Scattering) is 14% or less; (c) The hardness (shore A) measured at 40°C is 65 or less, (d) The melting temperature measured by DSC (Differential Scanning calorimetry) is 70°C or less.

[0020] The ethylene / α-olefin copolymer of the present invention has a low degree of crystallinity and a high proportion of amorphous regions, and therefore has excellent absorbency for polar substances such as crosslinking agents and crosslinking aids. Specifically, the ethylene / α-olefin copolymer of the present invention is produced by introducing a transition metal compound, a cocatalyst, ethylene, and an α-olefin monomer into a polymerization reactor and polymerizing the introduced α-olefin monomer. In particular, since the amount of the α-olefin monomer introduced relative to the amount of ethylene introduced is high, the ethylene / α-olefin copolymer is characterized by a high proportion of amorphous regions and wide spacing between crystalline regions.

[0021] The ethylene / α-olefin copolymer of the present invention has a d-spacing of 12 nm or more as measured by SAXS (Small-Angle X-Ray Scattering).

[0022] The d-spacing indicates the distance between domains in a crystal structure, and the lower the d-spacing value, the closer the distance between crystal structures, meaning higher crystallinity.

[0023] The d-spacing can be measured by small-angle X-ray scattering (SAXS). Specifically, using an Xenocs Xeuss 2.0 X-ray scattering instrument, X-rays were transmitted through the sample, and the scattering intensity (I(q)) according to the scattering vector (q) was measured. More specifically, the small-angle X-ray scattering (SAXS) measurement was performed by placing the sample 2.5 m away from the detector and irradiating it with X-rays. The detector used was a Pilatus 3 300K (2D detector). The resulting 2D diffraction pattern was obtained as an image, which was calibrated using the sample-to-detector distance obtained from a standard sample. The 2D diffraction pattern obtained by analyzing the test specimen was then circularly averaged to convert the scattering intensity (I(q)) according to the scattering vector (q).

[0024] [Formula 1] q=4πsinθ / λ

[0025] In the above formula 1, q is the scattering vector, θ is the half value of the scattering angle, and λ is the wavelength of the irradiated X-rays.

[0026] The distance between crystalline domains was analyzed by measuring the scattering intensity (I(q)) due to the scattering vector (q) obtained by SAXS. The measured scattering intensity (I(q)) was multiplied by the square of the scattering vector (q) to obtain I(q) × q due to the scattering vector (q). 2 A peak is observed in the graph. The scattering vector value (q*) of the observed peak was used to obtain the distance between crystalline domains (d-spacing).

[0027] [Formula 2] d-spacing=2π / q*

[0028] In the above formula 2, The q* is I(q)×q due to the scattering vector (q). 2 3 shows the scattering vector value at the peak of the graph.

[0029] The ethylene / α-olefin copolymer of the present invention has a high proportion of amorphous regions and low crystallinity, and therefore exhibits a d-spacing of 12 nm or more. When the d-spacing range is 12 nm or more, the ethylene / α-olefin copolymer has an increased absorptivity for the crosslinking agent component, which has the advantage of allowing a large amount of crosslinking agent to be impregnated in a short period of time.

[0030] The ethylene / α-olefin copolymer of the present invention may have a crystallinity of 14% or less, specifically 13% or less, or 12% or less, as measured by WAXS (Wide-Angle X-ray Scattering).

[0031] The α-olefin copolymer of the present invention exhibits a crystallinity in a low range such as the above range. The crystallinity can be measured by wide-angle X-ray scattering (WAXS). Using an Xenocs Xeuss 2.0 X-ray scattering device, X-rays were transmitted through the sample, and the scattering intensity (I(q)) according to the scattering vector (q) was measured. More specifically, the wide-angle X-ray scattering (WAXS) measurement was performed by placing the sample approximately 0.7 m away from the detector and irradiating it with X-rays. A Pilatus 3 300K (2D detector) was used as the detector. WAXS is a parallel beam method that measures the interference of X-rays generated when they collide with the sample during transmission. Peaks due to the crystalline structure are assigned, and the percentage of the crystalline peak area relative to the total area is calculated to determine the crystallinity.

[0032] Specifically, the scattering or diffraction intensity (I(q)) according to the scattering vector (q) obtained by WAXS was measured and analyzed. From the obtained scattering or diffraction intensity, the diffraction peaks due to the amorphous halo (Ia(q)), mesophase (Im(q)), and crystal (Ic(q)) were deconvoluted, and the crystallinity was calculated according to the following Equation 3.

[0033]

number

[0034] In the above formula 3, Im is the Mesophase Peak, Ic is Crystal Peak, Ia is an Amorphous halo Peak.

[0035] When the crystallinity of the ethylene / α-olefin copolymer of the present invention is within the above range, the relative amorphous content in the copolymer increases, and the absorption of the crosslinking agent component increases, thereby enabling the impregnation of the crosslinking agent component within a short period of time.

[0036] The ethylene / α-olefin copolymer of the present invention has a hardness (shore A) measured at 40° C. of 65 or less, specifically 63 or less, 62 or less, or 61 or less.

[0037] The hardness indicates Shore A hardness in accordance with the ASTM D2240 standard. Since the ethylene / α-olefin copolymer of the present invention contains many amorphous regions and has a fast impregnation rate with polar substances such as crosslinkers, the hardness measured at an impregnation temperature of 40°C exhibits a low value as described above.

[0038] When the hardness (shore A) of the ethylene / α-olefin copolymer of the present invention measured at 40°C is within the above range, there is an advantage that the crosslinking agent component easily penetrates into the ethylene / α-olefin copolymer, and the impregnation time of the crosslinking agent component is shortened.

[0039] The ethylene / α-olefin copolymer of the present invention has a melting temperature (Melting Temperature, Tm) measured by DSC (Differential Scanning calorimetry) of 70°C or lower, and specifically may be 65°C or lower, 60°C or lower, 58°C or lower, 45°C or higher, or 50°C or higher.

[0040] When the melting temperature of the ethylene / α-olefin copolymer of the present invention is within the above range, it exhibits excellent thermal stability and does not exhibit a decrease in light transmittance due to a highly crystalline region having a high melting temperature, thereby achieving an excellent level of light transmittance.

[0041] The melting temperature is measured using a differential scanning calorimeter (DSC). Specifically, the copolymer is heated to 150°C, maintained at that temperature for 5 minutes, cooled to 20°C, and then heated again. In this case, the temperature increase and decrease rates are each controlled at 10°C / min, and the result measured during the second temperature increase can be taken as the melting temperature.

[0042] The ethylene / α-olefin copolymer of the present invention is a low-density polymer having a density in the range of 0.85 to 0.89 g / cc, and the density may mean a density measured in accordance with ASTM D-792. Specifically, the density may be 0.850 g / cc or more, 0.860 g / cc or more, 0.870 g / cc or more, or 0.874 g / cc or more, or 0.890 g / cc or less, 0.880 g / cc or less, or 0.878 g / cc or less.

[0043] When the ethylene / α-olefin copolymer of the present invention has a density within the above range, it exhibits excellent crosslinkability and does not decrease in physical properties such as volume resistivity and light transmittance, and therefore can be usefully used as an insulating material.

[0044] The ethylene / α-olefin copolymer of the present invention has a melt index (MI, 190°C, 2.16 kg load) of 1 to 30 dg / min. Specifically, the melt index may be 1 dg / min or more, 2 dg / min or more, 3 dg / min or more, or 4 dg / min or more, and may be 30 dg / min or less, 20 dg / min or less, or 15 dg / min or less.

[0045] When the ethylene / α-olefin copolymer of the present invention has a melt index within the above range, it exhibits an appropriate production rate and is excellent in volume resistivity and light transmittance, and therefore can be usefully used as an insulating material.

[0046] The ethylene / α-olefin copolymer of the present invention has a melt index (MI 2.16 , 190℃, 2.16kg load) 10 The melt flow index (MFRR, Melt Flow Rate Ratio, MI) is the value of the melt flow index (MFRR, Melt Flow Rate Ratio, MI) 10 / MI 2.16 ) may be 8.0 or less, specifically 4.0 or more, 4.2 or more, 4.5 or more, 8.0 or less, or 7.5 or less.

[0047] The melt flow index serves as an index of the degree of long chain branching of the copolymer. When the ethylene / α-olefin copolymer of the present invention satisfies the melt flow index in addition to the above physical properties, it has excellent physical properties and can be suitably used in encapsulant compositions for solar cells, etc.

[0048] In particular, when the ethylene / α-olefin copolymer of the present invention has a low melt index of 1 to 100 dg / min as described above, it can have a low melt flow index of 8.0 or less as described above. Because the copolymer of the present invention has such a low melt index and melt flow index, it is characterized by a high molecular weight, a low content of long chain branches, and an excellent degree of crosslinking.

[0049] The ethylene / α-olefin copolymer of the present invention is produced by copolymerizing ethylene with an α-olefin monomer. In this case, the α-olefin, which means the portion of the copolymer derived from the α-olefin monomer, is a C4 to C20 α-olefin, specifically, 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, 1-eicosene, etc., and these may be used alone or in combination of two or more.

[0050] Among them, the α-olefin may be 1-butene, 1-hexene, or 1-octene, and preferably 1-butene, 1-hexene, or a combination thereof.

[0051] The content of the α-olefin in the ethylene / α-olefin copolymer may be appropriately selected within a range that satisfies the above physical property requirements, and specifically may be, but is not limited to, more than 0 and not more than 99 mol%, 10 mol% or more, and 50 mol% or less.

[0052] <Method of producing ethylene / α-olefin copolymer> The ethylene / α-olefin copolymer of the present invention is produced by a production method including the step of introducing a transition metal compound, a cocatalyst, ethylene and an α-olefin monomer into a polymerization reactor and polymerizing the mixture. The method for polymerizing the ethylene and α-olefin monomer is not particularly limited, and any conventional method widely used in the art can be suitably used.

[0053] In the present invention, the α-olefin monomer may be at least one selected from the group consisting 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, but is not limited thereto.

[0054] In particular, in consideration of the applications and improved effects of the ethylene / α-olefin copolymer produced by the present invention, the α-olefin monomer may be 1-butene, 1-hexene, or 1-octene.

[0055] In particular, in the production method of the present invention, the molar ratio of ethylene to the α-olefin monomer is 1:1.14 to 1:3.00, and specifically may be 1:1.14 to 1:2.00, 1:1.14 to 1:1.50, 1:1.14 to 1:1.30, or 1:1.14 to 1:1.25.

[0056] When the molar ratio of ethylene and α-olefin monomer is within the above range, a large amount of α-olefin monomer is used to produce an ethylene / α-olefin copolymer with a high proportion of amorphous regions. At the same time, if an excessive amount of α-olefin monomer is used, the crystalline region becomes too low, which causes problems such as film sagging during film production, making processing difficult, reduced film rigidity after production, and sticky surface, making storage difficult.

[0057] Furthermore, the properties (a) to (d) of the ethylene / α-olefin copolymer defined in the present invention can be achieved by adjusting the molar ratio of ethylene to the α-olefin monomer to an appropriate level as described above. Specifically, if the ratio of ethylene to the α-olefin monomer is low, the crystalline region in the copolymer increases, the melting temperature rises, the crystallinity increases, and the d-spacing decreases, making it impossible to satisfy the conditions (b) to (d) defined in the present invention. Conversely, if the ratio of ethylene to the α-olefin monomer is excessive, the crystalline region decreases and the rigidity decreases, making normal film processing impossible and making it difficult to use as a composition for encapsulant films.

[0058] The transition metal compound used in the polymerization may be, but is not limited to, a compound represented by the following chemical formula 1, a compound represented by the following chemical formula 2, or a combination thereof.

[0059] [ka]

[0060] In the above Chemical Formula 1, R1 is hydrogen; alkyl having 1 to 20 carbon atoms; cycloalkyl having 3 to 20 carbon atoms; alkenyl having 2 to 20 carbon atoms; alkoxy having 1 to 20 carbon atoms; aryl having 6 to 20 carbon atoms; arylalkoxy having 7 to 20 carbon atoms; alkylaryl having 7 to 20 carbon atoms; or arylalkyl having 7 to 20 carbon atoms; R2 and R3 are each independently hydrogen; halogen; alkyl having 1 to 20 carbon atoms; cycloalkyl having 3 to 20 carbon atoms; alkenyl having 2 to 20 carbon atoms; aryl having 6 to 20 carbon atoms; alkylaryl having 7 to 20 carbon atoms; arylalkyl having 7 to 20 carbon atoms; alkylamido having 1 to 20 carbon atoms; or arylamido having 6 to 20 carbon atoms; R4 and R5 are each independently hydrogen; alkyl having 1 to 20 carbon atoms; cycloalkyl having 3 to 20 carbon atoms; aryl having 6 to 20 carbon atoms; or alkenyl having 2 to 20 carbon atoms; R6 to R9 are each independently hydrogen; alkyl having 1 to 20 carbon atoms; cycloalkyl having 3 to 20 carbon atoms; aryl having 6 to 20 carbon atoms; or alkenyl having 2 to 20 carbon atoms; Two or more adjacent groups among R6 to R9 may be linked to each other to form a ring, Q1 is Si, C, N, P, or S; M1 is Ti, Hf, or Zr; X1 and X2 are each independently hydrogen; halogen; alkyl having 1 to 20 carbon atoms; alkenyl having 2 to 20 carbon atoms; aryl having 6 to 20 carbon atoms; alkylaryl having 7 to 20 carbon atoms; arylalkyl having 7 to 20 carbon atoms; alkylamino having 1 to 20 carbon atoms; or arylamino having 6 to 20 carbon atoms;

[0061] [ka]

[0062] In the above Chemical Formula 2, R 10 is hydrogen; alkyl having 1 to 20 carbon atoms; cycloalkyl having 3 to 20 carbon atoms; alkenyl having 2 to 20 carbon atoms; alkoxy having 1 to 20 carbon atoms; aryl having 6 to 20 carbon atoms; arylalkoxy having 7 to 20 carbon atoms; alkylaryl having 7 to 20 carbon atoms; or arylalkyl having 7 to 20 carbon atoms, R 11a ~R 11e are each independently hydrogen; halogen; alkyl having 1 to 20 carbon atoms; cycloalkyl having 3 to 20 carbon atoms; alkenyl having 2 to 20 carbon atoms; alkoxy having 1 to 20 carbon atoms; or aryl having 6 to 20 carbon atoms, R 12 is hydrogen; halogen; alkyl having 1 to 20 carbon atoms; cycloalkyl having 3 to 20 carbon atoms; alkenyl having 2 to 20 carbon atoms; aryl having 6 to 20 carbon atoms; alkylaryl having 7 to 20 carbon atoms; arylalkyl having 7 to 20 carbon atoms; alkylamido having 1 to 20 carbon atoms; or arylamido having 6 to 20 carbon atoms, R 13 and R 14are each independently hydrogen; alkyl having 1 to 20 carbon atoms; cycloalkyl having 3 to 20 carbon atoms; aryl having 6 to 20 carbon atoms; or alkenyl having 2 to 20 carbon atoms; R 15 ~R 18 are each independently hydrogen; alkyl having 1 to 20 carbon atoms; cycloalkyl having 3 to 20 carbon atoms; aryl having 6 to 20 carbon atoms; or alkenyl having 2 to 20 carbon atoms; R 15 ~R 18 two or more of the groups may be linked together to form a ring; Q2 is Si, C, N, P, or S; M2 is Ti, Hf, or Zr; X3 and X4 are each independently hydrogen; halogen; alkyl having 1 to 20 carbon atoms; alkenyl having 2 to 20 carbon atoms; aryl having 6 to 20 carbon atoms; alkylaryl having 7 to 20 carbon atoms; arylalkyl having 7 to 20 carbon atoms; alkylamino having 1 to 20 carbon atoms; or arylamino having 6 to 20 carbon atoms.

[0063] In the present invention, the transition metal compound represented by the chemical formula 1 and the transition metal compound represented by the chemical formula 2 are a cyclopentadiene in which benzothiophene is condensed by a cyclic bond, and an amide group (N-R1, NR 10 ) is stably bridged by Q1 or Q2, forming a structure in which a Group 4 transition metal is coordinated.

[0064] When a transition metal compound represented by Chemical Formula 1 is used as a catalyst in the polymerization reaction of ethylene and α-olefin monomers, it is possible to produce copolymers characterized by high activity, high molecular weight, and high copolymerizability even at high polymerization temperatures. In particular, due to the structural characteristics of the catalyst, it is difficult to introduce α-olefin monomers, and copolymers in the high-density region tend to be produced. In contrast, the transition metal compound represented by Chemical Formula 2 allows the introduction of large amounts of α-olefins, making it possible to produce polymers (elastomers) in the ultra-low-density region.

[0065] As described above, the transition metal compounds represented by Formula 1 or 2 used in the present invention are mixed and used in the catalyst composition. As described above, the transition metal compounds of Formula 1 or 2 have different copolymerizability with α-olefin monomers when used alone. Therefore, when these compounds are mixed to produce a copolymer, it is possible to produce a copolymer that has both a low-density region where a large amount of α-olefin monomer is mixed in and a high-density region where a small amount of α-olefin monomer is mixed in. This means that the copolymer has a high crystallinity distribution and a low free volume, which results in low charge mobility and excellent physical properties such as high electrical insulation.

[0066] In the present invention, the molar ratio of the transition metal compounds represented by Chemical Formula 1 and Chemical Formula 2 is 1:1.2 to 1:10, 1:1.5 to 1:9, 1:1.5 to 1:7, 1:2 to 1:7, 1:2 to 1:5, or 1:2 to 1:3.

[0067] When the transition metal compound represented by Chemical Formula 1 is used alone, or when the transition metal compound represented by Chemical Formula 1 is used in excess outside the above molar ratio, or when the transition metal compound represented by Chemical Formula 2 is used alone, or when the transition metal compound represented by Chemical Formula 2 is used in excess outside the above molar ratio, a copolymer having a low crystallinity distribution and poor electrical insulation properties may be produced.

[0068] In the present invention, the polymerization reaction may be carried out by continuously polymerizing ethylene and an α-olefin monomer in the presence of the catalyst composition by continuously introducing hydrogen, specifically, by introducing hydrogen at a rate of 10 to 100 cc / min.

[0069] The hydrogen gas serves to suppress the rapid reaction of the transition metal compound in the initial stage of polymerization and terminate the polymerization reaction. Therefore, by controlling the use and amount of hydrogen gas, it is possible to effectively produce an ethylene / α-olefin copolymer having a narrow molecular weight distribution.

[0070] For example, the hydrogen may be fed at 10 cc / min or more, 15 cc / min or more, 19 cc / min or more, or 22 cc / min or more, and simultaneously at 100 cc / min or less, 50 cc / min or less, 45 cc / min or less, 35 cc / min or less, or 29 cc / min or less. When fed under these conditions, the produced ethylene / α-olefin polymer can achieve the physical property characteristics of the present invention.

[0071] If the hydrogen gas content is less than 10 cc / min, the polymerization reaction may not be terminated uniformly, making it difficult to produce an ethylene / α-olefin copolymer having desired properties. If the hydrogen gas content is more than 100 cc / min, the termination reaction may proceed too quickly, resulting in the production of an ethylene / α-olefin copolymer having a very low molecular weight.

[0072] The polymerization reaction may be carried out at 100 to 200°C, and the number of unsaturated functional groups and molecular weight distribution in the ethylene / α-olefin copolymer can be more easily controlled by controlling the polymerization temperature together with the amount of hydrogen input. Specifically, the polymerization reaction may be carried out at 100 to 200°C, 120 to 180°C, 130 to 170°C, or 135 to 150°C.

[0073] Specifically, in Chemical Formula 1, R1 is hydrogen; alkyl having 1 to 20 carbon atoms; cycloalkyl having 3 to 20 carbon atoms; alkenyl having 2 to 20 carbon atoms; alkoxy having 1 to 20 carbon atoms; aryl having 6 to 20 carbon atoms; arylalkoxy having 7 to 20 carbon atoms; alkylaryl having 7 to 20 carbon atoms; or arylalkyl having 7 to 20 carbon atoms. More specifically, R1 may be methyl, ethyl, propyl, butyl, isobutyl, t-butyl, isopropyl, cyclohexyl, benzyl, phenyl, methoxyphenyl, ethoxyphenyl, fluorophenyl, bromophenyl, chlorophenyl, dimethylphenyl, or diethylphenyl.

[0074] Specifically, in Chemical Formula 1, R2 and R3 are each independently hydrogen; halogen; alkyl having 1 to 20 carbon atoms; cycloalkyl having 3 to 20 carbon atoms; alkenyl having 2 to 20 carbon atoms; aryl having 6 to 20 carbon atoms; alkylaryl having 7 to 20 carbon atoms; arylalkyl having 7 to 20 carbon atoms; alkylamido having 1 to 20 carbon atoms; or arylamido having 6 to 20 carbon atoms. More specifically, R2 and R3 may each independently be hydrogen; alkyl having 1 to 20 carbon atoms; aryl having 6 to 20 carbon atoms; alkylaryl having 6 to 20 carbon atoms; or arylalkyl having 7 to 20 carbon atoms.

[0075] Specifically, in Chemical Formula 1, R4 and R5 may be the same or different and each independently represent hydrogen, alkyl having 1 to 20 carbon atoms, cycloalkyl having 3 to 20 carbon atoms, aryl having 6 to 20 carbon atoms, or alkenyl having 2 to 20 carbon atoms, more specifically alkyl having 1 to 6 carbon atoms. Even more specifically, R4 and R5 may be methyl, ethyl, or propyl.

[0076] Specifically, in Chemical Formula 1, R6 to R9 may be the same or different and each independently represent hydrogen, alkyl having 1 to 20 carbon atoms, cycloalkyl having 3 to 20 carbon atoms, aryl having 6 to 20 carbon atoms, or alkenyl having 2 to 20 carbon atoms. More specifically, R6 to R9 may be the same or different and each independently represent hydrogen or methyl.

[0077] Two or more adjacent groups among R6 to R9 may be linked to each other to form an aliphatic ring having 5 to 20 carbon atoms or an aromatic ring having 6 to 20 carbon atoms, and the aliphatic ring or aromatic ring may be substituted with a halogen, an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms.

[0078] Specifically, in the above Chemical Formula 1, Q1 may be Si, C, N, P, or S, and more specifically, Q1 may be Si. Specifically, in the above Chemical Formula 1, M1 may be Ti, Hf, or Zr.

[0079] Specifically, in Chemical Formula 1, X1 and X2 may be the same or different and each independently represent hydrogen; halogen; alkyl having 1 to 20 carbon atoms; alkenyl having 2 to 20 carbon atoms; aryl having 6 to 20 carbon atoms; alkylaryl having 7 to 20 carbon atoms; arylalkyl having 7 to 20 carbon atoms; alkylamino having 1 to 20 carbon atoms; or arylamino having 6 to 20 carbon atoms.

[0080] The compound represented by Chemical Formula 1 may be a compound represented by any one of the following chemical formulas:

[0081] [ka]

[0082] [ka]

[0083] [ka]

[0084] [ka]

[0085] [ka]

[0086] [ka]

[0087] In addition, compounds having various structures within the range defined in Chemical Formula 1 may be used. In addition, in the chemical formula 2, the R10 is hydrogen; alkyl having 1 to 20 carbon atoms; cycloalkyl having 3 to 20 carbon atoms; alkenyl having 2 to 20 carbon atoms; alkoxy having 1 to 20 carbon atoms; aryl having 6 to 20 carbon atoms; arylalkoxy having 7 to 20 carbon atoms; alkylaryl having 7 to 20 carbon atoms; or arylalkyl having 7 to 20 carbon atoms, and more specifically, 10 may be hydrogen; alkyl having 1 to 20 carbon atoms; alkoxy having 1 to 20 carbon atoms; aryl having 6 to 20 carbon atoms; arylalkoxy having 7 to 20 carbon atoms; alkylaryl having 7 to 20 carbon atoms; or arylalkyl having 7 to 20 carbon atoms.

[0088] Specifically, in the above-mentioned Chemical Formula 2, R 11a ~R 11e are each independently hydrogen; halogen; alkyl having 1 to 20 carbon atoms; cycloalkyl having 3 to 20 carbon atoms; alkenyl having 2 to 20 carbon atoms; alkoxy having 1 to 20 carbon atoms; or aryl having 6 to 20 carbon atoms, and more specifically may be hydrogen; halogen; alkyl having 1 to 12 carbon atoms; cycloalkyl having 3 to 12 carbon atoms; alkenyl having 2 to 12 carbon atoms; alkoxy having 1 to 12 carbon atoms; or phenyl.

[0089] Specifically, in the above-mentioned Chemical Formula 2, R 12 is hydrogen; halogen; alkyl having 1 to 20 carbon atoms; cycloalkyl having 3 to 20 carbon atoms; alkenyl having 2 to 20 carbon atoms; aryl having 6 to 20 carbon atoms; alkylaryl having 7 to 20 carbon atoms; arylalkyl having 7 to 20 carbon atoms; alkylamido having 1 to 20 carbon atoms; or arylamido having 6 to 20 carbon atoms, and more specifically may be hydrogen; halogen; alkyl having 1 to 12 carbon atoms; cycloalkyl having 3 to 12 carbon atoms; alkenyl having 2 to 12 carbon atoms; or phenyl.

[0090] Specifically, in the above-mentioned Chemical Formula 2, R 13 and R 14are each independently hydrogen; alkyl having 1 to 20 carbon atoms; cycloalkyl having 3 to 20 carbon atoms; aryl having 6 to 20 carbon atoms; or alkenyl having 2 to 20 carbon atoms, and more specifically may be hydrogen; or alkyl having 1 to 12 carbon atoms.

[0091] Specifically, in the above-mentioned Chemical Formula 2, R 15 ~R 18 are each independently hydrogen; alkyl having 1 to 20 carbon atoms; cycloalkyl having 3 to 20 carbon atoms; aryl having 6 to 20 carbon atoms; or alkenyl having 2 to 20 carbon atoms, and more specifically may be hydrogen; alkyl having 1 to 12 carbon atoms; or cycloalkyl having 3 to 12 carbon atoms, or hydrogen; or methyl.

[0092] Specifically, in the above Chemical Formula 2, the R 15 ~R 18 Two or more of the groups may be linked together to form a ring. Specifically, in the above Chemical Formula 2, Q2 may be Si, C, N, P, or S, and more specifically, Q2 may be Si.

[0093] Specifically, in Chemical Formula 2, X3 and X4 are each independently hydrogen; halogen; alkyl having 1 to 20 carbon atoms; alkenyl having 2 to 20 carbon atoms; aryl having 6 to 20 carbon atoms; alkylaryl having 7 to 20 carbon atoms; arylalkyl having 7 to 20 carbon atoms; alkylamino having 1 to 20 carbon atoms; or arylamino having 6 to 20 carbon atoms, more specifically hydrogen; halogen; alkyl having 1 to 12 carbon atoms; cycloalkyl having 3 to 12 carbon atoms; or alkenyl having 2 to 12 carbon atoms, and even more specifically hydrogen; or alkyl having 1 to 12 carbon atoms.

[0094] The compound represented by Chemical Formula 2 may specifically be any one of the compounds represented by Chemical Formulas 2-1 to 2-10 below.

[0095] [ka]

[0096]

change

[0097]

change

[0098]

change

[0099]

change

[0100]

change

[0101]

change

[0102]

change

[0103]

change

[0104]

change

[0105] In the present invention, the α-olefin monomer as a comonomer may be an olefin monomer having 4 to 20 carbon atoms. Specific examples include 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, and one of these may be used alone or two or more may be used in combination. Among them, the α-olefin monomer may be 1-butene, 1-hexene, or 1-octene, and most preferably 1-butene.

[0106] In the present invention, the content of the α-olefin monomer may be appropriately selected within a range that satisfies the above physical property requirements, and specifically, may be more than 0 and up to 99 mol %, or 10 to 50 mol %.

[0107] <Composition for sealing film> The present invention also provides a composition for an encapsulant film, comprising the ethylene / α-olefin copolymer, which can be used to prepare a modified resin composition, such as a silane-modified resin composition or an aminosilane-modified resin composition.

[0108] Specifically, the composition for the encapsulant film may contain, in addition to the ethylene / α-olefin copolymer, a known crosslinking agent, a crosslinking aid, a silane coupling agent, and the like.

[0109] The crosslinking agent can act as a radical initiator in the preparation step of the silane-modified resin composition to initiate a reaction in which an unsaturated silane compound is grafted onto the resin composition. Also, in the lamination step of manufacturing an optoelectronic device, the crosslinking agent can form crosslinks between the silane-modified resin compositions or between the silane-modified resin composition and an unmodified resin composition, thereby improving the heat resistance and durability of the final product, for example, an encapsulant sheet.

[0110] The crosslinking agent may be any crosslinking compound known in the art that can initiate radical polymerization of vinyl groups or form crosslinks. For example, one or more crosslinking agents selected from the group consisting of organic peroxides, hydroperoxides, and azo compounds may be used.

[0111] Specifically, dialkyl peroxides such as t-butylcumyl peroxide, di-t-butyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, and 2,5-dimethyl-2,5-di(t-butylperoxy)-3-hexyne; hydroperoxides such as cumene hydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethyl-2,5-di(hydroperoxy)hexane, and t-butyl hydroperoxide; diacyl peroxides such as bis-3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, benzoyl peroxide, o-methylbenzoyl peroxide, and 2,4-dichlorobenzoyl peroxide; t-butylperoxyisobutyrate and t-butylperoxyacetate. peroxyesters such as t-butylperoxy-2-ethylhexyl carbonate (TBEC), t-butylperoxy-2-ethylhexanoate, t-butylperoxypivalate, t-butylperoxyoctoate, t-butylperoxyisopropyl carbonate, t-butylperoxybenzoate, di-t-butylperoxyphthalate, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, and 2,5-dimethyl-2,5-di(benzoylperoxy)-3-hexyne; and ketone peroxides such as methyl ethyl ketone peroxide and cyclohexanone peroxide, and azo compounds such as lauryl peroxide, azobisisobutyronitrile, and azobis(2,4-dimethylvaleronitrile), but these are not limited to these.

[0112] The organic peroxide may have a one-hour half-life temperature of 120 to 135°C, for example, 120 to 130°C, 120 to 125°C, and preferably 121°C. The "one-hour half-life temperature" refers to the temperature at which the half-life of the crosslinking agent is one hour. The temperature at which a radical initiation reaction efficiently occurs varies depending on the one-hour half-life temperature. Therefore, when an organic peroxide having a one-hour half-life temperature within the above range is used as a crosslinking agent, the radical initiation reaction, i.e., the crosslinking reaction, can be efficiently carried out at the temperature of the lamination process for manufacturing an optoelectronic device.

[0113] The crosslinking agent is included in an amount of 0.01 to 1 part by weight, for example, 0.05 to 0.55, 0.1 to 0.5, or 0.15 to 0.45 parts by weight, relative to 100 parts by weight of the composition for an encapsulant film. If the crosslinking agent is included in an amount less than 0.01 part by weight, the effect of improving heat resistance is negligible, whereas if the crosslinking agent is included in an amount greater than 1 part by weight, the formability of the encapsulant sheet may be reduced, which may cause problems such as process limitations and affect the physical properties of the encapsulant.

[0114] The resin composition may contain a crosslinking aid in addition to the crosslinking agent. The inclusion of the crosslinking aid in the resin composition can increase the degree of crosslinking between the resin components by the crosslinking agent, thereby further improving the heat resistance durability of the final product, for example, the encapsulant sheet.

[0115] As the crosslinking aid, various crosslinking aids known in the technical field may be used. For example, as the crosslinking aid, a compound containing at least one unsaturated group such as an allyl group or a (meth)acryloxy group may be used.

[0116] Examples of the compound containing an allyl group include polyallyl compounds such as triallyl isocyanurate (TAIC), triallyl cyanurate, diallyl phthalate, diallyl fumarate, and diallyl maleate, and examples of the compound containing a (meth)acryloxy group include poly(meth)acryloxy compounds such as ethylene glycol diacrylate, ethylene glycol dimethacrylate, and trimethylolpropane trimethacrylate, but are not particularly limited thereto.

[0117] The crosslinking aid is included in an amount of 0.01 to 0.5 parts by weight, for example, 0.01 to 0.3, 0.015 to 0.2, or 0.016 to 0.16 parts by weight, based on 100 parts by weight of the composition for an encapsulant film. If the crosslinking aid is included in an amount less than 0.01 part by weight, the effect of improving heat resistance is negligible, whereas if the crosslinking aid is included in an amount more than 0.5 part by weight, problems may arise that affect the properties of the final product, for example, the encapsulant sheet, and the production cost may increase.

[0118] The composition for an encapsulant film may further contain a silane coupling agent in addition to the ethylene / α-olefin copolymer, the crosslinking agent, and the crosslinking aid.

[0119] The silane coupling agent may be, for example, one or more selected from the group consisting of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-methacryloxypropyltrimethoxysilane (MEMO).

[0120] The silane coupling agent may be included in an amount of 0.1 to 0.4 parts by weight based on 100 parts by weight of the composition for encapsulant film. If it is used in an amount of less than 0.1 part by weight, adhesion to glass during fabrication of a solar module is poor, moisture easily penetrates, and long-term performance of the module cannot be guaranteed. If it is used in an amount of 1 part by weight or more, it acts as a factor increasing YI, which is undesirable.

[0121] The composition for an encapsulant film may further contain an unsaturated silane compound and an aminosilane compound. The unsaturated silane compound may be grafted to a main chain containing polymerized units of the monomer of the copolymer of the present invention in the presence of a radical initiator or the like, and may be included in the silane-modified resin composition or aminosilane-modified resin composition in a polymerized form.

[0122] The unsaturated silane compound may be vinyltrimethoxysilane, vinyltriethoxysilane, vinyltrippropoxysilane, vinyltriisopropoxysilane, vinyltributoxysilane, vinyltripentoxysilane, vinyltriphenoxysilane, or vinyltriacetoxysilane, and examples thereof include, but are not limited to, vinyltrimethoxysilane or vinyltriethoxysilane.

[0123] In addition, the aminosilane compound acts as a catalyst to promote the hydrolysis reaction that converts reactive functional groups, such as alkoxy groups of unsaturated silane compounds, e.g., vinyltriethoxysilane, grafted to the main chain of the copolymer into hydroxy groups during the graft modification step of the ethylene / α-olefin copolymer, thereby further improving the adhesive strength to the upper and lower glass substrates or backsheets made of fluororesin, etc. At the same time, the aminosilane compound directly participates in the copolymerization reaction as a reactant, thereby providing a component having an amine functional group to the aminosilane-modified resin composition.

[0124] The aminosilane compound is not particularly limited as long as it is a silane compound containing an amine group and is a primary amine or a secondary amine. For example, aminotrialkoxysilane, aminodialkoxysilane, etc. may be used as the aminosilane compound, and examples thereof include 3-aminopropyltrimethoxysilane (APTMS), 3-aminopropyltriethoxysilane (APTES), bis[(3-triethoxysilyl)propyl]amine, bis[(3-trimethoxysilyl)propyl]amine, 3-aminopropylmethyldiethoxysilane, 3-aminopropylmethyldimethoxysilane, N-[3-(trimethoxysilyl)propyl]ethylenediamine (DAS), aminoethylaminopropyltriethoxysilane, aminoethylaminopropylmethyldimethoxysilane, aminoethylaminopropylmethyldiethoxysilane, N-[3-(trimethoxysilyl)propyl]ethylenediamine (DAS), aminoethylaminopropyltriethoxysilane, aminoethylaminopropylmethyldimethoxysilane, aminoethylaminopropylmethyldiethoxysilane, N-[3-(trimethoxysilyl)propyl]ethylenediamine (DAS), aminoethylaminopropyltriethoxysilane, aminoethylaminopropylmethyldimethoxysilane, aminoethylaminopropylmethyldiethoxysilane, N-[3-(trimethoxysilyl)propyl]ethylenediamine (DAS), aminoethylaminopropyltriethoxysilane, aminoethylaminopropylmethyldiethoxy ...ethoxysilane, aminoethylaminopropylmethyldiethoxysilane Examples of suitable aminosilane compounds include silane, aminoethylaminomethyltriethoxysilane, aminoethylaminomethylmethyldiethoxysilane, diethylenetriaminopropyltrimethoxysilane, diethylenetriaminopropyltriethoxysilane, diethylenetriaminopropylmethyldimethoxysilane, diethyleneaminomethylmethyldiethoxysilane, (N-phenylamino)methyltrimethoxysilane, (N-phenylamino)methyltriethoxysilane, (N-phenylamino)methylmethyldimethoxysilane, (N-phenylamino)methylmethyldiethoxysilane, 3-(N-phenylamino)propyltrimethoxysilane, 3-(N-phenylamino)propyltriethoxysilane, 3-(N-phenylamino)propylmethyldimethoxysilane, 3-(N-phenylamino)propylmethyldiethoxysilane, and N-(N-butyl)-3-aminopropyltrimethoxysilane. The aminosilane compounds may be used alone or in combination. The content of the unsaturated silane compound and / or aminosilane compound is not particularly limited.

[0125] Furthermore, the composition for an encapsulant film may further contain one or more additives selected from a light stabilizer, a UV absorber, a heat stabilizer, and the like, as needed.

[0126] The light stabilizer may act to capture active species that initiate photodegradation of the resin and prevent photooxidation depending on the application of the composition. The type of light stabilizer that can be used is not particularly limited, and known compounds such as hindered amine compounds or hindered piperidine compounds may be used.

[0127] The UV absorber can absorb ultraviolet rays from sunlight or the like and convert them into harmless thermal energy within the molecule, thereby preventing the excitation of active species that initiate photodegradation in the resin composition, depending on the intended use of the composition. The specific type of UV absorber that can be used is not particularly limited, and for example, one or a mixture of two or more of inorganic UV absorbers such as benzophenone-based, benzotriazole-based, acrylonitrile-based, metal complex salt-based, hindered amine-based, ultrafine particle titanium oxide, or ultrafine particle zinc oxide may be used.

[0128] Examples of the heat stabilizer include phosphorus-based heat stabilizers such as tris(2,4-di-tert-butylphenyl)phosphite, bis[2,4-bis(1,1-dimethylethyl)-6-methylphenyl]ethyl ester phosphorous acid, tetrakis(2,4-di-tert-butylphenyl)[1,1-biphenyl]-4,4′-diylbisphosphonate, and bis(2,4-di-tert-butylphenyl)pentaerythritol diphosphite; and lactone-based heat stabilizers such as a reaction product of 8-hydroxy-5,7-di-tert-butyl-furan-2-one and o-xylene, and one or more of the above may be used.

[0129] The content of the light stabilizer, UV absorber, and / or heat stabilizer is not particularly limited. That is, the content of the additive may be appropriately selected in consideration of the use of the resin composition, the shape and density of the additive, etc., and is usually appropriately adjusted within the range of 0.01 to 5 parts by weight with respect to 100 parts by weight of the total solid content of the encapsulant film composition.

[0130] In addition to the above components, the encapsulant film composition of the present invention may further appropriately contain various additives known in the art according to the use to which the resin component is applied.

[0131] In addition, the encapsulant film composition can be molded by methods such as injection and extrusion and utilized as various molded products. Specifically, it can be used as an encapsulant for encapsulating elements in various optoelectronic devices, such as solar cells, and can be used as an industrial material applied to, for example, a temperature-rising lamination process, but is not limited to these uses.

[0132] Example Hereinafter, the present invention will be described in more detail with reference to examples. However, the following examples are for illustrative purposes only and the scope of the present invention is not limited thereto.

[0133] Production Example 1 (1) Preparation of Ligand Compounds <Synthesis of N-tert-butyl-1-(1,2-dimethyl-3H-benzo[b]cyclopenta[d]thiophen-3-yl)-1,1-dimethylsilanamine>

[0134] 4.65 g (15.88 mmol) of the compound of Chemical Formula 3 was quantitatively added to a 100 ml Schlenk flask, and then 80 ml of THF was added thereto. After adding tBuNH2 (4 eq, 6.68 ml) at room temperature, the reaction was carried out at room temperature for 3 days. After the reaction, THF was removed and then filtered with hexane. After drying the solvent, a yellow liquid was obtained in a yield of 4.50 g (86%).

[0135] 1 H-NMR(in CDCl3,500MHz):7.99(d,1H),7.83(d,1H),7.35(dd,1H),7.24(dd,1H),3.4 9(s,1H),2.37(s,3H),2.17(s,3H),1.27(s,9H),0.19(s,3H),-0.17(s,3H).

[0136] (2) Production of transition metal compounds [ka]

[0137] The ligand compound (1.06 g, 3.22 mmol / 1.0 eq) and 16.0 mL (0.2 M) of MTBE were placed in a 50 mL Schlenk flask and stirred. n-BuLi (2.64 mL, 6.60 mmol / 2.05 eq, 2.5 M in THF) was added at -40 °C and the mixture was allowed to react overnight at room temperature. Then, MeMgBr (2.68 mL, 8.05 mmol / 2.5 eq, 3.0 M in diethyl ether) was slowly added dropwise at -40 °C, followed by TiCl4 (2.68 mL, 3.22 mmol / 1.0 eq, 1.0 M in toluene) and the mixture was allowed to react overnight at room temperature. The reaction mixture was then filtered through Celite using hexane. After drying, a brown solid was obtained in a yield of 1.07 g (82%).

[0138] 1 H-NMR(in CDCl3,500MHz):7.99(d,1H),7.68(d,1H),7.40(dd,1H),7.30(dd,1H),3.22(s,1H),2.6 7(s,3H),2.05(s,3H),1.54(s,9H),0.58(s,3H),0.57(s,3H),0.40(s,3H),-0.45(s,3H).

[0139] Manufacturing Example 2 (1) Preparation of Ligand Compounds <Synthesis of N-tert-butyl-1-(1,2-dimethyl-3H-benzo[b]cyclopenta[d]thiophen-3-yl)-1,1-(methyl)(phenyl)silanamine>

[0140] (i) Preparation of chloro-1-(1,2-dimethyl-3H-benzo[b]cyclopenta[d]thiophen-3-yl)-1,1-(methyl)(phenyl)silan

[0141] Into a 250 mL Schlenk flask, 10 g (1.0 eq, 49.925 mmol) of 1,2-dimethyl-3H-benzo[b]cyclopenta[d]thiophene and 100 mL of THF were added. 22 mL (1.1 eq, 54.918 mmol, 2.5 M in hexane) of n-BuLi was added dropwise at -30 °C, and then stirred at room temperature for 3 hours. The stirred Li-complex THF solution was cannulated into a Schlenk flask containing 8.1 mL (1.0 eq, 49.925 mmol) of dichloro(methyl)(phenyl)silan and 70 mL of THF at -78 °C, and then stirred at room temperature overnight. After stirring, it was dried under vacuum and then extracted with 100 mL of hexane.

[0142] (ii) Preparation of N-tert-butyl-1-(1,2-dimethyl-3H-benzo[b]cyclopenta[d]thiophen-3-yl)-1,1-(methyl)(phenyl)silanamine

[0143] 42 mL (8 eq, 399.4 mmol) of t-BuNH2 was added to 100 mL of the extracted chloro-1-(1,2-dimethyl-3H-benzo[b]cyclopenta[d]thiophen-3-yl)-1,1-(methyl)(phenyl)silan hexane solution at room temperature, and then stirred at room temperature overnight. After stirring, it was dried under vacuum and then extracted with 150 mL of hexane. After drying the solvent, 13.36 g (68%, dr = 1:1) of a yellow solid was obtained.

[0144] 1H-NMR (CDCl3,500MHz): δ7.93(t,2H),7.79(d,1H),7.71(d,1H),7.60(d,2H),7.48(d,2H),7.40~7.10(m,10H,aro matic),3.62(s,1H),3.60(s,1H),2.28(s,6H),2.09(s,3H),1.76(s,3H),1.12(s,18H),0.23(s,3H),0.13(s,3H)

[0145] (2) Production of transition metal compounds [ka]

[0146] A 100 mL Schlenk flask was charged with 4.93 g (12.575 mmol, 1.0 eq) of the ligand compound of Formula 2-4 and 50 mL (0.2 M) of toluene. 10.3 mL (25.779 mmol, 2.05 eq, 2.5 M in hexane) of n-BuLi was added dropwise at -30 °C and the mixture was stirred overnight at room temperature. After stirring, 12.6 mL (37.725 mmol, 3.0 eq, 3.0 M in diethyl ether) of MeMgBr was added dropwise, followed by 13.2 mL (13.204 mmol, 1.05 eq, 1.0 M in toluene) of TiCl4, and the mixture was stirred overnight at room temperature. After stirring, the mixture was dried under vacuum and extracted with 150 mL of hexane. The solvent was removed to 50 mL, and then 4 mL of DME (37.725 mmol, 3.0 eq) was added dropwise. The mixture was stirred overnight at room temperature. The mixture was dried under vacuum again and extracted with 150 mL of hexane. After drying the solvent, 2.23 g of a brown solid (38%, dr = 1:0.5) was obtained.

[0147] 1H-NMR (CDCl3,500MHz): δ7.98(d,1H),7.94(d,1H),7.71(t,6H),7.50~7.30(10H),2.66(s,3H),2.61(s,3H),2.15(s,3H) ,1.62(s,9H),1.56(s,9H),1.53(s,3H),0.93(s,3H),0.31(s,3H),0.58(s,3H),0.51(s,3H),-0.26(s,3H),-0.39(s,3H)

[0148] Example 1 A 1.5 L continuous reactor was preheated to 135°C while being charged with hexane solvent at 7.0 kg / h and 1-butene at 1.09 kg / h. Triisobutylaluminum compound (0.045 mmol / min), a 3:7 molar mixture of the transition metal compounds obtained in Preparation Examples 1 and 2 (0.150 μmol / min), and dimethylanilinium tetrakis(pentafluorophenyl)borate cocatalyst (0.30 μmol / min) were simultaneously charged into the reactor. Ethylene (0.87 kg / h) and hydrogen gas (20 cc / min) were then introduced into the reactor, and the copolymerization reaction was carried out at 135°C in a continuous process at a pressure of 89 bar for at least 60 minutes, yielding a copolymer. The copolymer was then dried in a vacuum oven for at least 12 hours and its physical properties were measured.

[0149] Examples 2 to 4, Comparative Examples 1 to 5 Ethylene / α-olefin copolymers were produced in the same manner as in Example 1, except that the polymerization conditions were changed as shown in Table 1 below.

[0150] [Table 1]

[0151] Experimental Example 1 The physical properties of the ethylene / α-olefin copolymers prepared in the above examples and comparative examples were measured by the following methods.

[0152] (1) Density (g / cm 3 ) Measurement was carried out in accordance with ASTM D-792.

[0153] (2) Melt Index (MI) 2.16 , dg / min) Measurement was performed in accordance with ASTM D-1238 (condition E, 190°C, 2.16 kg load).

[0154] (3) Melt flow rate ratio, MFRR, MI 10 / MI2) MI according to ASTM D-1238 10 (190°C, 10kg load conditions) and MI 2.16 (190℃, 2.16kg load condition) and MI 10 / MI 2.16 It was calculated by

[0155] (4) Melting Temperature (Tm) It can be obtained using a PerkinElmer Differential Scanning Calorimeter (DSC 6000). Specifically, using DSC, the temperature of the copolymer was raised to 150°C under a nitrogen atmosphere, maintained for 1 minute, then cooled to -100°C, and then raised to 150°C again, and the DSC curve was observed. In this case, the heating rate and cooling rate were each 10°C / min.

[0156] (5) d-spacing The ethylene / α-olefin copolymer was placed in a 1T square mold, and the front and back were covered with 3T steel plates, which were then placed in a hot press at 190°C and 25N / cm. 2 240 seconds, 6 cycles of vacuum / pressure degassing, 190°C, 151N / cm 2 After continuous treatment for 240 seconds, the temperature was decreased by 15°C per minute to 30°C, and the pressure was 151N / cm 2 The pressure was maintained at 30°C and 151 N / cm 2 The temperature was maintained at this temperature for 300 seconds, completing the preparation of the test specimen.

[0157] The 1mm-thick, 1cm x 1cm (width x height) test piece manufactured as described above was measured using a Xenocs Xeuss2.0 X-ray scattering device. The sample was placed approximately 2.5m away from the detector and X-rays were incident on the sample. A Pilatus3 300K (2D detector) was used as the detector. The resulting 2D diffraction pattern was obtained as an image, which was calibrated using the sample-to-detector distance obtained from a standard sample. The scattering intensity (I(q)) due to the scattering vector (q) was calculated by circular averaging.

[0158] [Formula 1] q=4πsinθ / λ

[0159] In the above formula 1, q is the scattering vector, θ is the half value of the scattering angle, and λ is the wavelength of the irradiated X-rays.

[0160] The distance between crystalline domains was analyzed by measuring the scattering intensity (I(q)) due to the scattering vector (q) obtained by SAXS. The measured scattering intensity (I(q)) was multiplied by the square of the scattering vector (q) to obtain I(q) × q due to the scattering vector (q). 2 A peak is observed in the graph. The scattering vector value (q*) of the observed peak was used to obtain the distance between crystalline domains (d-spacing).

[0161] [Formula 2] d-spacing=2π / q*

[0162] In the above formula 2, The q* is I(q)×q due to the scattering vector (q). 2 3 shows the scattering vector value at the peak of the graph.

[0163] (6) Crystallinity The 1mm-thick, 1cm x 1cm (width x height) specimens prepared as described above were subjected to X-ray transmission through the sample using a Xenocs Xeuss2.0 X-ray scattering instrument, and the scattering intensity (I(q)) due to the scattering vector (q) was measured. The sample was placed approximately 0.7m away from the detector, and X-rays were incident on the sample for measurement. A Pilatus3 300K (2D detector) was used as the detector. WAXS is a parallel beam method that measures the interference of X-rays generated when they collide with the sample during transmission. Peaks due to the crystalline structure are assigned, and the percentage of the crystalline peak area relative to the total area is calculated to determine the degree of crystallinity.

[0164] Specifically, the scattering or diffraction intensity (I(q)) according to the scattering vector (q) obtained by WAXS was measured and analyzed. The diffraction peaks due to amorphous halo (Ia(q)), mesophase (Im(q)), and crystal (Ic(q)) in the obtained scattering or diffraction intensity were deconvoluted. Specifically, the deconvolution of the diffraction peaks was defined by combining Gaussian and Lorentzian functions according to the following method.

[0165] 1) The amorphous halo (1 in Figure 1) is defined as the sum of three Gaussian functions (2 in Figure 1). Each of the three Gaussian functions has a scattering vector of 0.943 Å. -1 , 1.369Å -1 , 1.812Å -1 The peak center is at .

[0166] 2) One diffraction peak (lm(q)) due to the mesophase is defined by the Lorentzian function. The scattering vector is 1.373 Å. -1 The peak center is (3 in Figure 1).

[0167] 3) Define the sum of two diffraction peaks from Crystal by combining Gaussian (G) and Lorentzian (L) functions in a 1:1 ratio (0.5×G+0.5×L). The scattering vector is 1.486 Å. -1 , 1.647Å -1 The peak center is (4 in Figure 1). From the above results, the crystallinity was calculated using the following [Equation 3].

[0168]

number

[0169] In the above formula 3, Im is the Mesophase Peak, Ic is Crystal Peak, Ia is an Amorphous halo Peak.

[0170] (7) Hardness (shore A) The ethylene / α-olefin copolymer was placed in a 3T square mold, and the front and back were covered with 3T steel plates, which were then placed in a hot press at 190°C and 25 N / cm. 2 240 seconds, 6 cycles of vacuum / pressure degassing, 190°C, 151N / cm 2 After continuous treatment for 240 seconds, the temperature was decreased by 15°C per minute to 30°C, and the pressure was 151N / cm 2 The pressure was maintained at 30°C and 151 N / cm 2 The temperature was maintained at this temperature for 300 seconds, completing the preparation of the test specimen.

[0171] The prepared test specimens were aged for 24 hours or more in a constant temperature and humidity chamber at 40°C, and then the Shore A hardness was measured using a portable hardness tester according to ASTM D2240. In this case, since the sample temperature changes when the test specimen is removed from the oven, the measurement was performed in a 40°C chamber for accurate measurement.

[0172] [Table 2]

[0173] As shown in Table 2, the ethylene / α-olefin copolymer according to the present invention was confirmed to have a d-spacing of 12 nm or more, a crystallinity of 14%, a Shore A hardness of 65 or less, and a melting temperature of 70°C or less.

[0174] Experimental Example 2 (1) Impregnation completion time The crosslinker was impregnated using a planetary mixer manufactured by Thermo Electron (Karlsruhe) GmbH. 500 g of ethylene / α-olefin copolymer was mixed with 1 phr (parts per hundred rubber) of t-butyl 1-(2-ethylhexyl) monoperoxycarbonate (TBEC), 0.5 phr of tetrakis(vinyldimethylsiloxy)silane (TVSS), and 0.2 phr of methacryloxypropyltrimethoxysilane (MEMO). The mixture was stirred at 40 rpm, and the torque was monitored over time. The impregnation was terminated when the torque value increased sharply. Before the crosslinker was absorbed into the ethylene / α-olefin copolymer, it acted as a lubricant, maintaining a low torque value. Once the crosslinker was completely absorbed, the torque value increased. The point at which the torque value suddenly increased was defined as the completion time of impregnation.

[0175] (2) Degree of crosslinking After impregnation with the crosslinking agent, an encapsulant film having an average thickness of 550 μm was produced using a microextruder at a low temperature (extruder barrel temperature of 100° C. or less) that would not cause high-temperature crosslinking.

[0176] The degree of crosslinking was evaluated in accordance with the CPIA (China Photovoltaic Industry Association) standard and ASTM D 2765. The encapsulant film produced above was cut into a 10 cm x 10 cm piece and then vacuum laminated at 150°C for 20 minutes (5 minutes of vacuum, 1 minute of pressure, and 14 minutes of pressure maintenance) to obtain a crosslinked test piece.

[0177] The crosslinked test pieces were cut to an appropriate size, and then weighed in 0.5g portions and placed in 200-mesh wire cages. They were then dissolved in xylene reflux for 5 hours. The test pieces were then dried in a vacuum oven, and the weights before and after reflux were compared to determine the degree of crosslinking for each test piece.

[0178] [Table 3]

[0179] As shown in the table, when the ethylene / α-olefin copolymers of the examples according to the present invention were used, the time required to complete impregnation of the crosslinking agent was shortened, and crosslinking was completed within a short period of time, and the degree of crosslinking was equal to or higher than that of the comparative examples.

Claims

1. An ethylene / α-olefin copolymer satisfies the following conditions (a) to (d), and has a melt flow rate ratio (MFRR, Melt Flow Rate Ratio, MI 10 / MI 2.16 ), which is the ratio of a melt index (MI 10 , 190°C, 10 kg load) to a melt index (MI 2.16 , 190°C, 2.16 kg load), of 8.0 or less: (a) the d-spacing measured by SAXS (Small-Angle X-Ray Scattering) is 12 nm or more; (b) the crystallinity as measured by WAXS (Wide-Angle X-ray Scattering) is 14% or less; (c) the hardness (Shore A) measured at 40°C is 65 or less, and (d) The melting temperature measured by DSC (differential scanning calorimetry) is 50 to 60°C.

2. 2. The ethylene / α-olefin copolymer according to claim 1, wherein the crystallinity is 13% or less.

3. 2. The ethylene / α-olefin copolymer according to claim 1, wherein the hardness (shore A) is 63 or less.

4. 2. The ethylene / α-olefin copolymer of claim 1, having a density of 0.85 to 0.89 g / cc.

5. 2. The ethylene / α-olefin copolymer according to claim 1, which has a melt index (MI, 190° C., 2.16 kg load) of 1 to 100 dg / min.

6. 2. The ethylene / α-olefin copolymer according to claim 1, wherein the α-olefin comprises at least one selected from the group consisting 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.

7. The ethylene / α-olefin copolymer according to claim 1, wherein the α-olefin is contained in an amount of more than 0 to 99 mol % based on the ethylene / α-olefin copolymer.

8. A composition for an encapsulant film, comprising the ethylene / α-olefin copolymer according to any one of claims 1 to 7.

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