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

Abstract

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

Description

Technical Field

[0001] Cross-reference to Related Applications

[0002] This application claims priority to Korean Patent Application No. 2021-0148244, filed on November 1, 2021, with the Korean Intellectual Property Office, the content of which is incorporated herein by reference. Technical Field

[0004] The present invention relates to an ethylene / α-olefin copolymer having excellent physical properties showing a reduced crosslinking agent impregnation time and a high degree of crosslinking, and an encapsulant film composition containing the same. Background Art

[0005] As global environmental problems, energy problems, etc. become increasingly serious, solar cells are attracting attention as a means of generating energy without worrying about environmental pollution and depletion. If solar cells are used outdoors, such as on the roof of a building, modular solar cells are usually used. When manufacturing a solar cell module, in order to obtain a crystalline solar cell module, a front glass / solar cell encapsulant / crystalline solar cell device / solar cell encapsulant / rear glass (or rear protective sheet) are stacked in sequence. As an encapsulant for solar cells, an ethylene / vinyl acetate copolymer or an ethylene / α-olefin copolymer having excellent transparency, flexibility, adhesiveness, etc. is usually used.

[0006] Research on solar cell encapsulants is gradually being carried out to improve the functions usually required, and among various physical properties of the ethylene / α-olefin copolymer, the degree of crosslinking can be used as an index for evaluating mechanical strength and heat resistance. When used in an encapsulant or the like, if the degree of crosslinking increases, excellent mechanical strength and heat resistance can be obtained, and the stability of the module can be increased for a long time.

[0007] Meanwhile, solar cells are usually placed in a harsh environment. In particular, in hot and humid regions, continuous research is needed on methods to effectively protect solar cell modules and prevent defects (such as output degradation) in this environment. In particular, it is necessary to improve the degree of crosslinking to improve mechanical strength and heat resistance, but polar materials used for crosslinking, such as crosslinking agents, crosslinking aids, and peroxides, have low affinity with the ethylene / α-olefin copolymer, and the impregnation time of the crosslinking components increases, so there are limitations in improving the degree of crosslinking.

[0008] [Prior Art Documents]

[0009] [Patent Documents]

[0010] (Patent Document 1) Japanese Unexamined Patent Publication No. 2010-258439 Summary of the Invention

[0011] Technical problem

[0012] An object of the present invention is to provide an ethylene / α-olefin copolymer having excellent physical properties showing a reduced crosslinking agent impregnation time and a high degree of crosslinking, and a method for producing the same.

[0013] Technical solution

[0014] To solve the above tasks, the present invention provides an ethylene / α-olefin copolymer and a composition for an encapsulant film containing the same.

[0015] (1) The present invention provides an ethylene / α-olefin copolymer satisfying the following conditions (a) to (d):

[0016] (a) d-spacing measured by small-angle X-ray scattering (SAXS): 12 nm or more;

[0017] (b) Crystallinity measured by wide-angle X-ray scattering (WAXS): 14% or less;

[0018] (c) Hardness (Shore A) measured at 40 °C: 65 or less; and

[0019] (d) Melting temperature measured by differential scanning calorimetry (DSC): 70 °C or less.

[0020] (2) The present invention provides the ethylene / α-olefin copolymer in (1), wherein the crystallinity is 13% or less.

[0021] (3) The present invention provides the ethylene / α-olefin copolymer in (1) or (2), wherein the hardness (Shore A) is 63 or less.

[0022] (4) The present invention provides the ethylene / α-olefin copolymer in any one of (1) to (3), wherein the melting temperature is 50 °C to 65 °C.

[0023] (5) The present invention provides the ethylene / α-olefin copolymer in any one of (1) to (4), wherein the density is 0.85 g / cc to 0.89 g / cc.

[0024] (6) The present invention provides the ethylene / α-olefin copolymer in any one of (1) to (5), wherein the melt index (MI, at 190 °C, under a load of 2.16 kg) is 1 dg / min to 100 dg / min.

[0025] (7) The present invention provides the ethylene / α-olefin copolymer in any one of (1) to (6), wherein the melt flow rate ratio (MFRR, MI 10 / MI2.16 ) is below 8.0, and the melt flow rate ratio is the melt index (MI 10 , at 190 °C, under a load of 10 kg) relative to the melt index (MI 2.16 , at 190 °C, under a load of 2.16 kg).

[0026] (8) The present invention provides an ethylene / α-olefin copolymer according to any one of (1) to (7), wherein the α-olefin includes one or more 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-icosene.

[0027] (9) The present invention provides an ethylene / α-olefin copolymer according to any one of (1) to (8), wherein, based on the ethylene / α-olefin copolymer, the content of the α-olefin is greater than 0 to 99 mol%.

[0028] (10) The present invention provides a composition for an encapsulant film containing the ethylene / α-olefin copolymer according to any one of (1) to (9).

[0029] Advantageous Effects

[0030] The ethylene / α-olefin copolymer of the present invention has a high proportion of amorphous regions and exhibits low crystallinity. Thus, the ethylene / α-olefin copolymer exhibits high absorbency, is immersed in a crosslinking agent for a short time, and exhibits excellent crosslinking degree. Brief Description of the Drawings

[0031] Figure 1 Shows the deconvolution result of the peak in Example 1. Detailed Description

[0032] Hereinafter, the present invention will be described in more detail to assist in understanding the present invention.

[0033] It should be understood that the words or terms used in the present invention and the claims should not be construed as having the meanings defined in a common dictionary. It should also be understood that based on the principle that the inventor can appropriately define the meanings of the words or terms to best explain the invention, these words or terms should be construed as having meanings consistent with their meanings in the relevant art and the technical idea of the invention.

[0034] Hereinafter, the present invention will be explained in detail.

[0035] <Ethylene / α-olefin Copolymer>

[0036] The ethylene / α-olefin copolymer of the present invention is characterized by satisfying the following conditions (a) to (d):

[0037] (a) d-spacing measured by small-angle X-ray scattering (SAXS): 12 nm or more;

[0038] (b) Crystallinity measured by wide-angle X-ray scattering (WAXS): 14% or less;

[0039] (c) Hardness (Shore A) measured at 40 °C: 65 or less; and

[0040] (d) Melting temperature measured by differential scanning calorimetry (DSC): 70 °C or less.

[0041] The ethylene / α-olefin copolymer of the present invention has a low crystallinity and a high proportion of amorphous regions, and exhibits excellent absorbability for polar materials such as crosslinking agents and crosslinking aids.

[0042] In particular, the ethylene / α-olefin copolymer of the present invention is prepared by injecting a transition metal compound, a cocatalyst, ethylene, and an α-olefin monomer into a polymerization reactor and then polymerizing. In particular, the injection amount of the α-olefin monomer relative to ethylene is high, the proportion of amorphous regions in the ethylene / α-olefin copolymer is high, and the distance between crystalline regions is wide.

[0043] The ethylene / α-olefin copolymer of the present invention has a d-spacing of 12 nm or more as measured by small-angle X-ray scattering (SAXS).

[0044] The d-spacing represents the d-spacing between domains in a crystal structure, and if the d-spacing value is small, it indicates that the d-spacing between crystal structures is close and the crystallinity is high.

[0045] The d-spacing can be measured by small-angle X-ray scattering (SAXS). In particular, the scattering intensity I(q) according to the scattering vector (q) is measured by transmitting X-rays through a specimen using an X-ray diffractometer model Xeuss 2.0 manufactured by Xenocs. More particularly, small-angle X-ray scattering (SAXS) measurement is performed by placing the specimen at a position 2.5 m away from the detector and irradiating X-rays, using Pilatus3300K (2D detector) as the detector. The scattered 2D diffraction pattern is obtained as an image and calibrated using the sample-to-detector distance obtained from a standard specimen. Thereafter, the scattering intensity I(q) according to the scattering vector (q) is converted by the circular averaging method using the two-dimensional diffraction pattern obtained by analyzing the specimen.

[0046] [General formula 1]

[0047] q = 4πsinθ / λ

[0048] In General formula 1,

[0049] q is a scattering vector, θ is half of the scattering angle, and λ is the wavelength of the irradiated X-ray.

[0050] The d-spacing between crystalline regions is analyzed by measuring the scattering intensity (I(q)) according to the scattering vector (q) obtained by SAXS. By cross-multiplying the scattering intensity (I(q)) with the square of the scattering vector (q), peaks are observed on the I(q)×q 2 graph according to the scattering vector (q). In this case, the d-spacing between crystalline regions is obtained by using the scattering vector value (q*) of the observed peak.

[0051] [General formula 2]

[0052] d-spacing = 2π / q*

[0053] In General formula 2,

[0054] q* represents the scattering vector value of the peak on the I(q)×q 2 graph according to the scattering vector (q).

[0055] The ethylene / α-olefin copolymer of the present invention has a high proportion of amorphous regions and low crystallinity, and the d-spacing is shown to be 12 nm or more. If the range of the d-spacing is 12 nm or more, the absorbability of the ethylene / α-olefin copolymer to the crosslinking agent component increases, and there is an advantage of impregnating a large amount of crosslinking agent in a short time.

[0056] The crystallinity of the ethylene / α-olefin copolymer of the present invention measured by wide-angle X-ray scattering (WAXS) can be 14% or less, particularly 13% or less, or 12% or less.

[0057] The ethylene / α-olefin copolymer of the present invention shows a low range of crystallinity as in the above range.

[0058] The crystallinity can be measured by wide-angle X-ray scattering (WAXS). The scattering intensity (I(q)) according to the scattering vector (q) is measured by transmitting X-rays through a specimen using an X-ray diffractometer of model Xeuss 2.0 manufactured by Xenocs. More particularly, wide-angle X-ray scattering (WAXS) measurement is performed by placing the specimen at a position 0.7 m away from the detector and irradiating X-rays, and using Pilatus3300K (2D detector) as the detector. WAXS is a parallel beam method, and its measurement principle is X-ray diffraction generated by collision with the specimen during transmission, and the crystallinity is obtained by identifying the peaks from the crystal structure and calculating the ratio of the crystal peak area to the total area.

[0059] Specifically, the scattering or diffraction intensity (I(q)) according to the scattering vector (q) obtained by WAXS is measured and analyzed. From the obtained scattering or diffraction intensity, the diffraction peaks of the amorphous halo (Ia(q)), mesophase (Im(q)), and crystal (Ic(q)) are deconvoluted, and the crystallinity is calculated according to the following [General Formula 3].

[0060] [General Formula 3]

[0061] Crystallinity =

[0062] In General Formula 3,

[0063] I m is the mesophase peak,

[0064] I c is the crystal peak, and

[0065] I a is the amorphous halo peak.

[0066] If 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, the absorbability of the crosslinking agent component increases, and short-time crosslinking agent impregnation can be achieved.

[0067] The hardness (Shore A) of the ethylene / α-olefin copolymer of the present invention measured at 40 °C is 65 or less, particularly 63 or less, 62 or less, or 61 or less.

[0068] The hardness represents Shore A hardness according to ASTM D 2240 standard. The ethylene / α-olefin copolymer of the present invention contains a large amount of amorphous regions, and the impregnation rate of polar materials such as crosslinking agents is fast. Therefore, the hardness measured at 40 °C, i.e., the impregnation temperature, is a low value as shown above.

[0069] If the hardness (Shore A) of the ethylene / α-olefin copolymer of the present invention measured at 40 °C is within the above range, the crosslinking agent component easily penetrates into the ethylene / α-olefin copolymer, and there is an advantage of reducing the impregnation time of the crosslinking agent component.

[0070] The melting temperature (Tm) of the ethylene / α-olefin copolymer of the present invention measured by differential scanning calorimetry (DSC) is 70 °C or less, 60 °C or less, or 58 °C or less, and is 45 °C or more or 50 °C or more.

[0071] If the melting temperature (Tm) of the ethylene / α-olefin copolymer of the present invention is within the above range, it exhibits excellent heat resistance without showing deterioration of the light transmittance due to high-crystalline regions with high melting points, and there is an advantage of achieving an excellent light transmittance level.

[0072] The melting temperature was measured using differential scanning calorimetry (DSC). Specifically, the copolymer was heated to 150 °C, held at this temperature for 5 minutes, then cooled to 20 °C, and then the temperature was raised again. In this case, the rate of temperature increase and the rate of temperature decrease were each controlled to be 10 °C / minute, and the measured result could be measured as the melting temperature in the part where the temperature increased for the second time.

[0073] The ethylene / α-olefin copolymer of the present invention is a low-density copolymer having a density in the range of 0.85 g / cc to 0.89 g / cc. In this case, the density can represent the density measured according to ASTM F-792. Specifically, the density can be 0.850 g / cc or more, 0.860 g / cc or more, 0.870 g / cc or more, or 0.8874 g / cc or more, and can be 0.890 g / cc or less, 0.880 g / cc or less, or 0.879 g / cc or less.

[0074] If the density of the ethylene / α-olefin copolymer of the present invention is within the above range, excellent crosslinking properties can be exhibited, physical properties such as volume resistivity and light transmittance may not deteriorate, and the ethylene / α-olefin copolymer can be advantageously used as an insulating material.

[0075] The melt index (MI, 190 °C, 2.16 kg load condition) of the ethylene / α-olefin copolymer of the present invention is 1 to 30 dg / minute. Specifically, the melt index can be 1 dg / minute or more, 2 dg / minute or more, 3 dg / minute or more, or 4 dg / minute or more, and is 30 dg / minute or less, 20 dg / minute or less, or 15 dg / minute or less.

[0076] If the melt index of the ethylene / α-olefin copolymer of the present invention is within the above range, an appropriate productivity can be exhibited, excellent volume resistivity and light transmittance can be obtained, and the ethylene / α-olefin copolymer can be advantageously used as an insulating material.

[0077] The melt flow rate ratio (MFRR, MI 10 / MI 2.16 ), that is, the value of the melt index (MI 10 , 190 °C, 10 kg load condition) relative to the melt index (MI, 190 °C, 2.16 kg load condition) is 8.0 or less, specifically 4.0 or more, 4.2 or more, or 4.5 or more, and is 8.0 or less or 7.5 or less.

[0078] The melt flow rate ratio is an index of the long-chain branching degree of the copolymer, and the ethylene / α-olefin copolymer of the present invention simultaneously satisfies the melt flow rate ratio and the above physical properties, and has excellent physical properties. Therefore, it can be suitably applied to the encapsulant composition for solar cells having excellent physical properties.

[0079] In particular, if 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 rate ratio of 8.0 or less. Since the copolymer of the present invention has the above low melt index and low melt flow rate ratio, the copolymer is characterized by having a high molecular weight, a low long-chain branch content, and excellent crosslinking degree.

[0080] The ethylene / α-olefin copolymer of the present invention is prepared by copolymerizing ethylene with an α-olefin monomer. In this case, the α-olefin represents a part of the α-olefin monomers in the copolymer. The α-olefin can be an α-olefin having 4 to 20 carbon atoms. In particular, 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. can be used, and any one or a mixture of two or more thereof can be used.

[0081] Among them, the α-olefin can be 1-butene, 1-hexene or 1-octene, preferably 1-butene, 1-hexene or a combination thereof.

[0082] In addition, in the ethylene / α-olefin copolymer, the content of the α-olefin can be appropriately and non-limitingly selected within the range that satisfies the physical conditions, particularly greater than 0 to 99 mol%, or 10 mol% or more and 50 mol% or more.

[0083] <Preparation method of ethylene / α-olefin copolymer>

[0084] The ethylene / α-olefin copolymer of the present invention is prepared by injecting a transition metal compound, a cocatalyst, ethylene and an α-olefin monomer into a polymerization reactor and then polymerizing.

[0085] The polymerization method of ethylene and α-olefin is not particularly limited, but a conventional method widely used in the art can be appropriately used.

[0086] In the present invention, the α-olefin monomer can be one or more 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, and is not limited thereto.

[0087] Among them, considering the use and improvement effect of the ethylene / α-olefin copolymer prepared in the present invention, the α-olefin monomer can be 1-butene, 1-hexene or 1-octene.

[0088] Particularly, in the preparation method of the present invention, the molar ratio of ethylene to the α-olefin monomer can be from 1:1.14 to 1:3.00, particularly from 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.

[0089] If the molar ratio of ethylene to the α-olefin monomer is within the above range, an ethylene / α-olefin copolymer with a high proportion of amorphous regions can be prepared due to a large amount of the α-olefin monomer. At the same time, if too much of the α-olefin monomer is used, the crystalline region is too small, and there are problems in processing due to the relaxation of the film during film formation. The stiffness of the formed film deteriorates, and it is difficult to store due to the adhesiveness of the film surface.

[0090] In addition, the conditions (a) to (d) of the ethylene / α-olefin copolymer defined in the present invention correspond to the physical properties achieved by controlling the molar ratio of ethylene to the α-olefin monomer at an appropriate level as described above. Particularly, if the α-olefin monomer is less than ethylene, the crystalline region in the copolymer increases, the melting temperature increases, and the crystallinity increases, so the conditions (b) to (d) defined in the present invention may not be satisfied. On the contrary, if the α-olefin monomer is too much compared with ethylene, the crystalline region decreases, resulting in deteriorated stiffness, and normal processing of the film becomes impossible, which may induce problems that are difficult to use as a composition for an encapsulant film.

[0091] In addition, the transition metal compound used for polymerization can be a compound represented by Formula 1, a compound represented by Formula 2, or a combination thereof, and is not limited thereto.

[0092] [Formula 1]

[0093]

[0094] In Formula 1, R 1 is hydrogen; an alkyl group having 1 to 20 carbon atoms; a cycloalkyl group having 3 to 20 carbon atoms; an alkenyl group having 2 to 20 carbon atoms; an alkoxy group having 1 to 20 carbon atoms; an aryl group having 6 to 20 carbon atoms; an arylalkoxy group having 7 to 20 carbon atoms; an alkylaryl group having 7 to 20 carbon atoms; or an arylalkyl group having 7 to 20 carbon atoms,

[0095] R 2 and R 3are each independently hydrogen; a halogen; an alkyl group having 1 to 20 carbon atoms; a cycloalkyl group having 3 to 20 carbon atoms; an alkenyl group having 2 to 20 carbon atoms; an aryl group having 6 to 20 carbon atoms; an alkylaryl group having 7 to 20 carbon atoms; an arylalkyl group having 7 to 20 carbon atoms; an alkylamido group having 1 to 20 carbon atoms; or an arylamido group having 6 to 20 carbon atoms,

[0096] R 4 and R 5 are each independently hydrogen; an alkyl group having 1 to 20 carbon atoms; a cycloalkyl group having 3 to 20 carbon atoms; an aryl group having 6 to 20 carbon atoms; or an alkenyl group having 2 to 20 carbon atoms,

[0097] R 6 to R 9 are each independently hydrogen; an alkyl group having 1 to 20 carbon atoms; a cycloalkyl group having 3 to 20 carbon atoms; an aryl group having 6 to 20 carbon atoms; or an alkenyl group having 2 to 20 carbon atoms,

[0098] R 2 to R 9 two or more adjacent groups among them may be connected to each other to form a ring,

[0099] Q 1 is Si, C, N, P or S,

[0100] M 1 is Ti, Hf or Zr, and

[0101] X 1 and X 2 are each independently hydrogen; a halogen; an alkyl group having 1 to 20 carbon atoms; an alkenyl group having 2 to 20 carbon atoms; an aryl group having 6 to 20 carbon atoms; an alkylaryl group having 7 to 20 carbon atoms; an arylalkyl group having 7 to 20 carbon atoms; an alkylamino group having 1 to 20 carbon atoms; or an arylamino group having 6 to 20 carbon atoms.

[0102] [Formula 2]

[0103]

[0104] In Formula 2,

[0105] R 10 is hydrogen; an alkyl group having 1 to 20 carbon atoms; a cycloalkyl group having 3 to 20 carbon atoms; an alkenyl group having 2 to 20 carbon atoms; an alkoxy group having 1 to 20 carbon atoms; an aryl group having 6 to 20 carbon atoms; an aryloxy group having 7 to 20 carbon atoms; an alkylaryl group having 7 to 20 carbon atoms; or an arylalkyl group having 7 to 20 carbon atoms,

[0106] R 11a to R 11eare each independently hydrogen; a halogen; an alkyl group having 1 to 20 carbon atoms; a cycloalkyl group having 3 to 20 carbon atoms; an alkenyl group having 2 to 20 carbon atoms; an alkoxy group having 1 to 20 carbon atoms; or an aryl group having 6 to 20 carbon atoms,

[0107] R 12 is hydrogen; a halogen; an alkyl group having 1 to 20 carbon atoms; a cycloalkyl group having 3 to 20 carbon atoms; an alkenyl group having 2 to 20 carbon atoms; an aryl group having 6 to 20 carbon atoms; an alkylaryl group having 7 to 20 carbon atoms; an arylalkyl group having 7 to 20 carbon atoms; an alkylamido group having 1 to 20 carbon atoms; or an arylamido group having 6 to 20 carbon atoms,

[0108] R 13 and R 14 are each independently hydrogen; an alkyl group having 1 to 20 carbon atoms; a cycloalkyl group having 3 to 20 carbon atoms; an aryl group having 6 to 20 carbon atoms; or an alkenyl group having 2 to 20 carbon atoms,

[0109] R 15 to R 18 are each independently hydrogen; an alkyl group having 1 to 20 carbon atoms; a cycloalkyl group having 3 to 20 carbon atoms; an aryl group having 6 to 20 carbon atoms; or an alkenyl group having 2 to 20 carbon atoms,

[0110] R 15 to R 18 two or more adjacent groups among R

[0111] Q 2 is Si, C, N, P or S,

[0112] M 2 is Ti, Hf or Zr, and

[0113] X 3 and X 4 are each independently hydrogen; a halogen; an alkyl group having 1 to 20 carbon atoms; an alkenyl group having 2 to 20 carbon atoms; an aryl group having 6 to 20 carbon atoms; an alkylaryl group having 7 to 20 carbon atoms; an arylalkyl group having 7 to 20 carbon atoms; an alkylamino group having 1 to 20 carbon atoms; or an arylamino group having 6 to 20 carbon atoms.

[0114] In the present invention, the transition metal compound represented by Formula 1 and the transition metal compound represented by Formula 2 form a structure in which benzothiophene is fused with cyclopentadiene through a cyclic bond, and the amide groups (N-R 1 , N-R 10 ) are stably crosslinked through Q 1 or Q 2 and coordinate-bonded to a Group 4 transition metal.

[0115] When using the transition metal compound represented by Formula 1 as a catalyst in the polymerization reaction of ethylene and α-olefin monomers, even at high polymerization temperatures, a copolymer with high activity, high molecular weight, and high copolymerization properties can still be obtained. In particular, due to the structural characteristics of this catalyst, it is difficult to introduce α-olefin monomers, and a copolymer in the high-density region tends to be produced. On the contrary, the transition metal compound of Formula 2 can introduce a large amount of α-olefin monomers and can produce a copolymer in the very low-density region (elastomer).

[0116] Thus, the transition metal compounds prepared as in Formula 1 and Formula 2 used in the present invention are mixed and used in the catalyst composition. As described above, if the transition metal compound of Formula 1 or Formula 2 is used alone, the copolymerization properties of the mixed α-olefin monomers are different. If they are mixed for the preparation of a copolymer, a copolymer with a low-density region in which a large amount of α-olefin monomers are mixed and a high-density region in which a small amount of α-olefin monomers are present can be prepared. This means that the copolymer has a high crystallinity distribution and a small free volume, so it shows a low charge mobility and thus shows excellent physical properties with high electrical insulation.

[0117] In the present invention, the molar ratio of the transition metal compound represented by Formula 1 to the transition metal compound represented by Formula 2 is characterized by being 1:1.2 to 1:10, or 1:1.5 to 1:9, or 1:1.5 to 1:7, 1:2 to 1:7, 1:2 to 1:5, or 1:2 to 1:3.

[0118] If the transition metal compound represented by Formula 1 is used alone, if the transition metal compound represented by Formula 1 is in excess and deviates from the molar ratio, if the transition metal compound represented by Formula 2 is used alone, or if the transition metal compound represented by Formula 2 is in excess and deviates from the molar ratio, the crystallinity distribution may be low, and a copolymer with poor electrical insulation may be obtained.

[0119] In the present invention, the polymerization reaction can be carried out by continuously polymerizing ethylene and α-olefin monomers by continuously injecting hydrogen in the presence of a catalyst composition. In particular, the polymerization reaction can be carried out by injecting hydrogen at 10 to 100 cc / min.

[0120] Hydrogen plays a role in suppressing the rapid reaction of the transition metal at the initial stage of polymerization and when terminating the polymerization reaction. Thus, by controlling the use or the amount of use of this hydrogen, an ethylene / α-olefin copolymer with a narrow molecular weight distribution can be effectively obtained.

[0121] For example, hydrogen can be injected at a rate of 10 cc / min or more, 15 cc / min or more, 19 cc / min or more, or 22 cc / min or more, while being 100 cc / min or less, 50 cc / min or less, 45 cc / min or less, 35 cc / min or less, or 25 cc / min or less. If hydrogen is injected under the above conditions, the resulting ethylene / α-olefin copolymer can achieve the physical properties in the present invention.

[0122] If hydrogen is injected in an amount less than 10 cc / min, the termination of the polymerization reaction occurs unevenly, and it is difficult to obtain an ethylene / α-olefin copolymer with desired physical properties. If hydrogen is injected at a rate greater than 100 cc / min, the termination of the reaction is too rapid, and it is conceivable that an ethylene / α-olefin copolymer with a very low molecular weight may be obtained.

[0123] In addition, the polymerization reaction can be carried out at 100 to 200 °C. By controlling the polymerization temperature and the injection amount of hydrogen, it is possible to more easily control the number of unsaturated functional groups and the molecular weight distribution in the ethylene / α-olefin copolymer. In particular, the polymerization reaction can be carried out at 100 to 200 °C, 120 to 180 °C, 130 to 170 °C, or 135 to 150 °C.

[0124] In particular, in Formula 1, R 1 is hydrogen; an alkyl group having 1 to 20 carbon atoms; a cycloalkyl group having 3 to 20 carbon atoms; an alkenyl group having 2 to 20 carbon atoms; an alkoxy group having 1 to 20 carbon atoms; an aryl group having 6 to 20 carbon atoms; an aryloxyalkyl group having 7 to 20 carbon atoms; an alkylaryl group having 7 to 20 carbon atoms; or an arylalkyl group having 7 to 20 carbon atoms. More particularly, R 1 can be methyl, ethyl, propyl, butyl, isobutyl, tert-butyl, isopropyl, cyclohexyl, benzyl, phenyl, methoxyphenyl, ethoxyphenyl, fluorophenyl, bromophenyl, chlorophenyl, dimethylphenyl, or diethylphenyl.

[0125] In particular, in Formula 1, R 2 and R 3 are each independently hydrogen; a halogen; an alkyl group having 1 to 20 carbon atoms; a cycloalkyl group having 3 to 20 carbon atoms; an alkenyl group having 2 to 20 carbon atoms; an aryl group having 6 to 20 carbon atoms; an alkylaryl group having 7 to 20 carbon atoms; an arylalkyl group having 7 to 20 carbon atoms; an alkylcarbonylamino group having 1 to 20 carbon atoms; or an arylcarbonylamino group having 6 to 20 carbon atoms. More particularly, R 2 and R 3 can each independently be an alkyl group having 1 to 20 carbon atoms; an aryl group having 6 to 20 carbon atoms; or an arylalkyl group having 7 to 20 carbon atoms.

[0126] In particular, in Formula 1, R 4 and R5 may be the same or different, and may each independently be hydrogen; an alkyl group having 1 to 20 carbon atoms; a cycloalkyl group having 3 to 20 carbon atoms; an aryl group having 6 to 20 carbon atoms; or an alkenyl group having 2 to 20 carbon atoms. More particularly, it is an alkyl group having 1 to 6 carbon atoms. More particularly, R 4 and R 5 may be methyl, ethyl or propyl.

[0127] Particularly, in Formula 1, R 6 to R 9 may be the same or different, and may each independently be hydrogen; an alkyl group having 1 to 20 carbon atoms; a cycloalkyl group having 3 to 20 carbon atoms; an aryl group having 6 to 20 carbon atoms; or an alkenyl group having 2 to 20 carbon atoms. More particularly, R 6 to R 9 may be the same or different, and may each independently be hydrogen or methyl.

[0128] R 2 to R 9 Two or more adjacent groups among R

[0129] Particularly, in Formula 1, Q 1 is Si, C, N, P or S. More particularly, Q 1 may be Si.

[0130] Particularly, in Formula 1, M 1 may be Ti, Hf or Zr.

[0131] Particularly, in Formula 1, X 1 and X 2 may be the same or different, and may each independently be hydrogen; a halogen; an alkyl group having 1 to 20 carbon atoms; an alkenyl group having 2 to 20 carbon atoms; an aryl group having 6 to 20 carbon atoms; an alkylaryl group having 7 to 20 carbon atoms; an arylalkyl group having 7 to 20 carbon atoms; an alkylamino group having 1 to 20 carbon atoms; or an arylamino group having 6 to 20 carbon atoms.

[0132] In addition, the compound represented by Formula 1 may be a compound represented by any one of the following compounds.

[0133] [Formula 1-1]

[0134]

[0135] [Formula 1-2]

[0136]

[0137] [Formula 1-3]

[0138]

[0139] [Formula 1-4]

[0140]

[0141] [Formula 1-5]

[0142]

[0143] [Formula 1-6]

[0144]

[0145] In addition, the compound may have various structures within the range defined in Formula 1.

[0146] In addition, in Formula 2, R 10 is hydrogen; an alkyl group having 1 to 20 carbon atoms; a cycloalkyl group having 3 to 20 carbon atoms; an alkenyl group having 2 to 20 carbon atoms; an alkoxy group having 1 to 20 carbon atoms; an aryl group having 6 to 20 carbon atoms; an aryloxyalkyl group having 7 to 20 carbon atoms; an alkylaryl group having 7 to 20 carbon atoms; or an arylalkyl group having 7 to 20 carbon atoms. More particularly, R 10 may be hydrogen; an alkyl group having 1 to 20 carbon atoms or 1 to 12 carbon atoms; an alkoxy group having 1 to 20 carbon atoms; an aryl group having 6 to 20 carbon atoms; an aryloxyalkyl group having 7 to 20 carbon atoms; an alkylaryl group having 7 to 20 carbon atoms; or an arylalkyl group having 7 to 20 carbon atoms.

[0147] Particularly, in Formula 2, R 11a to R 11e are each independently hydrogen; a halogen; an alkyl group having 1 to 20 carbon atoms; a cycloalkyl group having 3 to 20 carbon atoms; an alkenyl group having 2 to 20 carbon atoms; an alkoxy group having 1 to 20 carbon atoms; or an aryl group having 6 to 20 carbon atoms. More particularly, they are hydrogen; a halogen; an alkyl group having 1 to 12 carbon atoms; a cycloalkyl group having 3 to 12 carbon atoms; an alkenyl group having 2 to 12 carbon atoms; an alkoxy group having 1 to 12 carbon atoms; or a phenyl group.

[0148] Particularly, in Formula 2, R 12is hydrogen; halogen; an alkyl group having 1 to 20 carbon atoms; a cycloalkyl group having 3 to 20 carbon atoms; an alkenyl group having 2 to 20 carbon atoms; an aryl group having 6 to 20 carbon atoms; an alkylaryl group having 7 to 20 carbon atoms; an arylalkyl group having 7 to 20 carbon atoms; an alkylamido group having 1 to 20 carbon atoms; or an arylamido group having 6 to 20 carbon atoms, more particularly hydrogen; halogen; an alkyl group having 1 to 12 carbon atoms; a cycloalkyl group having 3 to 12 carbon atoms; an alkenyl group having 2 to 12 carbon atoms; or phenyl.

[0149] Particularly, in Formula 2, R 13 and R 14 are each independently hydrogen; an alkyl group having 1 to 20 carbon atoms; a cycloalkyl group having 3 to 20 carbon atoms; an aryl group having 6 to 20 carbon atoms; or an alkenyl group having 2 to 20 carbon atoms, more particularly hydrogen; or an alkyl group having 1 to 12 carbon atoms.

[0150] Particularly, in Formula 2, R 15 to R 18 are each independently hydrogen; an alkyl group having 1 to 20 carbon atoms; a cycloalkyl group having 3 to 20 carbon atoms; an aryl group having 6 to 20 carbon atoms; or an alkenyl group having 2 to 20 carbon atoms, more particularly hydrogen; an alkyl group having 1 to 12 carbon atoms; a cycloalkyl group having 3 to 12 carbon atoms; or hydrogen; or methyl.

[0151] Particularly, in Formula 2, R 15 to R 18 Two or more adjacent groups among them may be connected to each other to form a ring.

[0152] Particularly, in Formula 2, Q 2 is Si, C, N, P or S, more particularly, Q 2 may be Si.

[0153] Particularly, in Formula 2, X 3 and X 4 are each independently hydrogen; halogen; an alkyl group having 1 to 20 carbon atoms; an alkenyl group having 2 to 20 carbon atoms; an aryl group having 6 to 20 carbon atoms; an alkylaryl group having 7 to 20 carbon atoms; an arylalkyl group having 7 to 20 carbon atoms; an alkylamino group having 1 to 20 carbon atoms; or an arylamino group having 6 to 20 carbon atoms, particularly hydrogen; halogen; an alkyl group having 1 to 12 carbon atoms; a cycloalkyl group having 3 to 12 carbon atoms; or an alkenyl group having 2 to 12 carbon atoms, more particularly hydrogen; or an alkyl group having 1 to 12 carbon atoms.

[0154] In addition, the compound represented by Formula 2 may be any one of the compounds represented by the following Formula 2-1 to Formula 2-10.

[0155] [Formula 2-1]

[0156]

[0157] [Formula 2-2]

[0158]

[0159] [Formula 2-3]

[0160]

[0161] [Formula 2-4]

[0162]

[0163] [Formula 2-5]

[0164]

[0165] [Formula 2-6]

[0166]

[0167] [Formula 2-7]

[0168]

[0169] [Formula 2-8]

[0170]

[0171] [Formula 2-9]

[0172]

[0173] [Formula 2-10]

[0174]

[0175] In the present invention, the α-olefin monomer as a comonomer may be an olefin monomer having 4 to 20 carbon atoms. Specific examples may 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, 1-eicosene, etc., and any one of them or a mixture of two or more thereof may be used.

[0176] Among them, the α-olefin monomer may be 1-butene, 1-hexene or 1-octene, and most preferably 1-butene.

[0177] In the present invention, the content of the α-olefin monomer may be appropriately selected within the range that satisfies the above physical conditions, and particularly, within the range of more than 0 to 99 mol% or 10 to 50 mol%.

[0178] <Composition for encapsulant film>

[0179] In addition, the present invention provides a composition for an encapsulant film containing the ethylene / α-olefin copolymer. By using the composition for an encapsulant film, a modified resin composition, for example, a silane-modified resin composition or an aminosilane-modified resin composition, can be prepared.

[0180] In particular, in addition to the ethylene / α-olefin copolymer, the composition for an encapsulant film may contain known crosslinking agents, crosslinking aids, silane coupling agents, etc.

[0181] The crosslinking agent is a radical initiator in the preparation step of the silane-modified resin composition and can play a role in initiating the graft reaction of the unsaturated silane composition with the resin composition. In addition, during the lamination step of manufacturing optoelectronic devices, by forming crosslinking bonds in the silane resin composition or between the silane-modified resin composition and the unmodified resin composition, the heat resistance durability of the final product, such as an encapsulant sheet, can be improved.

[0182] Various crosslinking agents well-known in the art can be used as long as the crosslinking agent is a compound capable of initiating the radical polymerization of vinyl or forming crosslinking bonds, for example, one or more selected from the group consisting of organic peroxides, hydroxy peroxides, and azo compounds.

[0183] In particular, dialkyl peroxides such as tert-butylcumyl peroxide, di-tert-butyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, and 2,5-dimethyl-2,5-di(tert-butylperoxy)-3-hexyne; hydroperoxides such as cumene hydroperoxide, diisopropylbenzene hydroperoxide, 2,5-dimethyl-2,5-di(hydroperoxy)hexane, and tert-butyl hydroperoxide; diacyl peroxides such as bis-3,5,5-trimethylhexanoyl peroxide, octanoyl peroxide, benzoyl peroxide, o-methylbenzoyl peroxide, and 2,4-dichlorobenzoyl peroxide; ester peroxides such as tert-butyl isobutyrate peroxide, tert-butyl acetate peroxide, tert-butyl 2-ethylhexyl carbonate peroxide (TBEC), tert-butyl 2-ethylhexanoate peroxide, tert-butyl pivalate peroxide, tert-butyl octanoate peroxide, tert-butyl isopropyl carbonate peroxide, tert-butyl benzoate peroxide, di-tert-butyl phthalate peroxide, 2,5-dimethyl-2,5-di(benzoylperoxy)hexane, and 2,5-dimethyl-2,5-di(benzoylperoxy)-3-hexyne; ketone peroxides such as methyl ethyl ketone peroxide, cyclohexanone peroxide, and lauryl peroxide; and azo compounds such as azobisisobutyronitrile and azobis(2,4-dimethylvaleronitrile) can be used without limitation.

[0184] The organic peroxide may be an organic peroxide having a one-hour half-life temperature of 120 to 130 °C, 120 to 125 °C, preferably 121 °C. The "one-hour half-life temperature" refers to the temperature at which the half-life of the crosslinking agent becomes one hour. Depending on the one-hour half-life temperature, the temperature at which the radical initiation reaction can be effectively carried out may vary. Therefore, in the case of using an organic peroxide having a one-hour half-life temperature within the above range, the radical initiation reaction, i.e., the crosslinking reaction in the lamination process for manufacturing an optoelectronic device, can be effectively carried out.

[0185] Based on 100 parts by weight of the encapsulant film composition, the content of the crosslinking agent may be 0.01 to 1 part by weight, for example, 0.05 to 0.55 part by weight, 0.1 to 0.5 part by weight, or 0.15 to 0.45 part by weight. If the content of the crosslinking agent is less than 0.01 part by weight, the heat-resistant property may not be significant. If the amount is more than 1 part by weight, the moldability of the encapsulant sheet deteriorates, problems such as production process limitations may occur, and the physical properties of the encapsulant may be affected.

[0186] In addition, in addition to the crosslinking agent, the resin composition may contain a crosslinking aid. By including a crosslinking aid in the resin composition, the crosslinking degree in the resin composition can be increased by the crosslinking aid, and thus, the heat-resistant durability of the final product such as an encapsulant sheet can be further improved.

[0187] Various crosslinking aids well-known in the art can be used as the crosslinking aid. For example, as the crosslinking aid, a compound containing at least one or more unsaturated groups such as allyl and (meth)acryloyloxy can be used.

[0188] The allyl-containing compound may include, for example, polyallyl compounds such as triallyl isocyanurate (TAIC), triallyl cyanurate, diallyl phthalate, diallyl fumarate, and diallyl maleate; and the (meth)acryloyloxy-containing compound may include poly(meth)acryloyloxy compounds such as ethylene glycol diacrylate, ethylene glycol dimethacrylate, and trimethylolpropane trimethacrylate, and is not limited thereto.

[0189] Based on 100 parts by weight of the encapsulant film composition, the content of the crosslinking aid may be 0.01 to 0.5 part by weight, for example, 0.01 to 0.3 part by weight, 0.015 to 0.2 part by weight, or 0.016 to 0.16 part by weight. If the content of the crosslinking aid is less than 0.01 part by weight, the effect of improving heat resistance may not be obvious. If the amount is more than 0.5 part by weight, problems that may affect the physical properties of the final product may occur, and the production cost may increase.

[0190] In addition, in addition to the ethylene / α-olefin copolymer, crosslinking agent, and crosslinking aid, the encapsulant film composition may additionally include a silane coupling agent.

[0191] As the silane coupling agent, 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) can be used.

[0192] Based on 100 parts by weight of the encapsulant film composition, the content of the silane coupling agent can be 0.1 to 0.4 parts by weight. If the usage amount is less than 0.3 parts by weight, the adhesion to glass during the manufacturing process of the solar cell module may deteriorate, and water may easily penetrate, so the long-term performance of the module may not be guaranteed. If the amount is more than 1 part by weight, it acts as a factor increasing Y.I, which is not desirable.

[0193] In addition, the composition of the encapsulant film may additionally contain an unsaturated silane compound and an amino silane compound.

[0194] The unsaturated silane compound can be grafted onto the main chain of the polymerization unit including the copolymer monomer of the present invention in the presence of a radical initiator or the like, and is included in the silane-modified resin composition or amino silane-modified resin composition in a polymerized form.

[0195] The unsaturated silane compound can be vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane, vinyltriisopropoxysilane, vinyltributoxysilane, vinyltripentoxysilane, vinyltriphenoxysilane, or vinyltriacetoxysilane. In one embodiment, vinyltrimethoxysilane or vinyltriethoxysilane among them can be used, and it is not limited thereto.

[0196] In addition, the amino silane compound can act as a catalyst for the hydrolysis reaction that promotes the conversion of the unsaturated silane compound grafted onto the copolymer main chain (for example, the alkoxy group of vinyltriethoxysilane as a reactive functional group is converted to a hydroxyl group) in the graft modification step of the ethylene / α-olefin copolymer, thereby improving the adhesion strength between the upper and lower glass substrates or the adhesion strength to a backsheet composed of a fluororesin, etc. At the same time, the amino silane compound can directly participate in the polymerization reaction as a reactant and can provide an amino-modified resin composition having an amino functional group part.

[0197] An amino-silane compound is a silane compound containing an amino group, and there is no specific limitation as long as it is a primary amine or a secondary amine. For example, as the amino-silane compound, amino-trialkoxysilane, amino-dialkoxysilane, etc. can be used, and examples may include one or more selected from the group consisting of: 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, aminoethylaminomethyltriethoxysilane, aminoethylaminomethyldiethoxysilane, diethylenetriaminopropyltrimethoxysilane, diethylenetriaminopropyltriethoxysilane, diethylenetriaminopropylmethyldimethoxysilane, diethylenamino-methyldiethoxysilane, (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 amino-silane compound can be used alone or as a mixture type.

[0198] There is no specific limitation on the amount of the unsaturated silane compound and / or the amino-silane compound.

[0199] In addition, if necessary, the encapsulant film-forming composition may additionally contain one or more additives selected from light stabilizers, ultraviolet absorbers, and heat stabilizers.

[0200] According to the use of the composition, the light stabilizer can capture the photo-thermal initiation active substances of the resin to prevent photo-oxidation. There is no specific limitation on the type of the light stabilizer used. For example, known compounds such as hindered amine compounds and hindered piperidine compounds can be used.

[0201] The ultraviolet absorber absorbs ultraviolet rays from sunlight, etc. in the molecule and converts them into harmless heat energy, and can play a role in preventing the photo-thermal initiation active substances in the resin composition from being excited. There is no specific limitation on the specific type of the ultraviolet absorber used. For example, one or a mixture of two or more of benzophenone-based, benzotriazole-based, acrylonitrile-based, metal complex-based, hindered amine-based, inorganic (including ultrafine particle titanium oxide and ultrafine particle zinc oxide) ultraviolet absorbers, etc. can be used.

[0202] In addition, the heat stabilizer may include phosphorus-based heat stabilizers such as tris(2,4-di-tert-butylphenyl) phosphite, bis[2,4-bis(1,1-dimethylethyl)-6-methylphenyl] ethyl phosphite, tetra(2,4-di-tert-butylphenyl) [1,1-biphenyl]-4,4'-diyl bisphosphite, and bis(2,4-di-tert-butylphenyl) pentaerythritol diphosphite; and lactone-based heat stabilizers such as the reaction product of 8-hydroxy-5,7-di-tert-butylfuran-2-one and o-xylene, and one or more of them may be used.

[0203] There is no specific limitation on the amount of the light stabilizer, ultraviolet absorber, and / or heat stabilizer. That is, the amount of the additive can be appropriately selected in consideration of the use of the resin composition, the shape or density of the additive, etc. Generally, based on the total solid content of 100 parts by weight of the encapsulant film composition, the amount can be appropriately controlled within the range of 0.01 to 5 parts by weight.

[0204] In addition, in addition to the above components, according to the use of the resin component to be applied, the encapsulant film composition of the present invention may further contain various additives well known in the art.

[0205] In addition, the encapsulant film composition can be used in molded articles by injection molding, extrusion molding, etc. In particular, the composition can be used in various optoelectronic devices, for example, as an encapsulant for encapsulating devices in solar cells, and can be used as an industrial material applied in the heat lamination process, and is not limited thereto.

[0206] Examples

[0207] Hereinafter, the present invention will be explained in more detail with reference to the embodiments. However, the embodiments are provided for illustration only, and the protection scope of the present invention is not limited thereto.

[0208] Preparation Example 1

[0209] (1) Preparation of Ligand Compound

[0210] <Synthesis of N-tert-butyl-1-(1,2-dimethyl-3H-benzo[b]cyclopenta[d]thiophen-3-yl)-1,1-dimethylsilanamine>

[0211] Weigh 4.65 g (15.88 mmol) of the compound of formula 3 and add it to a 100 mL Schlenk flask, and then inject 80 mL of THF into it. At room temperature, add tBuNH 2 (4 eq, 6.68 mL) and react at room temperature for 3 days. After the reaction is completed, remove THF, and filter the obtained reaction product with hexane. After drying the solvent, 4.50 g (86%) of a yellow liquid is obtained.

[0212] 1 H-NMR (in CDCl 3 ₃, 500 MHz): 7.99 (d, 1H), 7.83 (d, 1H), 7.35 (dd, 1H), 7.24 (dd, 1H), 3.49 (s, 1H), 2.37 (s, 3H), 2.17 (s, 3H), 1.27 (s, 9H), 0.19 (s, 3H), -0.17 (s, 3H).

[0213] (2) Preparation of Transition Metal Compound

[0214] [Formula 1-1]

[0215]

[0216] The ligand compound (1.06 g, 3.22 mmol / 1.0 eq) and 16.0 mL (0.2 M) MTBE were placed in a 50 mL Schlenk flask and first stirred. n-BuLi (2.64 mL, 6.60 mmol / 2.05 eq, 2.5 M in THF) was added thereto at -40 °C and reacted overnight at room temperature. Subsequently, MeMgBr (2.68 mL, 8.05 mmol / 2.5 eq, 3.0 M in diethyl ether) was slowly added dropwise thereto at -40 °C in sequence, and TiCl 4 (2.68 mL, 3.22 mmol / 1.0 eq, 1.0 M in toluene) was added, and then reacted overnight at room temperature. Subsequently, the reaction mixture was filtered through diatomaceous earth using hexane. Thereafter, the solvent was dried to obtain 1.07 g (82%) of a brown solid.

[0217] 1 H-NMR (in CDCl 3 ₃, 500 MHz): 7.99 (d, 1H), 7.68 (d, 1H), 7.40 (dd, 1H), 7.30 (dd, 1H), 3.22 (s, 1H), 2.67 (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).

[0218] Preparation Example 2

[0219] (1) Preparation of Ligand Compound

[0220] <Synthesis of N-tert-butyl-1-(1,2-dimethyl-3H-benzo[b]cyclopenta[d]thiophen-3-yl)-1,1-(methyl)(phenyl)silylamine>

[0221] (i) Preparation of chloro-1-(1,2-dimethyl-3H-benzo[b]cyclopenta[d]thiophen-3-yl)-1,1-(methyl)(phenyl)silane

[0222] Place 10 g (1.0 eq, 49.925 mmol) of 1,2-dimethyl-3H-benzo[b]cyclopenta[d]thiophene and 100 mL of THF into a 250 mL Schlenk flask. Then, dropwise add 22 mL of n-BuLi (1.1 eq, 54.918 mmol, 2.5 M in hexane) thereto at -30 °C, and subsequently stir for 3 hours at room temperature. Introduce the stirred Li complex THF solution into a Schlenk flask containing 8.1 mL of dichloro(methyl)(propyl)silane (1.0 eq, 49.925 mmol) and 70 mL of THF through a conduit at -78 °C, and then stir overnight at room temperature. After stirring, perform vacuum drying and extract with 100 mL of hexane.

[0223] (ii) Preparation of N-tert-butyl-1-(1,2-dimethyl-3H-benzo[b]cyclopenta[d]thiophen-3-yl)-1,1-(methyl)(phenyl)silanylamine

[0224] Inject 42 mL of t-BuNH 2 (8 eq, 399.4 mmol) into the 100 mL of the extracted chloro-1-(1,2-dimethyl-3H-benzo[b]cyclopenta[d]thiophen-3-yl)-1,1-(methyl)(phenyl)silane hexane solution at room temperature, and then stir overnight at room temperature. After stirring, perform vacuum drying and extract with 150 mL of hexane. After drying the solvent, 13.36 g (68%, dr = 1:1) of a yellow solid is obtained.

[0225] 1 1H-NMR (in CDCl 3 3, 500 MHz): δ 7.93 (t, 2H), 7.79 (d, 1H), 7.71 (d, 1H), 7.60 (d, 2H), 7.48 (d, 2H), 7.40 - 7.10 (m, 10H, aromatic), 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).

[0226] (2) Preparation of transition metal compounds

[0227] [Formula 2-4]

[0228]

[0229] 4.93 g of the ligand compound of formula 2-4 (12.575 mmol, 1.0 eq) and 50 mL (0.2 M) of toluene were placed in a 100 mL Schlenk flask, and 10.3 mL of n-BuLi (25.779 mmol, 2.05 eq, 2.5 M in hexane) was added dropwise thereto at -30 °C, followed by stirring overnight at room temperature. After stirring, 12.6 mL of MeMgBr (37.725 mmol, 3.0 eq, 3.0 M in diethyl ether) was added dropwise thereto in sequence, and 13.2 mL of TiCl 4 (13.204 mmol, 1.05 eq, 1.0 M in toluene) was added, and then stirred overnight at room temperature. After stirring, the reaction product was dried under vacuum and extracted with 150 mL of hexane. The solvent was removed to 50 mL, then 4 mL of DME (37.725 mmol, 3.0 eq) was added dropwise and stirred overnight at room temperature. After drying under vacuum again and extracting with 150 mL of hexane, 2.23 g (38%, dr = 1:0.5) of a brown solid was obtained.

[0230] 1 H-NMR (in CDCl 3 3, 500 MHz): δ 7.98 (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).

[0231] Example 1

[0232] While injecting hexane solvent at 7.0 kg / hour and butene at 1.09 kg / hour, a 1.5 L continuous processing reactor was preheated to 135 °C. A triisobutylaluminum compound (0.045 mmol / minute), a mixture of the compounds obtained in Example 1 and Example 2 with a molar ratio of 3:7 (0.150 μmol / minute), and a dimethylanilinium tetrakis(pentafluorophenyl)borate cocatalyst (0.30 μmol / minute) were simultaneously placed in the reactor. Then, ethylene (0.87 kg / hour) and hydrogen (20 cc / minute) were injected into the reactor, and a copolymerization reaction was continuously carried out for 60 minutes or more while maintaining a pressure of 89 bar and a temperature of 135 °C, thereby obtaining a copolymer. After drying in a vacuum oven for 12 hours or more, the physical properties were measured.

[0233] Examples 2 to 4 and Comparative Examples 1 to 5

[0234] The ethylene / α-olefin copolymer was prepared by the same method as in Example 1, except that the polymerization conditions were changed as shown in Table 1 below.

[0235] [Table 1]

[0236] Catalyst Promoter Triisobutylaluminum C2 1-C4 C6 Hydrogen Temperature μmol / minute μmol / minute kg / hour kg / hour kg / hour cc / minute cc / minute ℃ Example 1 0.150 0.30 0.045 0.87 1.09 7.0 20 135 Example 2 0.145 0.29 0.050 0.87 1.02 7.0 18 135 Example 3 0.150 0.30 0.050 0.87 1.05 7.0 18 135 Example 4 0.150 0.30 0.045 0.87 1.00 7.0 11 134 Comparative Example 1 0.150 0.30 0.050 0.87 0.85 7.0 16 136 Comparative Example 2 0.150 0.30 0.050 0.87 0.90 7.0 17 135 Comparative Example 3 0.150 0.30 0.050 0.87 0.97 7.0 18 134 Comparative Example 4 0.145 0.29 0.045 0.87 0.95 7.0 10 135 Comparative Example 5 0.150 0.0 0.055 0.87 0.97 7.0 8 138

[0237] Experimental Example 1

[0238] For the ethylene / α-olefin copolymers prepared in the examples and comparative examples, the physical properties were measured according to the following methods.

[0239] (1) Density (g / cm 3 )

[0240] Measured according to ASTM D-792.

[0241] (2) Melt index (MI 2.16 , dg / min)

[0242] Measured according to ASTM D-1238 (Condition E, 190 °C, 2.16 kg load).

[0243] (3) Melt flow rate ratio (MFRR, MI 10 / MI 2.16 )

[0244] Measure M according to ASTM D-1238 10 (Condition E, 190 °C, 10 kg load) and MI 2.16 (Condition E, 190 °C, 2.16 kg load), and calculate MI 10 / MI 2.16 .

[0245] (4) Melting temperature (Tm)

[0246] The melting temperature (Tm) can be measured using differential scanning calorimetry (DSC) manufactured by PerkinElmer. In particular, using DSC in a nitrogen atmosphere, the temperature of the copolymer is raised to 150 °C, held for 1 minute, the temperature is lowered to 100 °C, and then raised to 150 °C again to obtain a DSC curve. In this case, the rate of temperature increase and decrease are 10 °C / min respectively.

[0247] (5) d-spacing

[0248] Place the ethylene / α-olefin copolymer in a 1T square frame, cover the front and back with 3T steel plates, and then inject it into a high-temperature press. At 190 °C and 25 N / cm 2 Treat for 240 seconds, degas by decompression / pressurization 6 times, at 190 °C and 151 N / cm 2 After treating for 240 seconds, the temperature is decreased by 15 °C per minute and cooled to 30 °C. In this case, the pressure is maintained at 151 N / cm 2 . Keep the obtained product at 30 °C and 151 N / cm 2 for 300 seconds to complete the manufacture of the specimen.

[0249] For the specimen thus obtained with a size of 1 cm × 1 cm (width × length) and a thickness of 1 mm, place the specimen at a position 2.5 m away from the detector and irradiate X-rays using an X-ray diffractometer named Xeuss 2.0 manufactured by Xenocs to conduct measurements. Use Pilatus3 300K (2D detector) as the detector, obtain the scattered 2D diffraction pattern as an image and calibrate it using the sample-to-detector distance obtained from the standard specimen. Then convert the scattering intensity (I(q)) according to the scattering vector (q) by the circular averaging method.

[0250] [General formula 1]

[0251] q = 4πsinθ / λ

[0252] In General formula 1,

[0253] q is the scattering vector, θ is half of the scattering angle, and λ is the wavelength of the irradiated X-ray.

[0254] Analyze the d-spacing between the crystalline regions by measuring the scattering intensity (I(q)) according to the scattering vector (q) obtained by SAXS. By cross-multiplying the scattering intensity (I(q)) with the square of the scattering vector (q), observe the peak on the I(q)×q 2 graph. In this case, obtain the d-spacing between the crystalline regions by using the scattering vector value (q*) of the observed peak.

[0255] [General formula 2]

[0256] d-spacing = 2π / q*

[0257] In General formula 2,

[0258] q* represents the scattering vector value of the peak on the I(q)×q 2 graph according to the scattering vector (q).

[0259] (6) Crystallinity

[0260] For a specimen thus obtained with a size of 1 cm × 1 cm (width × length) and a thickness of 1 mm, the scattering intensity (I(q)) according to the scattering vector q was measured by transmitting X-rays through the specimen using an X-ray diffractometer, model Xeuss 2.0, manufactured by Xenocs. The specimen was placed at a position 0.7 m away from the detector and irradiated with X-rays for measurement. A Pilatus3 300K (2D detector) was used as the detector. WAXS is a parallel beam method, and its measurement principle is the X-ray diffraction generated by the collision with the specimen during the transmission process. The crystallinity was obtained by selecting the peaks from the crystal structure and calculating the ratio of the crystal peak area to the total area.

[0261] In particular, 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, deconvolution was performed on the diffraction peaks of the amorphous halo (Ia(q)), mesophase (Im(q)), and crystal (Ic(q)). In particular, the deconvolution of the diffraction peaks was defined by the combination of Gaussian and Lorentz functions with the following method.

[0262] 1) The amorphous halo ( Figure 1 ① in Figure 1 ) was defined as the sum of three Gaussian functions ( ② in ). The peak centers of the three Gaussian functions were located at scattering vectors of

[0263] and respectively. Figure 1 )

[0264] 2) The diffraction peak through the mesophase (Im(q)) was defined by a Lorentz function. The peak center was located at a scattering vector of and ③ in Figure 1 ).

[0265] 3) The sum of the two diffraction peaks through the crystal was defined by the combination of Gaussian (G) and Lorentz (L) functions in a ratio of 1:1 (0.5 × G + 0.5 × L). The peak centers were located at scattering vectors

[0266] [General formula 3]

[0267] Crystallinity =

[0268] In general formula 3,

[0269] I m is the mesophase peak,

[0270] I c is the crystal peak, and

[0271] I a is a non-crystalline halo peak.

[0272] (7) Hardness (Shore A)

[0273] Put the ethylene / α-olefin copolymer into a 3T square frame, cover the front and back with 3T steel plates, and then inject it into a high-temperature press. At 190 °C and 25 N / cm 2 Process for 240 seconds, degas by decompression / pressurization 6 times, at 190 °C and 151 N / cm 2 After processing for 240 seconds, the temperature is reduced by 15 °C per minute and cooled to 30 °C. In this case, the pressure is maintained at 151 N / cm 2 . Keep the obtained product at 30 °C and 151 N / cm 2 for 300 seconds to complete the production of the specimen.

[0274] Age the prepared specimen in a constant temperature and humidity chamber at 40 °C for more than 24 hours, and measure the Shore A hardness using a portable hardness meter based on ASTM D2240. In this case, if the specimen is taken out of the oven, the sample temperature may change. For accurate measurement, the measurement is carried out in a chamber at 40 °C.

[0275] [Table 2]

[0276]

[0277] As shown in Table 2, the d-spacing of the ethylene / α-olefin copolymer of the present invention is 12 nm or more, the crystallinity is 14%, the Shore A hardness is 65 or less, and the melting temperature is 70 °C or less.

[0278] Experimental Example 2

[0279] (1) Impregnation completion time

[0280] For the impregnation of the crosslinking agent, a planetary stirrer from Thermo Electron (Karlsruhe) was used. 1 part per hundred rubber (phr) of tert-butyl 1-(2-ethylhexyl) monoperoxycarbonate (TBEC), 0.5 phr of tetra(ethenyldimethylsiloxy)silane (TVSS), and 0.2 phr of methacryloxypropyltrimethoxysilane (MEMO) were injected into 500 g of an ethylene / α-olefin copolymer. Stirring was carried out at 40 rpm while observing the change in torque value over time. When the torque value increased rapidly, the impregnation was terminated. Before being absorbed into the ethylene / α-olefin copolymer, the crosslinking agent acted as a lubricant and maintained a low torque value, but when all the crosslinking agent was absorbed, the torque value increased. Therefore, the point at which the torque value increased rapidly was defined as the impregnation completion time.

[0281] (2) Crosslinking degree

[0282] After immersing the crosslinking agent, an encapsulant film with an average thickness of 550 μm was formed at a low temperature where high-temperature crosslinking could not be achieved (under the condition that the extruder barrel temperature was below 100 °C) using a micro-extruder.

[0283] The crosslinking degree was evaluated according to the China Photovoltaic Industry Association (CPIA) standard and ASTM D2765. The so-formed encapsulant film was cut into a size of 10 cm × 10 cm and vacuum laminated at 150 °C for 20 minutes (maintaining vacuum for 5 minutes / pressurizing for 1 minute / depressurizing for 14 minutes) to obtain a crosslinked specimen.

[0284] The crosslinked specimen was cut into an appropriate size, 0.5 g was weighed on a 200-mesh wire cage, and dissolved under reflux in xylene for 5 hours. After that, the specimen was dried in a vacuum oven, and the weight before and after reflux was compared to measure the crosslinking degree of each specimen.

[0285] [Table 3]

[0286] Impregnation Completion Time (minutes) Crosslinking Degree (%) Example 1 35 78.1 Example 2 37 79.2 Example 3 35 79.4 Example 4 38 87.5 Comparative Example 1 58 79.8 Comparative Example 2 48 78.9 Comparative Example 3 45 78.5 Comparative Example 4 43 87.0 Comparative Example 5 42 86.5

[0287] As shown in the table, if the ethylene / α-olefin copolymer in the examples of the present invention was used, the impregnation completion time of the crosslinking agent was reduced, and it was found that crosslinking could be completed in a short time, and the crosslinking degree was the same as or better than that of the comparative examples.

Claims

1. An ethylene / α-olefin copolymer that satisfies the following conditions (a) to (d): (a) d-spacing measured by small-angle X-ray scattering (SAXS): 12 nm or more; (b) Crystallinity measured by wide-angle X-ray scattering (WAXS): 14% or less; (c) Shore A hardness measured at 40 °C: 65 or less; and (d) Melting temperature measured by differential scanning calorimetry (DSC): 70 °C or less.

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

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

4. The ethylene / α-olefin copolymer according to claim 1, wherein, the melting temperature is 50 °C to 65 °C.

5. The ethylene / α-olefin copolymer according to claim 1, wherein, the density is 0.85 g / cc to 0.89 g / cc.

6. The ethylene / α-olefin copolymer according to claim 1, wherein, the melt index MI under the conditions of 190 °C and a load of 2.16 kg is 1 dg / min to 100 dg / min.

7. The ethylene / α-olefin copolymer according to claim 1, wherein, Melt Flow Rate Ratio (MFRR) MI 10 / MI 2.16 is 8.0 or less, the melt flow rate ratio is the melt index MI at 190°C and 10 kg load 10 Relative to the melt index MI at 190°C and 2.16 kg load 2.16 The value of .

8. The ethylene / α-olefin copolymer according to claim 1, wherein, the α-olefin includes one or more 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.

9. The ethylene / α-olefin copolymer according to claim 1, wherein, based on the ethylene / α-olefin copolymer, the content of the α-olefin is greater than 0 and less than or equal to 99 mol%.

10. An encapsulant film composition comprising the ethylene / α-olefin copolymer according to any one of claims 1 to 9.

Images