Specification
Title of Invention: Composition for encapsulant film comprising ethylene/alpha-olefin copolymer and encapsulant film comprising same
technical field
[One]
Cross-Citation with Related Applications
[2]
This application claims the benefit of priority based on the Korean Patent Application 2020-0046028 dated April 16, 2020, and all contents disclosed in the documents of the Korean patent applications are incorporated as a part of this specification.
[3]
[4]
technical field
[5]
The present invention relates to a composition for an encapsulant film comprising an ethylene/alpha-olefin copolymer having high volume resistance and light transmittance, and an encapsulant film using the same.
[6]
background
[7]
While global environmental problems and energy problems are getting more and more serious, solar cells are attracting attention as a means of generating energy that does not cause environmental pollution and depletion. When a solar cell is used outdoors, such as on the roof of a building, it is generally used in the form of a solar cell module. In order to obtain a crystalline solar cell module at the time of manufacturing a solar cell module, a protective sheet for a solar cell module (front side protection member) / solar cell encapsulant / crystalline solar cell element / solar cell encapsulant / protective sheet for solar cell module (back side) protection member) in the order of In addition, at the time of manufacturing a thin-film solar cell module, it laminates|stacks in order of the thin film type solar cell element/solar cell sealing material/protective sheet for solar cell modules (back surface side protection member). As the solar cell encapsulant, an ethylene/vinyl acetate copolymer or an ethylene/alpha-olefin copolymer, which is generally excellent in transparency, flexibility, and adhesion, is used.
[8]
On the other hand, although the solar cell module is generally used for a long period of time outside, problems such as performance degradation due to various external stimuli are continuously observed. In particular, it is urgent to solve the PID (Potential Induced Degradation) phenomenon found in the form of high-output power plants.
[9]
In a large-capacity power generation system that obtains a high voltage by connecting a plurality of solar cell modules, the volume resistance of the encapsulant decreases as the temperature and humidity of the installed place increase, and a potential difference occurs between the solar cell and the frame. As a result, toward the end of the array in which several solar cell modules are connected in series, the potential difference between the solar cell and the frame increases. A phenomenon in which leakage current is generated in the presence of such a potential difference and the power generation efficiency is rapidly reduced is referred to as a PID phenomenon.
[10]
Under the above background, it is required to develop an ethylene/alpha-olefin copolymer capable of continuously preventing the PID phenomenon by improving the volume resistance without reducing the light transmittance.
[11]
[12]
[Prior art literature]
[13]
[Patent Literature]
[14]
(Patent Document 1) Japanese Patent Application Laid-Open No. 2010-258439
[15]
DETAILED DESCRIPTION OF THE INVENTION
technical challenge
[16]
It is an object of the present invention to provide a composition for an encapsulant film that contains an ethylene/alpha-olefin copolymer having a high crystallinity distribution while maintaining a narrow molecular weight distribution, thereby exhibiting high volume resistance and excellent insulation.
[17]
Another object of the present invention is to provide a method for preparing the composition for an encapsulant film and an encapsulant film prepared by using the composition for the encapsulant film.
[18]
means of solving the problem
[19]
In order to solve the above problems, the present invention provides a composition for an encapsulant film comprising an ethylene/alpha-olefin copolymer satisfying the following conditions (a) to (d).
[20]
(a) a density of 0.85 to 0.89 g/cc;
[21]
(b) the molecular weight distribution is 1.8 to 2.3;
[22]
(c) melt index (Melt Index, MI, 190 ℃, load condition of 2.16 kg) is 1 to 100 dg / min; and
[23]
(d) The Full Width at Half Maximum (FWHM) of the crystallization peak that appears when the crystallization temperature is measured by Cross-Fractionation Chromatography (CFC) is 15 or more.
[24]
[25]
In addition, the present invention provides an encapsulant film comprising the composition for the encapsulant film.
[26]
Effects of the Invention
[27]
The composition for an encapsulant film of the present invention uses an ethylene/alpha-olefin copolymer having a high crystallinity distribution and a low free volume, and thereby exhibits excellent volume resistance and light transmittance, so that various uses in the field of electrical and electronic industries widely available as
[28]
Modes for carrying out the invention
[29]
Hereinafter, the present invention will be described in more detail to help the understanding of the present invention.
[30]
The terms or words used in the description and claims of the present invention should not be construed as being limited to their ordinary or dictionary meanings, and the inventor appropriately defines the concept of the term in order to best describe his invention. Based on the principle that can be done, it should be interpreted as meaning and concept consistent with the technical idea of ​​the present invention.
[31]
[32]
[Composition for Encapsulant Film]
[33]
The composition for an encapsulant film of the present invention is characterized in that it includes an ethylene/alpha-olefin copolymer satisfying the following conditions (a) to (d).
[34]
(a) a density of 0.85 to 0.89 g/cc;
[35]
(b) the molecular weight distribution is 1.8 to 2.3;
[36]
(c) melt index (Melt Index, MI, 190 ℃, load condition of 2.16 kg) is 1 to 100 dg / min; and
[37]
(d) The Full Width at Half Maximum (FWHM) of the crystallization peak that appears when the crystallization temperature is measured by Cross-Fractionation Chromatography (CFC) is 15 or more.
[38]
[39]
The present invention relates to a composition for an encapsulant film having high volume resistance and excellent electrical insulation properties. Specifically, the ethylene/alpha-olefin copolymer included in the composition for an encapsulant film of the present invention is used as a catalyst by mixing the transition metal compound represented by Formula 1 and Formula 2 during preparation, and the transition metal represented by Formula 1 Due to the structural characteristics of the catalyst, it is difficult to introduce an alpha-olefin-based monomer to the compound, so a copolymer of a high-density region tends to be prepared. A low-density polymer (elastomer) can also be prepared, and the two transition metal compounds have different copolymerizability for incorporating an alpha-olefinic monomer when used alone.
[40]
The ethylene/alpha-olefin copolymer of the present invention prepared by using a mixed composition thereof as a catalyst has both a low-density region in which a large amount of alpha-olefinic monomer is mixed and a high-density region in which a small amount of alpha-olefin-based monomer is incorporated. As a copolymer, it has a wide crystallinity distribution and contains a small amount of free volume, and thus has excellent electrical insulation properties due to low charge mobility.
[41]
[42]
The ethylene/alpha-olefin copolymer contained in the composition for an encapsulant film of the present invention is a low-density polymer having a density in the range of 0.85 to 0.89 g/cc, wherein the density means a density measured according to ASTM D-792 can do. More specifically, the density may be 0.850 g/cc or more, 0.860 g/cc or more, or 0.870 g/cc or more, or 0.874 g/cc or more, and 0.890 g/cc or less, or 0.880 g/cc or less, 0.878 g It can be less than or equal to /cc.
[43]
If the density is out of the above range, there may be a problem in that the volume resistance or light transmittance of the ethylene/alpha-olefin copolymer is lowered.
[44]
In general, the density of the ethylene/alpha-olefin copolymer is affected by the type and content of the monomer used during polymerization, the degree of polymerization, and the like, and in the case of the copolymer, it is greatly affected by the content of the comonomer. In this case, as the content of the comonomer increases, a low-density ethylene/alpha-olefin copolymer can be prepared, and the content of the comonomer can be introduced into the copolymer may depend on the inherent copolymerizability of the catalyst.
[45]
The ethylene/alpha-olefin copolymer contained in the composition for an encapsulant film of the present invention is a copolymer prepared by using the compound represented by Chemical Formulas 1 and 2 as a catalyst, and exhibits a low density as described above, and as a result, excellent processability can indicate
[46]
[47]
The ethylene/alpha-olefin copolymer included in the composition for an encapsulant film of the present invention has a narrow molecular weight distribution (MWD) in the range of 1.8 to 2.3. More specifically, the molecular weight distribution may be 1.80 or more, 1.90 or more, 2.30 or less, 2.20 or less, 2.10 or less, 2.05 or less.
[48]
In general, when two or more kinds of monomers are polymerized, the molecular weight distribution increases, and as a result, impact strength and mechanical properties are reduced, and there is a possibility that a blocking phenomenon may occur. In particular, since the polymerizability of the monomer is different for each catalyst, the molecular weight of the finally prepared polymer is affected depending on the type of catalyst. There is a problem that the molecular weight distribution is also widened.
[49]
In order to prevent a decrease in the crosslinking characteristics, impact strength, mechanical properties, etc. of the copolymer, an appropriate amount of hydrogen is added during the polymerization reaction to narrow the molecular weight distribution, thereby preventing the β-hydride elimination reaction from arbitrarily occurring in the polymer chain. And it is possible to induce a uniform termination reaction by adding hydrogen. In this case, since the weight average molecular weight and melt index of the copolymer tend to decrease according to the hydrogen input, the catalyst structure affects the weight average molecular weight and melt index. It is necessary to determine the appropriate type of catalyst and the amount of hydrogen input within a range that can take both the unique characteristics and the effect of reducing the molecular weight distribution according to the hydrogen input.
[50]
In consideration of the above points, in the present invention, as described below, the transition metal compound represented by Formula 1 and the transition metal compound represented by Formula 2 were mixed and used as a catalyst and an optimal amount of hydrogen was added while preparing, It has a narrow molecular weight distribution within the above-described range, preventing deterioration of crosslinking properties, impact strength, mechanical properties, etc., while exhibiting high volume resistance and electrical insulation.
[51]
The weight average molecular weight (Mw) and the number average molecular weight (Mn) are polystyrene equivalent molecular weights analyzed by gel permeation chromatography (GPC), and the molecular weight distribution can be calculated from a ratio of Mw/Mn.
[52]
In addition, the ethylene/alpha-olefin copolymer may have a weight average molecular weight (Mw) of 40,000 to 150,000 g/mol. More specifically, the weight average molecular weight may be 45,000 g/mol or more, 50,000 g/mol or more, or 60,000 g/mol or more, and 130,000 g/mol or less, 100,000 g/mol or less, or 90,000 g/mol or less. .
[53]
[54]
The ethylene/alpha-olefin copolymer contained in the composition for an encapsulant film of the present invention has a melt index (Melt Index, MI, 190°C, 2.16kg load condition) of 1 to 100 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 100 dg/min or less, 20 dg/min or less, or 15 dg/min or more. min or less.
[55]
If the melt index is less than 1 dg/min, the production rate may be reduced due to a high load, and if the melt index is more than 100 dg/min, the volume resistance or light transmittance of the ethylene/alpha-olefin copolymer is lowered, or the film Since molding is difficult, there is a problem in that the use of a solar cell encapsulant composition is not suitable.
[56]
In addition, the ethylene / alpha-olefin copolymer has a melt flow index (MI 10 ) value measured at 190 ° C. and 10 kg load condition with respect to the melt index (MI 2.16 ) measured at 190 ° C. and 2.16 kg load condition ( 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, 7.0 or less, and 6.8 or less. The melt flow index is an indicator of the degree of long-chain branching of the copolymer, and the ethylene/alpha-olefin copolymer of the present invention satisfies the melt flow index along with the above-described physical properties. can be applied.
[57]
In particular, when the ethylene/alpha-olefin copolymer of the present invention has a low melt index of 1 to 100 dg/min as described above, it may have a low melt flow index of 8.0 or less as described above. Since the copolymer of the present invention has such a low melt index and melt flow index, the copolymer has a high molecular weight and a low content of long chain branches, and thus has excellent crosslinking degree.
[58]
In addition, the conventional copolymer has such a low melt index and melt flow index, and at the same time, it is difficult to have a wide crystallinity distribution because the full width at half maximum (FWHM) of the crystallization peak, which will be described later, is 15 or more. A copolymer was prepared by adding an appropriate amount of hydrogen while using the compound represented by Formula 1 and Formula 2 as a catalyst, and the polymerization was terminated due to the addition of hydrogen, so that the end of the copolymer was saturated and long chain branches were not formed, so melt flow A copolymer having a low index and a wide crystallinity distribution was prepared by using heterogeneous catalysts with different crystallinity characteristics while at the same time.
[59]
[60]
The ethylene/alpha-olefin copolymer contained in the composition for encapsulant film of the present invention has a full width at half maximum (FWHM) of the crystallization peak that appears when the crystallization temperature is measured by cross-fractionation chromatography (CFC). This is over 15. Here, the peak width at half maximum is a value derived from a crystallinity distribution graph plotted as a dW/dT value according to temperature measured in a bivariate distribution by cross-fractionation chromatography.
[61]
The cross-fractionation chromatography is a method that combines Temperature Rising Elution Fractionation (TREF) and Gel Filtration Chromatography (GPC). It is a kind of method.
[62]
Specifically, a high-temperature sample solution in which an ethylene/alpha-olefin copolymer is completely dissolved in a solvent is injected into a column filled with an inert carrier, and the temperature of the column is lowered to attach the sample to the surface of the filler, and then, in the column Slowly raise the temperature of the column while flowing ortho dichlorobenzene. The concentration of the copolymer eluted at each temperature is detected, and the component eluted at each temperature is sent to GPC online for each fraction at the same time to obtain a chromatogram, and the molecular weight distribution of each component is calculated therefrom. At this time, the higher the crystallinity of the elution component, the higher the elution temperature. Therefore, the crystallinity distribution of the copolymer can be known by finding the relationship between the elution temperature and the elution amount (% by weight) of the ethylene/alpha-olefin copolymer.
[63]
The ethylene/alpha-olefin copolymer has a high FWHM value of 15 or more, which indicates that the crystallinity distribution of the copolymer is high. Insulation is excellent.
[64]
As described above, in order to prepare an ethylene/alpha-olefin copolymer having excellent volume resistance and light transmittance, it is important to increase the FWHM value and narrow the molecular weight distribution. FWHM is related to the uniformity of crystallinity according to the copolymerizability in which the alpha-olefinic monomer is incorporated, and the molecular weight distribution is related to the uniformity of the chain length according to the growth rate of ethylene, etc. In the case of site, the molecular weight distribution is narrow due to constant chain growth, but in the same principle, the copolymerizability is constant and the crystallinity distribution is narrow and the FWHM value is small. It is difficult to prepare the resulting copolymer.
[65]
On the other hand, in the present invention, an ethylene/alpha-olefin copolymer having a high FWHM value of 15 or more and a narrow molecular weight distribution of 1.8 to 2.3 by using a mixture of heterogeneous catalysts having similar ethylene growth rates and different copolymerizability. has been manufactured
[66]
Specifically, the FWHM value may be 15 or more, 16 or more, 16.5 or more, 16.8 or more, 50 or less, 40 or less, 30 or less, 25 or less, or 21 or less.
[67]
[68]
In addition, the ethylene/alpha-olefin copolymer included in the composition for an encapsulant film of the present invention may have a melting temperature (Melting Temperature, Tm) of 70° C. or less. More specifically, the melting temperature may be 50 °C or higher, 55 °C or higher, or 58 °C or higher, and 70 °C or lower, 68 °C or lower, 67 °C or lower. By having a melting temperature in such a temperature range, excellent thermal stability may be exhibited.
[69]
In addition, the ethylene / alpha-olefin copolymer may have a crystallization temperature (Crystallization Temperatur, Tc) of 70 ℃ or less, 60 ℃ or less, 55 ℃ or less, 51 ℃ or less, 30 ℃ or more, 35 ℃ or more, 40 ℃ or more, 42°C or higher. This low crystallization temperature is due to the non-uniform distribution and high crystallinity distribution of the comonomer in the ethylene/alpha-olefin copolymer, and by having the above temperature range, excellent volume resistance and electrical insulation can be exhibited.
[70]
The melting temperature and crystallization temperature may be measured using a Differential Scanning Calorimeter (DSC). Specifically, the copolymer is heated to 150° C. and maintained for 5 minutes, then lowered to 20° C., and then the temperature is increased again. At this time, the rate of rise and fall of the temperature is controlled at 10°C/min, respectively, and the result measured in the section where the second temperature rises is the melting temperature, and the result measured in the section where the temperature is decreased is the crystallization temperature. can do.
[71]
[72]
The ethylene/alpha-olefin copolymer included in the composition for an encapsulant film of the present invention is prepared by copolymerizing ethylene and an alpha-olefin-based monomer, and in this case, it refers to a portion derived from the alpha-olefin-based monomer in the copolymer. The alpha-olefin is a C4 to C20 alpha-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-eicocene, etc. may be mentioned, and one type alone or a mixture of two or more types thereof may be mentioned.
[73]
Among them, the alpha-olefin may be 1-butene, 1-hexene, or 1-octene, and preferably 1-butene, 1-hexene, or a combination thereof.
[74]
In addition, the content of the alpha-olefin in the ethylene/alpha-olefin copolymer may be appropriately selected within the range satisfying the above-described physical property requirements, and specifically, more than 0 to 99 mol% or less, or 10 to 50 mol% may be, but is not limited thereto.
[75]
[76]
In addition, a modified resin composition, for example, a silane-modified resin composition or an amino silane-modified resin composition may be prepared by using the composition for an encapsulant film of the present invention.
[77]
Specifically, the composition for the encapsulant film may include a known crosslinking agent, a crosslinking aid, a silane coupling agent, etc. in addition to the above-described ethylene/alpha-olefin copolymer.
[78]
The crosslinking agent is a radical initiator in the manufacturing step of the silane-modified resin composition, and may serve to initiate a reaction in which the unsaturated silane compound is grafted to the resin composition. In addition, by forming a cross-linkage between the silane-modified resin composition or between the silane-modified resin composition and the unmodified resin composition in the lamination step in the manufacture of an optoelectronic device, the heat resistance durability of the final product, such as an encapsulant sheet, can be improved. have.
[79]
If the crosslinking agent is a crosslinking compound capable of initiating radical polymerization of a vinyl group or forming a crosslinking bond, various crosslinking agents known in the art can be used in various ways, for example, organic peroxides, hydroperoxides and azo compounds. One or two or more selected from the group consisting of may be used.
[80]
Specifically, t-bufilcumyl peroxide, di-t-butyl peroxide, di-cumyl peroxide, 2,5-dimethyl-2,5-di(t-butylperoxy)hexane, 2,5-dimethyl dialkyl peroxides such as -2,5-di(t-butylperoxy)-3-hexyne; hydroperoxides such as cumene hydroperoxide, diisopropyl benzene 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-butylperoxy isobutylate, t-butylperoxy acetate, t-butylperoxy-2-ethylhexylcarbonate (TBEC), t-butylperoxy-2-ethylhexanoate, t-butylperoxypiva Late, t-butylperoxy octoate, t-butylperoxyisopropyl carbonate, t-butylperoxybenzoate, di-t-butylperoxyphthalate, 2,5-dimethyl-2,5-di(benzoylper peroxy esters such as oxy)hexane and 2,5-dimethyl-2,5-di(benzoylperoxy)-3-hexyne; and ketone peroxides such as methyl ethyl ketone peroxide and cyclohexanone peroxide, lauryl peroxide, azobisisobutyronitrile, and azo compounds such as azobis(2,4-dimethylvaleronitrile). It may include one or more selected from, but is not limited thereto.
[81]
The organic peroxide may be an organic peroxide having a 1-hour half-life temperature of 120 to 135°C, for example, 120 to 130°C, 120 to 125°C, preferably 121°C. The "one-hour half-life temperature" means a temperature at which the half-life of the cross-linking agent becomes one hour. According to the one-hour half-life temperature, the temperature at which the radical initiation reaction efficiently occurs is different, and therefore, when an organic peroxide having a one-hour half-life temperature in the above-described range is used as a crosslinking agent, the lamination process temperature for manufacturing an optoelectronic device In the radical initiation reaction, that is, the crosslinking reaction can proceed effectively.
[82]
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, based on 100 parts by weight of the composition for the encapsulant film, and the crosslinking agent is used in an amount of less than 0.01 parts by weight. When included, the effect of improving the heat resistance properties is insignificant, and when included in excess of 1 part by weight, the moldability of the encapsulant sheet is reduced, and a problem of process restrictions may occur, and the physical properties of the encapsulant may be affected. .
[83]
[84]
In addition, the resin composition may include a crosslinking aid in addition to the crosslinking agent. When the crosslinking aid is included in the resin composition, the degree of crosslinking between the resin compositions by the crosslinking agent can be increased, and thus the heat resistance durability of the final product, for example, an encapsulant sheet can be further improved.
[85]
As the crosslinking aid, various crosslinking aids known in the art 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.
[86]
The compound containing the allyl group may be, for example, a polyallyl compound such as triallyl isocyanurate (TAIC), triallyl cyanurate, diallyl phthalate, diallyl fumarate or diallyl maleate. , The compound containing the (meth)acryloxy group may be, for example, a poly(meth)acryloxy compound such as ethylene glycol diacrylate, ethylene glycol dimethacrylate, and trimethylolpropane trimethacrylate. However, it is not particularly limited thereto.
[87]
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, and the crosslinking aid is 0.01 parts by weight When included in less than, the effect of improving the heat resistance properties is insignificant, and when included in excess of 0.5 parts by weight, a problem affecting the physical properties of the final product, such as an encapsulant sheet, may occur and the production cost may increase.
[88]
[89]
In addition, the composition for the encapsulant film may further include a silane coupling agent in addition to the ethylene/alpha-olefin copolymer, a crosslinking agent and a crosslinking aid.
[90]
Examples of the silane coupling agent include N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane, γ-amino At least one selected from the group consisting of propyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-methacryloxypropyltrimethoxysilane (MEMO) may be used.
[91]
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 an encapsulant film. When using less than 0.3, the adhesion to glass is poor when manufacturing a solar module, so moisture soaking becomes easy, so the long-term performance of the module cannot be guaranteed.
[92]
[93]
In addition, the composition for the encapsulant film may further include an unsaturated silane compound and an amino silane compound.
[94]
The unsaturated silane compound is grafted onto the main chain including the polymerization unit of the monomer of the copolymer of the present invention in the presence of a radical initiator and the like, and may be included in a polymerized form in a silane-modified resin composition or an amino silane-modified resin composition.
[95]
The unsaturated silane compound is vinyltrimethoxysilane, vinyltriethoxysilane, vinyltripropoxysilane, vinyltriisopropoxysilane, vinyltributoxysilane, vinyltripentoxysilane, vinyltriphenoxysilane, or vinyl It may be triacetoxy silane and the like, and as an example, vinyl trimethoxy silane or vinyl triethoxy silane may be used, but the present invention is not limited thereto.
[96]
In addition, the amino silane compound is an unsaturated silane compound grafted to the main chain of the copolymer in the grafting modification step of the ethylene/alpha-olefin copolymer, for example, a reactive functional group such as an alkoxy group of vinyltriethoxysilane. By acting as a catalyst for accelerating the decomposition reaction, the adhesive strength with the upper and lower glass substrates or the back sheet composed of a fluororesin or the like can be further improved. In addition, at the same time, the amino silane compound may also be directly involved as a reactant in the copolymerization reaction, thereby providing a moiety having an amine functional group to the amino silane-modified resin composition.
[97]
The amino silane 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, as the amino silane compound, aminotrialkoxysilane, aminodialkoxysilane, etc. may be used. Examples include 3-aminopropyltrimethoxysilane (APTMS), 3-aminopropyltriethoxysilane. (3-aminopropyltriethoxysilane; APTES), bis[(3-triethoxysilyl)propyl]amine, bis[(3-trimethoxysilyl)propyl]amine, 3-aminopropylmethyldiethoxysilane, 3-aminopropylmethyl Dimethoxysilane, N-[3-(trimethoxysilyl)propyl]ethylenediamine (N-[3-(Trimethoxysilyl)propyl]ethylenediamine; DAS), aminoethylaminopropyltriethoxysilane, aminoethylaminopropylmethyldime Toxysilane, aminoethylaminopropylmethyldiethoxysilane, aminoethylaminomethyltriethoxysilane, aminoethylaminomethylmethyldiethoxysilane, diethylenetriaminopropyltrimethoxysilane, diethylenetriaminopropyltriethoxysilane, Diethylenetriaminopropylmethyldimethoxysilane, diethyleneaminomethylmethyldiethoxysilane, (N-phenylamino)methyltrimethoxysilane, (N-phenylamino)methyltriethoxysilane, (N-phenylamino)methyl Methyldimethoxysilane, (N-phenylamino)methylmethyldiethoxysilane, 3-(N-phenylamino)propyltrimethoxysilane, 3-(N-phenylamino)propyltriethoxysilane, 3-(N- at least one selected from the group consisting of phenylamino)propylmethyldimethoxysilane, 3-(N-phenylamino)propylmethyldiethoxysilane, and N-(N-butyl)-3-aminopropyltrimethoxysilane can be heard The amino silane compounds may be used alone or in combination.
[98]
The content of the unsaturated silane compound and/or the amino silane compound is not particularly limited.
[99]
[100]
In addition, the composition for the encapsulant film may further include at least one additive selected from a light stabilizer, a UV absorber, a heat stabilizer, and the like, if necessary.
[101]
The light stabilizer may serve to prevent photooxidation by catching active species that initiate photodegradation of the resin depending on the application to which the composition is applied. The type of light stabilizer that can be used is not particularly limited, and, for example, a known compound such as a hindered amine-based compound or a hindered piperidine-based compound may be used.
[102]
The UV absorber absorbs ultraviolet rays from sunlight or the like according to the use of the composition, converts it into harmless thermal energy in the molecule, and may serve to prevent excitation of active species initiating photodegradation in the resin composition. Specific types of UV absorbers that can be used are not particularly limited, and for example, inorganic UV such as benzophenone-based, benzotriazole-based, acrylnitrile-based, metal complex salt-based, hindered amine-based, ultra-fine titanium oxide or ultra-fine zinc oxide. One type or a mixture of two or more types, such as an absorbent, can be used.

Claims
[Claim 1]
A composition for an encapsulant film comprising an ethylene/alpha-olefin copolymer satisfying the following conditions (a) to (d): (a) a density of 0.85 to 0.89 g/cc; (b) having a molecular weight distribution of 1.8 to 2.3; (c) melt index (Melt Index, MI, 190 ℃, load condition of 2.16 kg) is 1 to 100 dg / min; And (d) Cross-fractionation chromatography (Cross-Fractionation Chromatography, CFC), the full width at half maximum (FWHM) of the crystallization peak appearing when the crystallization temperature is measured by 15 or more.
[Claim 2]
The composition for an encapsulant film according to claim 1, wherein the melt index is 2 to 20 dg/min.
[Claim 3]
The composition for an encapsulant film according to claim 1, wherein the full width at half maximum of the crystallization peak is 16 to 50.
[Claim 4]
The composition for an encapsulant film according to claim 1, wherein the melting temperature of the ethylene/alpha-olefin copolymer is 70° C. or less.
[Claim 5]
The composition for an encapsulant film according to claim 1, wherein the ethylene/alpha-olefin copolymer has a weight average molecular weight (Mw) of 40,000 to 150,000 g/mol.
[Claim 6]
The method according to claim 1, wherein the ethylene / alpha-olefin copolymer is a melt index (MI 10 , 190 °C, 10 kg load condition) value to the melt index (MI 2.16 , 190 °C, 2.16 kg load condition) melt flow index (MFRR) , Melt Flow Rate Ratio, MI 10 /MI 2.16 ) is a composition for an encapsulant film of 8.0 or less.
[Claim 7]
The composition for an encapsulant film according to claim 1, wherein the crystallization temperature of the ethylene/alpha-olefin copolymer is 70° C. or less.
[Claim 8]
The method according to claim 1, wherein the alpha-olefin is propylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-decene, 1-undecene, 1 - A composition for an encapsulant film comprising at least one selected from the group consisting of dodecene, 1-tetradecene, 1-hexadecene, and 1-eicosene.
[Claim 9]
The composition for an encapsulant film according to claim 1, wherein the alpha-olefin is contained in an amount greater than 0 and 99 mol% or less compared to the copolymer.
[Claim 10]
The composition for an encapsulant film according to claim 1, further comprising at least one selected from the group consisting of an unsaturated silane compound, an amino silane compound, a crosslinking agent, a crosslinking aid, a light stabilizer, a UV absorber, and a heat stabilizer.
[Claim 11]
An encapsulant film comprising the composition for an encapsulant film of any one of claims 1 to 10.
[Claim 12]
A solar cell module comprising the encapsulant film of claim 11 .